Nuclear Theory·nucl-th

Wednesday·December 24, 2025

15 papers—9 primary·6 cross-listed

10
CT25: Progress toward next-generation PDFs for precision phenomenology at the LHC
A. Ablat · A. Courtoy · S. Dulat · Y. Fu · M. Guzzi · T. J. Hobbs · J. Huston · K. Mohan · P. Nadolsky · M. Ponce-Chavez · D. Stump · K. Xie · C.-P. Yuan
We summarize recent progress toward the next generation of CTEQ-TEA parton distribution functions, CT25, based on a global NNLO analysis that incorporates a significant sample of newly included LHC data. We present a baseline fit within the forthcoming full CT25 fit, which includes new Drell-Yan, top-pair, and inclusive-jet data at 8 and 13 TeV, and exhibits non-trivial pulls on the high- $x$ gluon and the flavor structure of the quark sea. In the context of progress toward CT25, we also summarize several recent and ongoing studies of the interplay between phenomenological PDFs and lattice-QCD calculations, simultaneous extractions of $α_{s} (M_{Z})$ within the CT framework, and an expanded program of uncertainty quantification that treats parametrization dependence as an explicit source of epistemic uncertainty, among other issues. We also briefly highlight CT efforts to understand the effects of partial implementations of N $^{3}$ LO corrections into PDF fits, which include benchmark calculations for Higgs and vector-boson processes. We comment on the implications of recent improvements to the CT analysis for precision phenomenology at the LHC and future facilities.
↳ hep-phhep-exnucl-th4 citations
11
Astrophysical constraints on the cold equation of state of the strongly interacting matter
Gábor Kasza🇭🇺 · János Takátsy🇭🇺 · György Wolf🇭🇺
At present, the only experimental access to the properties of cold, dense strongly interacting matter is provided by astrophysical observations. Neutron stars are the only known systems in the Universe that reach densities several times higher than normal nuclear density at nearly zero temperature, making them unique laboratories for studying dense matter. Since most neutron star observables are sensitive to the equation of state (EOS), observational data place stringent constraints on the EOS of strongly interacting matter. In this work, we investigate constraints arising from perturbative QCD calculations at asymptotically high densities ( $ρ \approx 40 ρ_{0}$ ), the mass of the heaviest observed neutron star (a black widow pulsar), NICER mass-radius measurements, and the tidal deformability inferred from the binary neutron star merger GW170817. We parametrize the EOS and allow its parameters to vary freely, using observational data to constrain the admissible parameter space. We find that neutron star observations significantly restrict the EOS of dense strongly interacting matter. While NICER has already provided measurements for five pulsars, the associated uncertainties remain relatively large. Within our modeling framework, we find that the existence of very massive neutron stars and constraints on the tidal deformability provide the most restrictive constraints on the EOS.
↳ astro-ph.HEhep-phnucl-thEur. Phys. J. Spec. Top. "High density nu…·2 citations
12
Internal structure of near-threshold states using compositeness
Tomona Kinugawa🇯🇵 · Tetsuo Hyodo🇯🇵
Understanding the internal structure of near-threshold states is essential for revealing the nature of exotic hadrons. Motivated by this challenge, we discuss the clustering structures of near-threshold $s$ -wave eigenstates using the compositeness, which characterizes the clustering nature of the states. We show that shallow bound states usually possess cluster-dominant structures, while near-threshold narrow resonances are non-cluster-dominant. Through this study, we establish a theoretical foundation for the threshold energy rule, which has been known empirically.
↳ hep-phnucl-th0 citations
13
Shear viscosity at finite magnetic field for graphene, non-relativistic and ultra-relativistic cases
Cho Win Aung · Thandar Zaw Win · Subhalaxmi Nayak · Sabyasachi Ghosh
The present article has addressed the finite magnetic field extension of the previous work by Cho et al. (Phys. Rev. B 108, 235172, 2023) on microscopic calculation of shear viscosity for electron fluid in graphene system. Our calculation is based on the kinetic theory approach in the relaxation time approximation. In the absence of a magnetic field, transport is governed by a single shear viscosity coefficient, whereas the application of a finite magnetic field induces anisotropy, giving rise to five independent shear viscosity coefficients associated with distinct velocity gradient tensors. These coefficients can be physically categorized into perpendicular, parallel, and Hall components relative to the magnetic field direction. When the scattering time equals the cyclotron time, the perpendicular component is suppressed by 80% and the parallel component by 50% and the Hall effect can reach maximum. Corresponding magnetic field strength for electron fluid in graphene is around 0.01-0.1 Tesla, and the same for non-relativistic electron fluid and ultra-relativistic quark fluid are around 10 Tesla and 10^{14} Tesla respectively. They may be considered as the required magnetic field strength in three different fluid systems to observe noticeable magnetic field response in their shear viscosity coefficients.
↳ cond-mat.str-elnucl-th0 citations
14
Inhomogeneous instabilities in high-density QCD
Jan M. Pawlowski🇩🇪 · Fabian Rennecke🇩🇪 · Franz R. Sattler🇩🇪
QCD at large densities exhibits a moat regime in the scalar-pseudoscalar sector. The resolution of its dynamics is pivotal for the access to the onset of new phases including the potential critical endpoint of QCD. In this work we present the first selfconsistent analysis of this regime with the functional renormalisation group approach to QCD. We map out the moat regime, including a first analysis of potential inhomogeneous instabilities at baryon chemical potential $μ_{B} ≳ 600$ MeV on the chiral crossover line.
↳ hep-phhep-thnucl-th19 citations
15
A possible solution to the gallium anomaly moving beyond the leptonic wave function factorization
M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · F. Dordei🇮🇹 · L. Ferro🇮🇹 · C. Giunti🇮🇹 · M. Pitzalis🇮🇹
For over thirty years, a $\sim 20%$ deficit, now exceeding $5 σ$ , has persisted between measured and predicted neutrino capture rates on $^{71}$ Ga, as observed in radioactive source experiments (namely GALLEX, SAGE, and more recently BEST) using $^{51}$ Cr and $^{37}$ Ar. This long-standing discrepancy, referred to as the gallium anomaly, has posed a significant challenge to our understanding of both experimental methods and theoretical predictions. In this work, we revisit the theoretical calculation of the neutrino capture cross-section by moving beyond the standard treatment of the leptonic wave functions, revealing limitations in the commonly used factorization approach based on the detailed balance principle. Incorporating phenomenologically constrained Gamow-Teller transition densities, able to correctly reproduce the precisely measured half-life of $^{71} Ge$ , we find that the revised cross-section can be significantly reduced, potentially resolving the gallium anomaly without invoking new physics.
↳ hep-phhep-exnucl-exnucl-th3 citations

Affiliations

first authorsco-authorsvia INSPIRE

CT25: Progress toward next-generation PDFs for precision phenomenology at the LHC

Astrophysical constraints on the cold equation of state of the strongly interacting matter

Internal structure of near-threshold states using compositeness

Shear viscosity at finite magnetic field for graphene, non-relativistic and ultra-relativistic cases

Inhomogeneous instabilities in high-density QCD

A possible solution to the gallium anomaly moving beyond the leptonic wave function factorization

Affiliations