Nuclear Theory·nucl-th

Wednesday·September 4, 2024

15 papers—3 primary·12 cross-listed

04
tParton: Implementation of next-to-leading order evolution of transversity parton distribution functions
Congzhou M Sha🇺🇸 · Bailing Ma🇺🇸
We provide code to solve the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the nucleon transversity parton distribution functions (PDFs), which encode nucleon transverse spin structure. Though codes are widely available for the evolution of unpolarized and polarized PDFs, there are few codes publicly available for the transversity PDF. Here, we present Python code which implements two methods of solving the leading order (LO) and next-to-leading order (NLO) approximations of the DGLAP equations for the transversity PDF, and we highlight the theoretical differences between the two.
↳ hep-phnucl-thphysics.comp-ph0 citations
05
Mini-Proceedings of the "Fourth International Workshop on the Extension Project for the J-PARC Hadron Experimental Facility (HEF-ex 2024)"
P.Achenbach · K.Aoki · S.Aoki · C.Curceanu · S.Diehl · T.Doi · M.Endo · M.Fujita · T.Fukuda · H.Garcia-Tecocoatzi · L.S.Geng · T.Gunji and 49 other authors
The mini proceedings of the "Fourth International Workshop on the Extension Project for the J-PARC Hadron Experimental Facility (HEF-ex 2024) [https://kds.kek.jp/event/46965]" held at J-PARC, February 19-21, 2024, are presented. The workshop was devoted to discussing the physics case that connects both the present and the future Hadron Experimental Facility at J-PARC, covering a wide range of topics in flavor, hadron, and nuclear physics related to both experimental and theoretical activities being conducted at the facility.
↳ nucl-exhep-exhep-phnucl-th5 citations
06
Corrections from space-time dependent electromagnetic fields to Wigner functions and spin polarization
Shi-Zheng Yang🇨🇳 · Jian-Hua Gao🇨🇳 · Shi Pu🇨🇳
We have derived the Wigner equations at global equilibrium with constant vorticity but space-time dependent electromagnetic fields up to second order in semiclassical expansion. We obtain the new second-order contributions to the charge currents and energy-momentum tensor from the varying electromagnetic fields. We also compute the new corrections to the spin polarization pesudo-vector from both contant and varying electromagnetic fields. We also find that the space-time dependent electromagnetic field provides a tighter constraint on the solutions of Wigner functions in global equilibrium compared with constant electromagnetic field.
↳ hep-phhep-thnucl-thPRD(2025)·7 citations
07
Self-consistent constraints on the collision terms in quantum kinetic theory
Shi-Yuan Wu🇨🇳 · Jian-Hua Gao🇨🇳
We derive self-consistent constraint conditions for collision terms in quantum kinetic theory using the Wigner function formalism. We present specific solutions for these collision terms that align with the constraints. we develop quantum kinetic theory at relaxation-time approximation. With this framework, we discuss spin polarization and electric charge separation effects in relativistic heavy-ion collisions.
↳ hep-phhep-thnucl-thPRD(2025)·1 citation
08
Particle production by $γ$ - $γ$ interactions in future electron-ion colliders
Carlos A. Bertulani🇺🇸 · Reinaldo Francener🇧🇷 · Victor P. Goncalves🇧🇷 · Juciene T. de Souza🇧🇷
The particle production in photon-photon ( $γ γ$ ) interactions present in electron-ion collisions is investigated. We present calculations for the total cross sections and event rates related to the production of light mesons [ $η, η^{'}, f_{0}$ and $f_{2}$ ], charmonium [ $η_{c}$ and $χ_{c}$ ] and charmoniumlike [ $X (3915), X (3940), X (4140)$ and $X (6900)$ ] states, considering the EIC, EicC, LHeC and FCC-eh energies. Our predictions demonstrate that experimental studies of these processes are feasible and useful to constrain the properties of light mesons and quarkonium states and shed some light on the configuration of the considered charmoniumlike states.
↳ hep-phnucl-thPRC(2025)·7 citations
09
Thermal Conductivity and Thermal Hall Effect in Dense Electron-Ion Plasma
Arus Harutyunyan · Armen Sedrakian
