Nuclear Theory·nucl-th

Tuesday·February 10, 2026

14 papers—5 primary·9 cross-listed

06
[Submitted on 5 Feb 2026] (cross-list from hep-ph)
Electromagnetic polarizabilities of the triplet hadrons in heavy hadron chiral perturbation theory
Hao Dang🇨🇳 · Liang-Zhen Wen🇨🇳 · Yan-Ke Chen🇨🇳 · Shi-Lin Zhu🇨🇳
We investigate the electromagnetic polarizabilities of singly heavy mesons and doubly heavy baryons within the framework of heavy hadron chiral perturbation theory up to $O (p^{3})$ . We estimate the low-energy constants using the non-relativistic constituent quark model. A striking prediction of our study is the giant electric polarizabilities of the $D^{*}$ mesons: $α_{E} (D ˉ^{* 0}) \approx 291.4 \times 1 0^{- 4} fm^{3}$ and $α_{E} (D^{*-}) \approx - 0.4 - 64.4 i \times 1 0^{- 4} fm^{3}$ . These anomalously large values arise from the near-degenerate mass between $D^{*}$ and $D π$ , which are orders of magnitude larger than those of their bottom counterparts. This kinematic coincidence induces a pronounced cusp structure in the chiral loops, reflecting the long-range dynamics of a pion cloud. For doubly heavy baryons, polarizabilities depend strongly on heavy-flavor composition: the $b c q$ system differs markedly from $cc q$ and $bb q$ due to mixing with scalar heavy-diquark states. Using heavy diquark-antiquark symmetry (HDAS), we unify the chiral dynamics of singly heavy mesons and doubly heavy baryons in the heavy-quark limit. The pion-loop contributions dominate the electromagnetic structure of heavy hadrons and provide essential benchmarks for future lattice QCD simulations.
Comments:
20 pages, 2 figures, 7 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2602.05502 [pdf]
PRD(2026)·2 citations
07
[Submitted on 29 Jan 2026] (cross-list from gr-qc)
Asymptotic Freedom and Vacuum Polarization Determine the Astrophysical End State of Relativistic Gravitational Collapse: Quark--Gluon Plasma Star Instead of Black Hole
Herman J. Mosquera Cuesta🇨🇴 · Fabián H. Zuluaga Giraldo🇨🇴 · Wilmer D. Alfonso Pardo🇨🇴 · Edgardo Marbello Santrich🇨🇴 · Guillermo U. Avendaño Franco🇺🇸 · Rafael Fragozo Larrazabal🇪🇸
A general relativistic model of an astrophysical hypermassive extremely magnetized ultra-compact self-bound quark--gluon plasma object that is supported against its ultimate gravitational implosion by the simultaneous action of the vacuum polarization driven by nonlinear electrodynamics (NLED: light-by-light scattering) and the quantum chromodynamics (QCD) asymptotic freedom, is presented. These QCD stars can be the final figures of the equilibrium of collapsing stellar cores. Post-supernova fallback material pushes the nascent remnant beyond its stability to collapse into a hybrid hypermassive neutron star (HHMNS). Hypercritical accretion can unbind the whole HHMNS's baryons to spontaneously break away color confinement, powering a first-order hadron-to-quark phase transition to a sea of ever-freer quarks and gluons. This core is hydro-stabilized by the steady, endlessly compression-admitting asymptotic freedom state, possibly via gluon-mediated enduring exchange of color charge among bound states. The nonlinear TOV equation indicates the occurrence of hypermassive QGP/QCD stars with a wide mass spectrum ( $0 ≲$ M $_{Star}^{QGP} ≲$ \,7\,M $_{⊙}$ and beyond), for star radii ( $0 ≲ R_{Star}^{QGP} ≲ 24$ \,km and beyond) with B-fields ( $1 0^{14} \leq$ B $_{Star}^{QGP} \leq 1 0^{16}$ \,G and beyond). Such QCD stars can emulate what the true black holes are supposed to gravitationally do in most astrophysical settings. This color quark star could be found through a search for its eternal ``yo-yo'' state gravitational-wave emission, or via lensing phenomena like gravitational rainbows, as in this scenario it is expected that the light deflection angle, directly influenced by the larger effective mass/radius and magnetic field of the deflecting object, increases as the incidence angle decreases for impact parameter lower values.
Comments:
25 pages, 4 figues
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2602.07004 [pdf]
Universe(2025)·1 citation
08
[Submitted on 8 Feb 2026] (cross-list from nucl-ex)
Observation of a broad $p$ -wave resonant state in $^{9}$ He
Y. L. Sun🇨🇳 · A. Corsi🇫🇷 · Y. Kubota🇯🇵 · G. Authelet🇫🇷 · H. Baba🇯🇵 · C. Caesar🇩🇪 · D. Calvet🇫🇷 · A. Delbart🇫🇷 · M. Dozono🇯🇵 · J. Feng🇨🇳 · F. Flavigny🇫🇷 · J.-M. Gheller🇫🇷 and 54 other authors
