Nuclear Theory·nucl-th

Friday·June 2, 2023

11 papers—2 primary·9 cross-listed

03
Noncommuting conserved charges in quantum thermodynamics and beyond
Shayan Majidy🇨🇦 · William F. Braasch Jr.🇺🇸 · Aleksander Lasek🇺🇸 · Twesh Upadhyaya🇺🇸 · Amir Kalev🇻🇦 · Nicole Yunger Halpern🇺🇸
Thermodynamic systems typically conserve quantities ("charges") such as energy and particle number. The charges are often assumed implicitly to commute with each other. Yet quantum phenomena such as uncertainty relations rely on observables' failure to commute. How do noncommuting charges affect thermodynamic phenomena? This question, upon arising at the intersection of quantum information theory and thermodynamics, spread recently across many-body physics. Charges' noncommutation has been found to invalidate derivations of the thermal state's form, decrease entropy production, conflict with the eigenstate thermalization hypothesis, and more. This Perspective surveys key results in, opportunities for, and work adjacent to the quantum thermodynamics of noncommuting charges. Open problems include a conceptual puzzle: Evidence suggests that noncommuting charges may hinder thermalization in some ways while enhancing thermalization in others.
↳ quant-phcond-mat.stat-mechhep-lathep-th+1Nature Rev.Phys.(2023)·78 citations
04
Complete Formalism of Cross Sections and Asymmetries for Longitudinally and Transversely Polarized Leptons and Hadrons in Deep Inelastic Scattering
Paul Anderson🇺🇸 · Douglas Higinbotham🇺🇸 · Sonny Mantry🇺🇸 · Xiaochao Zheng🇺🇸
Studies of the Deep Inelastic Scattering (DIS) have provided fundamental information of the nucleon structure for decades. The electron-ion collider (EIC) will be the first collider capable of DIS study with both polarized lepton and polarized hadron beams, providing the possibility of accessing new electroweak structure functions of the nucleon. In this work, we completed the DIS cross section derivations for both longitudinally and transversely polarized leptons and hadrons, with no approximations made, and with all three contributions $γ γ, γ Z, Z Z$ included. These results were derived using primarily tensor algebra and Feynman calculus, starting from previously established leptonic and hadronic tensors and carry out their contraction. Our results are presented in terms of both spin-averaged and spin-dependent cross sections, allowing direct comparison with experimentally measured cross sections and their asymmetries. We include also in our discussion comparisons of different conventions that exist in the literature.
↳ hep-phhep-exnucl-exnucl-th2 citations
05
Holographic neutrino transport in dense strongly-coupled matter
M. Järvinen🇰🇷 · E. Kiritsis🇫🇷 · F. Nitti🇫🇷 · E. Préau🇫🇷
A (toy) model for cold and luke-warm strongly-coupled nuclear matter at finite baryon density is used to study neutrino transport. The complete charged current two-point correlators are computed in the strongly-coupled medium and their impact on neutrino transport is analyzed. The full result is compared with various approximations for the current correlators and the distributions, including the degenerate approximation, the hydrodynamic approximation as well as the diffusive approximation and we comment on their successes. Further improvements are discussed.
↳ astro-ph.HEhep-phhep-thnucl-thJHEP(2023)·10 citations
06
Anisotropic Strange Stars in the Spotlight: Unveiling Constraints through Observational Data
H. C. Das · Luiz L. Lopes
Motivated by the recent suggestions that very massive pulsar (PSR J0952-0607) and very light compact object (HESS J1731-347) exist, in this article, we revisit the possibility of such objects being strange stars instead of the standard hadronic neutron stars. We study the possible presence of local anisotropy and how it affects the macroscopic properties of strange stars and compare our results with the recent constraints presented in the literature. We found that the presence of anisotropy increases the maximum mass, the radius of the canonical star, and its tidal deformability for positive values of $λ_{BL}$ and the opposite for negative values. We also show that although we cannot rule out the possibility of very compact objects being standard hadronic neutron stars, strange stars easily fulfill most of the observational constraints.
↳ astro-ph.HEnucl-thMNRAS(2023)·28 citations
07
Low-lying odd-parity nucleon resonances as quark-model like states
Curtis D. Abell🇦🇺 · Derek B. Leinweber🇦🇺 · Zhan-Wei Liu🇨🇳 · Anthony W. Thomas🇦🇺 · Jia-Jun Wu🇨🇳
