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Perturbative and non-perturbative properties of heavy quark transport in a thermal QCD medium
Authors:
Jiazhen Peng,
Jiale Lou,
Fei Sun,
Kejun Wu,
Wei Xie,
Zuman Zhang,
Shuang Li,
Sa Wang
Abstract:
We investigate the perturbative and non-perturbative aspects of heavy quark transport in a thermal QCD medium. Based on the Soft-Hard Factorized Model (SHFM), we extend the original perturbative framework to the near-critical temperature region, where non-perturbative effects become significant. The transition behavior of the semi-Quark-Gluon-Plasma (semi-QGP) is described via a temperature-depend…
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We investigate the perturbative and non-perturbative aspects of heavy quark transport in a thermal QCD medium. Based on the Soft-Hard Factorized Model (SHFM), we extend the original perturbative framework to the near-critical temperature region, where non-perturbative effects become significant. The transition behavior of the semi-Quark-Gluon-Plasma (semi-QGP) is described via a temperature-dependent background field incorporated in the background field effective theory. By implementing this approach, we quantitatively evaluate the collisional energy loss and momentum diffusion coefficients of charm and bottom quarks as functions of the incoming energy and medium temperature. Our results show a distinct suppression of both the energy loss and the diffusion coefficients relative to conventional perturbative estimates, especially near the critical temperature. This suppression originates from the emergence of a temperature-dependent color background field, which effectively reduces the color charge screening of the medium. These findings provide important theoretical insight into the phenomenology of heavy-flavor probes in QGP, offering a unified theoretical framework applicable across both high- and low-momentum regimes.
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Submitted 11 October, 2025;
originally announced October 2025.
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Dirac neutrino and dark matter in left-right symmetric models
Authors:
Shohei Okawa,
Yuji Omura,
Keyun Wu
Abstract:
We study neutrino mass generation and dark matter in a left-right symmetric model. The model is based on an $SU(3)_c\times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ gauge theory with a softly broken parity symmetry. Masses of the charged leptons and neutrinos are generated radiatively at one-loop and three-loop level respectively, through their interactions with newly introduced neutral fermion an…
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We study neutrino mass generation and dark matter in a left-right symmetric model. The model is based on an $SU(3)_c\times SU(2)_L \times SU(2)_R \times U(1)_{B-L}$ gauge theory with a softly broken parity symmetry. Masses of the charged leptons and neutrinos are generated radiatively at one-loop and three-loop level respectively, through their interactions with newly introduced neutral fermion and scalar particles. A mass hierarchy of those new particles is required to reproduce the observed patterns of the charged lepton spectrum and neutrino oscillation data. The resulting light particles, whose mass can be as light as GeV, serve as good dark matter candidates. The phenomenology of such dark matter candidates is governed by their interactions to left- or right-handed neutrinos. We study physics of dark matter with several benchmark parameter sets that reproduce the realistic neutrino mass matrix structure, and identify viable parameter spaces.
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Submitted 6 October, 2025;
originally announced October 2025.
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Soft-hard factorization of heavy-quark transport in QCD matter at finite chemical potential
Authors:
Jiale Lou,
Wu Wang,
Jiazhen Peng,
Fei Sun,
Kejun Wu,
Wei Xie,
Zuman Zhang,
Shuang Li,
Sa Wang
Abstract:
We calculate the collisional energy loss and momentum diffusion coefficients of heavy quarks traversing a hot and dense QCD medium at finite quark chemical potential, $μ\neq0$. The analysis is performed within an extended soft-hard factorization model (SHFM) that consistently incorporates the $μ$-dependence of the Debye screening mass $M_D(μ)$ and of the fermionic thermal distribution functions. B…
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We calculate the collisional energy loss and momentum diffusion coefficients of heavy quarks traversing a hot and dense QCD medium at finite quark chemical potential, $μ\neq0$. The analysis is performed within an extended soft-hard factorization model (SHFM) that consistently incorporates the $μ$-dependence of the Debye screening mass $M_D(μ)$ and of the fermionic thermal distribution functions. Both the energy loss and the diffusion coefficients are found to increase with $μ$, with the enhancement being most pronounced at low temperatures where the chemical potential effects dominate the medium response. To elucidate the origin of this dependence, we derive analytic high-energy approximations in which the leading $μ$-corrections appear as logarithmic terms: a soft logarithm $\simμ^{2}\ln(|t^{*}|/M_{D}^{2})$ from $t$-channel scattering off thermal gluonic excitations, and a hard logarithm $\simμ^{2}\ln(E_{1}T/|t^{*}|)$ from scattering off thermal quarks. In the complete result the dependence on the intermediate separation scale $t^{\ast}$ cancels, as required. We also confirm the expected mass hierarchy $-dE/dz(charm)<-dE/dz(bottom)$ at fixed velocity. Our findings demonstrate that finite chemical potential plays a significant role in heavy-quark transport and must be included in theoretical descriptions of heavy-flavor dynamics in baryon-rich environments, such as those probed in the RHIC Beam Energy Scan, and at FAIR and NICA.
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Submitted 28 September, 2025;
originally announced September 2025.
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Directed searches for gravitational waves from ultralight vector boson clouds around merger remnant and galactic black holes during the first part of the fourth LIGO-Virgo-KAGRA observing run
Authors:
The LIGO Scientific Collaboration,
the Virgo Collaboration,
the KAGRA Collaboration,
A. G. Abac,
I. Abouelfettouh,
F. Acernese,
K. Ackley,
C. Adamcewicz,
S. Adhicary,
D. Adhikari,
N. Adhikari,
R. X. Adhikari,
V. K. Adkins,
S. Afroz,
A. Agapito,
D. Agarwal,
M. Agathos,
N. Aggarwal,
S. Aggarwal,
O. D. Aguiar,
I. -L. Ahrend,
L. Aiello,
A. Ain,
P. Ajith,
T. Akutsu
, et al. (1747 additional authors not shown)
Abstract:
We present the first directed searches for long-transient and continuous gravitational waves from ultralight vector boson clouds around known black holes (BHs). We use LIGO data from the first part of the fourth LIGO-Virgo-KAGRA observing run. The searches target two distinct types of BHs and use two new semicoherent methods: hidden Markov model (HMM) tracking for the remnant BHs of the mergers GW…
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We present the first directed searches for long-transient and continuous gravitational waves from ultralight vector boson clouds around known black holes (BHs). We use LIGO data from the first part of the fourth LIGO-Virgo-KAGRA observing run. The searches target two distinct types of BHs and use two new semicoherent methods: hidden Markov model (HMM) tracking for the remnant BHs of the mergers GW230814_230901 and GW231123_135430 (referred to as GW230814 and GW231123 in this study), and a dedicated method using the Band Sampled Data (BSD) framework for the galactic BH in the Cygnus X-1 binary system. Without finding evidence of a signal from vector bosons in the data, we estimate the mass range that can be constrained. For the HMM searches targeting the remnants from GW231123 and GW230814, we disfavor vector boson masses in the ranges $[0.94, 1.08]$ and $[2.75, 3.28] \times 10^{-13}$ eV, respectively, at 30% confidence, assuming a 1% false alarm probability. Although these searches are only marginally sensitive to signals from merger remnants at relatively large distances, future observations are expected to yield more stringent constraints with high confidence. For the BSD search targeting the BH in Cygnus X-1, we exclude vector boson masses in the range $[0.85, 1.59] \times 10^{-13}$ eV at 95% confidence, assuming an initial BH spin larger than 0.5.
