Nuclear Theory·nucl-th

Monday·July 18, 2022

9 papers—4 primary·5 cross-listed

05
[Submitted on 14 Jul 2022] (cross-list from hep-ph)
Jet Broadening in Flowing Matter -- Resummation
Carlota Andres🇫🇷 · Fabio Dominguez🇪🇸 · Andrey V. Sadofyev🇪🇸 · Carlos A. Salgado🇪🇸
In this work, we obtain the leading corrections to the jet momentum broadening distribution in a QCD medium arising from the transverse flow of the matter. We first derive the single-particle propagator of a highly energetic parton resumming its multiple interactions with the homogeneous flowing matter, explicitly keeping the leading subeikonal flow terms. Then, we use this propagator to obtain the jet broadening distribution and its leading moments. We show that this distribution becomes anisotropic in the presence of transverse flow, since its odd moments are generally non-zero and proportional to the transverse velocity of the medium. Finally, we evaluate several odd moments, which we compare to the corresponding results at first order in opacity, showing that accounting for multiple in-medium scatterings is essential to describe some observables in dense nuclear matter.
Comments:
29 pages, 2 figures, v2: journal version, references added
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.07141 [pdf]
PRD(2022)·51 citations
06
[Submitted on 15 Jul 2022] (cross-list from astro-ph.HE)
Impact of systematic nuclear uncertainties on composition and decay heat of dynamical and disk ejecta in compact binary mergers
I. Kullmann · S. Goriely · O. Just · A. Bauswein · H.-T. Janka
Theoretically predicted yields of elements created by the rapid neutron capture (r-) process carry potentially large uncertainties associated with incomplete knowledge of nuclear properties and approximative hydrodynamical modelling of the matter ejection processes. We present an in-depth study of the nuclear uncertainties by varying theoretical nuclear input models that describe the experimentally unknown neutron-rich nuclei. This includes two frameworks for calculating the radiative neutron capture rates and 14 different models for nuclear masses, $β$ -decay rates and fission properties. Our r-process nuclear network calculations are based on detailed hydrodynamical simulations of dynamically ejected material from NS-NS or NS-BH binary mergers plus the secular ejecta from BH-torus systems. The impact of nuclear uncertainties on the r-process abundance distribution and the early radioactive heating rate is found to be modest (within a factor of $\sim 20$ for individual $A > 90$ abundances and a factor of 2 for the heating rate). However, the impact on the late-time heating rate is more significant and depends strongly on the contribution from fission. We witness significantly larger sensitivity to the nuclear physics input if only a single trajectory is used compared to considering ensembles of $\sim$ 200-300 trajectories, and the quantitative effects of the nuclear uncertainties strongly depend on the adopted conditions for the individual trajectory. We use the predicted Th/U ratio to estimate the cosmochronometric age of six metal-poor stars and find the impact of the nuclear uncertainties to be up to 2 Gyr.
Comments:
28 pages, 24 figures, accepted to MNRAS
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2207.07421 [pdf]
MNRAS(2023)·40 citations
07
[Submitted on 15 Jul 2022] (cross-list from hep-ph)
Nature of the $X (6900)$ in partial wave decomposition of $J / ψ J / ψ$ scattering
Qi Zhou🇨🇳 · Di Guo🇨🇳 · Shi-Qing Kuang🇨🇳 · Qin-He Yang🇨🇳 · Ling-Yun Dai🇨🇳
In this letter, we perform partial wave decomposition on coupled-channel scattering amplitudes, $J / ψ J / ψ$ - $J / ψ ψ (2 S)$ - $J / ψ ψ (3770)$ , to study the resonance appears in these processes. Effective Lagrangians are used to describe the interactions of four charmed vector mesons, and the scattering amplitudes are calculated up to the next-to-leading order. Partial wave projections are performed, and unitarization is implemented by Padé approximation. Then we fit the amplitudes to the $J / ψ J / ψ$ invariant mass spectra measured by LHCb and determine the unknown couplings. The pole parameters of the $X (6900)$ are extracted as $M = 6861. 0_{- 8.8}^{+ 6.3}$ ~MeV and $Γ = 129. 0_{- 3.4}^{+ 5.6}$ ~MeV. Our analysis implies that its quantum number prefers to be $0^{++}$ . The pole counting rule and phase shifts show that it is a normal Breit-Wigner resonance and, hence, should be a compact tetraquark.
Comments:
6 pages, 4 figures. To be the same as the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.07537 [pdf]
PRD(2022)·21 citations
08
[Submitted on 15 Jul 2022] (cross-list from hep-ph)
Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using $1/ N_{c}$ expansion
J. L. Goity🇺🇸 · C. Weiss🇺🇸 · C. T. Willemyns🇧🇪
We calculate the target normal single-spin asymmetry caused by two-photon exchange in inclusive electron-nucleon scattering in the resonance region. Our analysis uses the $1/ N_{c}$ expansion of low-energy QCD and combines $N$ and $Δ$ intermediate and final states using the contracted $S U (4)$ spin-flavor symmetry. The normal spin asymmetry obtained in leading-order accuracy in $1/ N_{c}$ has magnitude $\sim 1 0^{- 2}$ and different sign in $e p$ and $e n$ scattering. It can be measured in electron scattering at lab energies $\sim$ 0.5-1.5 GeV and provides a clean probe of two-photon exchange dynamics.
Comments:
7 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.07588 [pdf]
PLB(2022)·5 citations
09
[Submitted on 15 Jul 2022] (cross-list from nucl-ex)
Systematic Trends of 0 $_{2}^{+}$ , 1 $_{1}^{-}$ , 3 $_{1}^{-}$ and 2 $_{1}^{+}$ Excited States in Even-Even Nuclei
B. Pritychenko · B. Singh · M. Verpelli
The spin and parity ( $J^{π}$ ) assignments in even-even nuclei were reviewed across the nuclear chart using the Evaluated Nuclear Structure Data File (ENSDF). The prevalence of 2 $_{1}^{+}$ first or lowest excited states is confirmed. The properties of 0 $_{2}^{+}$ , 1 $_{1}^{-}$ , and 3 $_{1}^{-}$ lowest excited states were reexamined using the ENSDF data evaluation procedures. The $J^{π}$ systematic trends and correlations between level quantum numbers and nuclear physics phenomena are discussed.
Comments:
39 pages, 6 figures, 4 tables. NP/A (2022)
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2207.07639 [pdf]
NPA(2022)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

Jet Broadening in Flowing Matter -- Resummation

Impact of systematic nuclear uncertainties on composition and decay heat of dynamical and disk ejecta in compact binary mergers

Nature of the X(6900) in partial wave decomposition of J/ψJ/ψ scattering

Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using 1/Nc​ expansion

Systematic Trends of 02+​, 11−​, 31−​ and 21+​ Excited States in Even-Even Nuclei

Affiliations

Nature of the $X (6900)$ in partial wave decomposition of $J / ψ J / ψ$ scattering

Target normal single-spin asymmetry in inclusive electron-nucleon scattering with two-photon exchange: Analysis using $1/ N_{c}$ expansion

Systematic Trends of 0 $_{2}^{+}$ , 1 $_{1}^{-}$ , 3 $_{1}^{-}$ and 2 $_{1}^{+}$ Excited States in Even-Even Nuclei