Fri·Dec 8, 2023Friday·December 8, 2023

1. 01*

   Photonuclear reactions on the stable isotopes of selenium at bremsstrahlung end-point energies of 10-23 MeV

   F.A. Rasulova · N.V. Aksenov · S.I. Alekseev · R.A. Aliev · S.S. Belyshev · I. Chuprakov · N.Yu. Fursova · A.S. Madumarov · J.H. Khushvaktov · A.A. Kuznetsov🇷🇺 · B.S. Yuldashev

   The experiments were performed at bremsstrahlung end-point energies of 10-23 MeV with the beam from the MT-25 microtron with the use of the {\gamma}-activation technique. The experimental values of relative yields were compared with theoretical results obtained on the basis of TALYS with the standard parameters and the combined model of photonucleon reactions. Including isospin splitting in the combined model of photonucleon reactions allows to describe experimental data on reactions with proton escape in energies range from 10 to 23 MeV. Therefore, taking into account isospin splitting is necessary for a correct description of the decay of the GDR.

   nucl-exastro-ph.IMnucl-thPRC(2025)·2 citations
2. 02*

   Zero-Class Poisson for Rare-Event Studies

   Thomas M. Semkow

   We developed a statistical theory of zero-count-detector (ZCD), which is defined as a zero-class Poisson under conditions outlined in the paper. ZCD is often encountered in the studies of rare events in physics, health physics, and many other fields where counting of events occurs. We found no acceptable solution to ZCD in classical statistics and affirmed the need for the Bayesian statistics. Several uniform and reference priors were studied and we derived Bayesian posteriors, point estimates, and upper limits. It was showed that the maximum-entropy prior, containing the most information, resulted in the smallest bias and the lowest risk, making it the most admissible and acceptable among the priors studied. We also investigated application of zero-inflated Poisson and Negative-binomial distributions to ZCD. It was showed using Bayesian marginalization that, under limited information, these distributions reduce to the Poisson distribution.

   ↳ stat.APmath-phmath.MPnucl-exHealth Phys.(2025)·0 citations
3. 03*

   Global density-dependent $\alpha$-nucleon interaction for $\alpha$-nucleus elastic scattering

   T. Furumoto🇯🇵 · K. Tsubakihara · S. Ebata🇯🇵 · W. Horiuchi🇯🇵

   We provide a global density-dependent ${}^4$He-nucleon (DD-$\alpha N$) interaction to construct the $\alpha$-nucleus optical model potential (OMP) in a wide range of incident energies. The global parametrization for the DD-$\alpha N$ interaction is obtained based on the proton-${}^4$He OMP which reproduces the elastic scattering cross-section data very well in the incident energies of 12.04--500 MeV per nucleon. We derive the $\alpha$-nucleus potential by a folding procedure with the point-nucleon density obtained by a microscopic mean-field model using the present DD-$\alpha N$ interaction. The density dependence of the DD-$\alpha N$ interaction is fixed phenomenologically to reproduce the $\alpha$-nucleus elastic scattering cross-section data by the ${}^{16}$O, ${}^{40}$Ca, ${}^{58}$Ni, ${}^{90}$Zr, and ${}^{208}$Pb targets at $E/A=$ 10--342.5 MeV. We also show the total reaction cross sections, which are helpful in fixing one free parameter, the renormalization factor for the imaginary part of the $\alpha$-nucleus potential. Lastly, we show some examples, which clearly demonstrate the validity and power of the present DD-$\alpha N$ approach.

   ↳ nucl-thnucl-exPTEP(2024)·2 citations
4. 04*

   Revisiting inclusive production of J/psi and Upsilon in high-energy gamma-gamma collisions

   Yelyzaveta Yedelkina🇫🇷 · Jean-Philippe Lansberg🇫🇷 · Maxim Nefedov🇫🇷

   The impact of Next-to-Leading Order (NLO) QCD corrections to the differential distributions of J/psi and Upsilon mesons produced inclusively in gamma-gamma collisions is discussed for the kinematical conditions of LEP II for DELPHI and at the future Circular Electron-Positron Collider (CEPC). We take into account all sizeable contributions at LO in v^2 in NRQCD factorisation: 1) pure QED process gamma + gamma -> J/psi(3S^1_1) + \gamma up to alpha^3 alpha_s, 2) single-resolved-photon contributions up to alpha_s^4, 3) gamma+gamma -> J/psi + c c-bar up to alpha^2 alpha_s and 4) gamma+gamma -> J/psi + ggg up to alpha^2 alpha_s^3. We will also discuss the pure QED process as a contribution to the exclusive production in ultra-peripheral heavy-ion collisions (UPC) at the LHC.

   ↳ hep-phhep-exnucl-exnucl-thPoS(2024)·2 citations
5. 05*

   Ultracentral heavy ion collisions, transverse momentum and the equation of state

   Govert Nijs🇨🇭 · Wilke van der Schee🇨🇭

   Ultracentral heavy ion collisions due to their exceptionally large multiplicity probe an interesting regime of quark-gluon plasma where the size is (mostly) fixed and fluctuations in the initial condition dominate. Spurred by the recent measurement of the CMS collaboration we investigate the driving factors of the increase of transverse momentum, including a complete analysis of the influence of the QCD equation of state. Particularly interesting is the influence of the centrality selection as well as the initial energy deposition.

   ↳ nucl-thhep-phnucl-exPLB(2024)·25 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.