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Submitted 14 September, 2025; v1 submitted 8 September, 2025;
originally announced September 2025.
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The geometric bookkeeping guide to Feynman integral reduction and $\varepsilon$-factorised differential equations
Authors:
Iris Bree,
Federico Gasparotto,
Antonela Matijašić,
Pouria Mazloumi,
Dmytro Melnichenko,
Sebastian Pögel,
Toni Teschke,
Xing Wang,
Stefan Weinzierl,
Konglong Wu,
Xiaofeng Xu
Abstract:
We report on three improvements in the context of Feynman integral reduction and $\varepsilon$-factorised differential equations: Firstly, we show that with a specific choice of prefactors, we trivialise the $\varepsilon$-dependence of the integration-by-parts identities. Secondly, we observe that with a specific choice of order relation in the Laporta algorithm, we directly obtain a basis of mast…
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We report on three improvements in the context of Feynman integral reduction and $\varepsilon$-factorised differential equations: Firstly, we show that with a specific choice of prefactors, we trivialise the $\varepsilon$-dependence of the integration-by-parts identities. Secondly, we observe that with a specific choice of order relation in the Laporta algorithm, we directly obtain a basis of master integrals, whose differential equation on the maximal cut is in Laurent polynomial form with respect to $\varepsilon$ and compatible with a particular filtration. Thirdly, we prove that such a differential equation can always be transformed to an $\varepsilon$-factorised form. This provides a systematic algorithm to obtain an $\varepsilon$-factorised differential equation for any Feynman integral. Furthermore, the choices for the prefactors and the order relation significantly improve the efficiency of the reduction algorithm.
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Submitted 10 June, 2025;
originally announced June 2025.
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Untangling New Physics in Single Resonant Top Quarks
Authors:
Krish Wu,
Brandon Sun,
Nitish Polishetty,
Justin Kline,
Max Fieg,
Daniel Whiteson
Abstract:
Collisions of particles at the energy frontier can reveal new particles and forces via localized excesses. However, the initial observation may be consistent with a large variety of theoretical models, especially in sectors with new top quark partners, which feature a rich set of possible underlying interactions. We explore the power of the LHC dataset to distinguish between models of the singly p…
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Collisions of particles at the energy frontier can reveal new particles and forces via localized excesses. However, the initial observation may be consistent with a large variety of theoretical models, especially in sectors with new top quark partners, which feature a rich set of possible underlying interactions. We explore the power of the LHC dataset to distinguish between models of the singly produced heavy top-like quark which interacts with the Standard Model through an electromagnetic form factor. We study the heavy top decay to a top quark and a virtual photon which produces a pair of fermions, propose a technique to disentangle the models, and calculate the expected statistical significance to distinguish between various hypotheses.
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Submitted 19 February, 2025;
originally announced February 2025.
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Rationalisation of multiple square roots in Feynman integrals
Authors:
Georgios Papathanasiou,
Stefan Weinzierl,
Konglong Wu,
Yang Zhang
Abstract:
Feynman integrals are very often computed from their differential equations. It is not uncommon that the $\varepsilon$-factorised differential equation contains only dlog-forms with algebraic arguments, where the algebraic part is given by (multiple) square roots. It is well-known that if all square roots are simultaneously rationalisable, the Feynman integrals can be expressed in terms of multipl…
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Feynman integrals are very often computed from their differential equations. It is not uncommon that the $\varepsilon$-factorised differential equation contains only dlog-forms with algebraic arguments, where the algebraic part is given by (multiple) square roots. It is well-known that if all square roots are simultaneously rationalisable, the Feynman integrals can be expressed in terms of multiple polylogarithms. This is a sufficient, but not a necessary criterium. In this paper we investigate weaker requirements. We discuss under which conditions we may use different rationalisations in different parts of the calculation. In particular we show that we may use different rationalisations if they correspond to different parameterisations of the same integration path. We present a non-trivial example -- the one-loop pentagon function with three adjacent massive external legs involving seven square roots -- where this technique can be used to express the result in terms of multiple polylogarithms.
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Submitted 2 April, 2025; v1 submitted 13 January, 2025;
originally announced January 2025.
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Multi-Component Dark Matter from Minimal Flavor Violation
Authors:
Federico Mescia,
Shohei Okawa,
Keyun Wu
Abstract:
Minimal Flavor Violation (MFV) offers an appealing framework for exploring physics beyond the Standard Model. Interestingly, within the MFV framework, a new colorless field that transforms non-trivially under a global ${\rm SU}(3)^3$ quark flavor group can naturally be stable. Such a new field is thus a promising dark matter candidate, provided it is electrically neutral. We extend the MFV framewo…
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Minimal Flavor Violation (MFV) offers an appealing framework for exploring physics beyond the Standard Model. Interestingly, within the MFV framework, a new colorless field that transforms non-trivially under a global ${\rm SU}(3)^3$ quark flavor group can naturally be stable. Such a new field is thus a promising dark matter candidate, provided it is electrically neutral. We extend the MFV framework for dark matter and demonstrate that dark matter can naturally be multi-component across a broad parameter space. For illustration, we consider a gauge singlet, flavor triplet scalar field and identify parameter spaces for multi-component dark matter, where only the lightest flavor component is absolutely stable and heavy flavor components are decaying with lifetimes sufficiently longer than the age of the universe. Phenomenological, cosmological and astrophysical aspects of multi-component flavored dark matter are briefly discussed.
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Submitted 29 August, 2024;
originally announced August 2024.
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Self-dualities and Galois symmetries in Feynman integrals
Authors:
Sebastian Pögel,
Xing Wang,
Stefan Weinzierl,
Konglong Wu,
Xiaofeng Xu
Abstract:
It is well-known that all Feynman integrals within a given family can be expressed as a finite linear combination of master integrals. The master integrals naturally group into sectors. Starting from two loops, there can exist sectors made up of more than one master integral. In this paper we show that such sectors may have additional symmetries. First of all, self-duality, which was first observe…
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It is well-known that all Feynman integrals within a given family can be expressed as a finite linear combination of master integrals. The master integrals naturally group into sectors. Starting from two loops, there can exist sectors made up of more than one master integral. In this paper we show that such sectors may have additional symmetries. First of all, self-duality, which was first observed in Feynman integrals related to Calabi--Yau geometries, often carries over to non-Calabi--Yau Feynman integrals. Secondly, we show that in addition there can exist Galois symmetries relating integrals. In the simplest case of two master integrals within a sector, whose definition involves a square root $r$, we may choose a basis $(I_1,I_2)$ such that $I_2$ is obtained from $I_1$ by the substitution $r \rightarrow -r$. This pattern also persists in sectors, which a priori are not related to any square root with dependence on the kinematic variables. We show in several examples that in such cases a suitable redefinition of the integrals introduces constant square roots like $\sqrt{3}$. The new master integrals are then again related by a Galois symmetry, for example the substitution $\sqrt{3} \rightarrow -\sqrt{3}$. To handle the case where the argument of a square root would be a perfect square we introduce a limit Galois symmetry. Both self-duality and Galois symmetries constrain the differential equation.
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Submitted 24 June, 2025; v1 submitted 11 July, 2024;
originally announced July 2024.
