Fri·Jan 31, 2020Friday·January 31, 2020

1. 01*

   Electromagnetic radiation from the pre-equilibrium/pre-hydro stage of the quark-gluon plasma

   Jessica Churchill🇨🇦 · Li Yan🇨🇳 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦

   Photons produced in the pre-equilibrium/pre-hydro stage of the quark-gluon plasma produced in relativistic heavy-ion collisions were computed using parton distribution functions obtained from solutions of the Boltzmann equation. The effect of the initial gluon momentum anisotropy $\xi$ and the dependence on the saturation momentum $Q_s$ was investigated. We see that small $Q_s$ results in a photon yield enhancement, whereas a larger $Q_s$ results in a pre-equilibrium photon suppression, owing to the strict constraint of matching to experimental energy density.

   ↳ hep-phnucl-exnucl-thNPA(2021)·8 citations
2. 02*

   The Baghdad Atlas: A relational database of inelastic neutron-scattering $(n,n^{\prime }\gamma )$ data

   A.M. Hurst · L.A. Bernstein🇺🇸 · T. Kawano🇺🇸 · A.M. Lewis · K. Song

   A relational database has been developed based on the original ($n,n^{\prime }\gamma$) work carried out by A. M. Demidov $et$ $al$., at the Nuclear Research Institute in Baghdad, Iraq [$"Atlas$ $of$ $Gamma$-$Ray$ $Spectra$ $from$ $the$ $Inelastic$ $Scattering$ $of$ $Reactor$ $Fast$ $Neutrons"$, Nuclear Research Institute, Baghdad, Iraq (Moscow, Atomizdat 1978)] for 105 independent measurements comprising 76 elemental samples of natural composition and 29 isotopically-enriched samples. The information from this Atlas includes: $\gamma$-ray energies and relative intensities; nuclide and level data corresponding to the residual nucleus and meta data associated with the target sample that allows for the extraction of the flux-weighted ($n,n^{\prime }\gamma$) cross sections for a given transition relative to a defined value. The optimized angular-distribution-corrected fast-neutron flux-weighted partial $\gamma$-ray cross section for the production of the 846.8-keV $2_1^{+}\to 0_{\mathrm{gs}}^{+}$ $\gamma$-ray transition in ${}^{56}$Fe, determined to be $⟨{\sigma }_{\gamma }⟩=143(29)$ mb, is used for this purpose. However, different values for the adopted cross section can be readily implemented to accommodate user preference based on revised determinations of this quantity. The Atlas ($n,n^{\prime }\gamma$) data has been compiled into a series of CSV-style ASCII data sets and a suite of Python scripts have been developed to build and install the database locally. The database can then be accessed directly through the SQLite engine, or using alternative methods such as the Jupyter Notebook Python-browser interface. Several examples exploiting different interaction methodologies are distributed with the complete software package.

   ↳ physics.app-phnucl-exNucl.Instrum.Meth.A(2021)·6 citations
3. 03*

   Heavy-flavour jet production and charm fragmentation with ALICE at LHC

   Auro Mohanty (for the ALICE Collaboration)🇳🇱

   Heavy quarks, produced in hard parton scatterings in the early stage of ultra-relativistic heavy-ion collisions, are ideal probes to investigate the properties of the Quark--Gluon Plasma (QGP) produced in such collisions. Measurements of heavy-flavour jets can provide constraints on energy-loss models. In particular, they add information on how the radiated energy is dissipated in the medium. Studies of angular correlations between heavy-flavour and charged particles allow us to characterize the heavy-quark fragmentation process and its possible modification in a hot nuclear matter environment. This manuscript will focus on the latest results on heavy-flavour jets and D-meson correlations with charged particles studied with the ALICE detector in pp, p--Pb and Pb--Pb collisions.

   ↳ hep-exnucl-exSpringer Proc.Phys.(2020)·0 citations
4. 04*

   Angular distribution of fragments in neutron-induced nuclear fission at energies 1-200 MeV: data, theoretical models and relevant problems

   A. L. Barabanov · A. S. Vorobyev🇷🇺 · A. M. Gagarski · O. A. Shcherbakov · L. A. Vaishnene

   In recent years, investigations of angular distributions of fragments in neutron-induced nuclear fission have been extended to intermediate energies, up to 200 MeV, as well as to a wide range of target isotopes. Using as an example the latest data obtained by our group for the reaction 237-Np(n,f), we discuss the specific features of fission fragment angular distribution and present a method for their simulation based on the code TALYS. It is shown that a simplified model reasonably describes energy dependence of the angular distribution in the whole range 1-200 MeV. The ways to improve the model are discussed along with the possibilities to use it for obtaining new information on fission and pre-equilibrium processes in neutron-nucleus interaction. We consider also the relevant problems of describing fission fragment angular distributions.

   ↳ nucl-thnucl-exEPJ Web Conf.(2021)·3 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.