In this study, we examine thermal conductivity and the thermal Hall effect in electron-ion plasmas relevant to hot neutron stars, white dwarfs, and binary neutron star mergers, focusing on densities found in the outer crusts of neutron stars and the interiors of white dwarfs. We consider plasma consisting of single species of ions, which could be either iron $\isotope [56] F e$ or carbon $\isotope [12] C$ nuclei. The temperature range explored is from the melting temperature of the solid $T \sim 1 0^{9}$ ~K up to $1 0^{11}$ ~K. This covers both degenerate and non-degenerate electron regimes. We find that thermal conductivity increases with density and temperature for which we provide analytical scaling relations valid in different regimes. The impact of magnetic fields on thermal conductivity is also analyzed, showing anisotropy in low-density regions and the presence of the thermal Hall effect characterized by the Righi--Leduc coefficient. The transition from a degenerate to non-degenerate regime is characterized by a minimum ratio of thermal conductivity to temperature, which is analogous to the minimum observed already in the case of electrical conductivity. We provide also formulas fit to our numerical results, which can be used in dissipative magneto-hydrodynamics simulations of warm compact stars.
↳ astro-ph.HEastro-ph.SRnucl-thphysics.plasm-phParticles(2024)·6 citations
10
Density correlations under global and local charge conservation
Volodymyr Vovchenko🇺🇸
This work presents a formalism to compute spatial $n$ -point correlations of a conserved charge density in a large thermal system in the canonical ensemble, with explicit results presented up to 4th order. The resulting correlators contain local and balancing terms expressed through the grand-canonical susceptibilities for any equation of state. The new formalism is used to introduce a Gaussian local baryon number conservation in (spatial) rapidity in heavy-ion collisions at LHC conditions through a modulation of the balancing term. Connection to the conservation volume $V_{c}$ approach is established, indicating that the latter is appropriate for observables within a limited range around midrapidity. Quantitative analysis of the experimental data of the ALICE Collaboration on net proton cumulants in central Pb-Pb collisions at $s_{NN} = 5.02$ TeV shows significant evidence for local baryon conservation.
↳ hep-phnucl-exnucl-thPRC(2024)·13 citations
11
Parton distribution functions and transverse momentum dependence of heavy mesons
Fernando E. Serna🇨🇴 · Bruno El-Bennich🇧🇷 · Gastão Krein🇧🇷
The leading Fock state light-front wave functions of heavy quarkonia and $D$ and $B$ mesons are obtained from the projections of their Bethe-Salpeter wave functions on the light front. We compute therefrom their leading-twist time-reversal even transverse momentum distributions and parton distribution functions. Mirroring the behavior of parton distribution amplitudes, the support of both distributions is increasingly narrower and shifted towards larger $x$ as a function of the meson mass. The dependence of $x$ and $\k_{⊥}^{2}$ of the transverse distributions does not factorize into separate functions, and their fall-off with $\k_{⊥}^{2}$ is much slower than that of light mesons.
↳ hep-phnucl-thPRD(2024)·14 citations
12
Entropy in Toy Regge models
M.A.Braun🇷🇺
The probabilistic interpretation of the standard Regge-Gribov model with triple pomeron interactions is discussed. It is stated that introduction of probabilities within this model is not unique and depends on what is meant under the relevant substructures, The traditional interpretation in terms of partons (quarks and gluons) is shown to be external to the model, imported from the QCD, and actually referring to the single pomeron exchange without interactions. So this interpretation actually forgets the model as such. Alternative probabilities based on the pomerons as basic quantities within the model are discussed. Two different approaches are considered, based either on the pomerons in Fock's expansion of the wave function or on pomeron propagators in Feynman diagrams. These pomeron probabilities and entropy turn out to be very different from the mentioned standard ones in the purelyp obabilistic treatment. The entropy, in particular, either rises with the rapidity and saturates at a certain fixed value or first rises, reaches some maximum and goes down to zero afterwards. Possible observable manifestations of these probabilities and entropy are to be seen in the distributions of the cross-section in powers of the coupling constants to the participants. 23
↳ hep-phnucl-thEur.Phys.J.Plus(2025)·3 citations
13
Various Illustrative Brief Glances at the Flavour-Cryptoexotic Tetraquark States
Wolfgang Lucha🇦🇹
Constituting the largest subset of multiquark states so far observed by experiment, tetraquark mesons carrying overall quark flavour quantum numbers identical to those of the (conventional) quark-antiquark mesons necessitate their particularly deliberate phenomenological analyses. A collection of (more or less recent) insights specific to the latter subclass of exotic hadrons bears the promise to enable even significant improvement in the understanding of these hadrons by theoretical approaches such as, among others, the framework of QCD sum rules.
↳ hep-phhep-exnucl-thEPJ Web Conf.(2024)·0 citations
14
Inclusive photoproduction of vector quarkonium in ultra-peripheral collisions at the LHC
Jean-Philippe Lansberg🇫🇷 · Kate Lynch🇫🇷 · Charlotte Van Hulse🇪🇸 · Ronan McNulty🇫🇷
We explore the possibility of using ultra-peripheral proton-lead collisions at the LHC to study inclusive vector-quarkonium photoproduction, that occurs when a quasi-real photon emitted by a fully stripped lead ion breaks a proton to produce a vector quarkonium. Owing to the extremely large energies of the colliding hadrons circulating in the LHC, the range of accessible photon-nucleon centre-of-mass energies, W_gamma+p, largely exceeds what has been and will be studied at lepton-hadron colliders, HERA and the EIC. We perform a tune to HERA photoproduction data, use this tune to predict the yields of photoproduced J/psi, and estimate the corresponding transverse-momentum reach at LHC experiments. We also model the hadroproduction background and demonstrate that inclusive photoproduction can be isolated at the LHC from such background by imposing constraints on the hadronic activity in the lead-going direction at mid, forward, or far-forward rapidities depending on the capability of the detector under consideration. We find that the resulting cross sections are large enough to be measured by ALICE, ATLAS, CMS, and LHCb. We estimate the background-to-signal ratio after isolation to be of the order of 0.001 and 0.1 in the low and large transverse-momentum regions, respectively. In addition, we propose and assess the Jacquet-Blondel method to reconstruct the photon-nucleon centre-of-mass energy and the fractional energy of the quarkonium with respect to the photon.
↳ hep-phhep-exnucl-exnucl-thEPJC(2025)·10 citations
15
Implications of first neutrino-induced nuclear recoil measurements in direct detection experiments
D. Aristizabal Sierra🇨🇱 · N. Mishra🇺🇸 · L. Strigari🇺🇸
PandaX-4T and XENONnT have recently reported the first measurement of nuclear recoils induced by the $^{8}$ B solar neutrino flux, through the coherent elastic neutrino-nucleus scattering (CE $ν$ NS) channel. As long anticipated, this is an important milestone for dark matter searches as well as for neutrino physics. This measurement means that these detectors have reached exposures such that searches for low mass, $≲ 10$ GeV dark matter cannot be analyzed using the background-free paradigm going forward. It also opens a new era for these detectors to be used as neutrino observatories. In this paper we assess the sensitivity of these new measurements to new physics in the neutrino sector. We focus on neutrino non-standard interactions (NSI) and show that -- despite the still moderately low statistical significance of the signals -- these data already provide valuable information. We find that limits on NSI from PandaX-4T and XENONnT measurements are comparable to those derived using combined COHERENT CsI and LAr data, as well as those including the latest Ge measurement. Furthermore, they provide sensitivity to pure $τ$ flavor parameters that are not accessible using stopped-pion or reactor sources. With further improvements of statistical uncertainties as well as larger exposures, forthcoming data from these experiments will provide important, novel results for CE $ν$ NS-related physics.
↳ hep-phastro-ph.COhep-exnucl-ex+1PRD(2025)·37 citations

Affiliations

first authorsco-authorsvia INSPIRE