Nuclear Theory·nucl-th

Tuesday·March 11, 2025

17 papers—8 primary·9 cross-listed

01
Reconstructing jet anisotropies with cumulants
Tanner Mengel🇺🇸 · Niseem Magdy🇺🇸 · Ron Belmont🇺🇸 · Anthony Timmins🇺🇸 · Christine Nattrass🇺🇸
In relativistic heavy-ion collisions, where quark-gluon plasma forms, hadron production is anisotropic at both low and high transverse momentum, driven by flow dynamics and spatial anisotropies. To better understand these mechanisms, we use multi-particle correlations to reconstruct jet anisotropies. We simulate data using \textsc{TennGen}\xspace as a hydro-like background and combine it with \textsc{Pythia-8}\xspace generated jets, clustering them with the anti- $k_{t}$ \xspace algorithm. Jet anisotropies are unfolded using a Bayesian technique, ensuring the robustness of the reconstructed signals. Our results demonstrate that multi-particle cumulant methods can accurately capture the differential jet azimuthal anisotropies, providing crucial insights into high- $p_{T} \xspace$ behavior and the dynamics within heavy-ion collisions.
nucl-thnucl-exPRC(2025)·0 citations
02
Electron capture cross sections and nuclear partition functions for fp-shell nuclei
Jameel-Un Nabi · Muhammad Riaz
We present calculation of electron capture cross sections (ECC), in the limit of zero momentum transfer, using the pn QRPA model in stellar matter. Towards this aim we make use of our recently introduced recipe for estimation of nuclear partition functions. For low momentum transfer q tends to zero, the nuclear matrix elements of the P{\sigma}{\tau} plus operator provide the leading contribution to the total cross section which we estimate using the pn QRPA model in a multi shell single particle space with a schematic interaction. Key f p shell nuclei (odd A, even even and odd odd) bearing astrophysical importance were selected for the calculation of ECC in stellar environment. These f p shell nuclei play crucial role in pre supernova evolution of massive stars and core collapse. We further present microscopic calculation of ground and excited states Gamow Teller strength distributions and stellar electron capture rates on these suite of nuclei. We used two different sets of empirically determined pairing gaps to calculate the ECC and electron capture rates. Results are compared with experimental data and previous computations. Our calculated ECC are systematically smaller at low electron incident energies as compared to the shell model results.
nucl-thJ.Phys.G(2019)·11 citations
03
Phase transitions in the inner crust of neutron stars within the superfluid band theory: Competition between $^{1} S_{0}$ pairing and spin polarization under finite temperature and magnetic field
Kenta Yoshimura · Kazuyuki Sekizawa
Phase transitions of matter under changes of external environment such as temperature and magnetic field have attracted great interests to various quantum many-body systems. Several phase transitions must have occurred in neutron stars as well such as transitions from normal to superfluid/superconducting phases and crust formation. In this work, we extend the superfluid band theory, which has been formulated in our previous work [K. Yoshimura and K. Sekizawa, Phys. Rev. C 109, 065804 (2024)] based on the Kohn-Sham density functional theory (DFT) for superfluid systems, into the finite temperature and finite magnetic field systems. As a result of the finite temperature calculations, we find that the superfluidity of neutrons dissapears at around $k_{B} T = 0.6$ -- $0.9$ MeV, and ``melting'' of nuclear slabs, that is, a structural change into the uniform matter, takes place at around $k_{B} T = 2.5$ -- $4.5$ MeV. We also reveal that these transition temperatures exhibit a systematical dependence on the baryon densities. By turning on the magnetic field, we find that protons' spin gets polarized at around $B = 1 0^{16}$ G, whereas neutrons' spin is kept unpolarized on average up to around $B = 1 0^{17}$ G. Intriguingly, our microscopic calculations reveal that neutrons' spin is actually polarized locally inside and outside of the slab already at $B \sim 1 0^{16}$ G, while keeping the system unpolarized in total. As a conclusion, we have demonstrated validity and usefulness of the fully self-consistent superfluid nuclear band theory for describing neutron star matter under arbitrary temperature and magnetic field. Critical temperatures and magnetic fields have been predicted for 1) superfluid to normal transition, 2) crust formation, and 3) spin polarization, under conditions relevant to realistic neutron star environments.
