Mon·Oct 14, 2019Monday·October 14, 2019

1. 01*

   Three particle Lévy HBT from PHENIX

   Bálint Kurgyis (for the PHENIX Collaboration)🇭🇺

   Bose-Einstein correlations of identical bosons reveal information about the space-time structure of particle emission from the sQGP formed in ultra-relativistic heavy-ion collisions. Previous measurements of two particle correlations have shown that the source can best be described by a symmetric Levy distribution. Here we report on the measurement of three-particle correlations in 0-30 % centrality Au+Au collisions at $\sqrt{s_{{}_{\text{NN}}}}=200$ GeV, and describe them with a Levy type source. This measurement may shed light on hadron creation mechanisms beyond chaotic emission. We measure three particle correlation strength (${\lambda }_3$) as a function of pair transverse momentum. This parameter, combined with two-particle correlation strength ${\lambda }_2$ may reveal the level of chaoticity and coherence in particle production.

   nucl-exhep-exnucl-thPhys.Part.Nucl.(2020)·2 citations
2. 02*

   Towards a first measurement of the free neutron bound beta decay detecting hydrogen atoms at a throughgoing beamtube in a high flux reactor

   Wolfgang Schott🇩🇪 · Erwin Gutsmiedl🇩🇪 · Karina Bernert🇩🇪 · Ralf Engels🇩🇪 · Roman Gernhäuser🇩🇪 · Stefan Huber🇩🇪 · Igor Konorov🇩🇪 · Bastian Märkisch🇩🇪 · Stephan Paul🇩🇪 · Christoph Roick🇩🇪 · Heiko Saul🇩🇪 · Suzana Spasova🇩🇪

   In addition to the common 3-body decay of the neutron $n\to p{e}^{-}\overline{{\nu }_e}$ there should exist an effective 2-body subset with the electron and proton forming a Hydrogen bound state with well defined total momentum, total spin and magnetic quantum numbers. The atomic spectroscopic analysis of this bound system can reveal details about the underlying weak interaction as it mirrors the helicity distributions of all outgoing particles. Thus, it is unique in the information it carries, and an experiment unravelling this information is an analogue to the Goldhaber experiment performed more than 60 years ago. The proposed experiment will search for monoenergetic metastable BoB H atoms with 326 eV kinetic energy, which are generated at the center of a throughgoing beamtube of a high-flux reactor (e.g., at the PIK reactor, Gatchina). Although full spectroscopic information is needed to possibly reveal new physics our first aim is to prove the occurrence of this decay and learn about backgrounds. Key to the detection is the identification of a monoerergtic line of hydrogen atoms occurring at a rate of about 1 ${\mathrm{s}}^{-1}$ in the environment of many hydrogen atoms, however having a thermal distribution of about room temperature. Two scenarios for velocity (energy) filtering are discussed in this paper. The first builds on an purely electric chopper system, in which metastable hydrogen atoms are quenched to their ground state and thus remain mostly undetectable. This chopper system employs fast switchable Bradbury Nielsen gates. The second method exploits a strongly energy dependent charge exchange process of metastable hydrogen picking up an electron while traversing an argon filled gas cell, turning it into manipulable charged hydrogen. The final detection of hydrogen occurs through multichannel plate (MCP) detector.

   ↳ physics.ins-dethep-exnucl-exEPJ Web Conf.(2019)·4 citations
3. 03*

   Measurement of the Reactor Antineutrino Spectrum from ${}^{235}$U Fission using PROSPECT

   P. T. Surukuchi🇺🇸

   PROSPECT is a short-baseline reactor antineutrino experiment designed to search for short-baseline sterile neutrino oscillations and perform a precise measurement of ${}^{235}$U reactor antineutrino spectrum from the High Flux Isotope Reactor at Oak Ridge National Laboratory. This measurement probes our understanding of recent anomalous results observed in reactor antineutrinos. PROSPECT uses a $\sim$4-ton optically segmented, ${}^6$Li-loaded liquid scintillator detector with high light yield, world-leading energy resolution, and excellent pulse shape discrimination. The latest antineutrino spectrum measurement results from ${}^{235}$U fissions at HFIR are reported.

   ↳ hep-exnucl-exphysics.ins-det0 citations
4. 04*

   Nuclear incompressibility from spherical and deformed nuclei

   Danilo Gambacurta (ELI-NP, Romania)🇮🇹 · Gianluca Colò (University of Milano and INFN, Italy)🇮🇹 · Alessandro Pastore (University of York, UK)🇬🇧

   We present an analysis based on the deformed Quasi Particle Random Phase Approximation, on top of a deformed Hartree-Fock-Bogoliubov description of the ground state, aimed at studying the isoscalar monopole and quadrupole response in a deformed nucleus. This analysis is motivated by the need of understanding the coupling between the two modes and how it might affect the extraction of the nuclear incompressibility from the monopole distribution. After discussing this motivation, we present the main ingredients of our theoretical framework, and we show some results obtained with the SLy4 and SkM${}^{\ast }$ interactions for the nucleus ${}^{24}$Mg.

   ↳ nucl-thnucl-exJ.Phys.Conf.Ser.(2020)·5 citations
5. 05*

   Relativistic energy-density functional approach to magnetic-dipole excitation and its sum rule

   Tomohiro Oishi🇭🇷 · Goran Kruzic · Nils Paar🇭🇷

   Magnetic-dipole (M1) excitations of ${}^{18}$O and ${}^{42}$Ca nuclei are investigated within a relativistic nuclear energy density functional framework. In our last work \cite{2019OP}, these nuclei are found to have unique M1 excitation and its sum rule, because of their characteristic structure: the system consists of the shell-closure core plus two neutrons. For a more systematic investigation of the M1 mode, we have implemented a framework based on the relativistic nuclear energy density functional (RNEDF). For benchmark, we have performed the RNEDF calculations combined with the random-phase approximation (RPA). We evaluate the M1 excitation of ${}^{18}$O and ${}^{42}$Ca, whose sum-rule value (SRV) of the M1 transitions can be useful to test the computational implementation \cite{2019OP}. We also apply this RNEDF method to ${}^{208}$Pb, whose M1 property has been precisely measured \cite{1979Holt,1987Koehler,1988Laszewski,2016Birkhan}. Up to the level of the M1 sum rule, our result is in agreement with the experiments, except the discrepancy related with the quenching factors for $g$ coefficients.

   ↳ nucl-thastro-ph.HEnucl-ex0 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.