Nuclear Theory·nucl-th

Tuesday·July 6, 2021

10 papers—4 primary·6 cross-listed

05
[Submitted on 2 Jul 2021] (cross-list from hep-ph)
Gluon matter distribution in the proton and pion from extended holographic light-front QCD
Guy F. de Téramond🇨🇷 · H. G. Dosch🇩🇪 · Tianbo Liu🇨🇳 · Raza Sabbir Sufian🇺🇸 · Stanley J. Brodsky🇺🇸 · Alexandre Deur🇺🇸
The holographic light-front QCD framework provides a unified nonperturbative description of the hadron mass spectrum, form factors and quark distributions. In this article we extend holographic QCD in order to describe the gluonic distribution in both the proton and pion from the coupling of the metric fluctuations induced by the spin-two Pomeron with the energy momentum tensor in anti--de Sitter space, together with constraints imposed by the Veneziano model{\color{blue},} without additional free parameters. The gluonic and quark distributions are shown to have significantly different effective QCD scales.
Comments:
Version to be published in Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.01231 [pdf]
PRD(2021)·42 citations
06
[Submitted on 2 Jul 2021] (cross-list from hep-th)
Holographic Kolmogorov-Sinai entropy and the quantum Lyapunov spectrum
Georg Maier🇩🇪 · Andreas Schäfer🇩🇪 · Sebastian Waeber🇮🇱
In classical chaotic systems the entropy, averaged over initial phase space distributions, follows an universal behavior. While approaching thermal equilibrium it passes through a stage where it grows linearly, while the growth rate, the Kolmogorov-Sinai entropy, is given by the sum over all positive Lyapunov exponents. A natural question is whether a similar relation is valid for quantum systems. We argue that the Maldacena-Shenker-Stanford bound on quantum Lyapunov exponents $λ$ implies that the upper bound on the growth rate of the entropy, averaged over states in Hilbert space that evolve towards a thermal state with temperature $T$ and entropy $S_{e q}$ , should be given by $S_{e q} π T = \sum_{λ > 0} 2 π T$ . Strongly coupled, large $N$ theories with black hole duals should saturate the bound. By studying a large number of isotropization processes of random, spatially homogeneous, far from equilibrium initial states in large $N$ , $N = 4$ Super Yang Mills theory at strong coupling and computing the ensemble averaged growth rate of the dual black hole's apparent horizon area, we find both an analogous behavior as in classical chaotic systems and numerical evidence that the conjectured bound on averaged entropy growth is saturated granted that the Lyapunov exponents are degenerate $λ = \pm 2 π T$ . This fits to the behavior of classical systems with plus/minus symmetric Lyapunov spectra, a symmetry which implies the validity of Liouville's theorem.
Comments:
20 pages, 6 figures
Subjects:
High Energy Physics — Theory (hep-th); General Relativity and Quantum Cosmology (gr-qc); nlin.CD (nlin.CD); Nuclear Theory (nucl-th)
arXiv:
2107.01300 [pdf]
JHEP(2022)·2 citations
07
[Submitted on 4 Jul 2021] (cross-list from hep-ph)
Heavy and light flavor jet quenching in different collision systems at the LHC energies
Yu-Fei Liu🇨🇳 · Wen-Jing Xing🇨🇳 · Xiang-Yu Wu🇨🇳 · Guang-You Qin🇨🇳 · Shanshan Cao🇨🇳 · Hongxi Xing🇨🇳
Recent experiments have observed large anisotropic collective flows in high multiplicity proton-lead collisions at the Large Hadron Collider (LHC), which indicates the possible formation of mini quark-gluon plasma (QGP) in small collision systems. However, no jet quenching has been confirmed in such small systems so far. To understand this intriguing result, the system size scan experiments have been proposed to bridge the gap between large and small systems. In this work, we perform a systematic study on both heavy and light flavor jet quenching in different collision systems at the LHC energies. Using our state-of-the-art jet quenching model, which combines the next-to-leading-order perturbative QCD framework, a linear Boltzmann transport model and the (3+1)-dimensional viscous hydrodynamics simulation, we provide a good description of nuclear modification factor $R_{AA}$ for charged hadrons and $D$ mesons in central and mid-central Pb+Pb and Xe+Xe collisions measured by CMS collaboration. We further predict the transverse momentum and centrality dependences of $R_{AA}$ for charged hadrons, $D$ and $B$ mesons in Pb+Pb, Xe+Xe, Ar+Ar and O+O collisions at the LHC energies. Our numerical results show a clear system size dependence for both light and heavy flavor hadron $R_{AA}$ across different collision systems. Sizable jet quenching effect is obtained for both heavy and light flavor hadrons in central O+O collisions at the LHC energies. Our study provides a significant bridge for jet quenching from large to small systems, and should be helpful for finding the smallest QGP droplet and the disappearance of QGP in relativistic nuclear collisions.
Comments:
12 pages, 8 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.01522 [pdf]
PRC(2022)·18 citations
08
[Submitted on 5 Jul 2021] (cross-list from hep-ph)
Analysis of flux-integrated semi-exclusive cross sections for charged current quasi-elastic neutrino scattering off 40Ar at energies available at the MicroBooNE experiment
