Nuclear Theory·nucl-th

Wednesday·February 25, 2026

6 papers—3 primary·3 cross-listed

01
Probing Neutron Skins with KDAR Neutrinos: From Coherent to Diffractive Elastic Neutrino--Nucleus Scattering
Kyoungsu Heo🇰🇷 · Heesung Kwon🇰🇷 · Jaewon Kim🇰🇷 · Jubin Park🇰🇷 · Myung-Ki Cheoun🇰🇷 · Eunja Ha🇰🇷 · Kyung Kwang Joo🇰🇷
We investigate coherent elastic neutrino--nucleus scattering (CE $ν$ NS) induced by pion--decay--at--rest ( $π$ DAR) and kaon--decay--at--rest (KDAR) neutrinos, with emphasis on the transition from strict coherence to the diffractive regime. Organizing CE $ν$ NS observables in terms of the dimensionless variable $q R$ , we show that $π$ DAR measurements remain confined to the near--coherent region for all nuclei, whereas KDAR neutrinos ( $E_{ν} = 236$ ~MeV) extend the kinematics into $q R ≳ 1$ , where recoil spectra develop genuine shape sensitivity to the nuclear weak form factor. Using representative light, medium--mass, and heavy nuclei ( $^{12}$ C, $^{40}$ Ca, $^{48}$ Ca, and $^{208}$ Pb), we examine relevant cross sections and quantify the statistical sensitivity to the neutron skin thickness achievable at a JSNS $^{2}$ --like facility. For a total exposure of 10~ton $\cdot$ year and realistic KDAR fluences, projected $1 σ$ sensitivities reach $Δ R_{n p}^{(1 σ)}$ $≃ 0.09$ -- $0.02$ ~fm for $^{48}$ Ca and $≃ 0.07$ -- $0.02$ ~fm for $^{208}$ Pb as the fluence increases. These sensitivities are competitive with, and complementary to, parity--violating electron--scattering measurements such as CREX and PREX, while relying on an electroweakly clean neutral--current probe with distinct systematic uncertainties. Our results establish KDAR--based CE $ν$ NS as a quantitatively robust and complementary avenue for probing neutron skins and nuclear weak densities beyond the coherent limit.
nucl-thnucl-exPTEP(2026)·0 citations
02
Beyond Mean Field: Fluctuation Diagnostics and Fixed-Point Behavior
Pok Man Lo
We develop theoretical diagnostics for the breakdown of mean-field theory, demonstrate how spatial structure and finite interaction ranges enter the effective description, and show how these scales qualitatively modify the renormalization-group flow.
nucl-thcond-mat.stat-mechhep-thJ.Subatomic Part.Cosmol.(2026)·3 citations
03
Empirical formula for total inelastic cross-section of proton-nucleus scattering
Hemant Kumar · Tanmay Maji · Deepa Gupta · Ashavani Kumar
We propose a generic empirical formula for total inelastic cross-sections for various target nuclei scattered by a proton at different energies, which is applicable over a wide range of energy from $15 M e V$ to $1 T e V$ . The proposed model is parameterized based on the fitting of extensively studied experimental cross-section data for the Aluminium and Carbon nucleus targets, considering factorization over high-energy and low-energy regimes. The parameters in high-energy formula are determined by the fitting of the high-energy saturation value of the inelastic scattering cross-section data with mass numbers. The universality of the empirical formula is investigated by comparing the model prediction with the experimental data of inelastic proton-nucleus scattering over a wide range from light elements such as Deuterium to heavy elements such as Uranium. A detailed comparison with the existing models and GEANT4 simulation is also presented.
nucl-thhep-phnucl-exPRC(2026)·0 citations
04
Resummed azimuthal decorrelation and transverse momentum imbalance of dijets at the LHC
Rong-Jun Fu🇨🇳 · Rudi Rahn🇦🇹 · Ding Yu Shao🇨🇳 · Wouter J. Waalewijn🇳🇱 · Bin Wu🇪🇸
We present a theoretical study of the azimuthal decorrelation $δ ϕ$ and transverse momentum imbalance $q_{T}$ in dijet production at the LHC, offering intriguing insights into the dynamics of quantum chromodynamics. We define the jet axes using the recoil-free winner-take-all (WTA) recombination scheme. For the azimuthal decorrelation $δ ϕ$ , this axis choice eliminates non-global logarithms (NGLs) entirely. For the transverse momentum imbalance $q_{T}$ , NGLs emerge specifically in the small jet radius limit ( $R ≪ 1$ ). In this regime, the WTA scheme simplifies the theoretical framework by restricting jet radius logarithms to the soft sector. We derive factorization formulae for both observables within soft-collinear effective theory. To address the small- $R$ NGLs in the $q_{T}$ distribution, we refactorize the soft function into global soft, collinear-soft, and ultra-collinear-soft modes. We perform the resummation of global large logarithms $ln (δ ϕ)$ and $ln (q_{T} / Q)$ up to next-to-next-to-leading logarithmic accuracy. For the $q_{T}$ distribution, this is combined with a leading-logarithmic resummation of the non-global $ln R$ terms. We match our predictions to leading fixed-order $O (α_{s}^{3})$ calculations. We also numerically investigate the structure of the first subleading power corrections. Comparisons with PYTHIA8 simulations demonstrate that the observables we consider are robust against non-perturbative multi-parton interactions and hadronization effects.
↳ hep-phhep-exnucl-thJHEP(2026)·4 citations
05
Resolving the structure of bound states using lattice quantum field theories
Joseph Moscoso🇺🇸 · Felipe G. Ortega-Gama🇺🇸 · Raúl A. Briceño🇺🇸 · Andrew W. Jackura🇺🇸 · Charles Kacir🇺🇸 · Amy N. Nicholson🇺🇸
This work presents the first lattice calculation of a two-to-two particle matrix element of a local current. This exploratory calculation is performed using a leading-order pionless effective field theory of two nucleons in a finite 3D spatial volume, where the Hamiltonian can be diagonalized exactly for moderate volumes. By considering a range of couplings where the theory supports a deuteron-like bound state, we determine the finite-volume spectra and matrix elements of the conserved local vector current. Using the Lüscher formalism, we constrain the infinite-volume, purely hadronic amplitude for this theory. Using previously derived formalism, we then map the finite-volume matrix elements to scattering amplitudes describing a reaction coupling two-particle states via a current insertion, $\2 + \Jc \to \2$ . We then use a recently derived relation between this class of amplitudes and the bound-state elastic form factor to directly constrain the infinite-volume form factor. By varying over a range of values of the coupling of the theory, we explore the effects of this analysis for deep-bound states and shallow-bound states. We reproduce the expected result that for deep bound states, the finite-volume formalism is largely unnecessary, while for shallow bound states, it is absolutely critical to obtain a sensible result. We present a detailed outline of the analysis of this class of matrix elements, including the determination of the charge radius of the bound state. In the shallow bound state limit, we find good agreement with the prediction stemming from the anomalous threshold.
↳ hep-latnucl-th6 citations
06
Spatial confinement-deconfinement transition in accelerated gluodynamics within lattice simulation
Victor V. Braguta🇷🇺 · Vladimir A. Goy🇷🇺 · Jayanta Dey🇷🇺 · Artem A. Roenko🇷🇺
In this work we investigate the influence of weak acceleration on the confinement-deconfinement phase transition in gluodynamics. Our study is carried out within lattice simulation in the comoving reference frame of accelerated observer which is parameterized by the Rindler coordinates. We find that finite temperature confinement-deconfinement phase transition turns into spatial crossover in the Rindler spacetime. In other words, spatially separated confinement and deconfinement phases can coexist in the Rindler spacetime within certain intervals of temperature and acceleration. We determine the position of the boundary between the phases as a function of temperature for several accelerations and find that it can be described by the Tolman-Ehrenfest law with rather good accuracy although a minor deviation takes place. Moreover, the critical temperature of the system in the weak acceleration regime is found to remain unchanged as that of the standard homogeneous gluodynamics. Our results imply that the spatial confinement-deconfinement transition might take place in the vicinity of the Schwarzschild black hole horizon.
↳ hep-latgr-qchep-phhep-th+1PRD(2026)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

Probing Neutron Skins with KDAR Neutrinos: From Coherent to Diffractive Elastic Neutrino--Nucleus Scattering

Beyond Mean Field: Fluctuation Diagnostics and Fixed-Point Behavior

Empirical formula for total inelastic cross-section of proton-nucleus scattering

Resummed azimuthal decorrelation and transverse momentum imbalance of dijets at the LHC

Resolving the structure of bound states using lattice quantum field theories

Spatial confinement-deconfinement transition in accelerated gluodynamics within lattice simulation

Affiliations