Tue·Feb 11, 2020Tuesday·February 11, 2020

1. 01*

   Benchmarking ${}^{136}$Xe Neutrinoless $\beta \beta$ Decay Matrix Element Calculations with the ${}^{138}\mathrm{Ba}(p,t)$ Reaction

   B. M. Rebeiro🇿🇦 · S. Triambak🇿🇦 · P. E. Garrett🇨🇦 · B. A. Brown🇺🇸 · G. C. Ball🇨🇦 · R. Lindsay🇿🇦 · P. Adsley🇿🇦 · V. Bildstein🇨🇦 · C. Burbadge🇨🇦 · A. Diaz Varela🇨🇦 · T. Faestermann🇩🇪 · D. L. Fang🇨🇳 and 9 other authors

   We used a high-resolution magnetic spectrograph to study neutron pair-correlated $0^{+}$ states in ${}^{136}$Ba, produced via the ${}^{138}\mathrm{Ba}(p,t)$ reaction. In conjunction with state-of-the-art shell model calculations, these data benchmark part of the dominant Gamow-Teller component of the nuclear matrix element (NME) for ${}^{136}$Xe neutrinoless double beta ($0\nu \beta \beta$) decay. We demonstrate for the first time an evaluation of part of a $0\nu \beta \beta$ decay NME by use of an experimental observable, presenting a new avenue of approach for more accurate calculations of $0\nu \beta \beta$ decay matrix elements.

   nucl-exnucl-thPLB(2020)·18 citations
2. 02*

   Recent results on net-baryon fluctuations in ALICE

   Mesut Arslandok🇩🇪

   Recent results on the analysis of event-by-event net-baryon number fluctuations in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ and $5.02$ TeV are presented. The cumulants of the net-proton distributions, proxies for the net-baryon distributions, up to third order are discussed. The experimental results are compared with HIJING and EPOS model calculations and the dependence of fluctuation measurements on the phase-space coverage is addressed in the context of calculations from Lattice QCD (LQCD) and the Hadron Resonance Gas (HRG) model.

   nucl-exhep-exNPA(2021)·16 citations
3. 03*

   Study of the ${}^{25}$Mg(d,p)${}^{26}$Mg reaction to constrain the ${}^{25}$Al(p,$\gamma$)${}^{26}$Si resonant reaction rates in nova burning conditions

   C. B. Hamill · P. J. Woods🇬🇧 · D. Kahl🇬🇧 · R. Longland🇺🇸 · J. P. Greene · C. Marshall🇺🇸 · F. Portillo · K. Setoodehnia

   The rate of the ${}^{25}$Al($p$,$\gamma$)${}^{26}$Si reaction is one of the few key remaining nuclear uncertainties required for predicting the production of the cosmic $\gamma$-ray emitter ${}^{26}$Al in explosive burning in novae. This reaction rate is dominated by three key resonances ($J^{\pi }=0^{+}$, $1^{+}$ and $3^{+}$) in ${}^{26}$Si. Only the $3^{+}$ resonance strength has been directly constrained by experiment. A high resolution measurement of the ${}^{25}$Mg($d$,$p$) reaction was used to determine spectroscopic factors for analog states in the mirror nucleus, ${}^{26}$Mg. A first spectroscopic factor value is reported for the $0^{+}$ state at 6.256 MeV, and a strict upper limit is set on the value for the $1^{+}$ state at 5.691 MeV, that is incompatible with an earlier (${}^4$He,${}^3$He) study. These results are used to estimate proton partial widths, and resonance strengths of analog states in ${}^{26}$Si contributing to the ${}^{25}$Al($p$,$\gamma$)${}^{26}$Si reaction rate in nova burning conditions.

   nucl-exastro-ph.SRnucl-thEPJA(2020)·9 citations
4. 04*

   Far-forward neutrinos at the Large Hadron Collider

   Weidong Bai🇺🇸 · Milind Diwan🇺🇸 · Maria Vittoria Garzelli🇮🇹 · Yu Seon Jeong🇨🇭 · Mary Hall Reno🇺🇸