A.V. Butkevich🇷🇺
Flux-integrated semi-exclusive differential and integral cross sections for quasi-elastic neutrino charged-current scattering on argon are analyzed. We calculate these cross sections using the relativistic distorted-wave impulse approximation and compare with recent MicroBooNE data. We found that the measured cross sections can be described well within the experimental uncertainties with value of the nucleon axial mass $1 < M_{A} < 1.2$ GeV. The contribution of the exclusive channel $\boldmath (ν_{μ}, μ p)$ to the flux-integrated inclusive cross sections is about 50\%.
Comments:
17 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2107.01827 [pdf]
PRC(2022)·14 citations
09
[Submitted on 5 Jul 2021] (cross-list from physics.acc-ph)
A Muon-Ion Collider at BNL: the future QCD frontier and path to a new energy frontier of $μ^{+} μ^{-}$ colliders
Darin Acosta🇺🇸 · Wei Li🇺🇸
We propose the development and construction of a novel muon-ion collider (MuIC) at Brookhaven National Laboratory (BNL) in the USA as an upgrade to succeed the electron-ion collider (EIC) that is scheduled to commence in the early 2030s, by a joint effort of the nuclear and particle physics communities. The BNL facility could accommodate a muon storage beam with an energy up to about 1~TeV with existing magnet technology. When collided with a 275~GeV hadron beam, the MuIC center-of-mass energy of about 1~TeV will extend the kinematic coverage of deep inelastic scattering physics at the EIC (with polarized beams) by more than an order of magnitude in $Q^{2}$ and $x$ , opening a new QCD frontier to address many fundamental scientific questions in nuclear and particle physics. This coverage is comparable to that of the proposed Large Hadron-Electron Collider (LHeC) at CERN, but with complementary lepton and hadron kinematics and beam polarization. Additionally, the developmentof a MuIC at BNL will focus the worldwide R\&D efforts on muon collider technology and serve as a demonstrator toward a future muon-antimuon collider at { $O$ }(10)~TeV energies, which is an attractive option to reach the next high energy frontier in particle physics at an affordable cost and a smaller footprint than a future circular hadron collider. We discuss here the possible design parameters of the MuIC, kinematic coverage, science cases, and detector design considerations including estimates of resolutions on DIS kinematic variables. A possible road map toward the future MuIC and muon-antimuon colliders is also presented.
Comments:
10 pages, 4 figures, 4 tables. Additional references and discussion of synergies with nuSTORM are added. Comments are welcome!
Subjects:
Accelerator Physics (physics.acc-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.02073 [pdf]
Nucl.Instrum.Meth.A(2022)·34 citations
10
[Submitted on 5 Jul 2021] (cross-list from hep-ph)
The anomalous $Z b b ˉ$ couplings at the HERA and EIC
Bin Yan🇺🇸 · Zhite Yu🇺🇸 · C.-P. Yuan🇺🇸
To resolve the long-standing discrepancy between the precision measurement of bottom quark forward-backward asymmetry at LEP/SLC and the Standard Model prediction, we propose a novel method to probe the $Z b b ˉ$ coupling by measuring the single-spin asymmetry $A_{e}^{b}$ of the polarized lepton cross section in neutral current DIS processes with a $b$ -tagged jet at HERA and EIC. Depending on the tagging efficiency of the final state $b$ -jet, the measurement of $A_{e}^{b}$ at HERA can already partially break the degeneracy found in the anomalous $Z b b ˉ$ coupling, as implied by the LEP and SLC precision electroweak data. In the first year run of the EIC, the measurement of $A_{e}^{b}$ can already break the degeneracy, due to its much larger luminosity and higher electron beam polarization. With enough integrated luminosity collected at the EIC, it is possible to either verify or exclude the LEP data and resolve the $A_{FB}^{b}$ puzzle. We also discuss the complementary roles between the proposed $A_{e}^{b}$ measurement at EIC and the measurement of $g g \to Z h$ cross section at the HL-LHC in constraining the anomalous $Z b b ˉ$ coupling.
Comments:
6 pages, 2 figures, the published version in PLB
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2107.02134 [pdf]
PLB(2021)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE

Gluon matter distribution in the proton and pion from extended holographic light-front QCD

Holographic Kolmogorov-Sinai entropy and the quantum Lyapunov spectrum

Heavy and light flavor jet quenching in different collision systems at the LHC energies

Analysis of flux-integrated semi-exclusive cross sections for charged current quasi-elastic neutrino scattering off 40Ar at energies available at the MicroBooNE experiment

A Muon-Ion Collider at BNL: the future QCD frontier and path to a new energy frontier of μ+μ− colliders

The anomalous Zbbˉ couplings at the HERA and EIC

Affiliations

A Muon-Ion Collider at BNL: the future QCD frontier and path to a new energy frontier of $μ^{+} μ^{-}$ colliders

The anomalous $Z b b ˉ$ couplings at the HERA and EIC