nucl-thastro-ph.HEcond-mat.quant-gasPRC(2025)·4 citations
04
Quartet correlations near the surface of $N = Z$ nuclei
Yixin Guo · Tomoya Naito · Hiroyuki Tajima · Haozhao Liang
We theoretically investigate Cooper quartet correlations in $N = Z$ doubly-magic nuclei ( $^{40} Ca$ , $^{100} Sn$ , and $^{164} Pb$ ). We first examine the quartet condensation fraction in infinite symmetric nuclear matter by using the quartet Bardeen-Cooper-Schrieffer theory. Together with the total nucleon density profiles of doubly-magic nuclei obtained from the Skyrme Hartree-Fock calculation, we discuss the spatial distribution of quartet correlations in finite nuclei within the local density approximation. Large quartet condensate fractions are found at the surface region of an atomic nucleus due to the strong neutron-proton attractive interaction responsible for the deuteron formation in vacuum. Moreover, we discuss a possible microscopic origin of the Wigner term in the context of nucleon-quartet scattering in dilute symmetric nuclear matter. The nucleon-quartet scattering effect on the Wigner term is numerically estimated to be about one order of magnitude of the total empirical strength, indicating the importance of multinucleon clusters in the symmetry energy and mass formula in addition to the neutron-proton pairing.
nucl-thcond-mat.quant-gasphysics.atom-phPRC(2025)·4 citations
05
Microscopic Calculations of Stellar Weak Rates for sd- and fp-Shell Nuclei for Astrophysical Applications
Jameel-Un-Nabi · H. V. Klapdor-Kleingrothaus
Proton neutron quasiparticle RPA is used for the first time to calculate weak interaction rates for sd and fp shell nuclei at high temperatures and densities. The calculated rates take into consideration the latest experimental energy levels and ft value compilations. Particle emission processes from excited states are taken into account. The calculation is done for 700 nuclei with mass number ranging from 18 to 100. The astrophysical applications of the calculated rates are highlighted.
nucl-thActa Phys.Polon.B(1999)·3 citations
06
Effect of Nuclear Deformation on Electron Capture Cross-section on Chromium Isotopes
Asim Ullah · Jameel-Un Nabi · Muhammad Riaz
The electron capture plays significant role in the pre supernova and supernova evolutions of massive stars which in turn are of great importance in synthesizing heavy elements beyond iron. In this paper we study the effect of nuclear deformation on the computed electron capture cross section on selected even even chromium isotopes (464850Cr). The nuclear deformation parameters were computed using two different theoretical models: Interacting Boson Model (IBM 1) and Macroscopic (Yukawa plus exponential) microscopic (Folded Yukawa) model (Mac mic model). A third value of deformation parameter was adopted from experimental data. We chose the pn QRPA model to perform our calculations. The predictive power of the chosen model was first tested by calculating Gamow Teller (GT) strength distributions of selected fp shell nuclei where measured GT data was available. The calculated GT strength distributions were well fragmented over the energy range 0 12 MeV and were noted to be in decent agreement with experimental data. The total GT strength was found to increase (decrease) with decrease (increase) in the value of deformation parameter for the three chromium isotopes. The computed GT strength distributions satisfied the model independent Ikeda sum rule. The ECC were calculated as a function of the deformation parameter at core temperature 1.0 MeV. Our results show that the calculated ECC increased with increasing value of nuclear deformation.
