Nuclear Theory·nucl-th

Friday·July 12, 2024

8 papers—6 primary·2 cross-listed

01
[Submitted on 10 Jul 2024]
Radiative corrections to proton-proton fusion in pionless EFT
Evan Combes🇺🇸 · Emanuele Mereghetti🇺🇸 · Lucas Platter🇺🇸
We study the leading radiative correction to proton-proton fusion using the pionless effective field theory framework at leading order. We derive the relevant matrix elements and evaluate them using the method of regions. We benchmark the accuracy of our approximations by carrying out numerical computations of the full expressions. We show that the first order radiative corrections due to the exchange of a Coulomb photon between positron and proton-proton systems map onto the Sirlin function and the $O (α)$ contribution from the Fermi function. We furthermore find that the nuclear structure dependent radiative correction omitted in the previous analysis by Kurylov {\it et al} gives an up to 0.2~\% correction to the pp fusion S-factor with its size ultimately depending on a two-nucleon counterterm that renormalizes the axial two-body current $L_{1 A}$ .
Comments:
7 pages, 3 figures, additional four pages in supplemental material
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
2407.08015 [pdf]
PRC(2024)·5 citations
02
[Submitted on 11 Jul 2024]
Chiral dynamics in soft triaxial nuclei
Bo Li · Pengwei Zhao · Jie Meng
The chirality in soft triaxial nuclei is investigated for the first time with the time-dependent and tilted axis cranking covariant density functional theories on a three-dimensional space lattice in a microscopic and self-consistent way. Taking the puzzling chiral nucleus $^{106}$ Ag as an example, the experimental energies of the observed nearly degenerate bands are well reproduced without any free parameters beyond the well-defined density functional. A novel chiral mode in soft triaxial nuclei is newly revealed from the microscopic dynamics of the total angular momentum. This opens a new research area for the study of chirality, particularly in relation to soft nuclear shapes.
Comments:
6 pages, 4 figures. arXiv admin note: text overlap with arXiv:2202.03043
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2407.08210 [pdf]
PLB(2024)·8 citations
03
[Submitted on 11 Jul 2024]
Contact operators in renormalization of attractive singular potentials
Rui Peng🇨🇳 · Bingwei Long🇨🇳 · Fu-Rong Xu🇨🇳
We discuss renormalization of chiral nuclear forces in the 3P0 channel of N N scattering at next- to-next-to leading order (N2LO) if the one-pion exchange is treated nonperturbatively at leading order. The matrix elements of the subleading contact potentials become nearly dependent of each other for the so-called exceptional ultraviolet momentum cutoff, making it difficult to determine the strengths of those contact potentials from the empirical phase shifts, as reported in Ref. [1]. We argue that this issue can be resolved by adjusting the strategy by which the low-energy constants are deduced from the data, thus making those exceptional cutoffs amenable to chiral effective field theory.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2407.08342 [pdf]
PRC(2024)·16 citations
04
[Submitted on 11 Jul 2024]
Neutron star calculations with the phenomenological three-nucleon force
H. Moeini · G.H. Bordbar
In this work, we have studied the effect of three-nucleon interaction on the neutron stars structure. In our calculations, we have considered the neutron star matter as a beta-stable nuclear matter. We have put the results concerning the TBF effect in perspective against two-body results and other calculations of three-nucleon interactions, using the Urbana v14 potential and the parabolic approximation of the nuclear-matter energy for approximating the problem of asymmetric nuclear matter. As such, solving the Tolman-Oppenheimer-Volkoff equation, we have estimated bulk properties of neutron stars and investigated how the present calculations would agree with the expected dynamical-stability condition.
Comments:
18 pages, 7 figures, 2 tables
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
arXiv:
2407.08412 [pdf]
Eur.Phys.J.Plus(2024)·3 citations
05
[Submitted on 11 Jul 2024]
Calibrating global behaviour of equation of state by combining nuclear and astrophysics inputs in a machine learning approach
Sk Md Adil Imam · Prafulla Saxena · Tuhin Malik · N. K. Patra · B. K. Agrawal
We implemented symbolic regression techniques to identify suitable analytical functions that map various properties of neutron stars (NSs), obtained by solving the Tolman-Oppenheimer-Volkoff (TOV) equations, to a few key parameters of the equation of state (EoS). These symbolic regression models (SRMs) are then employed to perform Bayesian inference with a comprehensive dataset from nuclear physics experiments and astrophysical observations. The posterior distributions of EoS parameters obtained from Bayesian inference using SRMs closely match those obtained directly from the solutions of TOV equations. Our SRM-based approach is approximately 100 times faster, enabling efficient Bayesian analyses across different combinations of data to explore their sensitivity to various EoS parameters within a reasonably short time.