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Photoproduction of lepton pair in ultra-relativistic heavy-ion collisions
Authors:
Kewei Yu,
Jiazhen Peng,
Shuang Li,
Kejun Wu,
Wei Xie,
Fei Sun
Abstract:
Dilepton production provides a unique probe of the strong electromagnetic field produced in heavy-ion collisions. To map out the behavior of its transverse momentum broadening, we present a theoretical model based on the equivalent photon approximation, and then we update it to make direct comparisons with the recent experimental measurements. We find that the model calculations can describe well,…
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Dilepton production provides a unique probe of the strong electromagnetic field produced in heavy-ion collisions. To map out the behavior of its transverse momentum broadening, we present a theoretical model based on the equivalent photon approximation, and then we update it to make direct comparisons with the recent experimental measurements. We find that the model calculations can describe well, not only the average transverse momentum squared of $e^{+}e^{-}$ pairs in Au--Au collisions at $\sqrt{s_{\rm NN}}=200$ GeV, but also the acoplanarity of $μ^{+}μ^{-}$ pairs in Pb--Pb collisions at$\sqrt{s_{\rm NN}}=5.02$ TeV. Furthermore, the model predictions are also able to reproduce the measured dependencies of the pair mass and the transverse momentum squared.
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Submitted 12 June, 2024; v1 submitted 19 January, 2024;
originally announced January 2024.
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A $ν$ window onto leptoquarks?
Authors:
Matthew Kirk,
Shohei Okawa,
Keyun Wu
Abstract:
Upcoming neutrino telescopes promise a new window onto the interactions of neutrinos with matter at ultrahigh energies ($E_ν= 10^7$-$10^{10}$ GeV), and the possibility to detect deviations from the Standard Model predictions. In this paper, we update previous predictions for the enhancement of the neutrino-nucleon cross-section for motivated leptoquark models and show the latest neutrino physics b…
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Upcoming neutrino telescopes promise a new window onto the interactions of neutrinos with matter at ultrahigh energies ($E_ν= 10^7$-$10^{10}$ GeV), and the possibility to detect deviations from the Standard Model predictions. In this paper, we update previous predictions for the enhancement of the neutrino-nucleon cross-section for motivated leptoquark models and show the latest neutrino physics bound, as well as analyse the latest LHC pair production and Drell-Yan data, and flavour constraints (some of which were previously missed). We find that, despite the next generation of neutrino experiments probing the highest energies, they will not be enough to be competitive with collider searches.
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Submitted 8 January, 2024; v1 submitted 20 July, 2023;
originally announced July 2023.
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Snowmass Theory Frontier: Astrophysics and Cosmology
Authors:
Daniel Green,
Joshua T. Ruderman,
Benjamin R. Safdi,
Jessie Shelton,
Ana Achúcarro,
Peter Adshead,
Yashar Akrami,
Masha Baryakhtar,
Daniel Baumann,
Asher Berlin,
Nikita Blinov,
Kimberly K. Boddy,
Malte Buschmann,
Giovanni Cabass,
Robert Caldwell,
Emanuele Castorina,
Thomas Y. Chen,
Xingang Chen,
William Coulton,
Djuna Croon,
Yanou Cui,
David Curtin,
Francis-Yan Cyr-Racine,
Christopher Dessert,
Keith R. Dienes
, et al. (62 additional authors not shown)
Abstract:
We summarize progress made in theoretical astrophysics and cosmology over the past decade and areas of interest for the coming decade. This Report is prepared as the TF09 "Astrophysics and Cosmology" topical group summary for the Theory Frontier as part of the Snowmass 2021 process.
We summarize progress made in theoretical astrophysics and cosmology over the past decade and areas of interest for the coming decade. This Report is prepared as the TF09 "Astrophysics and Cosmology" topical group summary for the Theory Frontier as part of the Snowmass 2021 process.
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Submitted 14 September, 2022;
originally announced September 2022.
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Front Propagation from Radiative Sources
Authors:
Theodore Steele,
Kinwah Wu
Abstract:
Fronts are regions of transition from one state to another in a medium. They are present in many areas of science and applied mathematics, and modelling them and their evolution is often an effective way of treating the underlying phenomena responsible for them. In this paper, we propose a new approach to modelling front propagation, which characterises the evolution of structures surrounding radi…
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Fronts are regions of transition from one state to another in a medium. They are present in many areas of science and applied mathematics, and modelling them and their evolution is often an effective way of treating the underlying phenomena responsible for them. In this paper, we propose a new approach to modelling front propagation, which characterises the evolution of structures surrounding radiative sources. This approach is generic and has a wide range of applications, particularly when dealing with the propagation of phase or state transitions in media surrounding radiation emitting objects. As an illustration, we show an application in modelling the propagation of ionisation fronts around early stars during the cosmological Epoch of Reionisation (EoR) and show that the results are consistent with those of existing equations but provide much richer sources of information.
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Submitted 9 May, 2022;
originally announced May 2022.
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Direct Detection of Sub-GeV Dark Matter with $s>1$ through the DM-Electron Scattering (I): case study for $s=3/2$ and $s=2$ with (pseudo)scalar mediator
Authors:
Ke-yun Wu,
Acckin Lee
Abstract:
The observable signal of higher-spin particles is rare in current particle collider experiments. In the meantime, there have no evident constraints on the spin of the dark matter particles. And thereby it is natural to consider the possibility that the higher-spin particles behaves as dark matter. In this work, we investigate the direct detection of (spin-$3/2$) gravitino dark matter and (spin-…
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The observable signal of higher-spin particles is rare in current particle collider experiments. In the meantime, there have no evident constraints on the spin of the dark matter particles. And thereby it is natural to consider the possibility that the higher-spin particles behaves as dark matter. In this work, we investigate the direct detection of (spin-$3/2$) gravitino dark matter and (spin-$2$) massive KK-graviton dark matter respectively through the DM-electron scattering. Both the spin-independent (SI) and spin-independent (SD) interactions of DM are considered. Using the experiment datas of XENON10, XENON100 and XENON1T, we could give the restriction relation between the DM mass and cross section. For simplification, we only compute the corss section at leading order, while merely focus on the (pseudo)scalar mediators. Moreover, by evaluating and analyzing the form factor of DM, we uncover that if the mediator is scalar there have no significant signals to distinguish the DM with spin $3/2,2$ from the one with spin $0,1/2,1$.
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Submitted 25 March, 2022;
originally announced March 2022.
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Inflation: Theory and Observations
Authors:
Ana Achúcarro,
Matteo Biagetti,
Matteo Braglia,
Giovanni Cabass,
Robert Caldwell,
Emanuele Castorina,
Xingang Chen,
William Coulton,
Raphael Flauger,
Jacopo Fumagalli,
Mikhail M. Ivanov,
Hayden Lee,
Azadeh Maleknejad,
P. Daniel Meerburg,
Azadeh Moradinezhad Dizgah,
Gonzalo A. Palma,
Guilherme L. Pimentel,
Sébastien Renaux-Petel,
Benjamin Wallisch,
Benjamin D. Wandelt,
Lukas T. Witkowski,
W. L. Kimmy Wu
Abstract:
Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the inflationary era and its observational probes may therefore shed unique light on the physical laws underlying our universe. This white paper describes our current theoretical understanding of the inflationary era…
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Cosmic inflation provides a window to the highest energy densities accessible in nature, far beyond those achievable in any realistic terrestrial experiment. Theoretical insights into the inflationary era and its observational probes may therefore shed unique light on the physical laws underlying our universe. This white paper describes our current theoretical understanding of the inflationary era, with a focus on the statistical properties of primordial fluctuations. In particular, we survey observational targets for three important signatures of inflation: primordial gravitational waves, primordial non-Gaussianity and primordial features. With the requisite advancements in analysis techniques, the tremendous increase in the raw sensitivities of upcoming and planned surveys will translate to leaps in our understanding of the inflationary paradigm and could open new frontiers for cosmology and particle physics. The combination of future theoretical and observational developments therefore offer the potential for a dramatic discovery about the nature of cosmic acceleration in the very early universe and physics on the smallest scales.
