Nuclear Theory·nucl-th

Monday·November 4, 2024

7 papers—3 primary·4 cross-listed

04
The quark gap equation in light-cone gauge
Roberto Correa da Silveira🇧🇷 · Fernando E. Serna🇨🇴 · Bruno El-Bennich🇧🇷
We calculate the quark self-energy correction in light-cone gauge motivated by distribution amplitudes whose definition implies a Wilson line. The latter serves to preserve the gauge invariance of the hadronic amplitudes and becomes trivial in light-cone gauge. Therefore, the calculation of the distribution amplitudes simplifies significantly provided that wave functions and propagators are obtained in that gauge. In here, we explore the corresponding Dyson-Schwinger equation in its leading truncation and with a dressed vertex derived from a Ward identity in light-cone gauge. The quark's mass and wave renormalization functions, as well as a third complex-valued amplitude, are found to depend on the relative orientation of the quark momentum and a light-like four-vector, which expresses a geometric gauge dependence of the propagator.
↳ hep-phnucl-thPRD(2025)·0 citations
05
Estimate of the $S$ -wave $D^{*} K$ scattering length in the isospin-0 channel from Belle and LHCb data
N. N. Achasov🇷🇺 · G. N. Shestakov🇷🇺
It is shown that the Belle and LHCb data on the interference of the amplitudes of the $S$ and $D$ partial waves in the decays $D_{s 1} (2536)^{+} \to D^{*+} K_{S}^{0}$ and $D_{s 1} (2536)^{-} \to D ˉ^{* 0} K^{-}$ allow us to obtain an estimate of the $S$ -wave $D^{*} K$ scattering length in the channel with isospin $I = 0$ : $∣ a_{D^{*} K}^{(0)} ∣ = (0.94 \pm 0.06)$ fm. The possibility of explaining the found value by the contribution of the $D_{s 1} (2460)$ resonance is discussed. The decay of $B_{s 1} (5830) \to B^{*} K ˉ$ is also briefly discussed.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·0 citations
06
Isospin breaking in the $^{71}$ Kr and $^{71}$ Br mirror system
A. Algora🇪🇸 · A. Vitéz-Sveiczer🇭🇺 · A. Poves🇪🇸 · G. G. Kiss🇭🇺 · B. Rubio🇪🇸 · G. de Angelis🇮🇹 · F. Recchia🇮🇹 · S. Nishimura🇯🇵 · T. Rodriguez🇪🇸 · P. Sarriguren🇪🇸 · J. Agramunt🇪🇸 · V. Guadilla🇪🇸 and 56 other authors
Isospin symmetry is a fundamental concept in nuclear physics. Even though isospin symmetry is partially broken, it holds approximately for most nuclear systems, which makes exceptions very interesting from the nuclear structure perspective. In this framework, it is expected that the spins and parities of the ground states of mirror nuclei should be the same, in particular for the simplest systems where a proton is exchanged with a neutron or vice versa. In this work, we present evidence that this assumption is broken in the mirror pair $^{71}$ Br and $^{71}$ Kr system. Our conclusions are based on a high-statistics $β$ decay study of $^{71}$ Kr and on state-of-the-art shell model calculations. In our work, we also found evidence of a new state in $^{70}$ Se, populated in the $β$ -delayed proton emission process which can be interpreted as the long sought coexisting 0 $^{+}$ state.
↳ nucl-exnucl-thPRL(2025)·6 citations
07
Heavy element abundances from a universal primordial distribution
G. Roepke · D. Blaschke · F. K. Roepke
We present a freeze-out approach to the formation of heavy elements in expanding nuclear matter. Applying concepts used in the description of heavy-ion collisions or ternary fission, we determine the abundances of heavy elements taking into account in-medium effects such as Pauli blocking and the Mott effect, which describes the dissolution of nuclei at high densities of nuclear matter. With this approach, we search for a universal primordial distribution in an equilibrium state from which the gross structure of the solar abundances of heavy elements freezes out via radioactive decay of the excited states. The universal primordial state is characterized by the Lagrangian parameters of temperature and chemical potentials of neutrons and protons. We show that such a state exists and determine a temperature of 5.266 MeV, a neutron chemical potential of 940.317 MeV and a proton chemical potential of 845.069 MeV, at a baryon number density of 0.013 fm $^{- 3}$ and a proton fraction of 0.13. Heavy neutron-rich nuclei such as the hypothesized double-magic nucleus $^{358}$ Sn appear in the primordial distribution and contribute to the observed abundances after fission. We discuss astrophysical scenarios for the realization of this universal primordial distribution for heavy element nucleosynthesis, including supernova explosions, neutron star mergers and the inhomogeneous Big Bang. The latter scenario may be of interest in the light of early massive objects observed with the James Webb Space Telescope and opens new perspectives to explain universality of the observed r-process patterns and the lack of observations of population III stars.
↳ astro-ph.SRastro-ph.COastro-ph.HEnucl-th3 citations

Affiliations

first authorsco-authorsvia INSPIRE

The quark gap equation in light-cone gauge

Estimate of the S-wave D∗K scattering length in the isospin-0 channel from Belle and LHCb data

Isospin breaking in the 71Kr and 71Br mirror system

Heavy element abundances from a universal primordial distribution

Affiliations

Estimate of the $S$ -wave $D^{*} K$ scattering length in the isospin-0 channel from Belle and LHCb data

Isospin breaking in the $^{71}$ Kr and $^{71}$ Br mirror system