Tue·Feb 21, 2017Tuesday·February 21, 2017

1. 01*

   Photoproduction of $\eta$ and ${\eta }^{\prime }$ Mesons on Proton

   V.L. Kashevarov🇩🇪 · L. Tiator🇩🇪 · M. Ostrick (for the A2 Collaboration at MAMI)🇩🇪

   New high-precision total and differential cross sections for $\eta$ and ${\eta }^{\prime }$ photoproduction on the proton obtained by the A2 Collaboration at the Mainz Microtron are presented. The data for $\eta$ photoproduction demonstrate a cusp at the energy W$\sim$1.9~GeV. Furthermore, we present a new version of the $\eta$MAID model for $\eta$ and ${\eta }^{\prime }$ photoproduction. The model includes 23 nucleon resonances parametrized with Breit-Wigner shapes. The background is described by vector and axial-vector meson exchanges in the $t$ channel using the Regge phenomenology. Parameters of the resonances were obtained from a fit to preliminary data of the A2 Collaboration at MAMI and available data from other collaborations. The cusp is explained as a threshold effect due to the opening ${\eta }^{\prime }p$ decay channel of the $N(1895)1/2^{-}$ resonance.

   nucl-exhep-phnucl-thJPS Conf.Proc.(2017)·10 citations
2. 02*

   ${\rm Y}$ Production in Heavy-Ion Collisions from the STAR Experiment

   Zaochen Ye🇺🇸

   In these proceedings, we present recent results of ${\rm Y}$ measurements in heavy-ion collisions from the STAR experiment at RHIC. Nuclear modification factors ($R_{AA}$) for ${\rm Y}(1S)$ and ${\rm Y}(1S+2S+3S)$ in U+U collisions at \sqrtsNN\ = 193 GeV are measured through the di-electron channel and compared to those in Au+Au collisions at \sqrtsNN\ = 200 GeV and Pb+Pb collisions at \sqrtsNN\ = 2.76 TeV. The ratio between the ${\rm Y}(2S+3S)$ and ${\rm Y}(1S)$ yields in Au+Au collisions at \sqrtsNN\ = 200 GeV is measured in the di-muon channel and compared to those in p+p collisions and in Pb+Pb collisions at \sqrtsNN\ = 2.76 TeV. Prospects for future ${\rm Y}$ measurements with the STAR experiment are also discussed.

   ↳ hep-exnucl-exNucl.Part.Phys.Proc.(2017)·4 citations
3. 03*

   Production of 82Se enriched Zinc Selenide (ZnSe) crystals for the study of neutrinoless double beta decay

   I. Dafinei🇮🇹 · S. Nagorny🇮🇹 · S. Pirro🇮🇹 · L. Cardani🇮🇹 · M. Clemenza🇮🇹 · F. Ferroni🇮🇹 · M. Laubenstein🇮🇹 · S. Nisi🇮🇹 · L. Pattavina🇮🇹 · K. Schaeffner🇮🇹 · M. L. di Vacri🇮🇹 · A. Boyarintsev🇺🇦 and 6 other authors

   High purity Zinc Selenide (ZnSe) crystals are produced starting from elemental Zn and Se to be used for the search of the neutrinoless double beta decay (0{\nu}DBD) of 82Se. In order to increase the number of emitting nuclides, enriched 82Se is used. Dedicated production lines for the synthesis and conditioning of the Zn82Se powder in order to make it suitable for crystal growth were assembled compliant with radio-purity constraints specific to rare event physics experiments. Besides routine check of impurities concentration, high sensitivity measurements are made for radio-isotope concentrations in raw materials, reactants, consumables, ancillaries and intermediary products used for ZnSe crystals production. Indications are given on the crystals perfection and how it is achieved. Since very expensive isotopically enriched material (82Se) is used, a special attention is given for acquiring the maximum yield in the mass balance of all production stages. Production and certification protocols are presented and resulting ready-to-use Zn82Se crystals are described.

   ↳ physics.ins-detnucl-exJ.Cryst.Growth(2017)·38 citations
4. 04*

   Off-shell persistence of composite pions and kaons

   Si-Xue Qin🇺🇸 · Chen Chen🇧🇷 · Cedric Mezrag🇺🇸 · Craig D. Roberts🇺🇸

   In order for a Sullivan-like process to provide reliable access to a meson target as $t$ becomes spacelike, the pole associated with that meson should remain the dominant feature of the quark-antiquark scattering matrix and the wave function describing the related correlation must evolve slowly and smoothly. Using continuum methods for the strong-interaction bound-state problem, we explore and delineate the circumstances under which these conditions are satisfied: for the pion, this requires $-t\lesssim 0.6$GeV${}^2$, whereas $-t\lesssim 0.9$GeV${}^2$ will suffice for the kaon. These results should prove useful in evaluating the potential of numerous experiments at existing and proposed facilities.

   ↳ nucl-thhep-lathep-phnucl-exPRC(2018)·48 citations
5. 05*

   Evaluating Reactor Antineutrino Signals for WATCHMAN

   Steve Dye🇺🇸

   Increasing the distance from which an antineutrino detector is capable of monitoring the operation of a registered reactor, or discovering a clandestine reactor, strengthens the Non-Proliferation of Nuclear Weapons Treaty. This paper presents calculations of reactor antineutrino interactions from quasi-elastic neutrino-proton scattering and elastic neutrino-electron scattering in a water-based detector operated $\gtrsim 10$ km from a commercial power reactor. It separately calculates signal from the proximal reactor and background from all other registered reactors. The main results are differential and integral interaction rates from the quasi-elastic and elastic processes. There are two underground facilities capable of hosting a detector ($\sim 1$ kT H${}_2$O) project nearby ($L\sim 20$ km) an operating commercial reactor ($P_{th}\sim 3$ GW). These reactor-site combinations, which are under consideration for project WATCHMAN, are Perry-Morton on the southern shore of Lake Erie in the United States and Hartlepool-Boulby on the western shore of the North Sea in England. The signal rate from the proximal reactor is about five times greater at the Morton site than at the Boulby site due to shorter reactor-site separation distance, larger reactor thermal power, and greater neutrino oscillation survival probability. Although the background rate from all other reactors is larger at Morton than at Boulby, it is a smaller fraction of the signal rate from the proximal reactor at Morton than at Boulby. Moreover, the Hartlepool power plant has two cores whereas the Perry plant has a single core. The Boulby site, therefore, offers an opportunity for remotely monitoring the on/off cycle of a reactor core under more stringent conditions than does the Morton site.

   ↳ physics.ins-detnucl-exJ.Phys.Conf.Ser.(2019)·1 citation

* 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.