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Nuclear Schiff moment of fluorine isotope $^{19}$F
Authors:
Kia Boon Ng,
Stephan Foster,
Lan Cheng,
Petr Navratil,
Stephan Malbrunot-Ettenauer
Abstract:
Nuclear Schiff moments (NSMs) are sensitive probes for physics beyond the Standard Model of particle physics, signaling violations of time-reversal and parity-inversion symmetries in atomic nuclei. In this Letter, we report the first-ever calculation of a NSM in a nuclear ab initio framework, employing the no-core shell model to study the fluorine isotope $^{19}$F. We further perform quantum-chemi…
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Nuclear Schiff moments (NSMs) are sensitive probes for physics beyond the Standard Model of particle physics, signaling violations of time-reversal and parity-inversion symmetries in atomic nuclei. In this Letter, we report the first-ever calculation of a NSM in a nuclear ab initio framework, employing the no-core shell model to study the fluorine isotope $^{19}$F. We further perform quantum-chemistry calculations to evaluate the sensitivity of the hafnium monofluoride cation, HfF$^+$, to the NSM of $^{19}$F. Combined with recent high-precision measurements of the molecular electric dipole moment of HfF$^+$, our results enable the first experimental bound on the NSM of $^{19}$F.
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Submitted 26 July, 2025;
originally announced July 2025.
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The Spectrum of Low-$p_T$ $J/ψ$ in Heavy-Ion Collisions in a Statistical Two-Body Fractal Model
Authors:
Huiqiang Ding,
Luan Cheng,
Tingting Dai,
Enke Wang,
Wei-Ning Zhang
Abstract:
We establish a statistical two-body fractal (STF) model to study the spectrum of $J/ψ$. $J/ψ$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/ψ$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effec…
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We establish a statistical two-body fractal (STF) model to study the spectrum of $J/ψ$. $J/ψ$ serves as a reliable probe in heavy-ion collisions. The distribution of $J/ψ$ in hadron gas is influenced by flow, quantum and strong interaction effects. Previous models have predominantly focused on one or two of these effects while neglecting the others, resulting in the inclusion of unconsidered effects in the fitted parameters. Here, we study the issue from a new point of view by analyzing the fact that all three effects induce a self-similarity structure, involving a $J/ψ$-$π$ two-meson state and a $J/ψ$, $π$ two-quark state, respectively. We introduce modification factor $q_{TBS}$ and $q_2$ into the probability and entropy of charmonium. $q_{TBS}$ denotes the modification of self-similarity on $J/ψ$, $q_2$ denotes that of self-similarity and strong interaction between \emph{c }and $\bar{c}$ on quarks. By solving the probability and entropy equations, we derive the values of $q_{TBS}$ and $q_2$ at various collision energies and centralities. Substituting the value of $q_{TBS}$ into distribution function, we successfully obtain the transverse momentum spectrum of low-$p_T$ $J/ψ$, which demonstrates good agreement with experimental data. The STF model can be employed to investigate other mesons and resonance states.
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Submitted 13 December, 2023; v1 submitted 27 February, 2023;
originally announced February 2023.
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Electric dipole moments and the search for new physics
Authors:
Ricardo Alarcon,
Jim Alexander,
Vassilis Anastassopoulos,
Takatoshi Aoki,
Rick Baartman,
Stefan Baeßler,
Larry Bartoszek,
Douglas H. Beck,
Franco Bedeschi,
Robert Berger,
Martin Berz,
Hendrick L. Bethlem,
Tanmoy Bhattacharya,
Michael Blaskiewicz,
Thomas Blum,
Themis Bowcock,
Anastasia Borschevsky,
Kevin Brown,
Dmitry Budker,
Sergey Burdin,
Brendan C. Casey,
Gianluigi Casse,
Giovanni Cantatore,
Lan Cheng,
Timothy Chupp
, et al. (118 additional authors not shown)
Abstract:
Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss the current status and prospects in the near fu…
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Static electric dipole moments of nondegenerate systems probe mass scales for physics beyond the Standard Model well beyond those reached directly at high energy colliders. Discrimination between different physics models, however, requires complementary searches in atomic-molecular-and-optical, nuclear and particle physics. In this report, we discuss the current status and prospects in the near future for a compelling suite of such experiments, along with developments needed in the encompassing theoretical framework.
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Submitted 4 April, 2022; v1 submitted 15 March, 2022;
originally announced March 2022.
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Squeezed back-to-back correlation of $\bqD^0{\bar \bqD}^0$ in relativistic heavy-ion collisions
Authors:
Ai-Geng Yang,
Yong Zhang,
Luan Cheng,
Hao Sun,
Wei-Ning Zhang
Abstract:
We investigate the squeezed back-to-back correlation (BBC) of $D^0\!{\bar D}^0$ in relativistic heavy-ion collisions, using the in-medium mass modification calculated with a self-energy in hot pion gas and the source space-time distributions provided by the viscous hydrodynamic code VISH2+1. It is found that the BBC of $D^0\!{\bar D}^0$ is significant in peripheral Au+Au collisions at the RHIC ene…
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We investigate the squeezed back-to-back correlation (BBC) of $D^0\!{\bar D}^0$ in relativistic heavy-ion collisions, using the in-medium mass modification calculated with a self-energy in hot pion gas and the source space-time distributions provided by the viscous hydrodynamic code VISH2+1. It is found that the BBC of $D^0\!{\bar D}^0$ is significant in peripheral Au+Au collisions at the RHIC energy. A possible way to detect the BBC in experiment is presented.
