Fri·Dec 30, 2022Friday·December 30, 2022

1. 01*

   Production of pions, kaons, and (anti-)protons in Au+Au collisions at $\sqrt{s_{NN}}$ = 54.4 GeV at RHIC

   Krishan Gopal🇮🇳

   We report systematic measurements of bulk properties of the system created in Au+Au collisions at $\sqrt{s_{NN}}$ = 54.4 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The transverse momentum spectra of ${\pi }^{\pm }$, $K^{\pm }$, and $p$($\bar{p}$) are studied at mid-rapidity $(|y|<0.1)$ for different centrality classes. We also present mid-rapidity measurement of particle yields $(dN/dy)$ and particle ratios in Au+Au collisions at $\sqrt{s_{NN}}$ = 54.4 GeV. The kinetic freeze-out parameters ($T_{kin}$ and $⟨\beta ⟩$) are extracted from particle spectra using the blast-wave model, and all the results are compared with previously published experimental results.

   nucl-exhep-exEPJ Web Conf.(2023)·4 citations
2. 02*

   Neutron capture-induced nuclear recoils as background for CE$\nu$NS~measurements at reactors

   A. J. Biffl🇺🇸 · A. Gevorgian🇺🇸 · K. Harris🇺🇸 · A. N. Villano🇺🇸

   Nuclear reactors represent a promising neutrino source for CE$\nu$NS (coherent-elastic neutrino-nucleus scattering) searches. However, reactor sites also come with high ambient neutron flux. Neutron capture-induced nuclear recoils can create a spectrum that strongly overlaps the CE$\nu$NS signal for recoils $\lesssim$\,100\,eV for nuclear reactor measurements in silicon or germanium detectors. This background can be particularly critical for low-power research reactors providing a moderate neutrino flux. In this work we quantify the impact of this background and show that, for a measurement 10\,m from a 1\,MW reactor, the effective thermal neutron flux should be kept below $\sim$~7$\times$~10${}^{-4}$\,n/cm${}^2$s so that the CE$\nu$NS events can be measured at least at a 5$\sigma$ level with germanium detectors in 100~kg\,yr exposure time. This flux corresponds to 60\% of the sea-level flux but needs to be achieved in a nominally high-flux (reactor) environment. Improved detector resolution can help the measurements, but the thermal flux is the key parameter for the sensitivity of the experiment. For silicon detectors, the constraint is even stronger and thermal neutron fluxes must be near an order of magnitude lower. This constraint highlights the need of an effective thermal neutron mitigation strategy for future low threshold CE$\nu$NS searches. In particular, the neutron capture-induced background can be efficiently reduced by active veto systems tagging the deexcitation gamma following the capture.

   ↳ hep-exnucl-exphysics.ins-detPRD(2023)·2 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.