Nuclear Theory·nucl-th

Monday·April 27, 2026

11 papers—5 primary·6 cross-listed

06
[Submitted on 23 Apr 2026] (cross-list from hep-ph)
Gradient-Produced Neutrinos
Erwin H. Tanin🇺🇸 · Yikun Wang🇺🇸
Sufficiently strong electric fields can produce charged-particle pairs via the Schwinger effect. We argue that steep matter-density gradients, as can arise in neutron star interiors, would analogously produce neutrino-antineutrino pairs. We then discuss observational signatures of these gradient-produced (anti)neutrinos and how they could provide new probes of neutron-star structure and baryon-dense QCD.
Comments:
6+18 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
2604.21968 [pdf]
1 citation
07
[Submitted on 23 Apr 2026] (cross-list from hep-ph)
Hydrodynamics and Energy Correlators
João Barata🇨🇭 · Matvey V. Kuzmin🇬🇧 · Ian Moult🇺🇸 · Andrey V. Sadofyev🇪🇸 · João M. Silva🇵🇹
We study energy-energy correlators (EECs) in many-body quantum states, focusing on the matter produced in the aftermath of heavy-ion collisions. We analyze the angular structure of EECs in the collinear limit and identify a sequence of dynamical regimes. At the largest angular separations within the small-angle regime, the observable is dominated by disconnected contributions, leading to a classical scaling determined by the collective flow of the medium. We explicitly construct this contribution for hadrons produced from a hydrodynamic medium described by boost-invariant Gubser flow, obtaining the angular dependence of the EEC analytically. We further consider azimuthal perturbations to this flow, illustrating how EECs can be used to probe anisotropies in the initial state. At smaller angular separations, connected contributions become increasingly important. We argue that in this regime the EEC is controlled by collective hydrodynamic modes. The resulting angular behavior is similar to the one identified in the EECs of heavy and large-charge states of conformal field theories. At even smaller angles, this regime is expected to match onto the structure determined by the light-ray operator product expansion, before eventually crossing over to the smallest-angle behavior characteristic of dilute hadronic matter. Altogether, these results provide a unified picture of the angular structure of EECs in many-body QCD states and suggest new observables sensitive to the properties of matter in heavy-ion collisions.
Comments:
33 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2604.21971 [pdf]
4 citations
08
[Submitted on 24 Apr 2026] (cross-list from hep-ph)
Confronting Color Glass Condensate at next-to-leading order with HERA data
Carlisle Casuga🇫🇮 · Heikki Mäntysaari🇫🇮
We perform a global analysis of HERA total inclusive cross section and charm quark production data to extract the non-perturbative initial condition for the next-to-leading order Balitsky-Kovchegov (BK) equation. We extend our previous analyses to full next-to-leading order + next-to-leading logarithm (NLO+NLL) accuracy by combining the NLO DIS impact factors with the NLO BK equation that includes the resummation of large double and single logarithms. The developed Bayesian setup extracts the posterior that describes the distribution of the parameters that best fit the data. The posterior distribution allows for estimates of the theoretical uncertainty of the dipole amplitude and, hence, offers a streamlined method for propagating uncertainties in the BK initial condition in NLO CGC calculations.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2604.22332 [pdf]
2 citations
09
[Submitted on 24 Apr 2026] (cross-list from astro-ph.SR)
The Effect of Mass Loss and Convective Overshooting on the Pre-Collapse Structure, Composition, and Neutrino Emission of Red Supergiants
McKenzie A. Myers · Claire B. Campbell · Kelly M. Patton · Segen BenZvi · Marta Colomer Molla · Alec Habig · James P. Kneller · Dan Milisavljevic · Jeffrey Tseng
Prior to core collapse, the neutrino emission from red supergiants (RSGs) is so large that a nearby ( $≲ 1$ kpc) RSG will become visible in current and near-future neutrino detectors. The rate of emission and the spectra of the pre-supernova (pre-SN) neutrinos from RSGs are sensitive to the temperature, density, and detailed isotopic composition of the core. During the last year of the star's life, these properties change considerably. Several factors of stellar evolution modeling - such as the treatment of mass loss and convective overshooting - alter the thermal conditions and composition of the RSG core as it approaches collapse. In this paper we present the first study of how varying the treatment of mass loss and convective overshooting together affects the pre-collapse core properties and neutrino emission of RSGs. We use the stellar evolution instrument MESA and construct a grid of 32 models with zero-age main sequence masses of ${12, 15, 18, 20}$ $M_{⊙}$ , use the so-called 'Dutch' mass-loss scheme with wind efficiencies of ${0.2, 0.4, 0.8, 1.0}$ , and consider two convective overshooting schemes. Our models use a large 206-isotope nuclear network in order to accurately compute the structure and composition of the star. We find that, in the last few days of the star's life, the general trend of the conditions and composition in the core of the star is one of contraction, heating, and deleptonization, but that during this phase, this general trend will be interrupted by the initiation of core silicon burning and shell burning episodes that cause the core to expand and undergo convective mixing with material of a higher proton fraction that temporarily reverses the deleptonization. The pre-SN neutrino emission reflects these changes with a gradual shift to higher energies and larger flux that becomes dominated by beta processes a few hours prior to the collapse.
Comments:
17 pages, 12 figures
Subjects:
Solar and Stellar Astrophysics (astro-ph.SR); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2604.22605 [pdf]
2 citations
10
[Submitted on 24 Apr 2026] (cross-list from astro-ph.HE)
Dense Matter and Compact Stars in Strong Magnetic Fields
Monika Sinha🇮🇳 · Vivek Baruah Thapa🇮🇳
Compact stars serve as natural systems where matter exists at densities far beyond those achievable in laboratory experiments. Among them, magnetars are expected to possess interior magnetic fields that may reach values of the order of $1 0^{17} - 1 0^{18}$ G. These extreme conditions are expected to alter the microscopic and macroscopic properties of dense matter. In this review, we examine how strong magnetic fields affect fermionic matter through mechanisms such as Landau quantization and anomalous magnetic moment interactions. We further discuss the behaviour of magnetized hadronic matter within relativistic mean-field approaches and consider the possible emergence of additional degrees of freedom, including hyperons, $Δ$ resonances, meson condensates and quark matter. The consequences of these effects for neutron-star structure and observational constraints are also briefly outlined.
Comments:
Invited review article for publication in "Universe"
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2604.22680 [pdf]
Universe(2026)·3 citations
11
[Submitted on 24 Apr 2026] (cross-list from hep-ph)
Mechanisms of high energy polarized photoproduction of $π^{-} Δ^{++}$
Vanamali Shastry🇺🇸 · Łukasz Bibrzycki🇵🇱 · Vincent Mathieu🇪🇸 · Glòria Montaña🇪🇸 · Alessandro Pilloni🇮🇹 · César Fernández-Ramírez🇪🇸 · Robert J. Perry🇺🇸 · Arkaitz Rodas🇺🇸 · Adam P. Szczepaniak🇺🇸 · Daniel Winney🇲🇽
We present an amplitude analysis of high-energy polarized photoproduction of $π^{-} Δ^{++}$ within a Regge exchange framework. A Regge amplitude model incorporating $π$ , $ρ$ , $b_{1}$ , and $a_{2}$ trajectory exchanges is fit simultaneously to spin density matrix elements measured by the GlueX experiment at photon energies of $E_{γ} = 8.2$ -- $8.8$ GeV and differential cross section data from SLAC. By including SDME data, the fit constrains not only the magnitudes but also the relative phases of the helicity amplitudes. The results confirm the dominance of pion exchange at small momentum transfer, while natural parity exchanges become significant at larger $t$ . We analytically continue the $s$ -channel amplitude to the $t$ -channel, taking care of the kinematical singularities, and isolate the dynamical residues at the meson poles. The extracted $π N Δ$ coupling constant is found to be consistent with the value obtained from the decay width of the $Δ (1232)$ . For the $ρN Δ$ , $b_{1} N Δ$ , and $a_{2} N Δ$ vertices, first extractions of the relevant coupling constants are provided.
Comments:
19 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2604.22719 [pdf]
2 citations

Affiliations

first authorsco-authorsvia INSPIRE

Gradient-Produced Neutrinos

Hydrodynamics and Energy Correlators

Confronting Color Glass Condensate at next-to-leading order with HERA data

The Effect of Mass Loss and Convective Overshooting on the Pre-Collapse Structure, Composition, and Neutrino Emission of Red Supergiants

Dense Matter and Compact Stars in Strong Magnetic Fields

Mechanisms of high energy polarized photoproduction of π−Δ++

Affiliations

Mechanisms of high energy polarized photoproduction of $π^{-} Δ^{++}$