nucl-thInt.J.Mod.Phys.D(2019)·1 citation
07
Bound state formation within the Lindblad approach
Jan Rais🇩🇪 · Hendrik van Hees🇩🇪 · Carsten Greiner🇩🇪
The Lindblad master equation is a frequently used Markovian approach to describe open quantum systems in terms of the temporal evolution of a reduced density matrix. Here, the thermal environment is traced out to obtain an expression to describe the evolution of what is called a system: one particle or a chain of interacting particles, which is/are surrounded by a thermal heat bath. In this work, we investigate the formation of non-relativistic bound states, involving the Pöschl-Teller potential, in order to discuss the formation time and the thermal equilibrium, applying scales from nuclear physics. This problem is borrowed from the field of heavy-ion collisions, where the deuteron is a probe which is measured at temperature regimes around the chemical freeze out temperature, while the deuteron itself has a binding energy which is much lower. This is known and often described as a ``snowball in hell". We use a reformulated Lindblad equation, in terms of a diffusion-advection equation with sources and therefore provide a hydrodynamical formulation of a dissipative quantum master equation.
nucl-thquant-ph0 citations
08
Role of the isovector spin-orbit potential in mitigating the CREX-PREX dilemma
Athul Kunjipurayil · Marc Salinas · J. Piekarewicz
Pioneering electroweak measurements of the neutron skin thickness in lead-208 and calcium-48 are challenging our understanding of nuclear dynamics. Many theoretical models suggest that the slope of the symmetry energy controls the development of a neutron skin in neutron-rich nuclei. This led to the expectation that if lead-208 exhibits a large neutron skin, calcium-48 should as well. Given that the PREX collaboration reported a relatively thick neutron skin in lead, we anticipated that calcium would also have a significant neutron skin. Instead, the CREX collaboration reported a thin neutron skin in calcium. Although many suggestions have been proposed, the ``CREX-PREX dilemma" remains unsolved. Recently, an intriguing scenario has emerged, suggesting that an enhanced isovector spin-orbit interaction could simultaneously account for both results. Following this approach, we performed relativistic mean-field calculations with an increased isovector spin-orbit potential. Our findings indicate that while this modification significantly affects the structure of calcium-48, it has only a marginal impact on lead-208, thereby bringing the results into better agreement with experiment. However, the strong enhancement required to mitigate the CREX-PREX dilemma destroys the agreement with a successful spin-orbit phenomenology, primarily by modifying the well-known ordering of spin-orbit partners.
nucl-thnucl-exPRC(2025)·15 citations
09
Quantum energies of solitons with different topological charges
N. Graham🇺🇸 · H. Weigel🇿🇦
The vacuum polarization energy is the leading quantum correction to the classical energy of a soliton. We study this energy for two-component solitons in one space dimension as a function of the soliton's topological charge. We find that both the classical and the vacuum polarization energies are linear functions of the topological charge with a small offset. Because the combination of the classical and quantum offsets determines the binding energies, either all higher charge solitons are energetically bound or they are all unbound, depending on model parameters. This linearity persists even when the field configurations are very different from those of isolated solitons, and would not be apparent from an analysis of their bound state spectra alone.
