Nuclear Theory·nucl-th

Monday·October 21, 2024

7 papers—2 primary·5 cross-listed

03
Neutron-proton pairing in the unstable N=Z nuclei of the f-shell through two-nucleon transfer reactions
M. Assié🇫🇷 · H. Jacob🇫🇷 · Y. Blumenfeld🇫🇷 · V. Girard-Alcindor🇫🇷
Pair transfer is a unique tool to study pairing correlations in nuclei. Neutron-proton pairing is investigated in the N=Z nuclei of the f-shell, through the reaction (p,3He) in inverse kinematics, that allows to populate at the same time the lowest J=0+, T=1 (isovector pairing) state and J=1+, T=0 (isoscalar pairing) state. Radioactive beams of 56Ni and 52Fe produced by fragmentation at the GANIL/LISE facility combined with particle and gamma-ray detection make it possible to carry out this study from 48Cr (mid-shell nucleus) to 56Ni (doubly-magic nucleus). The cross-sections were extracted and compared with second-order distorted-wave born approximation (DWBA) calculations performed with neutron-proton amplitudes obtained from shell model calculations with GXPF1 interaction. Very low cross-sections for the J=1+,T=0 state (isoscalar channel) were observed. The cross-section for 56Ni is one of order of magnitude lower than for 40Ca showing a strong reduction of the isoscalar channel in the f-shell as compared to the sd-shell. On the other hand, the increase of the cross-section towards the middle of the shell for the isovector channel points towards a possible superfluid phase.
↳ nucl-exnucl-thEPJ Web Conf.(2024)·2 citations
04
Nature of X(3872) from recent BESIII data: Considering the universal feature of an S-wave threshold resonance
Xian-Wei Kang🇨🇳 · Jin-Zhe Zhang🇨🇳 · Xin-Heng Guo🇨🇳
We analyze the recent data from the BESIII collaboration on the $X (3872)$ state in the $J / ψ π^{+} π^{-}$ and $D^{0} D ˉ^{0} π^{0}$ decay channels. The quantum number and mass of the $X (3872)$ state allow us to exploit the universal feature of the very near-threshold $D D ˉ^{*}$ scattering in the $S$ wave. The analysis of $J / ψ π^{+} π^{-}$ data and $D^{0} D ˉ^{0} π^{0}$ data separately as well as the combined analysis of these data together, all support the conclusion that $X (3872)$ is an extremely weakly bound charm meson molecule.
↳ hep-phhep-exnucl-thCPC(2025)·3 citations
05
Constraining a relativistic mean field model using neutron star mass-radius measurements II: Hyperonic models
Chun Huang🇺🇸 · Laura Tolos🇪🇸 · Constança Providência🇵🇹 · Anna Watts🇳🇱
We investigate whether measurements of the neutron star mass and radius or the tidal deformability can provide information about the presence of hyperons inside a neutron star. This is achieved by considering two inference models, with and without hyperons, based on a field-theoretical approach. While current observations do not distinguish between the two scenarios, we have shown that data simulating expected observations from future large area X-ray timing telescopes could provide some information through Bayes factors. Inference using simulated data generated from an EOS containing hyperons decisively favours the hyperonic model over the nucleonic model. However, a 2\% uncertainty in the mass and radius determination may not be sufficient to constrain the parameters of the model when only six neutron star mass-radius measurements are considered.
↳ astro-ph.HEastro-ph.SRnucl-thMNRAS(2025)·40 citations
06
Quantum computation of SU(2) lattice gauge theory with continuous variables
Victor Ale🇺🇸 · Nora M. Bauer🇺🇸 · Raghav G. Jha🇺🇸 · Felix Ringer🇺🇸 · George Siopsis🇺🇸
We present a quantum computational framework for SU(2) lattice gauge theory, leveraging continuous variables instead of discrete qubits to represent the infinite-dimensional Hilbert space of the gauge fields. We consider a ladder as well as a two-dimensional grid of plaquettes, detailing the use of gauge fixing to reduce the degrees of freedom and simplify the Hamiltonian. We demonstrate how the system dynamics, ground states, and energy gaps can be computed using the continuous-variable approach to quantum computing. Our results indicate that it is feasible to study non-Abelian gauge theories with continuous variables, providing new avenues for understanding the real-time dynamics of quantum field theories.
↳ hep-lathep-thnucl-thquant-phJHEP(2025)·19 citations
07
The interplay of astrophysics and nuclear physics in determining the properties of neutron stars
Jacob Golomb · Isaac Legred · Katerina Chatziioannou · Philippe Landry
Neutron star properties depend on both nuclear physics and astrophysical processes, and thus observations of neutron stars offer constraints on both large-scale astrophysics and the behavior of cold, dense matter. In this study, we use astronomical data to jointly infer the universal equation of state of dense matter along with two distinct astrophysical populations: Galactic neutron stars observed electromagnetically and merging neutron stars in binaries observed with gravitational waves. We place constraints on neutron star properties and quantify the extent to which they are attributable to macrophysics or microphysics. We confirm previous results indicating that the Galactic and merging neutron stars have distinct mass distributions. The inferred maximum mass of both Galactic neutron stars, $M_{pop, EM} = 2.0 5_{- 0.06}^{+ 0.11} M_{⊙}$ (median and 90\% symmetric credible interval), and merging neutron star binaries, $M_{pop, GW} = 1.8 5_{- 0.16}^{+ 0.39} M_{⊙}$ , are consistent with the maximum mass of nonrotating neutron stars set by nuclear physics, $M_{TOV} = 2.2 8_{- 0.21}^{+ 0.41} M_{⊙}$ . The radius of a $1.4 M_{⊙}$ neutron star is $12. 2_{- 0.9}^{+ 0.8}$ km, consistent with, though $\sim 20%$ tighter than, previous results using an identical equation of state model. Even though observed Galactic and merging neutron stars originate from populations with distinct properties, there is currently no evidence that astrophysical processes cannot produce neutron stars up to the maximum value imposed by nuclear physics.
↳ astro-ph.HEnucl-thPRD(2025)·24 citations

Affiliations

first authorsco-authorsvia INSPIRE

Neutron-proton pairing in the unstable N=Z nuclei of the f-shell through two-nucleon transfer reactions

Nature of X(3872) from recent BESIII data: Considering the universal feature of an S-wave threshold resonance

Constraining a relativistic mean field model using neutron star mass-radius measurements II: Hyperonic models

Quantum computation of SU(2) lattice gauge theory with continuous variables

The interplay of astrophysics and nuclear physics in determining the properties of neutron stars

Affiliations