Thu·Feb 20, 2020Thursday·February 20, 2020

1. 01*

   A sensitivity study of the primary correlators used to characterize chiral-magnetically-driven charge separation

   Niseem Magdy (1) · Mao-Wu Nie (2,3) · Guo-Liang Ma (3,4) · Roy A. Lacey (5) · ((1) Department of Physics, University of Illinois at Chicago, Chicago Illinois, USA, (2) Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong, China (3) Key Laboratory of Particle Physics and Particle Irradiation, Ministry of Education, Shandong University, Qingdao, Shandong, China, (4) Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China, (5) Depts. of Chemistry and Physics, Stony Brook University, Stony Brook, New York, USA)

   A Multi-Phase Transport (AMPT) model is used to study the detection sensitivity of two of the primary correlators -- $\Delta \gamma$ and $R_{{\Psi }_2}$ -- employed to characterize charge separation induced by the Chiral Magnetic Effect (CME). The study, performed relative to several event planes for different input "CME signals", indicates a detection threshold for the fraction $f_{\mathrm{CME}}=\Delta {\gamma }_{\mathrm{CME}}/\Delta \gamma$, which renders the $\Delta \gamma$-correlator insensitive to values of the Fourier dipole coefficient $a_1\lesssim 2.5\%$, that is larger than the purported signal(signal difference) for ion-ion(isobaric) collisions. By contrast, the $R_{{\Psi }_2}$ correlator indicates concave-shaped distributions with inverse widths (${\sigma }_{{\mathrm{R}}_{{\mathrm{\Psi }}_2}}^{-1}$) that are linearly proportional to $a_1$, and independent of the character of the event plane used for their extraction. The sensitivity of the $R_{{\Psi }_2}$ correlator to minimal CME-driven charge separation in the presence of realistic backgrounds, could aid better characterization of the CME in heavy-ion collisions.

   nucl-exnucl-thPLB(2020)·9 citations
2. 02*

   Beam-energy and collision-system dependence of the linear and mode-coupled flow harmonics from STAR

   Niseem Magdy🇺🇸

   Recent measurements and hydrodynamic model calculations suggest that the higher-order flow coefficients $v_4$ and $v_5$ have two contributions: a linear contribution driven by the initial-state eccentricities, ${\epsilon }_n$, and a mode-coupled contribution derived from the lower-order eccentricity coefficients ${\epsilon }_2$ and ${\epsilon }_3$. Measurements of these two contributions to $v_4$ and $v_5$ provide crucial insights to discern initial-state models and to constrain the temperature-dependent specific shear viscosity, $\eta /s$, of the plasma produced in heavy-ion collisions. In this work, we have employed the two-subevents cumulant technique to provide the first beam-energy and collision-system dependence of the linear and mode-coupled contributions to the higher-order flow harmonics. Our results are shown and discussed for several centrality intervals for U+U collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$= 193 GeV, Au+Au collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$=200, and 54.4 GeV and Cu+Au collisions at $\sqrt{{\mathrm{s}}_{\mathrm{NN}}}$=200 GeV. The results are compared with similar studies performed by the ALICE experiment at LHC.

   nucl-exNPA(2021)·4 citations
3. 03*

   High-precision $Q$-value measurement confirms the potential of ${}^{135}$Cs for antineutrino-mass detection

   A. de Roubin (1)🇫🇮 · J. Kostensalo (1)🇫🇮 · T. Eronen (1)🇫🇮 · L. Canete (1)🇫🇮 · R. P. de Groote (1)🇫🇮 · A. Jokinen (1)🇫🇮 · A. Kankainen (1)🇫🇮 · D. A. Nesterenko (1)🇫🇮 · I. D. Moore (1)🇫🇮 · S. Rinta-Antila (1)🇫🇮 · J. Suhonen (1)🇫🇮 · M. Vilén (1) ((1) University of Jyväskylä, Finland)🇫🇮

   The ground-state-to-ground-state $\beta$-decay $Q$-value of ${}^{135}\text{Cs}(7/2^{+})\to {}^{135}\text{Ba}(3/2^{+})$ was directly measured for the first time utilizing the Phase-Imaging Ion-Cyclotron Resonance (PI-ICR) technique at the JYFLTRAP Penning-trap setup. It is the first direct determination of this $Q$-value and its value of 268.66(30)\,keV is a factor of three more precise than the currently adopted $Q$-value in the Atomic Mass Evaluation 2016. Moreover, the $Q$-value deduced from the $\beta$-decay endpoint energy has been found to deviate from our result by approximately 6 standard deviations. The measurement confirms that the first-forbidden unique ${\beta }^{-}$-decay transition ${}^{135}\text{Cs}(7/2^{+})\to {}^{135}\text{Ba}(11/2^{-})$ is a candidate for antineutrino-mass measurements with an ultra-low $Q$-value of $0.44(31)$ keV. This $Q$-value is almost an order of magnitude smaller than in any presently running or planned direct (anti)neutrino-mass experiment.

   nucl-exPRL(2020)·28 citations
4. 04*

   The GlueX DIRC Program

   A. Ali🇩🇪 · F. Barbosa🇺🇸 · J. Bessuille🇺🇸 · E. Chudakov🇺🇸 · R. Dzhygadlo🇩🇪 · C. Fanelli🇺🇸 · J. Frye🇺🇸 · J. Hardin🇺🇸 · A. Hurley🇺🇸 · G. Kalicy🇺🇸 · J. Kelsey🇺🇸 · W. Li🇺🇸 and 8 other authors

   The GlueX experiment is located in experimental Hall D at Jefferson Lab (JLab) and provides a unique capability to search for hybrid mesons in high-energy photoproduction, utilizing a ~9 GeV linearly polarized photon beam. The initial, low-intensity phase of GlueX was recently completed and a high-intensity phase has begun in 2020 which includes an upgraded kaon identification system, known as the DIRC (Detection of Internally Reflected Cherenkov light), utilizing components from the decommissioned BaBar DIRC. The identification of kaon final states will significantly enhance the GlueX physics program, to aid in inferring the quark flavor content of conventional (and potentially hybrid) mesons. In these proceedings we describe the installation of the GlueX DIRC and the analysis of initial commissioning data

   ↳ physics.ins-detnucl-exJINST(2020)·9 citations
5. 05*

   Nd${}^{+}$ isotope shift measurements in a cryogenically-cooled neutral plasma

   Nishant Bhatt · Kosuke Kato🇯🇵 · Amar C. Vutha🇨🇦

   We report measurements of the isotope shifts of two transitions ($4f^{4}6s\to [25044.7{]}_{7/2}^{\circ }$ and $4f^{4}6s\to [25138.6{]}_{7/2}^{\circ }$) in neodymium ions (Nd${}^{+}$) with hundredfold improved accuracy, using laser spectroscopy of a cryogenically-cooled neutral plasma. The isotope shifts were measured across a set of five spin-zero isotopes that spans a nuclear shape transition. We discuss the prospects for further improvements to the accuracy of Nd${}^{+}$ isotope shifts using optical clock transitions, which could enable higher precision tests of King plot linearity for new physics searches.

   ↳ physics.atom-phnucl-exphysics.plasm-phPRA(2020)·2 citations
6. 06*

   Heat radiation reduction in the cryostat with multilayer insulation technique

   D. Singh🇮🇳 · A. Pandey🇮🇳 · M. K. Singh🇹🇼 · L. Singh🇮🇳 · V. Singh🇮🇳

   Multilayer insulation (MLI) is an important technique for the reduction of radiation heat load in cryostats. The present work is focused on investigation for the selection of suitable reflective layer and spacer material in MLI systems. In our analysis, we have selected perforated double-Aluminized Mylar (DAM) with Dacron, unperforated DAM with Silk-net and perforated DAM with Glass-tissue for their evaluation as the reflective layer as well as spacer materials in MLI technique. Current work would discuss the calculation of the effect of layer density and the number of layers on the heat load. Knowing the key parameters of MLI, we have compared the heat load generation in spherical as well as cylindrical cryostats and the effect of layering near and outer surface on the heat load.

   ↳ physics.ins-dethep-exnucl-exJINST(2020)·4 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.