↳ hep-thhep-phnucl-thPRD(2025)·1 citation
10
Study of deeply virtual Compton scattering at the future Electron-Ion Collider
Elke-Caroline Aschenauer🇺🇸 · Varvara Batozskaya🇵🇱 · Salvatore Fazio🇮🇹 · Alexander Jentsch🇺🇸 · Jihee Kim🇺🇸 · Krešimir Kumerički🇭🇷 · Herve Moutarde🇫🇷 · Kornelija Passek-K.🇭🇷 · Daria Sokhan🇬🇧 · Hubert Spiesberger🇩🇪 · Paweł Sznajder🇵🇱 · Kemal Tezgin🇺🇸
This study presents the impact of future measurements of deeply virtual Compton scattering (DVCS) with the ePIC detector at the electron-ion collider (EIC), currently under construction at Brookhaven National Laboratory. The considered process is sensitive to generalized parton distributions (GPDs), the understanding of which is a cornerstone of the EIC physics programme. Our study marks a milestone in the preparation of DVCS measurements at EIC and provides a reference point for future analyses. In addition to presenting distributions of basic kinematic variables obtained with the latest ePIC design and simulation software, we examine the impact of future measurements on the understanding of nucleon tomography and DVCS Compton form factors, which are directly linked to GPDs. We also assess the impact of radiative corrections and background contribution arising from exclusive $π^{0}$ production.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·10 citations
11
Hadron Structure: Perspective and Insights
Daniele Binosi🇨🇳 · Craig D. Roberts🇨🇳 · Zhao-Qian Yao🇨🇳
The bulk of visible mass is supposed to emerge from nonperturbative dynamics within quantum chromodynamics (QCD) -- the strong interaction sector of the Standard Model. Following years of development and refinement, continuum and lattice Schwinger function methods have recently joined in revealing the three pillars that support this emergent hadron mass (EHM); namely, a nonzero gluon mass-scale, a process-independent effective charge, and dressed-quarks with constituent-like masses. One may argue that EHM and confinement are inextricably linked; and theory is now working to expose their manifold expressions in hadron observables and highlight the types of measurements that can be made in order to validate the paradigm. This contribution sketches the role played by EHM in shaping hadron electromagnetic and gravitational form factors, exciting nucleon resonances, and moulding hadron parton distributions.
↳ hep-phhep-exhep-latnucl-ex+1PoS(2025)·5 citations
12
Transport and response coefficients in second-order dissipative relativistic hydrodynamics with quantum corrections: probing the quark-gluon plasma
I. Kuntz🇧🇷 · R. da Rocha🇧🇷
A functional measure encompasses quantum corrections and is explored in the fluid/gravity correspondence. Corrections to response and transport coefficients in the second-order dissipative relativistic hydrodynamics are proposed, including the ones to the pressure, the relaxation time, and the shear relaxation. Their dependence on the quark-gluon plasma (QGP) temperature sets a temperature dependence on the running parameter encoding the one-loop quantum gravity correction, driven by a functional measure. The experimental range of the bulk viscosity-to-entropy density ratio of the QGP corroborates the existence of the functional measure.
↳ hep-thnucl-thEntropy(2025)·0 citations
13
Revisiting interpolating flows in $(1 + 1)$ hydrodynamics
Aritra Banerjee🇮🇳 · Abir Ghosh🇮🇳
We revisit the general analytic solution space for relativistic $(1 + 1)$ -dimensional hydrodynamics for a perfect fluid flowing along the longitudinal direction. We work out the explicit one-parameter family of interpolating flows between boost-invariant and boost-non-invariant regimes, where a direct and simple dialing of the parameter at the level of solutions is possible. We also discuss the construction of generalised rapidity distribution of entropy for such interpolating flows at the level of potentials.
↳ hep-thhep-phnucl-thPRD(2025)·0 citations
14
Non-hermitian Green's function theory with $N$ -body interactions: the coupled-cluster similarity transformation
Christopher J. N. Coveney · David P. Tew
We present the diagrammatic theory of the irreducible self-energy and Bethe-Salpeter kernel that naturally arises within the Green's function formalism for a general $N$ -body non-hermitian interaction. In this work, we focus specifically on the coupled-cluster self-energy generated by the similarity transformation of the electronic structure Hamiltonian. We develop the biorthogonal quantum theory to construct dynamical correlation functions where the time-dependence of operators is governed by a non-hermitian Hamiltonian. We extend the Gell-Mann and Low theorem to include non-hermitian interactions and to generate perturbative expansions of many-body Green's functions. We introduce the single-particle coupled-cluster Green's function and derive the perturbative diagrammatic expansion for the non-hermitian coupled-cluster self-energy in terms of the `non-interacting' reference Green's function, $Σ ~ [G_{0}]$ . From the exact equation-of-motion of the single-particle coupled-cluster Green's function, we derive the self-consistent renormalized coupled-cluster self-energy, $Σ ~ [G ~]$ , and demonstrate its relationship to the perturbative expansion of the self-energy, $Σ ~ [G_{0}]$ . Subsequently, we show that the usual electronic self-energy can be recovered from the coupled-cluster self-energy by neglecting the effects of the similarity transformation. We show how the coupled-cluster ground state energy can be obtained from the coupled-cluster self-energy and provide an overview of the relationship between approximations for the coupled-cluster self-energy, IP/EA-EOM-CC and the $G_{0} W_{0}$ approximation. As a result, we introduce the CC- $G_{0} W_{0}$ self-energy by leveraging the connections between Green's function and coupled-cluster theory. Finally, we derive the diagrammatic expansion of the coupled-cluster Bethe-Salpeter kernel.
