Nuclear Theory·nucl-th

Friday·May 20, 2022

6 papers—3 primary·3 cross-listed

04
[Submitted on 18 May 2022] (cross-list from hep-lat)
Schwinger model at finite temperature and density with beta VQE
Akio Tomiya🇯🇵
We investigate a quantum gauge theory at finite temperature and density using a variational algorithm for near-term quantum devices. We adapt $β$ -VQE to evaluate thermal and quantum expectation values and study the phase diagram for massless Schwinger model along with the temperature and density. By compering the exact variational free energy, we find the variational algorithm work for $T > 0$ and $μ > 0$ for the Schwinger model. No significant volume dependence of the variational free energy is observed in $μ / g \in [0, 1.4]$ . We calculate the chiral condensate and take the continuum extrapolation. As a result, we obtain qualitative picture of the phase diagram for massless Schwinger model.
Comments:
9 pages, 11 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2205.08860 [pdf]
16 citations
05
[Submitted on 19 May 2022] (cross-list from hep-ph)
Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics
M. Atzori Corona🇮🇹 · M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · F. Dordei🇮🇹 · C. Giunti🇮🇹 · Y.F. Li🇨🇳 · C. A. Ternes🇮🇹 · Y.Y. Zhang🇨🇳
Coherent elastic neutrino-nucleus scattering (CE $ν$ NS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CE $ν$ NS-related limits on the neutrino electric charge and magnetic moment.
Comments:
Matches the published version. 33 pages, 11 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2205.09484 [pdf]
JHEP(2022)·81 citations
06
[Submitted on 19 May 2022] (cross-list from nucl-ex)
Feasibility of studying astrophysically important charged-particle emission with the variable energy $γ$ -ray system at the Extreme Light Infrastructure -- Nuclear Physics facility
H.Y. Lan · W. Luo · Y. Xu · D.L. Balabanski · G.L. Guardo · M. La Cognata · D. Lattuada · C. Matei · R.G. Pizzone · T. Rauscher · J.L. Zhou
In the environment of a hot plasma, as achieved in stellar explosions, capture and photodisintegration reactions proceeding on excited states in the nucleus can considerably contribute to the astrophysical reaction rate. Such reaction rates including the excited-state contribution are obtained from theoretical calculations as the direct experimental determination of these astrophysical rates is currently unfeasible. In the present study, ( $γ$ ,p) and ( $γ$ , $α$ ) reactions in the mass and energy range relevant to the astrophysical $p$ process are considered and the feasibility of measuring them with the ELISSA detector system at the future Variable Energy $γ$ -ray (VEGA) facility at ELI-NP is investigated. The simulation results reveal that, for the ( $γ$ ,p) reaction on twelve targets of $^{29}$ Si, $^{56}$ Fe, $^{74}$ Se, $^{84}$ Sr, $^{91}$ Zr, $^{96, 98}$ Ru, $^{102}$ Pd, $^{106}$ Cd, and $^{115, 117, 119}$ Sn, and the ( $γ$ , $α$ ) reaction on five targets of $^{50}$ V, $^{87}$ Sr, $^{123, 125}$ Te, and $^{149}$ Sm, the yields of the reaction channels with the transitions to the excited states in the residual nucleus are relevant and even dominant. It is further found that for each considered reaction, the total yields of the charged-particle $X$ may be dominantly contributed from one, two or three ( $γ$ , $X_{i}$ ) channels within a specific, narrow energy range of the incident $γ$ -beam. Furthermore, the energy spectra of the ( $γ$ , $X_{i}$ ) channels with $0 \leq i \leq 10$ are simulated for each considered reaction, with the incident $γ$ -beam energies in the respective energy range as derived before. It becomes evident that measurements of the photon-induced reactions with charged-particle emissions considered in this work are feasible with the VEGA+ELISSA system and will provide knowledge useful for nuclear astrophysics.
Comments:
11 figures, 17 pages
Subjects:
Nuclear Experiment (nucl-ex); Instrumentation and Methods for Astrophysics (astro-ph.IM); Nuclear Theory (nucl-th)
arXiv:
2205.09599 [pdf]
PRC(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE

Schwinger model at finite temperature and density with beta VQE

Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics

Feasibility of studying astrophysically important charged-particle emission with the variable energy γ-ray system at the Extreme Light Infrastructure -- Nuclear Physics facility

Affiliations

Feasibility of studying astrophysically important charged-particle emission with the variable energy $γ$ -ray system at the Extreme Light Infrastructure -- Nuclear Physics facility