Nuclear Theory·nucl-th

Wednesday·July 22, 2026

14 papers—7 primary·7 cross-listed

08
[Submitted on 17 Jul 2026] (cross-list from hep-ph)
Zero of the proton electric form factor in the finite value of the spacelike momentum transfer squared
Erik Bartoš🇸🇰 · Stanislav Dubnička🇸🇰 · Noel Vincze🇸🇰 · Andrej Liptaj🇸🇰 · Anna Zuzana Dubničková🇸🇰
The behavior of the polarization data on $μ_{p} (G_{E}^{p} (t) / G_{M}^{p} (t))$ ratio, at the present day available up to $t = - 8.5$ GeV $^{2}$ , obtained in the Jefferson Lab experiments carried out by the Akhiezer-Rekalo polarization method, has a decreasing tendency, indicating possible existence of a zero of the proton electric form factor $G_{E}^{p} (t)$ in the finite spacelike momentum transfer squared value. However, recently appeared two papers, investigating these data, one of them including also other existing data on the nucleon electromagnetic structure in the spacelike and timelike regions, in which an existence of such zero is disproved. Nevertheless, reinvestigations we provide in this paper give clear arguments for the possible existence of such a zero.
Comments:
15 pages, 1 figure, 2 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2607.18307 [pdf]
0 citations
09
[Submitted on 19 Jul 2026] (cross-list from quant-ph)
A First Bound on the Moffat Energy and Thorium-229 Clock as a Probe of the Nonlocal Time-Energy Structure and a Proposed Experiment for the use of Nuclear Entanglement and Squeezed States to Test Nonlocal Quantum Field Theory
E. J. Thompson🇨🇦 · Arvin Kouroshnia🇨🇦 · J. W. Moffat🇨🇦 · C. Chyrak🇨🇦 · G. Gervais🇨🇦 · H. A. Carteret🇨🇦
In this paper we derive the nonlocal Time-Energy uncertainty principle and then apply the published $^{229}$ Th nuclear clock data as a first probe of the nonlocality scale $E_M$. By using the direct clock-energy channel, we find conservative lower bounds on $E_M$ at the tens of MeV scale, with optimistic present-data estimates reaching the hundred MeV scale. Including the known nuclear sensitivity enhancement of the $^{229}$ Th transition gives us stronger model dependent bounds in the GeV range, while nuclear-scale reference-energy scenarios can reach the TeV range. The conclusion we draw from this is that nuclear clocks already provide an experimental route from nonlocal time--energy uncertainty to measurable laboratory bounds on non-Planckian nonlocality. We explore the idea of using a squeezed-state experiment with the $^{229} Th$ nuclear clock to test the time--energy structure of nonlocal quantum field theory. The idea is reasonably obtainable within the near future of nuclear clock experiments. One would prepare an ensemble of thorium nuclei in a coherent superposition of the nuclear ground state and the low-lying isomeric clock state, entangle the participating nuclei through a collective interaction, and generate a family of spin-squeezed states with a tunable squeezing parameter $r$ . Then a phase-controlled analysis pulse will rotate the selected collective nuclear quadrature into a measurable ground-isomer population difference. Near a strongly polarized collective state the normalized operators $J_{y} / S$ and $J_{z} / S$ obey the same approximate canonical algebra as the phase and amplitude quadratures of a squeezed optical mode. We use this experiment to either probe or bound the nonlocal energy scale $E_{M}$ .
Comments:
45 pages, 1 figure. Fist paper is 17 pages, and the second paper is 28 pages
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2607.18333 [pdf]
1 citation
10
[Submitted on 20 Jul 2026] (cross-list from hep-ph)
Soft Gluon Wave Function and Evolution Operator in the CGC at Next-to-Leading Order
Ramkumar Radhakrishnan🇺🇸
We construct the soft gluon light cone wave function of a fast moving hadron and the associated unitary evolution operator $Ω$ up to $O (g^{2})$ in pure Yang Mills theory $(N_{f} = 0)$ , within the Color Glass Condensate (CGC) framework. Working in light cone gauge, we perform a Born Oppenheimer separation between fast valence and soft modes and implement the eikonal approximation, which allows $Ω$ to be written as a fully normal ordered series in soft gluon creation and annihilation operators. The expansion coefficients are functionals of the non-commuting valence color charge density operators $ρ$ . We fix the coefficients by using the unitarity and explicit diagrammatic calculations within light-cone perturbation theory (LCPT). As an application, we diagonalize the pure Yang Mills soft Hamiltonian through orders $g$ and $g^{2}$ and show that the off diagonal mixing elements between Fock sectors cancel leading to the coherent background field energy proportional to $ρ^{2}$ .
Comments:
v2: 57 pages, 1 figure. Added references ; v1: 57 pages, 1 figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2607.18373 [pdf]
0 citations
11
[Submitted on 20 Jul 2026] (cross-list from hep-th)
Viscoelastic and thermal response on nuclear pasta states at finite baryon density
Nicolás Grandi🇦🇷 · Scarlett Rebolledo🇺🇸 · Aldo Vera🇨🇱
We compute the viscoelastic and thermal response of non-homogeneous hadronic condensates at finite baryon density representing crystals of baryonic tubes and layers. We describe them using analytic solutions of the Skyrme model in $3 + 1$ dimensions as ground states for a perturbative approach. At low enough temperatures, the lowest-energy excitations are described by a free massless scalar field theory in $1 + 1$ dimensions. We apply the Green-Kubo formulas to such excitations to obtain the elasticity tensor and other response coefficients. The analytic results of our computations are compared with available results on the nuclear pasta phase.
