Nuclear Theory·nucl-th

Friday·July 26, 2024

13 papers—6 primary·7 cross-listed

07
On the sensitivity of nuclear clocks to new physics
Andrea Caputo🇨🇭 · Doron Gazit🇮🇱 · Hans-Werner Hammer🇩🇪 · Joachim Kopp🇨🇭 · Gil Paz🇺🇸 · Gilad Perez🇮🇱 · Konstantin Springmann🇮🇱
The recent demonstration of laser excitation of the $\approx 8$ eV isomeric state of Thorium-229 is a significant step towards a nuclear clock. The low excitation energy likely results from a cancellation between electromagnetic and strong contributions, which new physics can disrupt. In this Letter, we quantify the enhancement of a nuclear clock's sensitivity to new physics using a geometric model and a novel $d$ -wave halo model of the nucleus that reproduces measured differences between Thorium-229 states. We find likely enhancements of order $1 0^{4}$ while a worst case scenario with enhancement $≪ 1$ is unlikely.
↳ hep-phnucl-exnucl-thPRC(2025)·35 citations
08
Observability of dynamical tides in merging eccentric neutron star binaries
János Takátsy🇭🇺 · Bence Kocsis🇬🇧 · Péter Kovács🇭🇺
While dynamical tides only become relevant during the last couple of orbits for circular inspirals, orbital eccentricity can increase their impact during earlier phases of the inspiral by exciting tidal oscillations at each close encounter. We investigate the effect of dynamical tides on the orbital evolution of eccentric neutron star binaries using post-Newtonian numerical simulations and construct an analytic stochastic model that reproduces the numerical results. Our study reveals a strong dependence of dynamical tides on the pericenter distance, with the fractional energy transferred to dynamical tides over that dissipated in gravitational waves (GWs) exceeding $\sim 1%$ at separations $r_{p} ≲ 50$ km for large eccentricities. We demonstrate that the effect of dynamical tides on orbital evolution can manifest as a phase shift in the GW signal. We show that the signal-to-noise ratio of the GW phase shift can reach the detectability threshold of $8$ with a single aLIGO detector at design densitivity for eccentric neutron star binaries at a distance of $40$ Mpc. This requires a pericenter distance of $r_{p0} ≲ 68$ km ( $r_{p0} ≲ 76$ km) at binary formation with eccentricity close to $1$ for a reasonable tidal deformability and f-mode frequency of $500$ and $1.73$ kHz ( $700$ and $1.61$ kHz), respectively. The observation of the phase shift will enable measuring the f-mode frequency of neutron stars independently from their tidal deformability, providing significant insights into neutron star seismology and the properties of the equation of state. We also explore the potential of distinguishing between equal-radius and twin-star binaries, which could provide an opportunity to reveal strong first-order phase transitions in the nuclear equation of state.
↳ astro-ph.HEhep-phnucl-thPRD(2024)·7 citations
09
Incoherent diffractive production of jets in electron DIS off nuclei at high energy
Benjamin Rodriguez-Aguilar🇮🇹 · D.N. Triantafyllopoulos🇮🇹 · S.Y. Wei🇨🇳
We study incoherent diffractive production of two and three jets in electron-nucleus deep inelastic scattering (DIS) at small $x_{Bj}$ using the color dipole picture and the effective theory of the Color Glass Condensate (CGC). We consider color fluctuations in the CGC weight-function as the source of the nuclear break-up and the associated momentum transfer $∣ t ∣$ . We focus on the regime in which the two jets are almost back-to-back in transverse space and have transverse momenta $P_{⊥}$ much larger than both the momentum transfer and the saturation scale $Q_{s}$ . The cross section for producing such a hard dijet is parametrically dominated by large size fluctuations in the projectile wave-function that scatter strongly and for which a third, semi-hard, jet appears in the final state. The 2 + 1 jets cross section can be written in a factorized form in terms of incoherent quark and gluon diffractive transverse momentum distributions (DTMDs) when the third jet is explicit, or incoherent diffractive parton distribution functions (DPDFs) when the third jet is integrated over. We find that the DPDFs and the corresponding cross section saturate logarithmically when $∣ t ∣ ≪ Q_{s}^{2}$ , while they fall like $1/∣ t ∣^{2}$ in the regime $Q_{s}^{2} ≪ ∣ t ∣ ≪ P_{⊥}^{2}$ . We further show that there is no angular correlation between the hard jet momentum and the momentum transfer. For typical EIC kinematics the 2 jets and 2 + 1 jets cross sections are of the same order.
