Nuclear Theory·nucl-th

Tuesday·November 29, 2022

15 papers—7 primary·8 cross-listed

01
Quantum Entanglement and the Thermal Hadron
Pouya Asadi🇺🇸 · Varun Vaidya🇺🇸
This paper tests how effectively the bound states of strongly interacting gauge theories are amenable to an emergent description as a thermal ensemble. This description can be derived from a conjectured minimum free energy principle, with the entanglement entropy of two-parton subsystems playing the role of thermodynamic entropy. This allows us to calculate the ground state hadron spectrum and wavefunction over a wide range of parton masses without solving the Schrödinger equation. We carry out this analysis for certain illustrative models in 1+1 dimensions and discuss prospects for higher dimensions.
nucl-thhep-phhep-thquant-phPRD(2023)·12 citations
02
Quarkyonic or baryquark matter? On the dynamical generation of momentum space shell structure
Volker Koch🇺🇸 · Volodymyr Vovchenko🇺🇸
We study the equation of state of a mixture of (quasi-)free constituent quarks and nucleons with hard-core repulsion at zero temperature. Two opposite scenarios for the realization of the Pauli exclusion principle are considered: (i) a Fermi sea of quarks surrounded by a shell of baryons -- the quarkyonic matter, and (ii) a Fermi sea of nucleons surrounded by a shell of quarks which we call \emph{baryquark matter}. In both scenarios, the sizes of the Fermi sea and shell are fixed through energy minimization at fixed baryon number density. While both cases yield a qualitatively similar transition from hadronic to quark matter, we find that baryquark matter is energetically favored in this setup and yields a physically acceptable behavior of the speed of sound without the need to introduce an infrared regulator. In order to retain the theoretically more appealing quarkyonic matter as the preferred form of dense QCD matter will thus require modifications to the existing dynamical generation mechanisms, such as, for example, the introduction of momentum-dependent nuclear interactions.
nucl-thhep-phPLB(2023)·17 citations
03
A model-free procedure to correct for volume fluctuations in E-by-E analyses of particle multiplicities
Anar Rustamov🇩🇪 · Joachim Stroth🇩🇪 · Romain Holzmann🇩🇪
We develop an innovative and unbiased procedure, based on event mixing, to account for unavoidable contributions from volume (or system size) fluctuations to experimentally measured moments of particle multiplicity distributions produced in relativistic nuclear collisions. Within the wounded-nucleon model they are characterized by fluctuations of the number of wounded nucleons, the latter usually referred to as participants. For the first time we extract participant fluctuations directly from the data used for the fluctuation analysis, i.e., without involving model calculations. To achieve this we constructed a dedicated event-mixing algorithm that eliminates all possible correlations between produced particles while preserving the volume fluctuations. The procedure provides direct access to the cumulants of wounded-nucleon distributions, which can be used to account for non-critical contributions to the experimentally measured cumulants of multiplicity distributions.
nucl-thhep-phnucl-exNPA(2023)·17 citations
04
Probing Fractional Quantum Hall Sheets in Dense Baryonic Matter
Mannque Rho🇫🇷
Unlike the octet baryons for $N_{f} = 3$ , there is no skyrmion coming from the $η^{'}$ meson. It is instead described as a fractional quantum Hall droplet, a pancake or a pita involving a singular $η^{'}$ ring in which Chern-Simons fields live. By incorporating hidden local symmetry and hidden scale symmetry in nuclear dynamics, I describe how to access baryon-charged quantum Hall droplets in dense nuclear matter in terms of the nuclear scale-chiral effective field theory approach ``G $n$ EFT" with the $U_{A} (1)$ anomaly taken into account. I discuss how the single-flavor baryon that I will call $B^{s}$ could be exposed in superdense baryonic matter, figuring, perhaps, in ``quark stars" associated with the baryon-quark continuity involving CFL or phase transitions.
nucl-thhep-ph5 citations
05
High energy nucleus-nucleus collision and halo radii in different approaches of Glauber theory
Yu.M. Shabelski🇷🇺 · A.G. Shuvaev🇷🇺
The complete Glauber calculation of the differential cross sections of $^{12}$ C-- $^{12}$ C and halo nuclei on $^{12}$ C scattering was performed using the previously proposed in Refs.~\cite{Shabelski:2021iqk, Shabelski:2022xkw} method of generating function. The results are different as compared with the similar calculations in the optical model and the rigid target approximation. The halo nuclei radii extracted from the scattering data via the complete Glauber analysis come out to be larger than those obtained in the approximate approaches
nucl-thhep-phMod.Phys.Lett.A(2022)·1 citation
06
Global constraint on the magnitude of anomalous chiral effects in heavy-ion collisions
