Fri·Dec 24, 2021Friday·December 24, 2021

1. 01*

   Improvements in Antineutrino Detector Response by Including Fission Product Isomeric Transitions and Corrections using New Data

   Wei Eng Ang🇺🇸 · Sanghun Lee🇺🇸 · Shikha Prasad🇺🇸

   CEvNS detectors could provide new opportunities in nuclear physics applications if they can improve existing parameters such as neutrino detector size, portability, their sensitivity to a large range of reactor antineutrino energies, and resources required for operation. Thus, modelling the antineutrino spectrum is a crucial step to study the reactor antineutrino spectra and the CEvNS detector response. The first objective of this paper is to study the importance of fission product libraries in the construction of antineutrino spectrum using the summation method and with various corrections. We have used ENDF/B-VIII and JEFF3.3 as our base data to model the spectrum. We have also included the TAGS data (pandemonium free) when such data is available. The isomeric transitions correction has the highest impact on the antineutrino spectra increasing the values 29% to 37% on an average in the energy range of 0.5 MeV to 2 MeV. This correction also shows an increase of 4.71% to 7.13% in the range of 0 to 2 MeV, with improving isomeric transitions using the TAGS data. Next, the spectra including the isomeric transition correction using the Gross Theory causes reduction by 11.56 % to 69.46 % in the range of 6 to 8 MeV. The finite size, radiative, and weak magnetism corrections cause no more than 3.27% difference between the corrected and uncorrected spectra. Our second objective is to calculate pulse height distributions of Ge and Si based CEvNS sensors assuming a 20eV nuclear recoil threshold. In our study, we have assumed a 100kg detector placed 10m away from the 1MW TRIGA reactor. Our results show that the detector response with corrected spectra for a natural Ge and Si detector are 44.25events/day and 7.99events/day. The biggest impact on the detector response is due to the isomeric transition correction; with 37% difference between the corrected and uncorrected detector response is observed.

   ↳ hep-exnucl-exphysics.ins-det1 citation
2. 02*

   Radiative (anti)neutrino energy spectra from muon, pion, and kaon decays

   Oleksandr Tomalak🇺🇸

   To describe low-energy (anti)neutrino fluxes in modern coherent elastic neutrino-nucleus scattering experiments as well as high-energy fluxes in precision-frontier projects such as the Enhanced NeUtrino BEams from kaon Tagging (ENUBET) and the Neutrinos from STORed Muons (nuSTORM), we evaluate (anti)neutrino energy spectra from radiative muon (${\mu }^{-}\to e^{-}{\bar{\nu }}_e{\nu }_{\mu }(\gamma ),{\mu }^{+}\to e^{+}{\nu }_e{\bar{\nu }}_{\mu }(\gamma )$), pion ${\pi }_{\ell 2}$ (${\pi }^{-}\to {\mu }^{-}{\bar{\nu }}_{\mu }(\gamma ),{\pi }^{+}\to {\mu }^{+}{\nu }_{\mu }(\gamma )$), and kaon $K_{\ell 2}$ ($K^{-}\to {\mu }^{-}{\bar{\nu }}_{\mu }(\gamma ),K^{+}\to {\mu }^{+}{\nu }_{\mu }(\gamma )$) decays. We compare detailed $\mathrm{O}\left(\alpha \right)$ distributions to the well-known tree-level results, investigate electron-mass corrections and provide energy spectra in analytical form. Radiative corrections introduce continuous and divergent spectral components near the endpoint, on top of the monochromatic tree-level meson-decay spectra, which can change the flux-averaged cross section at $6\times 10^{-5}$ level for the scattering on ${}^{40}\mathrm{Ar}$ nucleus with (anti)neutrinos from the pion decay at rest. Radiative effects modify the expected (anti)neutrino fluxes from the muon decay around the peak region by $3-4$ permille, which is a precision goal for next-generation artificial neutrino sources.

   ↳ hep-phhep-exnucl-exnucl-thPLB(2022)·16 citations
3. 03*

   Electrical conductivity of the quark-gluon plasma from the low energy limit of photon and dilepton spectra

   Stefan Floerchinger🇩🇪 · Charlotte Gebhardt🇩🇪 · Klaus Reygers🇩🇪

   Fluid dynamic considerations are used to determine the electric current spectral density in the regime of small energies and momenta. The spectral density in this regime is parameterized by the electric conductivity, the charge susceptibility, and the relaxation time for the electric current, which is needed for relativistic causality. Experimentally, the spectral function can be accessed through the production rates of photons and dileptons in the expanding quark-gluon plasma. We use fluid dynamic simulations of high energy nuclear collisions, together with the transport limit of the spectral density, to obtain photon and dielectron spectra for different values of the conductivity and relaxation times. The yields of photon and dileptons produced in the plasma are compared to the background from decays of short-lived hadrons. We discuss how experiments can constrain the electrical conductivity and associated relaxation time of the quark-gluon plasma.

   ↳ nucl-thhep-phnucl-exPLB(2023)·18 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.