Mon·Aug 21, 2023Monday·August 21, 2023

1. 01*

   EXFOR-based simultaneous evaluation for fast neutron-induced fission cross section of thorium-232

   Vidya Devi · Naohiko Otuka · S. Ganesan

   The ${}^{232}$Th neutron-induced fission cross section was evaluated from 500 keV to 200 MeV. The experimental ${}^{232}$Th fission cross sections and their ratios to the ${}^{235,238}$U fission cross sections in the EXFOR library were reviewed and analysed by the least-squares method. The newly published ${}^{232}$Th/${}^{235}$U fission cross section ratios from the time-of-flight measurements at the CERN n_TOF and CSNS Back-n facilities were compiled in EXFOR. Additional simultaneous evaluation was performed by including the experimental ${}^{233,238}$U and ${}^{239,240,241}$Pu fission cross sections and their ratios. The new evaluation provides the ${}^{232}$Th fission cross section systematically lower than the JENDL-5 cross section. The reduction is 4% in the plateau region between 2 and 6 MeV and more significant in the subthreshold fission region. The present evaluation reduces the ${}^{232}$Th fission cross section averaged over the ${}^{252}$Cf spontaneous fission neutron spectrum from the JENDL-5 evaluation by 4%, which is closer to the other general purpose libraries but underestimates Grundl et al's measurement by 11%.

   nucl-exJ.Nucl.Sci.Tech.(2024)·3 citations
2. 02*

   Proton number cumulants in a modified van der Waals hadron resonance gas

   Kshitish Kumar Pradhan🇮🇳 · Ronald Scaria🇮🇳 · Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳

   An estimate of the proton number cumulants in the hadronic matter is presented considering a van der Waals-type interaction between the constituent particles. We argue that the attractive and repulsive parameters in the VDW hadron resonance gas (VDWHRG) model change as functions of baryochemical potential (${\mu }_B$) and temperature ($T$). This, in turn, affects the estimation of thermodynamic properties and, consequently, the conserved charge fluctuations. We employ a simple parametrization to bring in the center-of-mass energy ($\sqrt{s_{\mathrm{NN}}}$) dependence on temperature and baryochemical potential and then estimate the proton number cumulants with the modified approach. The modified van der Waals hadron resonance gas model (MVDWHRG) explains the existing experimental data very well.

   ↳ hep-phhep-exnucl-exnucl-th5 citations
3. 03*

   $K^{+}N$ elastic scatterings for estimation of in-medium quark condensate with strange quarks

   Yutaro Iizawa🇯🇵 · Daisuke Jido🇯🇵 · Stephan Hübsch🇯🇵

   We revisit the low-energy $K^{+}N$ elastic scatterings in the context of the in-medium quark condensate with strange quarks. The chiral ward identity connects the in-medium quark condensate to the soft limit value of the pseudoscalar correlation function evaluated in nuclear matter. The in-medium correlation function of the psuedoscalar fields with strangeness describes in-medium kaon propagation and is obtained by kaon-nucleon scattering amplitudes in the low density approximation. We construct the kaon-nucleon scattering amplitudes in chiral perturbation theory up to the next-to-leading order and add some terms of the next-to-next-to-leading order with the strange quark mass to improve expansion of the strange quark sector. We also consider the effect of a possible broad resonance state around $P_{\mathrm{lab}}=600$ MeV/c for $I=0$ reported in the previous study. The low energy constants are determined by existent $K^{+}N$ scattering data. We obtain good reproduction of the $K^{+}p$ scattering amplitude by chiral perturbation theory, while the description of the $KN$ amplitude with $I=0$ is not so satisfactory due to the lack of low energy data. Performing analytic continuation of the scattering amplitudes obtained by chiral perturbation theory to the soft limit, we estimate the in-medium strange quark condensate.

   ↳ hep-phnucl-exnucl-thPTEP(2024)·5 citations
4. 04*

   KinFit -- A Kinematic Fitting Package for Hadron Physics Experiments

   Waleed Esmail🇩🇪 · Jana Rieger🇸🇪 · Jenny Taylor🇩🇪 · Malin Bohman🇸🇪 · Karin Schönning🇸🇪

   A kinematic fitting package, KinFit, based on the Lagrange multiplier technique has been implemented for generic hadron physics experiments. It is particularly suitable for experiments where the interaction point is unknown, such as experiments with extended target volumes. The KinFit package includes vertex finding tools and fitting with kinematic constraints, such as mass hypothesis and four-momentum conservation, as well as combinations of these constraints. The new package is distributed as an open source software via GitHub. This paper presents a comprehensive description of the KinFit package and its features, as well as a benchmark study using Monte Carlo simulations of the $pp\to p{K}^{+}\Lambda \to p{K}^{+}p{\pi }^{-}$ reaction. The results show that KinFit improves the parameter resolution and provides an excellent basis for event selection.

   ↳ physics.data-annucl-exComput.Softw.Big Sci.(2024)·6 citations
5. 05*

   Sequential decays of the triple strange process $\bar{p}p\to {\bar{\Omega }}^{+}{\Omega }^{-}\to K^{+}\bar{\Lambda }{K}^{-}\Lambda \to K^{+}\bar{p}{\pi }^{+}{K}^{-}p{\pi }^{-}$: a model-independent approach

   Deepak Pachattu🇮🇳

   A model-independent irreducible tensor formalism is developed to analyse $\bar{\Omega }\Omega$ production in $\bar{p}p$ collisions and its subsequent decay via the triple-strange decay process, ${\bar{\Omega }}^{+}{\Omega }^{-}\to K^{+}\bar{\Lambda }{K}^{-}\Lambda \to K^{+}\bar{p}{\pi }^{+}{K}^{-}p{\pi }^{-}$. These processes are relevant for the upcoming experiments at PANDA. We not only provide expressions for the density matrix of the $\Omega \bar{\Omega }$ system but also for the products at each stage of the decay. The Fano statistical tensors so obtained not only completely characterize the relevant final systems but also provide expressions for joint angular distributions. Finally, we show which of the Fano statistical tensors characterizing the $\bar{\Omega }\Omega$ system can be inferred from the Fano statistical tensors characterizing the final $\bar{p}p$ system, wherein we also obtain the relation between the production cross sections for $\Omega \bar{\Omega }$ and the final $p\bar{p}$ system.

   ↳ nucl-thhep-phnucl-exNPA(2024)·1 citation
6. 06*

   Emergent interaction-driven elliptic flow of few fermionic atoms

   Sandra Brandstetter🇩🇪 · Philipp Lunt🇩🇪 · Carl Heintze🇩🇪 · Giuliano Giacalone🇩🇪 · Lars H. Heyen🇩🇪 · Maciej Gałka🇩🇪 · Keerthan Subramanian🇩🇪 · Marvin Holten🇩🇪 · Philipp M. Preiss🇩🇪 · Stefan Floerchinger🇩🇪 · Selim Jochim🇩🇪

   Hydrodynamics provides a successful framework to effectively describe the dynamics of complex many-body systems ranging from subnuclear to cosmological scales by introducing macroscopic quantities such as particle densities and fluid velocities. According to textbook knowledge, it requires coarse graining over microscopic constituents to define a macroscopic fluid cell, which is large compared to the interparticle spacing and the mean free path. In addition, the entire system must consist of many such fluid cells. In high energy heavy ion collisions, hydrodynamic behaviour is inferred from the observation of elliptic flow. Here, we demonstrate the emergence of elliptic flow in a system of few strongly interacting atoms. In our system a hydrodynamic description is a priori not applicable, as all relevant length scales, i.e. the system size, the inter-particle spacing, and the mean free path are comparable. The single particle resolution, deterministic control over particle number and interaction strength in our experiment allow us to explore the boundaries between a microscopic description and a hydrodynamic framework in unprecedented detail.

   ↳ cond-mat.quant-gasnucl-exnucl-thquant-phNat.Phys.(2025)·36 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.