   We present a new calculation of the energy distribution of high-energy neutrinos from the decay of charm and bottom hadrons produced at the Large Hadron Collider (LHC). In the kinematical region of very forward rapidities, heavy-flavor production and decay is a source of tau neutrinos that leads to thousands of { charged-current} tau neutrino events in a 1 m long, 1 m radius lead neutrino detector at a distance of 480 m from the interaction region. In our computation, next-to-leading order QCD radiative corrections are accounted for in the production cross-sections. Non-perturbative intrinsic-$k_T$ effects are approximated by a simple phenomenological model introducing a Gaussian $k_T$-smearing of the parton distribution functions, which might also mimic perturbative effects due to multiple initial-state soft-gluon emissions. The transition from partonic to hadronic states is described by phenomenological fragmentation functions. To study the effect of various input parameters, theoretical predictions for $D_s^{\pm }$ production are compared with LHCb data on double-differential cross-sections in transverse momentum and rapidity. The uncertainties related to the choice of the input parameter values, ultimately affecting the predictions of the tau neutrino event distributions, are discussed. We consider a 3+1 neutrino mixing scenario to illustrate the potential for a neutrino experiment to constrain the 3+1 parameter space using tau neutrinos and antineutrinos. We find large theoretical uncertainties in the predictions of the neutrino fluxes in the far-forward region. Untangling the effects of tau neutrino oscillations into sterile neutrinos and distinguishing a 3+1 scenario from the standard scenario with three active neutrino flavours, will be challenging due to the large theoretical uncertainties from QCD.

   ↳ hep-phhep-exnucl-exnucl-thJHEP(2020)·67 citations
5. 05*

   Conceptual Design of Beryllium Target for the KLF Project

   Igor Strakovsky (GWU)🇺🇸 · Moskov Amaryan (ODU)🇺🇸 · Mikhail Bashkanov (York U.)🇬🇧 · William J. Briscoe (GWU)🇺🇸 · Eugene Chudakov (JLab)🇺🇸 · Pavel Degtyarenko (JLab)🇺🇸 · Sean Dobbs (FSU)🇺🇸 · Alexander Laptev (LANL)🇺🇸 · Ilya Larin (Massachusetts U. Amherst)🇺🇸 · Alexander Somov (JLab)🇺🇸 · Timothy Whitlatch (JLab)🇺🇸

   The Kaon Production Target (KPT) is an important component of the proposed K-Long facility which will be operated in JLab Hall~D, targeting strange baryon and meson spectroscopy. In this note we present a conceptual design for the Be-target assembly for the planned K-Long beam line, which will be used along with the GlueX spectrometer in its standard configuration for the proposed experiments. The high quality 12-GeV CEBAF electron beam enables production of a K${}_L$ flux at the GlueX target on the order of $1\times 10^4{K}_L/sec$, which exceeds the K${}_L$ flux previously attained at SLAC by three orders of magnitude. An intense K${}_L$ beam would open a new window of opportunity not only to locate "missing resonances" in the strange hadron spectrum, but also to establish their properties by studying different decay channels systematically. The most important and radiation damaging background in K${}_L$ production is due to neutrons. The Monte Carlo simulations for the proposed conceptual design of KPT show that the resulting neutron and gamma flux lead to a prompt radiation dose rate for the KLF experiment that is below the JLab Radiation Control Department radiation dose rate limits in the experimental hall and at the site boundary, and will not substantially affect the performance of the spectrometer.

   ↳ physics.ins-dethep-exnucl-exphysics.acc-ph2 citations
6. 06*

   The Impact of the Charge Barrier Height on Germanium (Ge) Detectors with Amorphous-Ge Contacts for Light Dark Matter Searches

   W.-Z. Wei🇺🇸 · R. Panth🇺🇸 · J. Liu🇺🇸 · H. Mei🇺🇸 · D.-M. Mei🇺🇸 · G.-J. Wang🇺🇸

   Germanium (Ge) detectors with ability of measuring a single electron-hole (e-h) pair are needed in searching for light dark matter (LDM) down to the MeV scale. We investigate the feasibility of Ge detectors with amorphous-Ge (a-Ge) contacts to achieve the sensitivity of measuring a single e-h pair, which requires extremely low leakage current. Three Ge detectors with a-Ge contacts are used to study the charge barrier height for blocking electrons and holes. Using the measured bulk leakage current and the D$\ddot{o}$hler-Brodsky model, we obtain the values for charge barrier height and the density of localized energy states near the Fermi energy level for the top and bottom contacts, respectively. We predict that the bulk leakage current is extremely small and can be neglected at helium temperature ($\sim$4 K). Thus, Ge detectors with a-Ge contacts possess the potential to measure a single e-h pair for detecting LDM particles.

   ↳ physics.ins-dethep-exnucl-exEPJC(2020)·12 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.