Nuclear Theory·nucl-th

Thursday·November 30, 2023

8 papers—2 primary·6 cross-listed

01
Intertwined quantum phase transitions in odd-mass Nb isotopes
A. Leviatan🇮🇱 · N. Gavrielov🇫🇷 · F. Iachello🇺🇸
A detailed analysis of odd-mass Nb isotopes, in the framework of the interacting boson-fermion model with configuration mixing, discloses the effects of an abrupt crossing of states in normal and intruder configurations (Type~II QPT), on top of which superimposed a gradual evolution from spherical- to deformed-core shapes within the intruder configuration (Type~I QPT). The pronounced presence of both types of QPTs demonstrates, for the first time, the occurrence of intertwined QPTs in odd-mass nuclei.
nucl-thEPJ Web Conf.(2025)·0 citations
02
pynucastro 2.1: an update on the development of a python library for nuclear astrophysics
Alexander Smith Clark · Eric T. Johnson · Zhi Chen · Kiran Eiden · Michael Zingale · Brendan Boyd · Parker T. Johnson · Luis Rangel DaCosta
pynucastro is a python library that provides visualization and analyze techniques to classify, construct, and evaluate nuclear reaction rates and networks. It provides tools that allow users to determine the importance of each rate in the network, based on a specified list of thermodynamic properties. Additionally, pynucastro can output a network in C++ or python for use in simulation codes, include the AMReX-Astrophysics simulation suite. We describe the changes in pynucastro since the last major release, including new capabilities that allow users to generate reduced networks and thermodynamic tables for conditions in nuclear statistical equilibrium.
nucl-thastro-ph.IMastro-ph.SRnucl-exJ.Phys.Conf.Ser.(2024)·2 citations
03
Transverse Energy-Energy Correlators in the Color-Glass Condensate at the Electron-Ion Collider
Zhong-Bo Kang🇺🇸 · Jani Penttala🇺🇸 · Fanyi Zhao🇺🇸 · Yiyu Zhou🇺🇸
We investigate the transverse energy-energy correlators (TEEC) in the small- $x$ regime at the upcoming Electron-Ion Collider (EIC). Focusing on the back-to-back production of electron-hadron pairs in both $e p$ and $e A$ collisions, we establish a factorization theorem given in terms of the hard function, quark distributions, soft functions, and TEEC jet functions, where the gluon saturation effect is incorporated. Numerical results for TEEC in both $e p$ and $e A$ collisions are presented, together with the nuclear modification factor $R_{A}$ . Our analysis reveals that TEEC observables in deep inelastic scattering provide a valuable approach for probing gluon saturation phenomena. Our findings underscore the significance of measuring TEEC at the EIC, emphasizing its efficacy in advancing our understanding of gluon saturation and nuclear modifications in high-energy collisions.
↳ hep-phhep-exnucl-exnucl-thPRD(2024)·23 citations
04
Did a Kilonova Set Off in Our Galactic Backyard 3.5 Myr ago?
Leonardo Chiesa · Albino Perego · Federico Maria Guercilena
The recent detection of the live isotopes $^{60} Fe$ and $^{244} Pu$ in deep ocean sediments dating back to the past 3-4 Myr poses a serious challenge to the identification of their production site(s). While $^{60} Fe$ is usually attributed to standard core-collapse supernovae, actinides are r-process nucleosynthesis yields, which are believed to be synthesized in rare events, such as special classes of supernovae or binary mergers involving at least one neutron star. Previous works concluded that a single binary neutron star merger cannot explain the observed isotopic ratio. In this work, we consider a set of numerical simulations of binary neutron star mergers producing long-lived massive remnants expelling both dynamical and spiral-wave wind ejecta. The latter, due to a stronger neutrino irradiation, also produce iron-group elements. Assuming that large-scale mixing is inefficient before the fading of the kilonova remnant and that the spiral-wave wind is sustained over a 100-200 ms timescale, the ejecta emitted at mid-high latitudes provide a $^{244} Pu$ over $^{60} Fe$ ratio compatible with observations. The merger could have happened 80-150 pc away from the Earth and between 3.5 and 4.5 Myr ago. We also compute expected isotopic ratios for eight other live radioactive nuclides showing that the proposed binary neutron star merger scenario is distinguishable from other scenarios proposed in the literature.
↳ astro-ph.HEastro-ph.SRnucl-thphysics.geo-phApJL(2024)·7 citations
05
End-to-end complexity for simulating the Schwinger model on quantum computers
Kazuki Sakamoto🇯🇵 · Hayata Morisaki🇯🇵 · Junichi Haruna🇯🇵 · Etsuko Itou🇯🇵 · Keisuke Fujii🇯🇵 · Kosuke Mitarai🇯🇵