Comments:
37 pages, 2 figures
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2607.18463 [pdf]
0 citations
12
[Submitted on 20 Jul 2026] (cross-list from hep-ex)
Ultra-peripheral Collisions
Jesus Guillermo Contreras🇨🇿 · Spencer Robert Klein🇺🇸
Photons in ultra-peripheral collisions of heavy ions (and protons) can be used for a variety of physics purposes - for studies of nuclear structure at low Bjorken $- x$ , as probes of beyond-standard-model physics at the highest possible photon energies, and to explore new regimes of quantum mechanics via interferometry between two photon sources that share no common origin. This review will present the origins of photons in ultra-peripheral collisions and discuss the important physics that is being done with these photons, with particular emphasis on those on the energy frontier for photon physics.
Comments:
Review, to appear in forthcoming "Encyclopedia of Nuclear Physics"
Subjects:
High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2607.18535 [pdf]
0 citations
13
[Submitted on 20 Jul 2026] (cross-list from hep-ph)
Transport phenomena and observables associated with viscous properties of an anisotropic hot QCD medium at finite baryon asymmetry
Shubhalaxmi Rath🇨🇱 · Nicolás A. Neill🇨🇱
We have studied the transport phenomena and observables associated with viscous properties of a baryon asymmetric hot QCD medium in the presence of a weak-momentum anisotropy arising due to the asymptotic expansion of the matter in the initial stages of ultrarelativistic heavy-ion collisions. This study facilitates the understanding of the sound attenuation in the medium through the Prandtl number, the nature of flow through the Reynolds number, fluid behavior through the specific shear viscosity, and conformal symmetry through the specific bulk viscosity for an anisotropic hot QCD medium at finite baryon asymmetry. We have determined the shear and bulk viscosities by solving the relativistic Boltzmann transport equation in the relaxation time approximation method. The interactions among partons are incorporated through their distribution functions within the quasiparticle model of hot QCD medium at finite temperature, anisotropy and baryon asymmetry. We have observed a decrease in the shear and bulk viscosities in the presence of expansion-induced anisotropy for baryonless scenario as well as for baryon asymmetric scenario. Conversely, these viscosities are larger in baryon asymmetric matter compared to their counterparts in baryonless matter. The impact of anisotropy on baryon asymmetric matter is observed to be as conspicuous as on baryonless matter. The above results are broadly attributed to the squeezing of the distribution function due to the momentum anisotropy generated by the asymptotic expansion of baryon asymmetric matter and the dispersion relations of partons in the presence of anisotropy. Additionally, the aforesaid observables are also significantly modulated by the expansion-induced anisotropy in the baryon asymmetric medium, indicating new predictions for the sound attenuation, flow characteristics, fluid behavior and conformal symmetry of the said medium.
Comments:
30 pages, 8 figures. arXiv admin note: text overlap with arXiv:2508.04934
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2607.18581 [pdf]
0 citations
14
[Submitted on 21 Jul 2026] (cross-list from hep-lat)
Resolving the $T_{cc}^{+}$ with $π$ Exchange from Lattice QCD
Nelson Pitanga Lachini🇬🇧 · Raúl A. Briceño🇺🇸
We revisit the lattice QCD description of the doubly charmed tetraquark $T_{cc}^{+}$ using a finite-volume scattering formalism that incorporates one-pion exchange nonperturbatively, thereby making the nearest left-hand cut explicit while respecting unitarity and analyticity. We simultaneously determine the $D D^{⋆} π$ coupling and the isoscalar $D D^{⋆}$ scattering amplitude by reanalyzing the previously computed finite-volume $D D^{⋆}$ spectrum below the $D^{⋆} D^{⋆}$ threshold, on lattices with pion mass $m_{π} \approx 391 MeV$ . We find that the inclusion of pion exchange changes the $T_{cc}^{+}$ from a real-valued to a complex-valued pole in the second sheet of the $J^{P} = 1^{+}$ , $D D^{⋆}$ amplitude below threshold. We further predict that the $T_{cc}^{+}$ pole will move closer to the real-energy axis as the pion mass approaches its physical value.
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2607.19009 [pdf]
1 citation

Affiliations

first authorsco-authorsvia INSPIRE

Zero of the proton electric form factor in the finite value of the spacelike momentum transfer squared

A First Bound on the Moffat Energy and Thorium-229 Clock as a Probe of the Nonlocal Time-Energy Structure and a Proposed Experiment for the use of Nuclear Entanglement and Squeezed States to Test Nonlocal Quantum Field Theory

Soft Gluon Wave Function and Evolution Operator in the CGC at Next-to-Leading Order

Viscoelastic and thermal response on nuclear pasta states at finite baryon density

Ultra-peripheral Collisions

Transport phenomena and observables associated with viscous properties of an anisotropic hot QCD medium at finite baryon asymmetry

Resolving the Tcc+​ with π Exchange from Lattice QCD

Affiliations

Resolving the $T_{cc}^{+}$ with $π$ Exchange from Lattice QCD