We report on the two-body invariant-mass spectroscopy of $^{9}$ He, populated via the 1 $p$ 1 $n$ knockout reaction from the two-neutron halo nucleus $^{11}$ Li at $\sim$ 250 MeV/nucleon. A broad $p$ -wave resonant state of $^{9}$ He was observed at 1.28(1) MeV with a width of 0.82(4) MeV.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2602.07810 [pdf]
1 citation
09
[Submitted on 8 Feb 2026] (cross-list from hep-ph)
Shear viscosity of a massless quark-gluon gas in chemical equilibrium in terms of all $2 \leftrightarrow 2$ cross sections
Okey Ohanaka🇺🇸 · Zi-Wei Lin🇺🇸
The analytical expressions of the shear viscosity of both one and two particle species with Boltzmann statistics and $2 \to 2$ elastic scatterings are known from the Chapman-Enskog method and have been shown to be quite accurate. The expression for a multi-species hadronic gas under $2 \to 2$ elastic scatterings is also known. Here we use the Chapman-Enskog method to derive the explicit expression of shear viscosity of a massless quark-gluon gas of $N_{f}$ quark flavors in chemical equilibrium subjected to all $2 \to 2$ parton scatterings including for the first time inelastic scatterings. We then verify the expression in a general single-species limit, where the shear viscosity of the quark-gluon gas should reduce to the result for a single particle species. In addition, we show the explicit analytical result in terms of the seven independent cross sections for the special case of isotropic and energy-independent cross sections. The analytical expressions derived here can be useful for determining the shear viscosity of parton transport models with any $2 \to 2$ scattering cross sections. They can also be coupled with finite temperature QCD cross sections to help study the shear viscosity of the quark gluon plasma.
Comments:
19 pages, no figures; added a Discussions section and a new Appendix with minor change of title to match the journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2602.08155 [pdf]
PRD(2026)·2 citations
10
[Submitted on 9 Feb 2026] (cross-list from nucl-ex)
Search for the QCD Critical Point in High Energy Nuclear Collisions: A Status Report
Yu Zhang🇨🇳 · Zhaohui Wang🇨🇳 · Xiaofeng Luo🇨🇳 · Nu Xu🇨🇳
We review recent results of net-proton multiplicity fluctuations from STAR experiment, aiming to locate the QCD critical point in high-energy nuclear collisions at RHIC. We show net-proton number cumulant and proton number factorial cumulant ratios up to fourth order using experimental data from RHIC BES-II Au+Au collisions in collider mode and fixed-target mode. The comparison is made between experimental data and non-critical model calculations from Lattice QCD, HRG, hydrodynamic simulations and transport model UrQMD. In addition, we discuss initial volume fluctuation effect, which plays significant role in fixed-target energies. Finally, an outlook on experimental research on the QCD critical point in future experiments will be presented.
Comments:
10 pages, 6 figures, contribution to the special issue of EPJ titled 'High density nuclear matter'
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2602.08356 [pdf]
Eur. Phys. J. Spec. Top. (2026)·8 citations
11
[Submitted on 9 Feb 2026] (cross-list from quant-ph)
Quantum-classical framework for many-fermion response and structure
Weijie Du · Yangguang Yang · Zixin Liu · Chao Yang · James P. Vary
Response functions are key observables for probing the structure and dynamics of many-body systems. We introduce and demonstrate a quantum-classical framework for computing response functions of general many-fermion systems that also provides the full bound-state spectrum. The framework employs the Lorentz integral transform and a new Hamiltonian input scheme that enables practical and scalable circuit constructions for general many-fermion Hamiltonians. Within this framework, we develop a hybrid strategy to evaluate the Lorentz integral and propose three protocols to extract response functions and bound-state structural information. As a demonstration, we apply the method to ${}^{19}\mathrm{O}$ with realistic internucleon interactions, computing both the bound-state spectrum and the response function. We envision that our approach will open new avenues for exploring the structure and dynamics of a broad class of many-body systems across diverse fields.
Comments:
9 pages, 2 figures. We welcome comments
Subjects:
Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
arXiv:
2602.08357 [pdf]
PLB(2026)·3 citations
12
[Submitted on 9 Feb 2026] (cross-list from hep-ph)
Neutrinoless double beta decays of hyperons in covariant chiral perturbation theory
Zi-Ying Zhao🇨🇳 · Ze-Rui Liang🇨🇳 · Feng-Kun Guo🇨🇳 · Li-Ping He🇨🇳 · De-Liang Yao🇨🇳