↳ hep-phnucl-thPRD(2024)·7 citations
10
Net-proton fluctuations influenced by baryon stopping and quark deconfinement
Oleh Savchuk🇺🇸
Preliminary data from the Beam-Energy Scan II measurements by the STAR Collaboration at the Relativistic Heavy Ion Collider suggest a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy. At the same energy range where the structure appears, a transition from hadrons to quarks is expected, the deconfinement transition. In this paper, the role of quark deconfinement in establishing fluctuaitions in the early stages of the collision is considered. Two models are compared: one with stopping occurring on a baryon-by-baryon basis, and a second where stopping proceeds through quark degrees of freedom. In the latter model, the fluctuation of baryon number is significantly reduced and this signal is found to survive recombination into hadrons and the subsequent diffusion. The transformation from baryon to quark stopping thus produces a dip in the fourth-to-second-order cumulant ratio when plotted vs. beam energy, consistent with observations.
↳ hep-phnucl-thPRC(2025)·6 citations
11
Aspects of Rotating Anisotropic Dark Energy Stars
O. P. Jyothilakshmi · Lakshmi J. Naik · V. Sreekanth
By employing modified Chaplygin fluid prescription for the dark energy, we construct slowly rotating isotropic and anisotropic dark energy stars. The slow rotation is incorporated via general relativistic Hartle-Thorne formalism; whereas the anisotropy is introduced through Bowers-Liang prescription. We consider both the monopole and quadrupole deformations and present a complete analysis of rotating dark energy stars. By numerically solving the rotating stellar structure equations in presence of anisotropy, we analyse and quantify various properties of dark energy stars such as mass ( $M$ ), radius, mass deformation, angular momentum ( $J$ ), moment of inertia, and quadrupole moment ( $Q$ ), for three different equation of state parameters. We find that anisotropic slow rotation results in significant deformation of stellar mass and thereby affects other global properties studied. For the values of angular frequencies considered, the effect of anisotropy on the stellar structure is found to be more prominent than that due to rotation. The dimensionless quadrupole moment $QM / J^{2}$ measuring deviation from a Kerr metric black hole was obtained for anisotropic dark energy stars. We observe that dark energy stars with higher anisotropic strength tend to approach the Kerr solution more closely. We report that our results have considerable agreement with various astrophysical observational measurements.
↳ gr-qcastro-ph.HEnucl-thEPJC(2024)·3 citations
12
Effects of Final State Interactions on Landau Singularities
Ajay S. Sakthivasan🇩🇪 · Maxim Mai🇩🇪 · Akaki Rusetsky🇩🇪 · Michael Döring🇺🇸
In certain kinematic and particle mass configurations, triangle singularities may lead to line-shapes which mimic the effects of resonances. This well-known effect is scrutinized here in the presence of final-state rescattering. The goal is achieved first by utilizing general arguments provided by Landau equations, and second by applying a modern scattering formalism with explicit two- and three-body unitarity.
↳ hep-phhep-exhep-latnucl-thJHEP(2024)·16 citations
13
Tunneling time in coupled-channel systems
Peng Guo · Vladimir Gasparian · Antonio Pérez-Garrido · Esther Jódar
In present work, we present a couple-channel formalism for the description of tunneling time of a quantum particle through a composite compound with multiple energy levels or a complex structure that can be reduced to a quasi-one-dimensional multiple-channel system.
↳ cond-mat.othernucl-thquant-phPRResearch(2024)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE

On the sensitivity of nuclear clocks to new physics

Observability of dynamical tides in merging eccentric neutron star binaries

Incoherent diffractive production of jets in electron DIS off nuclei at high energy

Net-proton fluctuations influenced by baryon stopping and quark deconfinement

Aspects of Rotating Anisotropic Dark Energy Stars

Effects of Final State Interactions on Landau Singularities

Tunneling time in coupled-channel systems

Affiliations