Wed·Feb 20, 2019Wednesday·February 20, 2019

1. 01*

   Elliptical flow coalescence to identify the $f_0$(980) content

   An Gu🇺🇸 · Terrence Edmonds🇺🇸 · Jie Zhao🇺🇸 · Fuqiang Wang🇺🇸

   We use a simple coalescence model to generate $f_0$(980) particles for three configurations: a $s\bar{s}$ meson, a $u\bar{u}s\bar{s}$ tetraquark, and a $K^{+}{K}^{-}$ molecule. The phase-space information of the coalescing constituents is taken from a multi-phase transport (AMPT) simulation of heavy-ion collisions. It is shown that the number of constituent quarks scaling of the elliptic flow anisotropy can be used to discern $s\bar{s}$ from $u\bar{u}s\bar{s}$ and $K^{+}{K}^{-}$ configurations.

   nucl-exnucl-thPRC(2020)·5 citations
2. 02*

   Space-Time Discriminant to Separate Double-Beta Decay from ${}^8$B Solar Neutrinos in Liquid Scintillator

   Runyu Jiang🇺🇸 · Andrey Elagin🇺🇸

   We present a technique for separating double beta-decay from ${}^8$B solar neutrino interactions in a liquid scintillator detector. The technique uses position and time of photo-electrons (PEs) to separate directional Cherenkov light from isotropic sintillation light in the reconstruction of the kinematics of candidate events. Here we introduce a Cherenkov-scintillation space time boundary defined as the light cone in the 2-dimensional space of the arrival time and the polar angle of each PE with respect to the axis from the center of the detector to the vertex. The PEs located near the boundary correspond to photons that were emitted early and contain a high fraction of directional Cherenkov PEs. We apply weights derived from the distance to the boundary of each individual PE, which are then used in a spherical harmonics analysis that separates the two-track event topology of double-beta decay from the one-track topology of ${}^8$B events. The Geant-4 simulation assumes a detector of 6.5 m radius filled with ${}^{130}$Te-loaded liquid scintillator and surrounded by photo-detectors with time and space resolutions of 100 ps and 3 mm respectively. The scintillation properties and photo-detector quantum efficiency are modeled after KamLAND. Assuming a fiducial volume of 3 m radius, a photo-coverage of 65% and vertex resolution of ${\sigma }_{r_v}=$ 5.2 cm at 2.53 MeV the method of reconstructing event topology predicts factors of 1.3 and 2.3 in background suppression at 90% and 70% signal efficiency respectively. Additionally, the PEs near the Cherenkov-scintillation space-time boundary can be used to reconstruct the directionality of one-electron candidate events, allowing for further ${}^8$B background suppression due to the correlation between the direction of the scattered electron and the position of the sun. We find polar and azimuthal angular resolutions of 0.46 and 0.84 radians respectively.

   ↳ physics.ins-dethep-exnucl-ex10 citations
3. 03*

   New paradigm for fluctuations in heavy-ion collisions

   Giuliano Giacalone🇫🇷 · Pablo Guerrero-Rodríguez🇪🇸 · Matthew Luzum🇧🇷 · Cyrille Marquet🇫🇷 · Jean-Yves Ollitrault🇫🇷

   Since their discovery, fluctuations in the initial state of heavy-ion collisions have been understood as originating mostly from the random positions of nucleons within the colliding nuclei. We consider an alternative approach where all the focus is on fluctuations generated by QCD interactions, that we evaluate at leading logarithmic accuracy in the color glass condensate effective theory. We validate our approach using BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC) data on anisotropic flow. In particular, we show that, compared to standard Glauber-inspired calculations, our formalism provides a better description of the centrality dependence of the ratio of elliptic flow and triangular flow. It also naturally explains the evolution of elliptic flow fluctuations between RHIC and LHC energies.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2019)·35 citations
4. 04*

   Non-linearity effects on the light-output calibration of light charged particles in CsI(Tl) scintillator crystals

   D. Dell'Aquila🇺🇸 · S. Sweany🇺🇸 · K.W. Brown🇺🇸 · Z. Chajecki🇺🇸 · W.G. Lynch🇺🇸 · F.C.E. Teh🇺🇸 · C.-Y. Tsang🇺🇸 · M.B. Tsang🇺🇸 · K. Zhu🇺🇸 · C. Anderson🇺🇸 · A. Anthony🇺🇸 · S. Barlini🇮🇹 and 15 other authors

   The light output produced by light ions (Z<=4) in CsI(Tl) crystals is studied over a wide range of detected energies (E<=300 MeV). Energy-light calibration data sets are obtained with the 10 cm crystals in the recently upgraded High-Resolution Array (HiRA10). We use proton recoil data from 40,48Ca + CH2 at 28 MeV/u, 56.6 MeV/u, 39 MeV/u and 139.8 MeV/u and data from a dedicated experiment with direct low-energy beams. We also use the punch through points of p, d, and t particles from 40,48Ca + 58,64Ni, 112,124Sn collisions reactions at 139.8 MeV/u. Non-linearities, arising in particular from Tl doping and light collection efficiency in the CsI crystals, are found to significantly affect the light output and therefore the calibration of the detector response for light charged particles, especially the hydrogen isotopes. A new empirical parametrization of the hydrogen light output, L(E,Z=1,A), is proposed to account for the observed effects. Results are found to be consistent for all 48 CsI(Tl) crystals in a cluster of 12 HiRA10 telescopes.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2019)·25 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.