Neutrinoless double beta ( $0 ν β β$ ) decays of spin-1/2 hyperons are investigated in a covariant baryon chiral perturbation theory framework, extended by a $Δ L = 2$ operator proportional to the Majorana neutrino mass, where $L$ denotes the lepton number. Within the light Majorana neutrino exchange mechanism, the decay amplitudes are found to emerge at the one-loop level, representing the long-range contribution. The extended-on-mass-shell scheme is employed to renormalize the one-loop amplitudes and restore consistent chiral power counting. Consequently, the differential decay rates for all accessible hyperon $0 ν β β$ channels are predicted and the corresponding branching ratios are more than 20 orders of magnitude smaller than the current experimental upper bounds. Interestingly, it is found that the leading contribution to hyperon $0 ν β β$ decay is actually from short-range counterterm operators, as required by the renormalization argument. Neutrinoless transition form factors are proposed to determine this leading contribution through future lattice QCD simulations.
Comments:
35 pages, 7 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2602.08453 [pdf]
3 citations
13
[Submitted on 9 Feb 2026] (cross-list from nucl-ex)
First Extraction of the Matter Radius of $^{132}$ Sn via Proton Elastic Scattering at 200 MeV/Nucleon
Y. Hijikata🇯🇵 · J. Zenihiro🇯🇵 · S. Terashima🇨🇳 · Y. Matsuda🇯🇵 · H. Sakaguchi🇯🇵 · P. Arthuis🇫🇷 · T. Miyagi🇯🇵 · S. Ota🇯🇵 · H. Baba🇯🇵 · S. Chebotaryov🇰🇷 · M. Dozono🇯🇵 · T. Furuno🇯🇵 and 25 other authors
The angular distribution of the differential cross sections for proton elastic scattering from $^{132}$ Sn at 196-210 MeV/nucleon was successfully measured over a momentum transfer range of 0.80 to 2.1 fm $^{- 1}$ . Using a relativistic impulse approximation, the root-mean-square matter radius of $^{132}$ Sn was extracted to be $4.75 8_{- 0.024}^{+ 0.023}$ fm, which was compared with the state-of-the-art ab initio calculations. Combined with the charge radius measured at ISOLDE, there are no theoretical calculations consistent with both matter and charge radii within the experimental errors.
Comments:
18 pages, 8 figures
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2602.08455 [pdf]
PTEP(2026)·2 citations
14
[Submitted on 9 Feb 2026] (cross-list from quant-ph)
Non-Hermitian Renormalization Group from a Few-Body Perspective
Hiroyuki Tajima🇯🇵 · Masaya Nakagawa🇯🇵 · Haozhao Liang🇯🇵 · Masahito Ueda🇯🇵
Non-Hermiticity plays a fundamental role in open quantum systems and describes a wide variety of effects of interactions with environments, including quantum measurement. However, understanding its consequences in strongly interacting systems is still elusive due to the interplay between non-perturbative strong correlations and non-Hermiticity. While the Wilsonian renormalization group (RG) method has been applied to tackle this problem, its foundation, based on the existence of the partition function, is ill-defined. In this paper, we establish a microscopic foundation of the non-Hermitian RG method from a few-body perspective. We show that the invariance of the scattering amplitude under RG transformations enables us to rigorously derive the non-Hermitian RG equation, giving a physically transparent interpretation of RG flows. We discuss a detailed structure of such RG flows in a non-relativistic two-body system with inelastic two-body loss, and show its relation to a non-Hermitian quantum scale anomaly. Our analysis suggests that non-Hermitian complex potentials often used in high-energy physics can be interpreted as being caused by quantum measurement, where the detection of elastically scattered particles updates the observer's knowledge, resulting in a nonunitary state change of the system. We apply our formalism to nuclear physics, find the emergence of a critical semicircle, and show that several nuclei are located near the critical semicircle in the coherent neutron-nucleus scattering. We also propose that the localized dineutron in two-neutron halo nuclei can be interpreted as the quantum measurement effect on the imaginary potential associated with absorption into the core nucleus. Our result bridges different contexts of non-Hermitian systems in high-energy and atomic, molecular, and optical physics, opening an interdisciplinary playground of non-Hermitian few-body physics.
Comments:
19 pages, 8 figures
Subjects:
Quantum Physics (quant-ph); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
arXiv:
2602.08705 [pdf]
2 citations

Affiliations

first authorsco-authorsvia INSPIRE