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Submitted 22 April, 2018; v1 submitted 5 December, 2017;
originally announced December 2017.
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Productions of $Z^0$ and $W^+/W^-$ in Relativistic Heavy-Ion Collisions at the LHC
Authors:
Peng Ru,
Ben-Wei Zhang,
Luan Cheng,
Enke Wang,
Wei-Ning Zhang
Abstract:
The productions of massive gauge bosons, $Z^0$ and $W^+/W^-$, in heavy-ion reactions at the LHC, provide an excellent tool to study the cold nuclear matter effects in high-energy nuclear collisions. In this paper we investigate $Z^0$ and $W^+/W^-$ productions in p+Pb and Pb+Pb at the LHC, at NLO and NNLO with DYNNLO incorporating the nuclear PDFs (nPDFs) parametrization sets EPS09 and DSSZ, within…
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The productions of massive gauge bosons, $Z^0$ and $W^+/W^-$, in heavy-ion reactions at the LHC, provide an excellent tool to study the cold nuclear matter effects in high-energy nuclear collisions. In this paper we investigate $Z^0$ and $W^+/W^-$ productions in p+Pb and Pb+Pb at the LHC, at NLO and NNLO with DYNNLO incorporating the nuclear PDFs (nPDFs) parametrization sets EPS09 and DSSZ, within the framework of perturbative QCD. The numerical simulations of the transverse momentum spectra, rapidity dependence, and related nuclear modification factors for $Z^0$ and $W$ particles, as well as the charge asymmetry for W boson, are provided and tested against the latest experimental data. It is found that the theoretical results with EPS09 and DSSZ nPDFs can give good descriptions of the recent data on $Z^0$ and $W^{\pm}$ particles in p+Pb and Pb+Pb within the experimental error bars, though some differences between results with EPS09 and DSSZ can be observed, especially in the rapidity dependence of the $Z^0$ yield. Theoretical predictions for future measurements on $Z^0$ and $W$ in p+Pb and Pb+Pb collisions at the LHC are also provided.
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Submitted 9 May, 2015; v1 submitted 9 December, 2014;
originally announced December 2014.
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An Explanation for Heavy Quark Energy Loss Puzzle by Flow Effects
Authors:
Luan Cheng,
Enke Wang
Abstract:
The heavy quark energy loss puzzle is explained by collective flow effects in a dynamic medium. The dead cone and LPM effect are found to be changed comparing to the static medium case. Instead of only one dead cone in the static medium, the collective flow induces two dead cones from two different kinds of processes. One is from the projectile emitting gluon process, the same as that in the stati…
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The heavy quark energy loss puzzle is explained by collective flow effects in a dynamic medium. The dead cone and LPM effect are found to be changed comparing to the static medium case. Instead of only one dead cone in the static medium, the collective flow induces two dead cones from two different kinds of processes. One is from the projectile emitting gluon process, the same as that in the static medium. The other is from the gluon emission off the exchanged gluon process, decreasing with increasing flow velocity $v_z$ along jet direction, which lead to the increase of heavy quark energy loss. The differences of the effective average energy loss among charm, bottom and light quarks are very little from a full 3D ideal hydrodynamic simulation for 0-10$%$ central Au-Au collisions at RHIC energy. This would yield similar high $p_{T}$ suppressions between light and heavy quarks for central Au-Au collisions.
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Submitted 26 January, 2011; v1 submitted 6 August, 2009;
originally announced August 2009.
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Flow Effects on Jet quenching with Detailed Balance
Authors:
Luan Cheng,
Enke Wang
Abstract:
A new model potential in the presence of collective flow describing the interaction of the hard jet with scattering centers is derived based on the static color-screened Yukawa potential. The flow effect on jet quenching with detailed balance is investigated in pQCD. It turns out that the collective flow changes the emission current and the LPM destructive interference comparing to that in the sta…
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A new model potential in the presence of collective flow describing the interaction of the hard jet with scattering centers is derived based on the static color-screened Yukawa potential. The flow effect on jet quenching with detailed balance is investigated in pQCD. It turns out that the collective flow changes the emission current and the LPM destructive interference comparing to that in the static medium. Considering the collective flow with velocity v_z along the jet direction, the energy loss is (1 - v_z) times that in the static medium to the first order of opacity. The flow dependence of the energy loss will affect the suppression of high p_T hadron spectrum and anisotropy parameter v_2 in high-energy heavy-ion collisions.
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Submitted 1 February, 2011; v1 submitted 11 February, 2009;
originally announced February 2009.