↳ cond-mat.str-elcond-mat.mtrl-scinucl-thphysics.chem-ph+1PRResearch(2026)·5 citations
15
Quasi-Classical Approximation of Electromagnetic Radiation by Fermions embedded in Rigidly Rotating Medium in Strong Magnetic Field
Matteo Buzzegoli🇷🇴 · Kirill Tuchin🇺🇸 · Nandagopal Vijayakumar🇺🇸
We develop the quasi-classical (WKB) approximation of the synchrotron radiation by a fermion embedded into uniformly rotating system in external magnetic field. We show that it gives an accurate approximation of the exact expression that we recently obtained at a tiny fraction of the numerical cost. Our results can be used to compute the electromagnetic radiation of the quark-gluon plasma produced in relativistic heavy-ion collisions.
↳ hep-phhep-thnucl-thPRC(2025)·5 citations
16
Novel concept for low-energy antineutron production and its application for antineutron scattering experiments
Alessandra Filippi🇮🇹 · Hiroyuki Fujioka🇯🇵 · Takashi Higuchi🇯🇵 · Luca Venturelli🇮🇹
Extensive data of antiproton scattering cross sections with protons and nuclei have advanced our understanding of hadronic interactions with antinucleons. However, low-energy antineutron scattering data are scarce, thereby limiting our understanding of the S-wave antinucleon-nucleon and antinucleon-nucleus interactions. We present a novel production scheme of extremely low-energy antineutrons that could remedy this situation. This method is based on backward charge-exchange reaction ( $p p ˉ \to n n ˉ$ ), and can reach the lowest momentum of 9 MeV/c, which would be well suited to study of the S-wave antinucleon-nucleon or antinucleon-nucleus interactions.
↳ nucl-exhep-exnucl-thphysics.ins-det5 citations
17
Parton distribution functions of ground state mesons composed of $c$ or $b$ quarks
Qian Wu🇨🇳 · Zhu-Fang Cui🇨🇳 · Jorge Segovia🇪🇸
The valence quark parton distribution functions (PDFs) of all ground state heavy mesons that composed of $b$ or $c$ quarks, are discussed; namely, the pseudoscalar $η_{c} (1 S)$ , $η_{b} (1 S)$ and $B_{c}$ , together with the corresponding vector ones, $J / ψ$ , $Υ (1 S)$ and $B_{c}^{*}$ . We use a QCD-inspired constituent quark model, which has been applied with success to conventional heavy mesons, so that one advantage here is that all parameters have already been fixed by previous studies. The wave functions of the heavy mesons in the rest frame are obtained by solving the Schrödinger equation, then boosted to its light-front based on Susskind's Lorentz transformation. The PDFs at the hadron scale, are then obtained by integrating out the transverse momenta of the modulus square of the light-front wave function. Our study shows how the valence quark distributions differ between pseudoscalar and vector mesons, as well as among charmonia, bottomonia and bottom-charmed mesons. Comparisons with other theoretical calculations demonstrate that the PDFs obtained herein are in general narrower but align well with the expected patterns. Moreover, each PDF's point-wise behavior is squeezed with respect to the scale-free parton-like PDF.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE