Wed·Sep 25, 2024Wednesday·September 25, 2024

1. 01*

   A background for thermal photons in heavy ion collisions

   Satya Ranjan Nayak🇮🇳 · Gauri Devi🇮🇳 · B.K. Singh🇮🇳

   In this work, we present the transverse momentum spectra of prompt and decay photons in Au-Au collisions for $\sqrt{s_{NN}}=$ 200 GeV, 62.4 GeV, 39 GeV, and 27 GeV. The major sources of the photons in Angantyr include hard processes, Parton showers, and resonance decay. The multiparton interactions and hadronic rescatterings significantly increase the photon yield. The model shows a good match with the available experimental data at high $p_T$. The difference in yield at low $p_T$ suggests that Quark Gluon Plasma of $T_{eff}$ = 0.167 GeV/c in central Au-Au collision at 200 GeV is formed, the new effective temperature is less than the ones extracted without removing background photons. At low $p_T$ the decay photon spectra scales with $(\frac{d{N}_{ch}}{d\eta }{)}^{1.25}$, the scaling is independent of collision energy and system size. The scaling no longer holds at high $p_T$ and the spectra become beam energy dependent. The scaled $p_T$ spectra of p-p and d-Au collisions show an opposite trend at high $p_T$, their scaled yield is greater than the Au-Au collision at the same energy.

   nucl-exhep-phPLB(2025)·1 citation
2. 02*

   Study of the Involvement of ${}^8$Be and ${}^9$B Nuclei in the Dissociation of Relativistic ${}^{10}$C, ${}^{10}$B, and ${}^{12}$C Nuclei

   D. A. Artemenkov🇷🇺 · V.Bradnova · G. I.Britvich · A.A.Zaitsev🇷🇺 · P. I. Zarubin🇷🇺 · I. G. Zarubina · V. A. Kalinin · R. R. Kattabekov · N.K.Kornegrutsa · M. Yu. Kostin · A. V. Maksimov · K. Z. Mamatkulov and 11 other authors

   The results obtained by estimating the contribution of ${}^8$Be and ${}^9$B nuclei to the coherent dissociation of ${}^{10}$C, ${}^{10}$B, and ${}^{12}$C relativistic nuclei in nuclear track emulsions (``white'' stars) are presented. The selection of ``white'' stars accompanied by ${}^9$B leads to a distinct peak appearing in the distribution of the excitation energy of 2$\alpha$2$p$ ensembles and having a maximum at 4.1 $\pm$ 0.3 MeV. A ${}^8$Be nucleus manifests itself in the coherent-dissociation reaction ${}^{10}$B $\to$ 2He + H with a probability of (25 $\pm$ 5)\%, (14 $\pm$ 3)\% of it being due to ${}^9$B decays. The ratio of the branching fractions of the ${}^9$B + $n$ and ${}^9$Be + $p$ mirror channels is estimated at 6 $\pm$ 1. An analysis of the relativistic dissociation of ${}^{12}$C nuclei in a nuclear track emulsion revealed nine 3$\alpha$ events corresponding to the Hoyle state.

   nucl-exPhys.Atom.Nucl.(2017)·4 citations
3. 03*

   Nucleon Gravitational Form Factors

   Z.-Q. Yao🇨🇳 · Y.-Z. Xu🇪🇸 · D. Binosi🇮🇹 · Z.-F. Cui🇨🇳 · M. Ding🇩🇪 · K. Raya🇪🇸 · C. D. Roberts🇨🇳 · J. Rodríguez-Quintero🇪🇸 · S. M. Schmidt🇩🇪

   A symmetry-preserving analysis of strong interaction quantum field equations is used to complete a unified treatment of pion, kaon, nucleon electromagnetic and gravitational form factors. Findings include a demonstration that the pion near-core pressure is roughly twice that in the proton, so both are significantly greater than that of a neutron star; parton species separations of the nucleon's three gravitational form factors, in which, inter alia, the glue-to-quark ratio for each form factor is seen to take the same constant value, independent of momentum transfer; and a determination of proton radii orderings, with the mechanical (normal force) radius being less than the mass-energy radius, which is less than the proton charge radius. This body of predictions should prove useful in an era of anticipated experiments that will enable them to be tested.

   ↳ hep-phhep-exhep-latnucl-ex+1EPJA(2025)·60 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.