Mon·Jul 3, 2023Monday·July 3, 2023

1. 01*

   Study of Reaction Mechanism and Dependence of Incomplete Fusion on Projectile Energy and Entrance Channel Mass-Asymmetry of 12C + 169Tm, 16O + 169Tm And 16O + 75As Systems At 4-7.5MeV/Nucleon Energy Beam

   Getahun Kebede

   This study focus on the correlation between entrance channel properties and incomplete fusion reaction. The dynamics of heavy-ion fusion reactions involved in the interaction of 12C and 16O with 169Tm and 75As targets were examined at 3-8MeV/nucleon specific energies. The influence of projectile energy and entrance channel mass-asymmetry on the incomplete fusion process in the interaction of 12C + 169Tm, 16O + 169Tm and 16O + 75As systems at energies ranging from 4-7.5 MeV/Nucleon was examined in this study. The PACE4 statistical model was used to compare and analyze the measured cross sections from the EXFOR data base. The values of level density parameter, which is a sensitive input parameter, were optimized using a representative non-a-emitting channel from the respective systems. The experimentally measured excitation functions for representative non {\alpha}-emitting channels were found to be in good agreement with the theoretical predictions in general. However, for {\alpha}-emitting channels in the current systems, the measured excitation functions were greater than the theoretical model code predictions, which could be attributed to incomplete fusion reaction at these energies. The observed enhancements in {\alpha}-emitting channels were attributable to the contribution coming from incomplete fusion reactions. The incomplete fusion fraction, which explains the relative relevance of incomplete fusion processes, was attempted to be approximated. The incomplete fusion fraction was shown to be sensitive to the projectile energy and mass-asymmetry of the entrance channel. Further, the results showed that incomplete fusion reactions were higher for more mass-asymmetric systems than mass-symmetric one.

   nucl-exnucl-th0 citations
2. 02*

   Repulsive $\Lambda$ potentials in dense neutron star matter and binding energy of $\Lambda$ in hypernuclei

   Asanosuke Jinno🇯🇵 · Koichi Murase🇯🇵 · Yasushi Nara🇯🇵 · Akira Ohnishi🇯🇵

   The repulsive three-body force between the lambda ($\Lambda$) hyperon and medium nucleons is a key element in solving the hyperon puzzle in neutron stars. We investigate the binding energies of $\Lambda$ hyperon in hypernuclei to verify the repulsive $\Lambda$ potentials from the chiral effective field theory ($\chi$EFT) employing the Skyrme Hartree-Fock method. We find that the $\chi$EFT $\Lambda$ potential with the $\Lambda NN$ three-body forces reproduces the existing hypernuclear binding energy data, whereas the $\Lambda$ binding energies are overestimated without the $\Lambda NN$ three-body force. Additionally, we search for the parameter space of the $\Lambda$ potentials by varying the Taylor coefficients of the $\Lambda$ potential and the effective mass of $\Lambda$ at the saturation density. Our analysis demonstrates that the parameter region consistent with the $\Lambda$ binding energy data spans a wide range of the parameter space, including even more repulsive potentials than the $\chi$EFT prediction. We confirm that these strong repulsive $\Lambda$ potentials suppress the presence of $\Lambda$ in the neutron star matter. We found that the $\Lambda$ potentials repulsive at high densities are favored when the depth of the $\Lambda$ potential at the saturation density, $U_{\Lambda }({\rho }_0)=J_{\Lambda }$, is $J_{\Lambda }\gtrsim -29\text{MeV}$, while attractive ones are favored when $J_{\Lambda }\lesssim -31\text{MeV}$. This suggests that the future high-resolution data of hypernuclei could rule out the scenario in which $\Lambda$s appear through the precise determination of $J_{\Lambda }$ within the accuracy of $1\text{MeV}$.

   ↳ nucl-thnucl-exPRC(2023)·25 citations
3. 03*

   HBT signature for clustered substructures probing primordial inhomogeneity in hot and dense QCD matter

   Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵 · Katsuya Inoue🇯🇵 · Kenta Shigaki🇯🇵 · Yorito Yamaguchi🇯🇵

   We propose a novel approach to probe primordial inhomogeneity in hot and dense matter which could be realized in non-central heavy-ion collisions. Although the Hanbury Brown and Twiss (HBT) interferometry is commonly used to infer the system size, the cluster size should be detected if substructures emerge in space. We demonstrate that a signal peak in the HBT two-particle correlation stands at the relative momentum corresponding to the spatial scale of pseudo one-dimensional modulation. We assess detectability using the data prepared by an event generator (AMPT model) with clustering implemented in the particle distribution.

   ↳ hep-phnucl-exnucl-thPRC(2024)·13 citations
4. 04*

   Ambiguities in Partial Wave Analysis of Two Spinless Meson Photoproduction

   JPAC Collaboration: W. A. Smith🇺🇸 · D. I. Glazier🇬🇧 · V. Mathieu🇪🇸 · M. Albaladejo🇪🇸 · M. Albrecht🇺🇸 · Z. Baldwin🇺🇸 · C. Fernández-Ramírez🇪🇸 · N. Hammoud🇵🇱 · M. Mikhasenko🇩🇪 · G. Montaña🇺🇸 · R. J. Perry🇪🇸 · A. Pilloni🇮🇹 and 3 other authors

   We describe the formalism to analyze the mathematical ambiguities arising in partial-wave analysis of two spinless mesons produced with a linearly polarized photon beam. We show that partial waves are uniquely defined when all accessible observables are considered, for a wave set which includes $S$ and $D$ waves. The inclusion of higher partial waves does not affect our results, and we conclude that there are no mathematical ambiguities in partial-wave analysis of two mesons produced with a linearly polarized photon beam. We present Monte Carlo simulations to illustrate our results.

   ↳ hep-phnucl-exnucl-thPRD(2023)·10 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.