Subjects:
Nuclear Theory (nucl-th); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR); General Relativity and Quantum Cosmology (gr-qc)
arXiv:
2407.08553 [pdf]
PRD(2024)·9 citations
06
[Submitted on 11 Jul 2024]
A unitary coupled-channel three-body amplitude with pions and kaons
Yuchuan Feng🇺🇸 · Fernando Gil🇪🇸 · Michael Döring🇺🇸 · Raquel Molina🇪🇸 · Maxim Mai🇺🇸 · Vanamali Shastry🇺🇸 · Adam Szczepaniak🇺🇸
Three-body dynamics above threshold is required for the reliable extraction of many amplitudes and resonances from experiment and lattice QCD. The S-matrix principle of unitarity can be used to construct dynamical coupled-channel approaches in which three particles scatter off each other, re-arranging two-body subsystems by particle exchange. This paper reports the development of a three-body coupled-channel, amplitude including pions and kaons. The unequal-mass amplitude contains two-body S- and P-wave subsystems ("isobars") of all isospins, $I = 0, 1/2, 1, 3/2, 2$ , and it also allows for transitions within a given isobar. The $f_{0} (500) (" σ "), f_{0} (980), ρ (700), K_{0}^{*} (700) (" κ ")$ , and $K^{*} (892)$ resonances are included, apart from repulsive isobars. Different methods to evaluate the amplitude for physical momenta are discussed. Production amplitudes for $a_{1}$ quantum numbers are shown as a proof of principle for the numerical implementation.
Comments:
27 pages, 11 figures, version accepted for publication
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2407.08721 [pdf]
PRD(2024)·27 citations
07
[Submitted on 10 Jul 2024] (cross-list from hep-ph)
Towards an Interpretation of the First Measurements of Energy Correlators in the Quark-Gluon Plasma
Carlota Andres🇵🇹 · Fabio Dominguez🇪🇸 · Jack Holguin🇬🇧 · Cyrille Marquet🇫🇷 · Ian Moult🇺🇸
Energy correlators have recently been proposed as a class of jet substructure observables that directly link experimental measurements of the asymptotic energy flux with the field theoretic description of the underlying microscopic dynamics. This link holds particular promise in heavy-ion physics, where both experimental measurements and theoretical interpretations are inherently complex. With recent measurements of energy correlators in proton-proton collisions, the first measurement of these observables on inclusive jets in heavy-ion collisions underscores the importance of a theoretical understanding of their behavior in this complex environment. In this manuscript, we extend our previous calculations to account for several effects necessary for a qualitative understanding of the behavior of energy correlators on inclusive jets in heavy-ion collisions. Through a semi-analytic approach implemented in a hydrodynamically expanding quark-gluon plasma (QGP), we account for medium-induced radiation with leading broadening effects, selection biases arising from energy loss, and a description of the confinement transition. Our results represent a crucial first step towards interpreting the measurements of energy correlators on inclusive jets in heavy-ion collisions, which marks a significant milestone in connecting heavy-ion experiment and fundamental quantum field theory, in the quest to disentangle the microscopic dynamics of the QGP.
Comments:
25 pages, 7 figures, with one additional figure compared to v1, additional references added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2407.07936 [pdf]
JHEP(2025)·46 citations
08
[Submitted on 11 Jul 2024] (cross-list from physics.chem-ph)
Selected Configuration Interaction for Resonances
Yann Damour · Anthony Scemama · Fábris Kossoski · Pierre-François Loos
Electronic resonances are metastable states that can decay by electron loss. They are ubiquitous across various fields of science, such as chemistry, physics, and biology. However, current theoretical and computational models for resonances cannot yet rival the level of accuracy achieved by bound-state methodologies. Here, we generalize selected configuration interaction (SCI) to treat resonances using the complex absorbing potential (CAP) technique. By modifying the selection procedure and the extrapolation protocol of standard SCI, the resulting CAP-SCI method yields resonance positions and widths of full configuration interaction quality. Initial results for the shape resonances of \ce{N2-} and \ce{CO-} reveal the important effect of high-order correlation, which shifts the values obtained with CAP-augmented equation-of-motion coupled-cluster with singles and doubles by more than \SI{0.1}{\eV}. The present CAP-SCI approach represents a cornerstone in the development of highly-accurate methodologies for resonances.
Comments:
10 pages, 2 figures (supporting information available)
Subjects:
physics.chem-ph (physics.chem-ph); cond-mat.mtrl-sci (cond-mat.mtrl-sci); Nuclear Theory (nucl-th)
arXiv:
2407.08576 [pdf]
J.Phys.Chem.Lett.(2024)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE