Wed·Jun 29, 2022Wednesday·June 29, 2022

1. 01*

   Towards solar measurements of nuclear reaction rates

   Earl Patrick Bellinger🇺🇸 · Jørgen Christensen-Dalsgaard

   Nuclear reaction rates are a fundamental yet uncertain ingredient in stellar evolution models. The astrophysical S-factor pertaining to the initial reaction in the proton-proton chain is uncertain at the 1% level, which contributes a systematic but generally unpropagated error of similar order in the theoretical ages of stars. In this work, we study the prospect of improving the measurement of this and other reaction rates in the pp chain and CNO cycle using helioseismology and solar neutrinos. We show that when other aspects of the solar model are improved, then it shall be possible using current solar data to improve the precision of this measurement by nearly an order of magnitude, and hence the corresponding uncertainty on the ages of low-mass stars by a similar amount.

   ↳ astro-ph.SRnucl-exnucl-thMNRAS(2022)·5 citations
2. 02*

   Understanding the QCD medium by the diffusion of charm quarks using a Color String Percolation Model

   Kangkan Goswami🇮🇳 · Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳

   We study the drag and diffusion coefficients of the charm quark in the deconfined matter produced in the ultra-relativistic collisions by taking the Color String Percolation Model (CSPM) approach. CSPM, being a QCD-inspired model, can give us essential information about the hot and dense system produced in ultra-relativistic collisions. With the information on initial percolation temperature and percolation density, we estimate the relaxation time (${\tau }_c$), drag coefficient ($\gamma$), transverse momentum diffusion coefficient ($B_0$), and spatial diffusion coefficient ($D_s$) of charm quark inside a deconfined medium. Finally, we compare the obtained results with lattice QCD and with various other theoretical models. A good agreement can be observed between the results obtained from CSPM and lattice QCD.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2023)·13 citations
3. 03*

   Impact of magnetic field on giant dipole resonance of ${}^{40}$Ca using the EQMD model

   Ya-Ting Cao · Xian-Gai Deng🇨🇳 · Yu-Gang Ma🇨🇳

   By taking into account the magnetic field in the extended quantum molecular dynamics model (EQMD), we analyzed its effects on giant dipole resonance (GDR) by studying the responses and strengths of the dipole moments. The selected system is the ${}^{40}$Ca nucleus which is excited through the Coulomb interaction by ${}^{16}$O. Particle acceleration term in Liénard-Wiechert potential is discussed which, however, has small impact on magnetic field. The peak energy, strength and width of GDR, temperature, and angular momentum of ${}^{40}$Ca as a function of beam energy are investigated. It is found that the magnetic field enhances the peak energy, strength and width of GDR which is not only due to the temperature effects but also due to the enhancement of the angular momentum of nucleus. At beam energy {E} $>$ 200 MeV/nucleon, magnetic field maintains a constant value for the strength of GDR. The work sheds light on examining important roles of the magnetic field on nuclear structure in low-intermediate energy heavy-ion collisions.

   ↳ nucl-thnucl-exPRC(2022)·9 citations
4. 04*

   Probing the QCD phase diagram with HBT femtoscopy

   Sándor Lökös🇭🇺

   Intensity interferometry originates from the field of radio astronomy on the trace of Robert Hanbury Brown and Richard Quincy Twiss. In high energy physics, the phenomena was discovered by Goldhaber, Goldhaber, Lee and Pais. In radio astronomy the method is exceeded by more modern approaches but in high energy physics, the measurements of Hanbury Brown-Twiss (HBT) or Goldhaber-Goldhaber-Lee-Pais (GGLP) type of correlations are important tools to access the spatio-temporal properties of the matter under extreme conditions on subatomic scales. In this paper, I review recent experimental results from energies of the Relativistic Heavy Ion Collider (RHIC) to the Large Hadron Collider (LHC) and discuss their possible implication on the equation of state of the QCD matter.

   ↳ hep-exnucl-exActa Phys.Polon.Supp.(2022)·2 citations
5. 05*

   Hyperon productions from Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV

   Purabi Ghosh🇮🇳 · Sushant K. Singh🇮🇳 · Santosh K. Agarwalla🇮🇳 · Jajati K. Nayak🇮🇳

   We evaluate centrality dependence of hyperon, $\Lambda ,\Xi ,\Omega$ and $K$ meson yields from Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV using rate equation and compare with experimental observations. An increase in the yield per participating nucleon is observed with centrality. Higher rate of multistrange productions compared to single-strange are also observed in case of central collisions. Using rate equation or momentum integrated Boltzmann equation we discuss the yield microscopically which are then normalised with thermal pions to get the yield ratio,($H_s+\overline{H_s}$)/(${\pi }^{+}+{\pi }^{-}$) at various centralities. We have also evaluated the relative yield of anti hyperons per participant at various centralities and compared with observations made at RHIC. Increase in the rate of $\Xi$ yield compared to $\Lambda$ is realised in most central collisions. We find multi strange $\Xi ,\Omega$ freeze-out at a temperature very close to $T_c$ and $\Lambda ,K$ do little later.

   ↳ nucl-thhep-exhep-phnucl-ex0 citations
6. 06*

   A reassessment of nuclear effects in muonic deuterium using pionless effective field theory at N3LO

   Vadim Lensky (JGU Mainz)🇩🇪 · Franziska Hagelstein (JGU Mainz and PSI Villigen)🇩🇪 · Vladimir Pascalutsa (JGU Mainz)🇩🇪

   We provide a systematic assessment of the order-${\alpha }^5$ nuclear contributions to the Lamb shift of muonic deuterium, including the accompanying radiative corrections due to vacuum polarization, up to next-to-next-to-next-to-leading order (N3LO) within the pionless effective field theory (EFT). We also evaluate higher-order corrections due to the single-nucleon structure, which are expected to be the most important corrections beyond N3LO. We find a correlation between the deuteron charge and Friar radii, which can be useful to judge the quality of charge form factor parametrisations. We refine the theoretical description of the $2\gamma$-exchange contribution, especially in the elastic contribution and the radiative corrections, ameliorating the original discrepancy between theory and experiment in the size of $2\gamma$-exchange effects. Based on the experimental Lamb shift of muonic deuterium, we obtain the deuteron charge radius, $r_d(\mu \text{D})=2.12763(13{)}_{\text{exp}}(77{)}_{\text{theory}}$~fm, which is consistent with (but less precise than) the value obtained by combining the H-D isotope shift with the muonic hydrogen Lamb shift. The theory uncertainty is evaluated using a Bayesian procedure and is dominated by the truncation of the pionless EFT series.

   ↳ nucl-thhep-phnucl-exphysics.atom-phPLB(2022)·8 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.