Recent lattice QCD results for the low-lying odd-parity excitations of the nucleon near the $N^{*} (1535)$ and $N^{*} (1650)$ resonance positions have revealed that the lattice QCD states have magnetic moments consistent with predictions from a constituent-quark-model. Using Hamiltonian Effective Field Theory (HEFT) to describe pion-nucleon scattering in the $I (J^{P}) = \frac{1}{2} (\frac{1}{2}^{-})$ channel, we represent these two quark-model like states as two single-particle bare basis states, dressed and mixed by meson-baryon scattering channels. By constraining the free parameters of the Hamiltonian with $S_{11}$ pion-nucleon scattering data, we perform the first calculation of the finite-volume spectrum using two bare-baryon basis states. By comparing this spectrum to contemporary lattice QCD results at three lattice volumes, we analyse the eigenvectors of the Hamiltonian to gain insight into the structure and composition of these two low-lying resonances. We find that an interpretation of the two low-lying nucleon resonances as quark-model like states dressed by meson-baryon interactions is consistent with both the $S_{11}$ scattering data and lattice QCD. We introduce a novel HEFT formalism for estimating scattering-state contaminations in lattice QCD correlation functions constructed with standard three-quark operators. Not only are historical lattice QCD results described with excellent accuracy, but correlation functions with large scattering-state contaminations are identified.
↳ hep-lathep-phnucl-thPRD(2023)·35 citations
08
Chiral Transport Phenomena and Compact Stars
Cristina Manuel🇪🇸
I will review the main chiral transport phemomena arising in systems made up of (almost) massless fermions associated to the quantum chiral anomaly. These quantum effects might have relevant implications in compact stars, and I will review some relevant works that reveal so. I will also show how a conservation law that has the same form of the chiral anomaly also emerge in perfect classical fluids, which expresses a conservation law of magnetic, fluid and mixed helicities for isentropic fluids, and why this should also be relevant in compact stars.
↳ hep-phnucl-thJ.Phys.Conf.Ser.(2023)·0 citations
09
Elastic pion-proton and pion-pion scattering via the holographic Pomeron and Reggeon exchange
Zhibo Liu🇨🇳 · Akira Watanabe🇨🇳
The elastic pion-proton and pion-pion scattering are studied in a holographic QCD model, focusing on the Regge regime. Taking into account the Pomeron and Reggeon exchange, which are described by the Reggeized $2^{++}$ glueball and vector meson propagator respectively, the total and differential cross sections are calculated. The adjustable parameters involved in the model are determined with the experimental data of the pion-proton total cross sections. The differential cross sections can be predicted without any additional parameters, and it is shown that our predictions are consistent with the data. The energy dependence of the Pomeron and Reggeon contribution is also discussed.
↳ hep-phhep-exnucl-exnucl-thPRD(2023)·6 citations
10
Exclusive $η_{c}$ production by $γ^{*} γ$ interactions in electron-ion collisions
Izabela Babiarz🇵🇱 · Victor P. Goncalves🇩🇪 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱
One of the main goals of future electron-ion colliders is to improve our understanding of the structure of hadrons. In this letter, we study the exclusive $η_{c}$ production by $γ^{*} γ$ interactions in $e A$ collisions and demonstrate that future experimental analysis of this process can be used to improve the description of the $η_{c}$ transition form factor. The rapidity, transverse momentum and photon virtuality distributions are estimated considering the energy and target configurations expected to be present at the EIC, EicC and LHeC and assuming different predictions for the light-front wave function of the $η_{c}$ meson. Our results indicate that the electron-ion colliders can be considered an alternative to providing supplementary data to those obtained in $e^{-} e^{+}$ colliders.
↳ hep-phnucl-thPLB(2023)·10 citations
11
Constraining Palatini gravity with GR-independent equations of state for neutron stars
Eva Lope-Oter🇪🇸 · Aneta Wojnar🇪🇸
We demonstrate how to construct GR-independent equations of state. We emphasize the importance of using theory-based principles instead of relying solely on astrophysical observables and General Relativity (GR). We build a set of equations of state based on first principles, including chiral perturbation theory and perturbation theory in quantum chromodynamics. Interpolation methods are employed to assume thermodynamic stability and causality in the intermediate region. These equations of state are then used to constrain quadratic Palatini $f (R)$ gravity, indicating that the parameter lies within the range $- 6.47 ≲ β ≲ 1.99$ km $^{2}$ . Additionally, we briefly discuss the problem of phase transitions and twin stars.
↳ gr-qcastro-ph.HEhep-phnucl-thJCAP(2024)·19 citations

Affiliations

first authorsco-authorsvia INSPIRE