Wen-Ya Wu🇨🇳 · Qi-Ye Shou🇨🇳 · Panos Christakoglou🇳🇱 · Prottay Das🇮🇳 · Md. Rihan Haque🇵🇱 · Guo-Liang Ma🇨🇳 · Yu-Gang Ma🇨🇳 · Bedangadas Mohanty🇮🇳 · Chun-Zheng Wang🇨🇳 · Song Zhang🇨🇳 · Jie Zhao🇨🇳
When searching for anomalous chiral effects in heavy-ion collisions, one of the most crucial points is the relationship between the signal and the background. In this letter, we present a simulation in a modified blast wave model at LHC energy, which can simultaneously characterize the majority of measurable quantities, in particular, the chiral magnetic effect (CME) and the chiral magnetic wave (CMW) observables. Such a universal description, for the first time, naturally and quantitatively unifies the CME and the CMW studies and brings to light the connection with the local charge conservation (LCC) background. Moreover, a simple phenomenological approach is performed to introduce the signals, aiming at quantifying the maximum allowable strength of the signals within experimental precision. Such a constraint provides a novel perspective to understand the experimental data and sheds new light on the study of anomalous chiral effects as well as charge dependent correlations.
nucl-thnucl-exPRC(2023)·22 citations
07
Directed flow of light flavor hadrons for Au+Au collisions at $S_{N N} =$ 7.7-200 GeV
Tribhuban Parida🇮🇳 · Sandeep Chatterjee🇮🇳
We have studied the directed flow of light-flavor hadrons for Au + Au collisions at $S_{N N} =$ 7.7 - 200 GeV. The initial condition is taken from a suitable Glauber model which is further evolved within the framework of relativistic hydrodynamics. Model calculations of the rapidity-odd directed flow ( $v_{1}$ ) of identified light-flavor hadrons are compared with the available experimental data after suitably calibrating the initial condition to describe the rapidity dependence of charged particle multiplicity and net-proton yield. For reasonable choice of the initial condition, we are able to describe the measured rapidity and beam energy dependence of identified hadron $v_{1}$ including the observed $v_{1}$ splitting between baryons and anti-baryons.
nucl-thhep-ph12 citations
08
Establishing the Range of Applicability of Hydrodynamics in High-Energy Collisions
Victor E. Ambrus🇷🇴 · S. Schlichting🇩🇪 · C. Werthmann🇩🇪
We simulate the space-time dynamics of high-energy collisions based on a microscopic kinetic description in the conformal relaxation time approximation, in order to determine the range of applicability of an effective description in relativistic viscous hydrodynamics. We find that hydrodynamics provides a quantitatively accurate description of collective flow when the average inverse Reynolds number is sufficiently small and the early pre-equilibrium stage is properly accounted for. We further discuss the implications of our findings for the (in)applicability of hydrodynamics in proton-proton, proton-nucleus and light nucleus collisions.
↳ hep-phnucl-thPRL(2023)·54 citations
09
Opacity dependence of transverse flow, pre-equilibrium and applicability of hydrodynamics in heavy-ion collisions
Victor E. Ambrus🇩🇪 · S. Schlichting🇩🇪 · C. Werthmann🇩🇪
We evaluate the full opacity dependence of collective flow in high-energy heavy-ion collisions within a microscopic kinetic description based on the Boltzmann equation in the conformal relaxation time approximation. By comparing kinetic theory calculations to hydrodynamic and hybrid simulations for an average initial state, we point out shortcomings and inaccuracies of hydrodynamic models and present modified simulation setups to improve them.
↳ hep-phnucl-thPRD(2023)·36 citations
10
Effective Chiral Magnetic Effect from Neutrino Radiation
Naoki Yamamoto🇯🇵 · Di-Lun Yang🇹🇼
We develop an approach to chiral kinetic theories for electrons close to equilibrium and neutrinos away from equilibrium based on a systematic power counting scheme for different timescales of electromagnetic and weak interactions. Under this framework, we derive electric and energy currents along magnetic fields induced by neutrino radiation in general nonequilibrium states. This may be regarded as an effective chiral magnetic effect (CME), which is present without a chiral chemical potential, unlike the conventional CME. We also consider the so-called gain region of core-collapse supernovae as an example and find that the effective CME enhanced by persistent neutrino emission in time is sufficiently large to lead to the inverse cascade of magnetic and fluid kinetic energies and observed magnitudes of pulsar kicks. Our framework may also be applicable to other dense-matter systems involving nonequilibrium neutrinos.
↳ hep-phastro-ph.HEnucl-thPRL(2023)·8 citations
11
Toward nuclear physics from lattice QCD on quantum computers
Arata Yamamoto🇯🇵 · Takumi Doi🇯🇵
One of the ultimate missions of lattice QCD is to simulate atomic nuclei from the first principle of the strong interaction. This is an extremely hard task for the current computational technology, but might be reachable in coming quantum computing era. In this paper, we discuss the computational complexities of classical and quantum simulations of lattice QCD. It is shown that the quantum simulation scales better as a function of a nucleon number and thus will outperform for large nuclei.