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Submitted 29 September, 2022; v1 submitted 15 March, 2022;
originally announced March 2022.
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Snowmass 2021 CMB-S4 White Paper
Authors:
Kevork Abazajian,
Arwa Abdulghafour,
Graeme E. Addison,
Peter Adshead,
Zeeshan Ahmed,
Marco Ajello,
Daniel Akerib,
Steven W. Allen,
David Alonso,
Marcelo Alvarez,
Mustafa A. Amin,
Mandana Amiri,
Adam Anderson,
Behzad Ansarinejad,
Melanie Archipley,
Kam S. Arnold,
Matt Ashby,
Han Aung,
Carlo Baccigalupi,
Carina Baker,
Abhishek Bakshi,
Debbie Bard,
Denis Barkats,
Darcy Barron,
Peter S. Barry
, et al. (331 additional authors not shown)
Abstract:
This Snowmass 2021 White Paper describes the Cosmic Microwave Background Stage 4 project CMB-S4, which is designed to cross critical thresholds in our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. We provide an overview of the science case, the technical design, and project plan.
This Snowmass 2021 White Paper describes the Cosmic Microwave Background Stage 4 project CMB-S4, which is designed to cross critical thresholds in our understanding of the origin and evolution of the Universe, from the highest energies at the dawn of time through the growth of structure to the present day. We provide an overview of the science case, the technical design, and project plan.
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Submitted 15 March, 2022;
originally announced March 2022.
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Snowmass2021 Cosmic Frontier: Cosmic Microwave Background Measurements White Paper
Authors:
Clarence L. Chang,
Kevin M. Huffenberger,
Bradford A. Benson,
Federico Bianchini,
Jens Chluba,
Jacques Delabrouille,
Raphael Flauger,
Shaul Hanany,
William C. Jones,
Alan J. Kogut,
Jeffrey J. McMahon,
Joel Meyers,
Neelima Sehgal,
Sara M. Simon,
Caterina Umilta,
Kevork N. Abazajian,
Zeeshan Ahmed,
Yashar Akrami,
Adam J. Anderson,
Behzad Ansarinejad,
Jason Austermann,
Carlo Baccigalupi,
Denis Barkats,
Darcy Barron,
Peter S. Barry
, et al. (107 additional authors not shown)
Abstract:
This is a solicited whitepaper for the Snowmass 2021 community planning exercise. The paper focuses on measurements and science with the Cosmic Microwave Background (CMB). The CMB is foundational to our understanding of modern physics and continues to be a powerful tool driving our understanding of cosmology and particle physics. In this paper, we outline the broad and unique impact of CMB science…
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This is a solicited whitepaper for the Snowmass 2021 community planning exercise. The paper focuses on measurements and science with the Cosmic Microwave Background (CMB). The CMB is foundational to our understanding of modern physics and continues to be a powerful tool driving our understanding of cosmology and particle physics. In this paper, we outline the broad and unique impact of CMB science for the High Energy Cosmic Frontier in the upcoming decade. We also describe the progression of ground-based CMB experiments, which shows that the community is prepared to develop the key capabilities and facilities needed to achieve these transformative CMB measurements.
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Submitted 15 March, 2022;
originally announced March 2022.
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Snowmass2021 CMB-HD White Paper
Authors:
The CMB-HD Collaboration,
:,
Simone Aiola,
Yashar Akrami,
Kaustuv Basu,
Michael Boylan-Kolchin,
Thejs Brinckmann,
Sean Bryan,
Caitlin M. Casey,
Jens Chluba,
Sebastien Clesse,
Francis-Yan Cyr-Racine,
Luca Di Mascolo,
Simon Dicker,
Thomas Essinger-Hileman,
Gerrit S. Farren,
Michael A. Fedderke,
Simone Ferraro,
George M. Fuller,
Nicholas Galitzki,
Vera Gluscevic,
Daniel Grin,
Dongwon Han,
Matthew Hasselfield,
Renee Hlozek
, et al. (40 additional authors not shown)
Abstract:
CMB-HD is a proposed millimeter-wave survey over half the sky that would be ultra-deep (0.5 uK-arcmin) and have unprecedented resolution (15 arcseconds at 150 GHz). Such a survey would answer many outstanding questions about the fundamental physics of the Universe. Major advances would be 1.) the use of gravitational lensing of the primordial microwave background to map the distribution of matter…
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CMB-HD is a proposed millimeter-wave survey over half the sky that would be ultra-deep (0.5 uK-arcmin) and have unprecedented resolution (15 arcseconds at 150 GHz). Such a survey would answer many outstanding questions about the fundamental physics of the Universe. Major advances would be 1.) the use of gravitational lensing of the primordial microwave background to map the distribution of matter on small scales (k~10 h Mpc^(-1)), which probes dark matter particle properties. It will also allow 2.) measurements of the thermal and kinetic Sunyaev-Zel'dovich effects on small scales to map the gas density and velocity, another probe of cosmic structure. In addition, CMB-HD would allow us to cross critical thresholds: 3.) ruling out or detecting any new, light (< 0.1 eV) particles that were in thermal equilibrium with known particles in the early Universe, 4.) testing a wide class of multi-field models that could explain an epoch of inflation in the early Universe, and 5.) ruling out or detecting inflationary magnetic fields. CMB-HD would also provide world-leading constraints on 6.) axion-like particles, 7.) cosmic birefringence, 8.) the sum of the neutrino masses, and 9.) the dark energy equation of state. The CMB-HD survey would be delivered in 7.5 years of observing 20,000 square degrees of sky, using two new 30-meter-class off-axis crossed Dragone telescopes to be located at Cerro Toco in the Atacama Desert. Each telescope would field 800,000 detectors (200,000 pixels), for a total of 1.6 million detectors.
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Submitted 10 March, 2022;
originally announced March 2022.
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Spin-Dependent Scattering of Scalar and Vector Dark Matter and an Electron
Authors:
Ke-Yun Wu,
Zhao-Hua Xiong
Abstract:
The property of dark matter is unknown so far. However, a model-independent classification of dark matter candidates can be achieved by using various symmetries, as done in the Standard Model. Fermionic dark matter has been researched extremely, one favored candidate is the neutralino in the Minimal Supersymmetric Standard Model, which are required by fermion-boson symmetry and preservation of R-p…
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The property of dark matter is unknown so far. However, a model-independent classification of dark matter candidates can be achieved by using various symmetries, as done in the Standard Model. Fermionic dark matter has been researched extremely, one favored candidate is the neutralino in the Minimal Supersymmetric Standard Model, which are required by fermion-boson symmetry and preservation of R-parity. Bosonic dark matter has not been studied sufficiently, especially the scenario of dark matter with mass of sub-GeV. In this paper, we consider the effect of spin-dependent (SD) on scalar and vector dark matter, which are mediated by pseudo-scalar and axial-vector, and evaluate effect on the dark matter-electron scattering cross section. We list all the interaction and form factor of dark matter-electron SD scattering, and use XENON10/100/1T experiment data to derive the exclude limit of SD cross section. We find that the SD scattering of scalar and vector dark matter can be three orders of magnitude stronger than spin-independent (SI) scattering, due to the $p$-wave scattering.
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Submitted 21 April, 2022; v1 submitted 1 March, 2022;
originally announced March 2022.
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Can sub-GeV dark matter coherently scatter on the electrons in the Atom?
