Nuclear Theory·nucl-th

Wednesday·October 15, 2025

11 papers—4 primary·7 cross-listed

05
Method to search for the triple-neutron state in an electron scattering experiment
Tianhao Shao · Jinhui Chen · Yu-Gang Ma · Josef Pochodzalla
An electron scattering experiment to search for the trineutron state $^{3} n$ by reaction $^{4} He (e, e^{'} p π^{+})^{3} n$ is designed for the A1 facility at Mainzer Microtron. The detailed principles, setup, and simulation of this experiment are presented. With the momenta of the scattered electron, the produced proton and $π^{+}$ from the reaction measured by three spectrometers with their triple coincidence, the missing mass spectrum of $^{3} n$ can be obtained. The production rate of $^{3} n$ based on the cross section of the reaction and a MC simulation is estimated to be about 1.5 per day, which can provide a confidence level of the signal greater than 5 $σ$ with a beam time longer than 16 days. According to a MC simulation that evaluates the energy losses of particles in materials and the performance of three spectrometers, the estimated resolution and the predicted shape of the missing mass spectrum are presented. This work provides a new experimental concept for the search for multineutron states in future experiments with an electron beam.
↳ physics.ins-detnucl-exnucl-thEPJA(2025)·0 citations
06
Exact WKB method for radial Schrödinger equation
Okuto Morikawa · Shoya Ogawa
We revisit exact WKB quantization for radial Schrödinger problems from the modern resurgence perspective, with emphasis on how ``physically meaningful'' quantization paths should be chosen and interpreted. Using connection formulae at simple turning points and at regular singular points, we show that the nontrivial-cycle data give the spectrum. In particular, for the $3$ -dimensional harmonic oscillator and the $3$ -dimensional Coulomb potential, we explicitly compute a closed contour which starts at $+ \infty$ , bulges into the $r < 0$ sector to encircle the origin, and returns to $+ \infty$ . Also we propose that the appropriate slice of the closed path provides a physical local basis at $r = 0$ , which is used by an origin-to- $\infty$ open path. Via the change of variables $r = e^{x}$ ( $x \in (- \infty, \infty)$ ), the origin data are pushed to the boundary condition of convergence at $x \to - \infty$ , which renders the equivalence between open-connection and closed-cycle quantization transparent. The Maslov contribution from the regular singularity is incorporated either as a small-circle monodromy which is justified in terms of renormalization group, or, equivalently, as a boundary phase; we also develop an optimized/variational perturbation theory on exact WKB. Our analysis clarifies, in radial settings, how mathematical monodromy data and physical boundary conditions dovetail, thereby addressing recent debates on path choices in resurgence-based quantization.
↳ quant-phnucl-thJ.Phys.A(2026)·2 citations
07
The mass of $^{101}$ Sn and Bayesian extrapolations to the proton drip line
Christian M. Ireland · Georg Bollen · Scott E. Campbell · Xiangcheng Chen · Hannah Erington · Nadeesha D. Gamage · Kyle Godbey · Alicen M. Houff · Christopher Izzo · Bailey Knight · Sudhanva Lalit · Erich Leistenschneider and 14 other authors
The favorable energy configurations of nuclei at magic numbers of $N$ neutrons and $Z$ protons are fundamental for understanding the evolution of nuclear structure. The $Z = 50$ (tin) isotopic chain is a frontier for such studies, with particular interest at and around the doubly-magic \textsuperscript{100}Sn isotope, for which the mass is a topic of debate. Precise mass values for neutron-deficient isotopes provide necessary anchor points for mass models to test extrapolations near the proton drip line, where experimental studies remain out of reach. In this work, we report the first Penning trap mass measurement of \textsuperscript{101}Sn. The determined mass excess of $- 59 889.89 (96)$ ~keV for \textsuperscript{101}Sn represents a factor of 300 improvement over the current precision and indicates that \textsuperscript{101}Sn is less bound than previously thought. Mass predictions from a recently developed Bayesian model combination (BMC) framework employing statistical machine learning and nuclear masses computed within seven global models based on nuclear Density Functional Theory (DFT) agree within 1 $σ$ with experimental masses from the $48 \leq Z \leq 52$ isotopic chains. The framework's resilience to new mass data gave confidence in the extrapolation of tin masses down to $N = 46$ . Our calculations suggest that \textsuperscript{96}Sn is a two-proton drip line nucleus and predict a mass excess of $- 58090 (800)$ ~keV for $^{100}$ Sn, showing a preference within 1 $σ$ for the mass of \textsuperscript{100}Sn derived from the $β$ -delayed $Q$ -value measured at GSI.
↳ nucl-exnucl-thPRC(2026)·5 citations
08
Universality of the chiral soliton lattice and its interaction with quark matter
Fabrizio Canfora🇨🇱 · Nicolás Grandi🇦🇷 · Marcela Lagos🇨🇱 · Luis Urrutia-Reyes🇨🇱 · Aldo Vera🇨🇱
In this paper, we show that the chiral soliton lattice (ChSL) is, in a precise sense, a universal feature of the low-energy limit of QCD minimally coupled to Maxwell theory. Here, we disclose that not only can the ChSL be obtained from the gauged Skyrme model in $3 + 1$ dimensions, including the back-reaction of the Maxwell $U (1)$ gauge field, we also demonstrate that the ChSL remains unchanged when higher-order terms arising from QCD, specifically the sub-leading corrections in the 't Hooft large $N_{c}$ expansion, are included. By considering a suitable ansatz adapted to describe topological solitons at finite baryon density in a constant magnetic field, the generalized Skyrme model coupled to the Maxwell theory is reduced to the effective Lagrangian of the ChSL phase, which describes a lattice of domain walls made of hadrons. One of the key points in this construction is the fact that even when the usual topological charge density vanishes, the presence of the Callan-Witten term in the topological charge density allows for a non-vanishing baryon number. In the present approach, the magnetic field can be external, as is usually assumed for the ChSL, or it can be self-consistently generated by the hadronic layers themselves. Finally, we show how our formulation allows us to study the coupling of the ChSL with quark matter. In particular, we derive the exact analytical spectrum of the Dirac equation in the high-density limit, providing a microscopic characterization of the fermionic excitations within the inhomogeneous hadronic background provided by the ChSL. The comparison of the present spectrum of the Dirac operator within the ChSL with the spectrum of the usual Dirac operator in a constant magnetic field discloses the fundamental role of both the quark-Skyrmion coupling and the hadronic profile in opening a gap and generating a shift in the spectrum itself.
↳ hep-thhep-phnucl-th3 citations
09
First simultaneous global QCD analysis of kaon and pion parton distributions with lattice QCD constraints
P. C. Barry🇺🇸 · Chueng-Ryong Ji🇺🇸 · W. Melnitchouk🇺🇸 · N. Sato🇺🇸 · Fernanda Steffens🇩🇪
We perform the first simultaneous global QCD analysis of pion and kaon parton distribution functions (PDFs), constrained by pion- and kaon-induced Drell-Yan (DY) and leading neutron electroproduction data, together with lattice QCD data on pion and kaon PDF moments. The analysis indicates a softer valence $u ˉ$ distribution in the $K^{-}$ than in the $π^{-}$ , and a significantly more peaked valence $s$ -quark density in $K^{-}$ compared with the $u ˉ$ . The effective exponent governing the high- $x$ behavior of the PDF is found to be larger for $u ˉ$ in the kaon, $β_{u ˉ}^{K^{-}} = 1.6 (2)$ , than in the pion, $β_{u ˉ}^{π^{-}} = 1.16 (4)$ , in the range $0.7 \leq x \leq 0.95$ . From the gluon momentum fractions we find the pion's gluon content accounts for $\approx 1/3$ of the mass budget of the pion at $μ = 2 GeV$ , but only $\approx 1/4$ for the kaon.
↳ hep-phhep-exhep-latnucl-thPRD(2026)·19 citations
10
The probe limit in MHD and its implications for magnetic transport
Giorgio Frangi🇬🇧 · Matej Bajec🇸🇮 · Guri K. Buza🇸🇮 · Alexander Soloviev🇸🇮 · Sašo Grozdanov🇬🇧
Many phenomenological and effective field-theoretical (EFT) applications of magnetohydrodynamics (MHD) in the presence of a background magnetic field employ a simplifying assumption whereby the electromagnetic and the energy-momentum fluctuations decouple. In studies of magnetic transport, for example in magnetic diffusion, the conservation of energy and momentum is then neglected. In this paper, we investigate the details and the consistency of this so-called $probe limit$ in different parametric regimes of MHD plasmas. In the first part of the paper, our discussion explores the hydrodynamic (higher-form) theory of MHD. In the second part, we then explicitly test the probe limit by using a microscopic holographic (AdS/CFT) model of a strongly coupled plasma. In the process, we develop the holographic Schwinger-Keldysh EFT prescription for describing the bulk 2-form fields and their dual 1-form symmetries. Moreover, we find evidence of a phase transition at low temperatures and show that magnetic Hall transport can emerge as a consequence of background charge density that breaks the charge conjugation symmetry of the state. Finally, we discuss the implications for magnetic transport, with a particular view towards the dynamics of dense nuclear matter in neutron stars.
↳ hep-thastro-ph.HEnucl-th2 citations
11
Initial-state geometry and multiplicity distributions in pp and pPb collisions
R. Terra🇧🇷 · A. V. Giannini🇵🇹 · F. S. Navarra🇧🇷
This work investigates the possibility of accessing the initial geometric shape of the proton in proton-proton and proton-nucleus collisions at the LHC. In particular, we look for manifestations of the configuration in which the proton is made of three quarks linked by a Y-shape gluon string, called baryon junction. This initial state spatial configuration has been used in the past to describe data on baryon rapidity distributions, diffractive $J / ψ$ production and multiplicity distributions in pp collisions. In spite of its success in explaining the data, the evidence of the baryon junction still needs confirmation. Further studies will be undertaken at the electron-ion collider. In this work we study multiplicity distributions measured in pp and pPb collisions. Different initial state geometries are used as input in a Monte Carlo event generator which implements the $k_{T}$ -factorization formalism of the CGC with KLN unintegrated gluon distributions. The results show that the data on multiplicity distributions are good enough to discriminate between different initial state geometries. Moreover, they indicate that it is crucial to take into account the intrinsic fluctuations of the saturation scale.
↳ hep-phnucl-thPRD(2026)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Method to search for the triple-neutron state in an electron scattering experiment

Exact WKB method for radial Schrödinger equation

The mass of 101Sn and Bayesian extrapolations to the proton drip line

Universality of the chiral soliton lattice and its interaction with quark matter

First simultaneous global QCD analysis of kaon and pion parton distributions with lattice QCD constraints

The probe limit in MHD and its implications for magnetic transport

Initial-state geometry and multiplicity distributions in pp and pPb collisions

Affiliations

The mass of $^{101}$ Sn and Bayesian extrapolations to the proton drip line