↳ hep-latnucl-thquant-phPTEP(2024)·10 citations
12
Elastic scattering of 3He+4He with SONIK
S. N. Paneru · C. R. Brune · D. Connolly · D. Odell · M. Poudel · D. R. Phillips · J. Karpesky · B. Davids · C. Ruiz · A. Lennarz · U. Greife · M. Alcorta and 13 other authors
Measurements of the elastic scattering cross section of 3He and 4He are important in order to improve constraints on theoretical models of 4He(3He,g)7Be, a key reaction in Big Bang nucleosynthesis and solar neutrino production. The astrophysical S-factor for this reaction is a significant source of uncertainty in the standard solar-model prediction of the 7Be and 8B solar neutrino fluxes. The elastic scattering measurements reported in the literature do not extend to low energies and lack proper uncertainty quantification. A new measurement of the 4He(3He,3He)4He reaction has been made at center-of-mass energies Ec.m. = 0.38-3.13 MeV using the Scattering of Nuclei in Inverse Kinematics (SONIK) scattering chamber: a windowless, extended gas target surrounded by an array of 30 collimated silicon charged particle detectors situated at TRIUMF. This is the first elastic scattering measurement of 3He+4He made below 500 keV and it has greater angular range and better precision than previous measurements. The elastic scattering data were analyzed using both R-matrix and Halo Effective Field Theory (Halo EFT) frameworks, and values of the s-wave scattering length and effective range were extracted. The resulting improvement in knowledge of the s-wave effective-range function at low energies will reduce the overall uncertainty in S34 at solar energies.
↳ nucl-exnucl-thPRC(2024)·12 citations
13
Nature of $X (3872)$ in $B^{0} \to K^{0} X (3872)$ and $B^{+} \to K^{+} X (3872)$ decays
Hao-Nan Wang🇨🇳 · Li-Sheng Geng🇨🇳 · Qian Wang🇨🇳 · Ju-Jun Xie🇨🇳
We investigate the decays of $B^{0} \to K^{0} X (3872)$ and $B^{+} \to K^{+} X (3872)$ based on the picture where the $X (3872)$ resonance is strongly coupled to the $D D ˉ^{*} + c . c .$ channel. In addition to the decay mechanism where the $X (3872)$ resonance is formed from the $c c ˉ$ pair hadronization with the short-distance interaction, we have also considered the $D D ˉ^{*}$ rescattering diagrams in the long-distance scale, where $D$ and $D ˉ^{*}$ are formed from $c$ and $c ˉ$ separately. Because of the difference of the mass thresholds of charged and neutral $D D ˉ^{*}$ channels, and the rather narrow width of the $X (3872)$ resonance, at the $X (3872)$ mass, the loop functions of $D^{0} D ˉ^{* 0}$ and $D^{+} D ˉ^{*-}$ are much different. Taking this difference into account, the ratio of $B [B^{0} \to K^{0} X (3872)] / B [B^{+} \to K^{+} X (3872)] ≃ 0.5$ can be naturally obtained. Based on this result, we also evaluate the decay widths of $B_{s}^{0} \to η (η^{'}) X (3872)$ . It is expected that future experimental measurements of these decays can be used to elucidate the nature of the $X (3872)$ resonance.
↳ hep-phhep-exnucl-exnucl-thChin.Phys.Lett.(2023)·14 citations
14
AMY Lorentz invariant parton cascade -- the thermal equilibrium case
Aleksi Kurkela🇳🇴 · Robin Törnkvist🇸🇪 · Korinna Zapp🇸🇪
We introduce ALPACA, a Lorentz invariant parton cascade encoding the AMY effective kinetic theory of QCD at high temperatures. It solves the Boltzmann equation by explicitly simulating the evolution of parton ensembles corresponding to single events. We discuss how the effective masses and temperature entering the elastic collision and splitting/merging rates can be estimated from just a single event. We perform an extensive validation of the framework by showing that it reproduces the expected behaviour in thermal equilibrium.
↳ hep-phnucl-thEPJC(2024)·15 citations
15
Gluon helicity distribution in the nucleon from lattice QCD and machine learning
Tanjib Khan🇧🇩 · Tianbo Liu🇨🇳 · Raza Sabbir Sufian🇺🇸
We present the first lattice QCD determination of the light cone gluon helicity correlation parton distribution function (PDF) with numerical evidence toward disfavoring negative gluon polarization in the nucleon. We present a solution for eliminating an inevitable contamination term that dominates the Euclidean correlations and makes determining gluon helicity PDF unfeasible. The proposed synergy between lattice QCD and artificial intelligence offers a superior platform to alleviate the defining challenge of extracting quark and gluon PDFs from the lattice data that are available in a limited domain due to a finite range of accessible hadron momenta. We suggest a systematically improvable method to extract PDFs from the lattice data, independent of inadequate parametrizations. The result of the gluon helicity will improve our understanding of the role of spin in the strong interaction and the nucleon spin structure.
↳ hep-lathep-phnucl-thPRD(2023)·34 citations

Affiliations

first authorsco-authorsvia INSPIRE