Authors:
Ji-Heng Guo,
Yu-Xuan Sun,
Wenyu Wang,
Ke-Yun Wu
Abstract:
A novel detection of sub-GeV dark matter is proposed in the paper. The electron cloud is boosted by the dark matter and emits an electron when it is dragged back by the heavy nucleus, namely the coherent scattering of the electron cloud of the atom. The survey in the X-ray diffraction shows that the atomic form factors are much more complicate than the naive consideration. The results of the relat…
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A novel detection of sub-GeV dark matter is proposed in the paper. The electron cloud is boosted by the dark matter and emits an electron when it is dragged back by the heavy nucleus, namely the coherent scattering of the electron cloud of the atom. The survey in the X-ray diffraction shows that the atomic form factors are much more complicate than the naive consideration. The results of the relativistic Hartree-Fock(RHF) method give non-trivial shapes of the atoms. The detailed calculation of the recoil of the electron cloud, the kinetics, the fiducial cross section and the corresponding calculation of detection rate are given analytically. The numerical results show that the limits of the RHF form factors are much stringent than the recoil of a single electron, almost 4 orders stronger, and also gives tight limitations comparing to the Migdal effect below about several hundred MeV. The physical picture and the corresponding results are promising and need further explorations.
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Submitted 25 September, 2023; v1 submitted 22 December, 2021;
originally announced December 2021.
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Direct Detection of Spin-Dependent Sub-GeV Dark Matter via Migdal Effect
Authors:
Wenyu Wang,
Ke-Yun Wu,
Lei Wu,
Bin Zhu
Abstract:
Motivated by the current strong constraints on the spin-independent dark matter (DM)-nucleus scattering, we investigate the spin-dependent (SD) interactions of the light Majorana DM with the nucleus mediated by an axial-vector boson. Due to the small nucleus recoil energy, the ionization signals have now been used to probe the light dark matter particles in direct detection experiments. With the e…
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Motivated by the current strong constraints on the spin-independent dark matter (DM)-nucleus scattering, we investigate the spin-dependent (SD) interactions of the light Majorana DM with the nucleus mediated by an axial-vector boson. Due to the small nucleus recoil energy, the ionization signals have now been used to probe the light dark matter particles in direct detection experiments. With the existing ionization data, we derive the exclusion limits on the SD DM-nucleus scattering through Migdal effect in the MeV-GeV DM mass range. It is found that the lower limit of the DM mass can reach about several MeVs. Due to the momentum transfer correction induced by the light mediator, the bounds on the SD DM-nucleus scattering cross sections can be weakened in comparison with the heavy mediator.
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Submitted 24 December, 2021; v1 submitted 13 December, 2021;
originally announced December 2021.
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BICEP / Keck XIV: Improved constraints on axion-like polarization oscillations in the cosmic microwave background
Authors:
BICEP/Keck Collaboration,
:,
P. A. R. Ade,
Z. Ahmed,
M. Amiri,
D. Barkats,
R. Basu Thakur,
C. A. Bischoff,
D. Beck,
J. J. Bock,
H. Boenish,
E. Bullock,
V. Buza,
J. R. Cheshire IV,
J. Connors,
J. Cornelison,
M. Crumrine,
A. Cukierman,
E. V. Denison,
M. Dierickx,
L. Duband,
M. Eiben,
S. Fatigoni,
J. P. Filippini,
S. Fliescher
, et al. (68 additional authors not shown)
Abstract:
We present an improved search for axion-like polarization oscillations in the cosmic microwave background (CMB) with observations from the Keck Array. An all-sky, temporally sinusoidal rotation of CMB polarization, equivalent to a time-variable cosmic birefringence, is an observable manifestation of a local axion field and potentially allows a CMB polarimeter to detect axion-like dark matter direc…
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We present an improved search for axion-like polarization oscillations in the cosmic microwave background (CMB) with observations from the Keck Array. An all-sky, temporally sinusoidal rotation of CMB polarization, equivalent to a time-variable cosmic birefringence, is an observable manifestation of a local axion field and potentially allows a CMB polarimeter to detect axion-like dark matter directly. We describe improvements to the method presented in previous work, and we demonstrate the updated method with an expanded dataset consisting of the 2012-2015 observing seasons. We set limits on the axion-photon coupling constant for mass $m$ in the range $10^{-23}$-$10^{-18}~\mathrm{eV}$, which corresponds to oscillation periods on the order of hours to years. Our results are consistent with the background model. For periods between $1$ and $30~\mathrm{d}$ ($1.6 \times 10^{-21} \leq m \leq 4.8 \times 10^{-20}~\mathrm{eV}$), the $95\%$-confidence upper limits on rotation amplitude are approximately constant with a median of $0.27^\circ$, which constrains the axion-photon coupling constant to $g_{φγ} < (4.5 \times 10^{-12}~\mathrm{GeV}^{-1}) m/(10^{-21}~\mathrm{eV}$), if axion-like particles constitute all of the dark matter. More than half of the collected BICEP dataset has yet to be analyzed, and several current and future CMB polarimetry experiments can apply the methods presented here to achieve comparable or superior constraints. In the coming years, oscillation measurements can achieve the sensitivity to rule out unexplored regions of the axion parameter space.
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Submitted 14 March, 2022; v1 submitted 6 August, 2021;
originally announced August 2021.
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Ultra high-energy cosmic rays from beyond the Greisen-Zatsepin-Kuz'min horizon
Authors:
Ellis R. Owen,
Qin Han,
Kinwah Wu,
Y. X. Jane Yap,
Pooja Surajbali
Abstract:
Ultra-high-energy (UHE) cosmic rays (CRs) of energies $\sim (10^{18}-10^{20})~{\rm eV}$, accelerated in violent astrophysical environments, interact with cosmic background radiation fields via photo-hadronic processes, leading to strong attenuation. Typically, the Universe would become `opaque' to UHE CRs after several tens of Mpc, setting the boundary of the Greisen-Zatsepin-Kuz'min (GZK) horizon…
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Ultra-high-energy (UHE) cosmic rays (CRs) of energies $\sim (10^{18}-10^{20})~{\rm eV}$, accelerated in violent astrophysical environments, interact with cosmic background radiation fields via photo-hadronic processes, leading to strong attenuation. Typically, the Universe would become `opaque' to UHE CRs after several tens of Mpc, setting the boundary of the Greisen-Zatsepin-Kuz'min (GZK) horizon. In this work, we investigate the contribution of sources beyond the conventional GZK horizon to the UHE CR flux observed on Earth, when photo-spallation of the heavy nuclear CRs is taken into account. We demonstrate this contribution is substantial, despite the strong attenuation of UHE CRs. A significant consequence is the emergence of an isotropic background component in the observed flux of UHE CRs, coexisting with the anisotropic foreground component that are associated with nearby sources. Multi-particle CR horizons, which evolve over redshift, are determined by the CR nuclear composition. Thus, they are dependent on the source populations and source evolutionary histories.
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Submitted 27 July, 2021;
originally announced July 2021.
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BICEP / Keck XII: Constraints on axion-like polarization oscillations in the cosmic microwave background
Authors:
BICEP/Keck Collaboration,
:,
P. A. R. Ade,
Z. Ahmed,
M. Amiri,
D. Barkats,
R. Basu Thakur,
C. A. Bischoff,
J. J. Bock,
H. Boenish,
E. Bullock,
V. Buza,
J. R. Cheshire IV,
J. Connors,
J. Cornelison,
M. Crumrine,
A. Cukierman,
M. Dierickx,
L. Duband,
S. Fatigoni,
J. P. Filippini,
S. Fliescher,
N. Goeckner-Wald,
J. Grayson,
G. Hall
, et al. (58 additional authors not shown)
Abstract:
We present a search for axion-like polarization oscillations in the cosmic microwave background (CMB) with observations from the Keck Array. A local axion field induces an all-sky, temporally sinusoidal rotation of CMB polarization. A CMB polarimeter can thus function as a direct-detection experiment for axion-like dark matter. We develop techniques to extract an oscillation signal. Many elements…
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We present a search for axion-like polarization oscillations in the cosmic microwave background (CMB) with observations from the Keck Array. A local axion field induces an all-sky, temporally sinusoidal rotation of CMB polarization. A CMB polarimeter can thus function as a direct-detection experiment for axion-like dark matter. We develop techniques to extract an oscillation signal. Many elements of the method are generic to CMB polarimetry experiments and can be adapted for other datasets. As a first demonstration, we process data from the 2012 observing season to set upper limits on the axion-photon coupling constant in the mass range $10^{-21}$-$10^{-18}~\mathrm{eV}$, which corresponds to oscillation periods on the order of hours to months. We find no statistically significant deviations from the background model. For periods larger than $24~\mathrm{hr}$ (mass $m < 4.8 \times 10^{-20}~\mathrm{eV}$), the median 95%-confidence upper limit is equivalent to a rotation amplitude of $0.68^\circ$, which constrains the axion-photon coupling constant to $g_{φγ} < \left ( 1.1 \times 10^{-11}~\mathrm{GeV}^{-1} \right ) m/\left (10^{-21}~\mathrm{eV} \right )$, if axion-like particles constitute all of the dark matter. The constraints can be improved substantially with data already collected by the BICEP series of experiments. Current and future CMB polarimetry experiments are expected to achieve sufficient sensitivity to rule out unexplored regions of the axion parameter space.
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Submitted 17 November, 2020; v1 submitted 6 November, 2020;
originally announced November 2020.
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Searching for Anisotropic Cosmic Birefringence with Polarization Data from SPTpol
Authors:
F. Bianchini,
W. L. K. Wu,
P. A. R. Ade,
A. J. Anderson,
J. E. Austermann,
J. S. Avva,
L. Balkenhol,
E. Baxter,
J. A. Beall,
A. N. Bender,
B. A. Benson,
L. E. Bleem,
J. E. Carlstrom,
C. L. Chang,
P. Chaubal,
H. C. Chiang,
T. L. Chou,
R. Citron,
C. Corbett Moran,
T. M. Crawford,
A. T. Crites,
T. de Haan,
M. A. Dobbs,
W. Everett,
J. Gallicchio
, et al. (47 additional authors not shown)
Abstract:
We present a search for anisotropic cosmic birefringence in 500 deg$^2$ of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) $E$ and $B$ fields. We then measure the angular power spectrum of this map, which is fo…
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We present a search for anisotropic cosmic birefringence in 500 deg$^2$ of southern sky observed at 150 GHz with the SPTpol camera on the South Pole Telescope. We reconstruct a map of cosmic polarization rotation anisotropies using higher-order correlations between the observed cosmic microwave background (CMB) $E$ and $B$ fields. We then measure the angular power spectrum of this map, which is found to be consistent with zero. The non-detection is translated into an upper limit on the amplitude of the scale-invariant cosmic rotation power spectrum, $L(L+1)C_L^{αα}/2π< 0.10 \times 10^{-4}$ rad$^2$ (0.033 deg$^2$, 95% C.L.). This upper limit can be used to place constraints on the strength of primordial magnetic fields, $B_{1 \rm Mpc} < 17 {\rm nG} $ (95% C.L.), and on the coupling constant of the Chern-Simons electromagnetic term $g_{aγ} < 4.0 \times 10^{-2}/H_I $ (95% C.L.), where $H_I$ is the inflationary Hubble scale. For the first time, we also cross-correlate the CMB temperature fluctuations with the reconstructed rotation angle map, a signal expected to be non-vanishing in certain theoretical scenarios, and find no detectable signal. We perform a suite of systematics and consistency checks and find no evidence for contamination.
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Submitted 4 October, 2020; v1 submitted 14 June, 2020;
originally announced June 2020.
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Compton scattering from $^4$He at the TUNL HI$γ$S facility
Authors:
X. Li,
M. W. Ahmed,
A. Banu,
C. Bartram,
B. Crowe,
E. J. Downie,
M. Emamian,
G. Feldman,
H. Gao,
D. Godagama,
H. W. Grießhammer,
C. R. Howell,
H. J. Karwowski,
D. P. Kendellen,
M. A. Kovash,
K. K. H. Leung,
D. Markoff,
S. Mikhailov,
R. E. Pywell,
M. H. Sikora,
J. A. Silano,
R. S. Sosa,
M. C. Spraker,
G. Swift,
P. Wallace
, et al. (4 additional authors not shown)
Abstract:
Differential cross sections for elastic Compton scattering from $^4$He have been measured with high statistical precision at the High Intensity $γ$-ray Source at laboratory scattering angles of $55^\circ$, $90^\circ$, and $125^\circ$ using a quasi-monoenergetic photon beam with a weighted mean energy value of $81.3$ MeV. The results are compared to previous measurements and similar fore-aft asymme…
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Differential cross sections for elastic Compton scattering from $^4$He have been measured with high statistical precision at the High Intensity $γ$-ray Source at laboratory scattering angles of $55^\circ$, $90^\circ$, and $125^\circ$ using a quasi-monoenergetic photon beam with a weighted mean energy value of $81.3$ MeV. The results are compared to previous measurements and similar fore-aft asymmetry in the angular distribution of the differential cross sections is observed. This experimental work is expected to strongly motivate the development of effective-field-theory calculations of Compton scattering from $^4$He to fully interpret the data.
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Submitted 24 April, 2020; v1 submitted 14 December, 2019;
originally announced December 2019.
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Messengers from the Early Universe: Cosmic Neutrinos and Other Light Relics
Authors:
Daniel Green,
Mustafa A. Amin,
Joel Meyers,
Benjamin Wallisch,
Kevork N. Abazajian,
Muntazir Abidi,
Peter Adshead,
Zeeshan Ahmed,
Behzad Ansarinejad,
Robert Armstrong,
Carlo Baccigalupi,
Kevin Bandura,
Darcy Barron,
Nicholas Battaglia,
Daniel Baumann,
Keith Bechtol,
Charles Bennett,
Bradford Benson,
Florian Beutler,
Colin Bischoff,
Lindsey Bleem,
J. Richard Bond,
Julian Borrill,
Elizabeth Buckley-Geer,
Cliff Burgess
, et al. (114 additional authors not shown)
Abstract:
The hot dense environment of the early universe is known to have produced large numbers of baryons, photons, and neutrinos. These extreme conditions may have also produced other long-lived species, including new light particles (such as axions or sterile neutrinos) or gravitational waves. The gravitational effects of any such light relics can be observed through their unique imprint in the cosmic…
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The hot dense environment of the early universe is known to have produced large numbers of baryons, photons, and neutrinos. These extreme conditions may have also produced other long-lived species, including new light particles (such as axions or sterile neutrinos) or gravitational waves. The gravitational effects of any such light relics can be observed through their unique imprint in the cosmic microwave background (CMB), the large-scale structure, and the primordial light element abundances, and are important in determining the initial conditions of the universe. We argue that future cosmological observations, in particular improved maps of the CMB on small angular scales, can be orders of magnitude more sensitive for probing the thermal history of the early universe than current experiments. These observations offer a unique and broad discovery space for new physics in the dark sector and beyond, even when its effects would not be visible in terrestrial experiments or in astrophysical environments. A detection of an excess light relic abundance would be a clear indication of new physics and would provide the first direct information about the universe between the times of reheating and neutrino decoupling one second later.
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Submitted 12 March, 2019;
originally announced March 2019.
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BICEP2 / Keck Array IX: New Bounds on Anisotropies of CMB Polarization Rotation and Implications for Axion-Like Particles and Primordial Magnetic Fields
Authors:
Keck Array,
BICEP2 Collaborations,
:,
P. A. R. Ade,
Z. Ahmed,
R. W. Aikin,
K. D. Alexander,
D. Barkats,
S. J. Benton,
C. A. Bischoff,
J. J. Bock,
R. Bowens-Rubin,
J. A. Brevik,
I. Buder,
E. Bullock,
V. Buza,
J. Connors,
B. P. Crill,
L. Duband,
C. Dvorkin,
J. P. Filippini,
S. Fliescher,
T. St. Germaine,
T. Ghosh,
J. Grayson
, et al. (43 additional authors not shown)
Abstract:
We present the strongest constraints to date on anisotropies of cosmic microwave background (CMB) polarization rotation derived from 150 GHz data taken by the BICEP2/Keck Array CMB experiments up to and including the 2014 observing season (BK14). The definition of the polarization angle in BK14 maps has gone through self-calibration in which the overall angle is adjusted to minimize the observed T…
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We present the strongest constraints to date on anisotropies of cosmic microwave background (CMB) polarization rotation derived from 150 GHz data taken by the BICEP2/Keck Array CMB experiments up to and including the 2014 observing season (BK14). The definition of the polarization angle in BK14 maps has gone through self-calibration in which the overall angle is adjusted to minimize the observed TB and EB power spectra. After this procedure, the QU maps lose sensitivity to a uniform polarization rotation but are still sensitive to anisotropies of polarization rotation. This analysis places constraints on the anisotropies of polarization rotation, which could be generated by CMB photons interacting with axionlike pseudoscalar fields or Faraday rotation induced by primordial magnetic fields. The sensitivity of BK14 maps ($\sim 3μ$K-arcmin) makes it possible to reconstruct anisotropies of the polarization rotation angle and measure their angular power spectrum much more precisely than previous attempts. Our data are found to be consistent with no polarization rotation anisotropies, improving the upper bound on the amplitude of the rotation angle spectrum by roughly an order of magnitude compared to the previous best constraints. Our results lead to an order of magnitude better constraint on the coupling constant of the Chern-Simons electromagnetic term $g_{aγ}\leq 7.2\times 10^{-2}/H_I$ (95% confidence) than the constraint derived from the B-mode spectrum, where $H_I$ is the inflationary Hubble scale. This constraint leads to a limit on the decay constant of $10^{-6}\lesssim f_a/M_{\rm pl}$ at mass range of $10^{-33}< m_a< 10^{-28}$ eV for $r=0.01$, assuming $g_{aγ}\simα/(2πf_a)$ with $α$ denoting the fine structure constant. The upper bound on the amplitude of the primordial magnetic fields is 30nG (95% confidence) from the polarization rotation anisotropies.
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Submitted 20 June, 2019; v1 submitted 6 May, 2017;
originally announced May 2017.
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CMB-S4 Science Book, First Edition
Authors:
Kevork N. Abazajian,
Peter Adshead,
Zeeshan Ahmed,
Steven W. Allen,
David Alonso,
Kam S. Arnold,
Carlo Baccigalupi,
James G. Bartlett,
Nicholas Battaglia,
Bradford A. Benson,
Colin A. Bischoff,
Julian Borrill,
Victor Buza,
Erminia Calabrese,
Robert Caldwell,
John E. Carlstrom,
Clarence L. Chang,
Thomas M. Crawford,
Francis-Yan Cyr-Racine,
Francesco De Bernardis,
Tijmen de Haan,
Sperello di Serego Alighieri,
Joanna Dunkley,
Cora Dvorkin,
Josquin Errard
, et al. (61 additional authors not shown)
Abstract:
This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical…
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This book lays out the scientific goals to be addressed by the next-generation ground-based cosmic microwave background experiment, CMB-S4, envisioned to consist of dedicated telescopes at the South Pole, the high Chilean Atacama plateau and possibly a northern hemisphere site, all equipped with new superconducting cameras. CMB-S4 will dramatically advance cosmological studies by crossing critical thresholds in the search for the B-mode polarization signature of primordial gravitational waves, in the determination of the number and masses of the neutrinos, in the search for evidence of new light relics, in constraining the nature of dark energy, and in testing general relativity on large scales.
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Submitted 9 October, 2016;
originally announced October 2016.
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Bounds on Higgs And Top Quark Masses From The Other Degenerate Vacua Near The Planck Scale With Gravitational Contributions
Authors:
Fei Wang,
Guo-Li Liu,
Kun Wu
Abstract:
Based on the weak coupling expansion of gravity, we calculate the gravitational contributions to yukawa coupling, scalar quartic coupling as well as gauge couplings with general Landau-DeWitt gauge-fixing choice and a gauge preserving (of SM gauge group) cut off regularization scheme. We find that the results depend on the Landau-DeWitt gauge-fixing parameter. Based on the two loop RGE of SM coupl…
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Based on the weak coupling expansion of gravity, we calculate the gravitational contributions to yukawa coupling, scalar quartic coupling as well as gauge couplings with general Landau-DeWitt gauge-fixing choice and a gauge preserving (of SM gauge group) cut off regularization scheme. We find that the results depend on the Landau-DeWitt gauge-fixing parameter. Based on the two loop RGE of SM couplings with one loop full gravitational contributions in harmonic gauge, we study the constraints on the higgs and top quark mass from the requirement of existing the other degenerate vacua at the Planck-dominated region. Our numerical calculations show that nature will not develop the other degenerate vacua at the Planck-dominated region with current higgs and top quark masses. On the other hand, requiring the existence of the other degenerate vacua at the Planck-dominated region will constrain the higgs and top mass to lie at approximately 130 and 174 GeV, respectively.
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Submitted 24 June, 2015;
originally announced June 2015.
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Charged Higgs Pair Production at the LHC as a Probe of the Top-Seesaw Assisted Technicolor Models
Authors:
Guo-Li Liu,
Xiao-Fei Guo,
Kun Wu,
Ji Jiang,
Ping Zhou
Abstract:
The top-seesaw assisted technicolor (TC) model, which was proposed recently to explain the 126 GeV Higgs mass discovered by the Large Hadron Colliders (LHC), predicts light and heavy charged Higgs bosons in addition to the neutral Higgses. In this paper we will study the pair productions of the charged Higgs, proceeding through gluon-gluon fusion and quark-anti-quark annihilation, at the LHC in th…
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The top-seesaw assisted technicolor (TC) model, which was proposed recently to explain the 126 GeV Higgs mass discovered by the Large Hadron Colliders (LHC), predicts light and heavy charged Higgs bosons in addition to the neutral Higgses. In this paper we will study the pair productions of the charged Higgs, proceeding through gluon-gluon fusion and quark-anti-quark annihilation, at the LHC in the frame of the top-seesaw assisted TC model. We find that in a large part of parameter space the production cross sections of the light charged Higgs pair at the LHC can be quite large compared with the low standard model backgrounds, while it is impossible for the pair production of the heavy ones to be detected with the strong final mass suppression. Therefore, at the LHC future experiments, the light charged Higgs pair production may be served as a probe of this new TC model.
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Submitted 28 May, 2015; v1 submitted 7 January, 2015;
originally announced January 2015.
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Energy and Centrality Dependence of Chemical Freeze-out Thermodynamics parameters
Authors:
N. Yu,
F. Liu,
K. Wu
Abstract:
Driven by the Beam Energy Scan (BES) program at the RHIC, researches and discussions on the QCD phase diagram have flourished recently. In order to provide a reference from microscopic transport models, we performed a systematic analysis, using a multiphase transport (AMPT) model for the particle yields and a statistical model (THERMUS) for the thermal fit, for Au+Au collisions at…
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Driven by the Beam Energy Scan (BES) program at the RHIC, researches and discussions on the QCD phase diagram have flourished recently. In order to provide a reference from microscopic transport models, we performed a systematic analysis, using a multiphase transport (AMPT) model for the particle yields and a statistical model (THERMUS) for the thermal fit, for Au+Au collisions at $\sqrt{s_{\text{NN}}}$=7.7-200 GeV. It is found that at a fixed collision centrality the chemical freeze-out parameter, temperature $T_{\text{ch}}$, increases with collision energy and somehow saturates at certain values of $T_{\text{ch}}$ in collisions near $\sqrt{s_{\text{NN}}}$=10 GeV, indicating the limiting temperature in hadronic interactions; meanwhile the baryon chemical potential $μ_B$ decrease with the collision energy. The saturation temperature is also found to be dependent on partonic interaction. At a given collision energy, it is found that both $T_{\text{ch}}$ and $μ_B$ decrease towards more peripheral collisions in the grand canonical approach. The energy and centrality dependence of other chemical freeze-out parameters, strangeness chemical potential $μ_S$, strangeness undersaturation factor $γ_S$, and the volume of the fireball $V$ are also presented in this paper. The chemical potential ratio $μ_s/μ_B$ is also compared with lattice QCD calculation. The AMPT default model gives better descriptions on both the particle yields and the chemical freeze-out parameters than those from the AMPT string-melting model.
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Submitted 3 September, 2014; v1 submitted 21 April, 2014;
originally announced April 2014.
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A Guide to Designing Future Ground-based CMB Experiments
Authors:
W. L. K. Wu,
J. Errard,
C. Dvorkin,
C. L. Kuo,
A. T. Lee,
P. McDonald,
A. Slosar,
O. Zahn
Abstract:
In this follow-up work to the High Energy Physics Community Summer Study 2013 (HEP CSS 2013, a.k.a. Snowmass), we explore the scientific capabilities of a future Stage-IV Cosmic Microwave Background polarization experiment (CMB-S4) under various assumptions on detector count, resolution, and sky coverage. We use the Fisher matrix technique to calculate the expected uncertainties in cosmological pa…
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In this follow-up work to the High Energy Physics Community Summer Study 2013 (HEP CSS 2013, a.k.a. Snowmass), we explore the scientific capabilities of a future Stage-IV Cosmic Microwave Background polarization experiment (CMB-S4) under various assumptions on detector count, resolution, and sky coverage. We use the Fisher matrix technique to calculate the expected uncertainties in cosmological parameters in $νΛ$CDM that are especially relevant to the physics of fundamental interactions, including neutrino masses, effective number of relativistic species, dark-energy equation of state, dark-matter annihilation, and inflationary parameters. To further chart the landscape of future cosmology probes, we include forecasted results from the Baryon Acoustic Oscillation (BAO) signal as measured by DESI to constrain parameters that would benefit from low redshift information. We find the following best 1-sigma constraints: $σ$ constraints: $σ(M_ν)= 15$ meV, $σ(N_{\rm eff})= 0.0156$, Dark energy Figure of Merit = 303, $σ(p_{ann})= 0.00588\times3\times10^{-26}$ cm$^3$/s/GeV, $σ(Ω_K)= 0.00074$, $σ(n_s)= 0.00110$, $σ(α_s)= 0.00145$, and $σ(r)= 0.00009$. We also detail the dependences of the parameter constraints on detector count, resolution, and sky coverage.
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Submitted 17 February, 2014;
originally announced February 2014.
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Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure
Authors:
K. N. Abazajian,
K. Arnold,
J. Austermann,
B. A. Benson,
C. Bischoff,
J. Bock,
J. R. Bond,
J. Borrill,
E. Calabrese,
J. E. Carlstrom,
C. S. Carvalho,
C. L. Chang,
H. C. Chiang,
S. Church,
A. Cooray,
T. M. Crawford,
K. S. Dawson,
S. Das,
M. J. Devlin,
M. Dobbs,
S. Dodelson,
O. Dore,
J. Dunkley,
J. Errard,
A. Fraisse
, et al. (52 additional authors not shown)
Abstract:
This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relation…
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This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve sigma(sum m_nu) = 16 meV and sigma(N_eff) = 0.020. Such a mass measurement will produce a high significance detection of non-zero sum m_nu, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics --- the origin of mass. This precise a measurement of N_eff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that N_eff = 3.046.
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Submitted 30 May, 2014; v1 submitted 20 September, 2013;
originally announced September 2013.
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On Symplectic and Multisymplectic Srtuctures and their Discrete Versions in Lagrangian Formalism
Authors:
H. Y. Guo,
Y. Q. Li,
K. Wu
Abstract:
We introduce the Euler-Lagrange cohomology to study the symplectic and multisymplectic structures and their preserving properties in finite and infinite dimensional Lagrangian systems respectively. We also explore their certain difference discrete counterparts in the relevant regularly discretized finite and infinite dimensional Lagrangian systems by means of the difference discrete variational…
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We introduce the Euler-Lagrange cohomology to study the symplectic and multisymplectic structures and their preserving properties in finite and infinite dimensional Lagrangian systems respectively. We also explore their certain difference discrete counterparts in the relevant regularly discretized finite and infinite dimensional Lagrangian systems by means of the difference discrete variational principle with the difference being regarded as an entire geometric object and the noncommutative differential calculus on regular lattice. In order to show that in all these cases the symplectic and multisymplectic preserving properties do not necessarily depend on the relevant Euler-Lagrange equations, the Euler-Lagrange cohomological concepts and content in the configuration space are employed.
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Submitted 13 August, 2001; v1 submitted 6 April, 2001;
originally announced April 2001.
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Two Particle Physics Models With Spontaneous CP Violation From Gauge Theory On Discrete Group
Authors:
Han-Ying Guo,
Ke Wu,
Chi Xiong
Abstract:
Based on the differential calculus and the gauge theory on discrete groups, we reconstruct two physics models with spontaneous CP violation: (1) The Georgi-Glashow-Lee model with two Higgs triplets; (2) The Weinberg-Salam-Branco model with three Higgs doublets and the natural flavor conservation (NFC). We focus on the Lagrangian terms containing the Higgs particles and show that with an appropri…
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Based on the differential calculus and the gauge theory on discrete groups, we reconstruct two physics models with spontaneous CP violation: (1) The Georgi-Glashow-Lee model with two Higgs triplets; (2) The Weinberg-Salam-Branco model with three Higgs doublets and the natural flavor conservation (NFC). We focus on the Lagrangian terms containing the Higgs particles and show that with an appropriate choice of the discrete groups, we can obtain the physically meaningful Yukawa couplings and the Higgs potentials which lead to the spontaneous CP violation consequently.
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Submitted 22 January, 1998;
originally announced January 1998.