The Schwinger model is one of the simplest gauge theories. It is known that a topological term of the model leads to the infamous sign problem in the classical Monte Carlo method. In contrast to this, recently, quantum computing in Hamiltonian formalism has gained attention. In this work, we estimate the resources needed for quantum computers to compute physical quantities that are challenging to compute on classical computers. Specifically, we propose an efficient implementation of block-encoding of the Schwinger model Hamiltonian. Considering the structure of the Hamiltonian, this block-encoding with a normalization factor of $O (N^{3})$ can be implemented using $O (N + lo g^{2} (N / ε))$ T gates. As an end-to-end application, we compute the vacuum persistence amplitude. As a result, we found that for a system size $N = 128$ and an additive error $ε = 0.01$ , with an evolution time $t$ and a lattice spacing a satisfying $t /2 a = 10$ , the vacuum persistence amplitude can be calculated using about $1 0^{13}$ T gates. Our results provide insights into predictions about the performance of quantum computers in the FTQC and early FTQC era, clarifying the challenges in solving meaningful problems within a realistic timeframe.
↳ quant-phhep-lathep-thnucl-thQuantum(2024)·15 citations
06
Study on Lambda(1405) in the flavor SU(3) limit in the HAL QCD method
Kotaro Murakami🇯🇵 · Sinya Aoki🇯🇵
We study interactions between the S-wave octet pseudo-scalar (PS) meson and octet baryon in the flavor SU(3) limit using the HAL QCD method at the PS meson mass $m_{M} \approx 670 MeV$ . We focus on the singlet and two octet channels, where the poles corresponding to $Λ (1405)$ have been predicted in the chiral unitary model. For calculations with $Λ$ -baryon source operators with zero momentum, we employ the conventional stochastic calculation combined with the covariant-approximation averaging to calculate the all-to-all propagators. Due to a zero of the R-correlator (a kind of wave function), the leading order (LO) potential obtained by the single channel analysis has a singular point in all channels, which makes it difficult to obtain reliable binding energies. To overcome this problem, we take a linear combination of two octet R-correlators with a relative weight such that it does not cross zero, as two octet channels are suggested to couple to the same low-energy states with different weights. The potential calculated from such the linear combination shows strong attraction without singularities, though its shape depends on the relative weight. Our estimation for the binding energy in the octet channel is $E_{bind}^{8_{s (a)}} = 163 (7) (_{- 64}^{+ 16}) MeV$ , which is consistent with 156(8) MeV estimated from the two-point correlation function within errors.
↳ hep-lathep-phnucl-thPoS(2024)·4 citations
07
Ellipticity of dilepton production from a hot and magnetized hadronic medium
Rajkumar Mondal🇮🇳 · Nilanjan Chaudhuri🇮🇳 · Snigdha Ghosh🇮🇳 · Sourav Sarkar🇮🇳 · Pradip Roy🇮🇳
We study the azimuthal angle and transverse momentum dependence of dilepton production from hot and magnetized hadronic matter using $ρ^{0}$ -meson dominance. The thermomagnetic spectral function of the $ρ^{0}$ is evaluated using the real time method of thermal field theory and Schwinger proper-time formulation. A continuous spectrum is obtained in which there is sizeable Landau cut contributions in the low invariant mass region as a consequence of finite background field. The emission rate of the dileptons is found to be significantly anisotropic in this region and the later effectively increases with the strength of the background field. In addition, we also evaluate the elliptic flow parameter ( $v_{2}$ ) as a function of invariant mass for different values of magnetic field and temperature. We find that in low invariant mass region $v_{2}$ remains positive at lower values of $e B$ signifying that the production rate could be larger along the direction transverse to the background field. This behaviour is consistent with the angular dependence of dilepton production rate.
↳ hep-phnucl-thEPJA(2023)·7 citations
08
Baryon Transport in Color Flux Tubes
Scott Pratt🇺🇸
Color flux tubes are a standard perspective from which to understand stopping in high-energy collisions. Mechanisms for baryon transport and polarization within a tube are considered here, both in regards to the the transport of baryons from the target and projectile toward mid-rapidity, and in regards to the correlations of baryon-antibaryon pairs created in the tube. The roles of tube merging and gluon radiation with a tube are emphasized.
↳ hep-phnucl-thPRC(2024)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE