Nuclear Theory·nucl-th

Wednesday·November 16, 2022

22 papers—4 primary·18 cross-listed

05
Hall Droplet Sheets in Holographic QCD
Francesco Bigazzi🇮🇹 · Aldo L. Cotrone🇮🇹 · Andrea Olzi🇮🇹
In single-flavor QCD, the low energy description of baryons as Skyrmions is not available. In this case, it has been proposed by Komargodski that baryons can be viewed as kinds of charged quantum Hall droplets, or "sheets". In this paper we propose a string theory description of the sheets in single-flavor holographic QCD, focusing on the Witten-Sakai-Sugimoto model. The sheets have a "hard" gluonic core, described by D6-branes, and a "soft" mesonic shell, dual to non-trivial D8-brane gauge field configurations. We first provide the description of an infinitely extended sheet with massless or moderately massive quarks. Then, we construct a semi-infinite sheet ending on a one-dimensional boundary, a "vortex string". The holographic description allows for the precise calculation of sheet observables. In particular, we compute the tension and thickness of the sheet and the vortex string, and provide their four dimensional effective actions.
↳ hep-thhep-phnucl-thJHEP(2023)·17 citations
06
Confinement-deconfinement transition in $S U (3)$ -Higgs theory
Sanatan Digal🇮🇳 · Vinod Mamale🇮🇳 · Sabiar Shaikh🇮🇳
We study lattice cutoff effects on the confinement-deconfinement transition and the $Z_{3}$ symmetry in $S U (3)$ -Higgs theory in $3 + 1$ dimensions. The Higgs in this study is a complex triplet with vanishing bare mass and quartic coupling. The lattice cutoff is regulated by varying the number of temporal lattice sites, $N_{τ}$ . Our results show that the nature of the confinement-deconfinement transition depends on $N_{τ}$ . For $N_{τ} = 2$ the transition is found to be the end point of a first-order transition and is first order for $N_{τ} \geq 3$ . The distributions of the Polyakov loop and other observables, sensitive to the $Z_{3}$ symmetry, show that the strength of $Z_{3}$ explicit breaking decreases with $N_{τ}$ . Up to $T ≃ 2 T_{c}$ , the free energy difference between $Z_{3}$ states decreases with $N_{τ}$ , suggesting the realization of $Z_{3}$ symmetry in the continuum limit.
↳ hep-lathep-phnucl-thPRD(2023)·0 citations
07
Polarization phenomena in the reaction $e^{+} + e^{-} \to p + p ˉ + π^{0}$ in frame of the non-resonant mechanism
G.I. Gakh🇺🇦 · M.I. Konchatnij🇺🇦 · N.P. Merenkov🇺🇦 · E. Tomasi-Gustafsson🇫🇷
The dependence of the nucleon polarization in the reaction $e^{+} + e^{-} \to N + N ˉ + π^{0}$ over different invariant variables in frame of the non-resonant mechanism, has been derived. The nucleon polarization is expressed in terms of six invariant complex amplitudes, assuming the conservation of the hadron electromagnetic currents and the P-invariance of the hadron electromagnetic interaction. An inclusive experimental setup when the proton (or the antiproton) and the pion are detected in coincidence is considered. Numerical estimations were performed for the so called normal polarization in the energy range from threshold up to $s = 16$ GeV $^{2}$ , using a specific parametrization of the nucleon electromagnetic form factors and taking into account the unpolarized differential cross section of the non-resonant mechanism, as previously calculated.
↳ hep-phnucl-thPRD(2022)·1 citation
08
Magnetic field-dependent electric charge transport in hadronic medium at finite temperature
Ritesh Ghosh🇮🇳 · Manu Kurian🇨🇦
Electric charge transport of hadronic matter at finite temperature and magnetic field is studied within the linear sigma model. Anisotropic transport coefficients associated with the charge transport are estimated both in the weak and strong regimes of the magnetic field using the transport theory approach. In a weakly magnetized medium, the magnetic field effects are incorporated through the Lorentz force term in the Boltzmann equation. Strong magnetic field puts further constraints on the motion of charged particles through Landau quantization. Magnetic field-dependent thermal relaxation time is obtained from interaction rates of hadrons with the S-matrix approach by considering the Landau level kinematics of the charged hadrons. Mean-field effects are embedded in the analysis through the temperature-dependent hadron masses. Further, the hadronic medium response to a time-varying external electric field is studied in weak and strong magnetic field regimes. It is seen that electromagnetic responses of the hadronic matter have a strong dependence on the mean-field effects, sigma mass, the strength of the external fields, and its evolution in the medium.
↳ hep-phnucl-thPRC(2023)·11 citations
09
Leptonic and semi-leptonic neutrino interactions with muons in the proto-neutron star cooling
Ken'ichi Sugiura🇯🇵 · Shun Furusawa🇯🇵 · Kohsuke Sumiyoshi🇯🇵 · Shoichi Yamada🇯🇵
It is known that muons are scarce just after the birth of a proto-neutron star via a supernova explosion but get more abundant as the proto-neutron star cools via neutrino emissions on the Kelvin-Helmholtz timescale. In this paper we evaluate all the relevant rates of the neutrino interactions with muons at different times in the proto-neutron star cooling. We are particularly interested in the late phase ( $t ≳ 10 s$ ), which will be accessible in the next Galactic supernova but has not been studied well so far. We calculate both leptonic and semi-leptonic processes, for the latter of which we pay attention also to the form factors with their dependence on the transferred momentum as well as to the modification of the dispersion relations for nucleons on the mean field level. We find that the flavor-exchange reactions $ν_{e} + μ^{-} \to ν_{μ} + e^{-}$ and $ν ˉ_{μ} + μ^{-} \to ν ˉ_{e} + e^{-}$ can be dominant, particularly at low energies, over the capture of $ν_{e}$ on neutron and the scatterings of $ν ˉ_{μ}$ on nucleons as the opacity sources for these species and that the inverse muon decay $ν ˉ_{e} + ν_{μ} + e^{-} ⇆ μ^{-}$ can overwhelm the scatterings of $ν ˉ_{e}$ and $ν_{μ}$ on nucleons again at low energies. At high energies, on the other hand, the corrections in the semi-leptonic processes mentioned above are more important. We also show the non-trivial energy- and angular dependences of the flavor-exchange reactions and the inverse muon decay. In the study of the diffusion coefficients from these reactions, we find that $ν ˉ_{μ}$ is most affected. These pieces of information are indispensable for numerical computations and the interpretation of results thereof for the proto-neutron star cooling particularly at the very late phase.
↳ astro-ph.HEhep-phnucl-thPTEP(2022)·12 citations
10
Non-perturbative diffusion of Heavy Quark moving in a hot and magnetised Quark Gluon Plasma
Surasree Mazumder🇮🇳 · Vinod Chandra🇮🇳 · Santosh K Das🇮🇳
Heavy Quarks (HQs) serve as excellent probes to understand various characteristics of deconfined hot QCD medium, comprising light quarks and gluons, created in the Heavy Ion Collisions (HICs). Strong magnetic fields in non-central HICs may significantly affect HQ dynamics in this medium. Exploring the impact of the magnetic field on the perturbative and non-perturbative transport coefficients of HQ is an intriguing endeavor. This necessitates the development of a comprehensive theoretical framework accommodating the non-perturbative Quantum Chromo Dynamics(npQCD) description alongside perturbative QCD(pQCD). The present work provides such a formulation in which Quarkonium potential in the hot and magnetic QCD medium is implemented as the effective gluon propagator to calculate the rate of elastic scattering between HQ and the light partons inside a medium of hot Quark Gluon Plasma(QGP) in the presence of a strong but uniform magnetic field. Diffusion coefficients of a charm quark have been computed for a short-range Yukawa potential ( pQCD) as well as a long-range confining/non-perturbative potential (npQCD) for two cases in which the velocity of the charm quark is parallel and perpendicular to the magnetic field respectively. Non-perturbative contribution is seen to dominate over the perturbative one in the regime of low temperatures and low to intermediate momenta of charm quark. As the momentum of charm quark as well as the temperature of the medium increase pQCD starts to gain on the npQCD contribution, ultimately prevailing at higher temperatures and charm momenta.
↳ hep-phnucl-th6 citations
11
Azimuthal decorrelation for photon induced dijet production in ultra-peripheral collisions of heavy ions
Cheng Zhang🇨🇳 · Qian-Shun Dai🇨🇳 · Ding Yu Shao🇨🇳
We study the azimuthal angular decorrelation of the dijet production via photon fusion in ultra-peripheral heavy ion collisions. The impact parameter dependent cross section of quark-antiquark pairs production is derived using the equivalent photon approximation, and the contribution from final-state QCD radiations to the azimuthal angular distribution are calculated within Soft-Collinear Effective Theory. We carry out the QCD resummation of large logarithms of the azimuthal angle as well as the jet radius at next-to-leading logarithmic accuracy. In the end we present the normalized differential cross section for azimuthal decorrelation of the dijet pair and find that our results are consistent with the measurements reported by the ATLAS collaboration.
↳ hep-phhep-exnucl-thJHEP(2023)·6 citations
12
Magnetised neutron star crust within effective relativistic mean-field model
Vishal Parmar🇮🇳 · H. C. Das🇮🇳 · M. K. Sharma🇮🇳 · S. K. Patra🇮🇳
Even though the crystallize nature of the neutron star crust plays a pivotal role in describing various fascinating astrophysical observations, its microscopic structure is not fully understood in the presence of a colossal magnetic field. In the present work, we study the crustal properties of a neutron star within an effective relativistic mean field framework in the presence of magnetic field strength $\sim 1 0^{17}$ G. We calculate the equilibrium composition of the outer crust by minimizing the Gibbs free energy using the most recent atomic mass evaluations. The magnetic field significantly affects the equation of state (EoS) and the properties of the outer crust, such as neutron drip density, pressure, and melting temperature. For the inner crust, we use the compressible liquid drop model for the first time to study the crustal properties in a magnetic environment. The inner crust properties, such as mass and charge number distribution, isospin asymmetry, cluster density, etc., show typical quantum oscillations (De Haas-van Alphen effect) sensitive to the magnetic field's strength. The density-dependent symmetry energy influences the magnetic inner crust like the field-free case. We study the probable modifications in the pasta structures and it is observed that their mass and thickness changes by $\sim 10 - 15%$ depending upon the magnetic field strength. The fundamental torsional oscillation mode frequency is investigated for the magnetized crust in the context of quasiperiodic oscillations (QPO) in soft gamma repeaters. The magnetic field strengths considered in this work influences only the EoS of outer and shallow regions of the inner crust, which results in no significant change in global neutron star properties. However, the outer crust mass and its moment of inertia increase considerably with increase in magnetic field strength.
↳ astro-ph.HEastro-ph.SRnucl-thPRD(2023)·18 citations
13
Is the compact object associated with HESS J1731-347 a strange quark star?
Francesco Di Clemente (Dipartimento di Fisica e Scienze della Terra, Univ. Ferrara and INFN Sez. Ferrara)🇮🇹 · Alessandro Drago (Dipartimento di Fisica e Scienze della Terra, Univ. Ferrara and INFN Sez. Ferrara)🇮🇹 · Giuseppe Pagliara (Dipartimento di Fisica e Scienze della Terra, Univ. Ferrara and INFN Sez. Ferrara)🇮🇹
The analysis of the central compact object within the supernova remnant HESS J1731-347 suggests that it has a small radius and, even more interestingly, a mass of the order or smaller than one solar mass. This raises the question of which astrophysical process could lead to such a small mass, since the analysis of various types of SN explosions indicate that is it not possible to produce a neutron star with a mass smaller than about $1.17 M_{⊙}$ . Here we show that masses of the order or smaller than one solar mass can be obtained in the case of strange quark stars and that it is possible to build a coherent model explaining not only the mass and the radius of that object, but also its slow cooling suggested in various analyses. We also show that an astrophysical path exists which leads to the formation of such an object, and we discuss the role played in that scenario by strangelets assumed to constitute the dark matter.
↳ astro-ph.HEastro-ph.SRnucl-thApJ(2024)·59 citations
14
Preparation for Quantum Simulation of the 1+1D O(3) Non-linear {\sigma}-Model using Cold Atoms
Anthony N. Ciavarella🇺🇸 · Stephan Caspar🇺🇸 · Hersh Singh🇺🇸 · Martin J. Savage🇺🇸
The 1+1D O(3) non-linear {\sigma}-model is a model system for future quantum lattice simulations of other asymptotically-free theories, such as non-Abelian gauge theories. We find that utilizing dimensional reduction can make efficient use of two-dimensional layouts presently available on cold atom quantum simulators. A new definition of the renormalized coupling is introduced, which is applicable to systems with open boundary conditions and can be measured using analog quantum simulators. Monte Carlo and tensor network calculations are performed to determine the quantum resources required to reproduce perturbative short-distance observables. In particular, we show that a rectangular array of 48 Rydberg atoms with existing quantum hardware capabilities should be able to adiabatically prepare low-energy states of the perturbatively-matched theory. These states can then be used to simulate non-perturbative observables in the continuum limit that lie beyond the reach of classical computers.
↳ quant-phcond-mat.quant-gashep-latnucl-thPRA(2023)·18 citations
15
Emergence of Hadron Mass and Structure
Minghui Ding🇩🇪 · Craig D. Roberts🇨🇳 · Sebastian M. Schmidt🇩🇪
Visible matter is characterised by a single mass scale; namely, the proton mass. The proton's existence and structure are supposed to be described by quantum chromodynamics (QCD); yet, absent Higgs boson couplings, chromodynamics is scale invariant. Thus, if the Standard Model is truly a part of the theory of Nature, then the proton mass is an emergent feature of QCD; and emergent hadron mass (EHM) must provide the basic link between theory and observation. Nonperturbative tools are necessary if such connections are to be made; and in this context, we sketch recent progress in the application of continuum Schwinger function methods to an array of related problems in hadron and particle physics. Special emphasis is given to the three pillars of EHM -- namely, the running gluon mass, process-independent effective charge, and running quark mass; their role in stabilising QCD; and their measurable expressions in a diverse array of observables.
↳ hep-phhep-exhep-latnucl-ex+1Particles(2023)·117 citations
16
Detection of the 4.4-MeV gamma rays from $^{16}$ O( $ν, ν^{'}$ ) $^{16}$ O(12.97 $MeV, 2^{-})$ with a water-Cherenkov detector in the supernova neutrino bursts
Makoto Sakuda🇯🇵 · Toshio Suzuki🇯🇵 · Mandeep Singh Reen🇮🇳 · Ken'ichiro Nakazato🇯🇵 · Hideyuki Suzuki🇯🇵
We first discuss and determine the isospin mixing of the two $2^{-}$ states (12.53 MeV and 12.97 MeV) of $^{16}$ O nucleus using the inelastic electron scattering data. We then evaluate the cross section of 4.4-MeV $γ$ rays produced in the neutrino neutral-current (NC) reaction $^{16}$ O( $ν, ν^{'}$ ) $^{16}$ O $(12.97 MeV, 2^{-}$ ) in a water Cherenkov detector at the low energy below 100 MeV. The detection of $γ$ rays for $E_{γ} > 5$ MeV from the NC reaction $^{16}$ O( $ν, ν^{'}$ ) $^{16}$ O $(E_{x} > 16 MeV, T = 1$ ) with a water Cherenkov detector in the supernova neutrino bursts has been proposed and discussed by several authors previously. In this article, we discuss a new NC reaction channel from $^{16}$ O(12.97 $MeV, 2^{-}$ ) producing a 4.4-MeV $γ$ ray, the cross section of which is more robust and even larger at the low energy ( $E_{ν} < 25$ MeV) than the NC cross section from $^{16}$ O $(E_{x} > 16 MeV, T = 1$ ). We also evaluate the number of such events induced by neutrinos from supernova explosion which can be observed by the Super-Kamiokande, a 32 kton water Cherenkov detector in the Earth.
↳ astro-ph.HEhep-phnucl-thPTEP(2023)·2 citations
17
On the sound velocity bound in neutron stars
Shrijan Roy🇮🇳 · Teruaki Suyama🇯🇵
It has been suggested in the literature that the sound velocity of the nuclear matter $v_{s}$ violates the so-called sound velocity bound $v_{s} \leq c / 3$ at high density, where $c$ is the speed of light. In this paper, we revisit this issue and confront the current measurements of mass, radius, and tidal deformability of neutron stars with $1 0^{5}$ different equations of state which are parametrized at low density and saturates the sound velocity bound beyond twice the saturation density where the equation of state has not been constrained yet, by which we can conservatively obtain the maximum mass of the neutron stars compatible both with the observed properties of neutron stars and the sound velocity bound. We find that majority of the models are eliminated by the incompatibility with the observations and, especially, the recently detected massive pulsar ( $2.35 \pm 0.17 M_{⊙}$ ) is hardly realized by our simulations. Our study strongly supports the violation of the sound velocity bound.
↳ astro-ph.HEgr-qcnucl-thResults Phys.(2024)·11 citations
18
Deep-learning quasi-particle masses from QCD equation of state
Fu-Peng Li🇨🇳 · Hong-Liang Lü🇨🇳 · Long-Gang Pang🇨🇳 · Guang-You Qin🇨🇳
The interactions of quarks and gluons are strong at non-perturbative region. The equation of state (EoS) of a strongly-interacting quantum chromodynamics (QCD) medium can only be studied using the first-principle lattice QCD calculations. However, the complicated QCD EoS can be reproduced using simple statistical formula by treating the medium as a free parton gas whose fundamental degree of freedoms are dressed quarks and gluons called quasi-particles, with temperature-dependent masses. We use deep neural network and auto differentiation to solve this variational problem in which the masses of quasi gluons, up/down and strange quarks are three unknown functions, whose forms are represented by deep neural network. We reproduce the QCD EoS using these machine learned quasi-particle masses, and calculate the shear viscosity over entropy density ( $η / s$ ) as a function of temperature of the hot QCD matter.
↳ hep-phnucl-thPLB(2023)·31 citations
19
The universal scaling of kinetic freeze-out parameters across different collision systems at the LHC energy
Lian Liu🇨🇳 · Zhong-Bao Yin🇨🇳 · Liang Zheng🇨🇳
In this paper, we perform the Tsallis Blast-Wave analysis on the transverse momentum spectra of identified hadrons produced in a wide range of collision systems at the Large Hadron Collider (LHC) including pp, pPb, XeXe and PbPb collisions. The kinetic freeze-out properties are investigated across these systems varying with the event multiplicity. We find that the extracted kinetic freeze-out temperature, radial flow velocity and the non-extensive parameter exhibit a universal scaling behavior for these systems with very different geometric size, especially when the independent baryon Tsallis non-extensive parameter is considered. This universality may indicate the existence of a unified partonic evolution stage in different collision systems at the LHC energies.
↳ hep-phnucl-thCPC(2023)·13 citations
20
Molecular $P_{ψ}$ pentaquarks from light-meson exchange saturation
Zi-Ying Yang🇨🇳 · Fang-Zheng Peng🇨🇳 · Mao-Jun Yan🇨🇳 · Mario Sánchez Sánchez🇫🇷 · Manuel Pavon Valderrama🇨🇳
Theoretical predictions for the spectrum of heavy meson-baryon bound states are a fundamental tool for disentangling the nature of the different pentaquark states that have been observed in experimental facilities. Here we explore this spectrum in a phenomenological model that describes the heavy meson-baryon interaction in terms of a contact-range interaction, where the coupling strength is saturated by the exchange of light scalar and vector mesons, i.e. $σ$ , $ρ$ and $ω$ exchanges. Saturation determines the couplings modulo an unknown proportionality constant that can be calibrated from a molecular candidate. If we use the $P_{ψ}^{N} (4312)$ as input, we predict a series of molecular pentaquarks including the $P_{ψ}^{N} (4440)$ and $P_{ψ}^{N} (4457)$ , the recent $P_{ψ s}^{Λ} (4338)$ and the $P_{ψ s}^{Λ} (4459)$ .
↳ hep-phhep-exhep-latnucl-thPRD(2025)·28 citations
21
Forward Inclusive Jet Productions in pA Collisions
Lei Wang🇨🇳 · Lin Chen🇨🇳 · Zhan Gao🇨🇳 · Yu Shi🇨🇳 · Shu-Yi Wei🇨🇳 · Bo-Wen Xiao🇨🇳
Motivated by recent experimental LHC measurements on the forward inclusive jet productions and based on our previous calculations on forward hadron productions, we calculate single inclusive jet cross-section in $p A$ collisions at forward rapidity within the color glass condensate framework up to the next-to-leading-order. Moreover, with the application of jet algorithm and proper subtraction of the rapidity and collinear divergences, we further demonstrate that the resulting next-to-leading-order hard coefficients are finite. In addition, in order to deal with the large logarithms that can potentially spoil the convergence of the perturbative expansion and improve the reliability of the numerical predictions, we introduce the collinear jet function and the threshold jet function and resum these large logarithms hidden in the hard coefficients.
↳ hep-phnucl-thPRD(2023)·20 citations
22
Transverse momentum dependent distribution functions in the threshold limit
Zhong-Bo Kang🇺🇸 · Kajal Samanta🇺🇸 · Ding Yu Shao🇨🇳 · Yang-Li Zeng🇨🇳
We apply the joint threshold and transverse momentum dependent (TMD) factorization theorem to introduce new threshold-TMD distribution functions, including threshold-TMD parton distribution functions (PDFs) and fragmentation functions (FFs). We apply Soft-Collinear Effective Theory and renormalization group methods to carry out QCD evolution for both threshold-TMD PDFs and FFs. We show the universality of threshold-TMD functions among three standard processes, i.e. the Drell-Yan production in $pp$ collisions, semi-inclusive deep-inelastic scattering and back-to-back two hadron production in $e^{+} e^{-}$ collisions. In the end, we present the numerical predictions for different threshold-TMD functions and also transverse momentum distributions at $pp$ , $e p$ , and $e^{+} e^{-}$ collisions.
↳ hep-phhep-exnucl-exnucl-thJHEP(2023)·4 citations

Affiliations

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