Fri·Sep 13, 2019Friday·September 13, 2019

1. 01*

   Role of event multiplicity on hadronic phase lifetime and QCD phase boundary in ultrarelativistic collisions at energies available at the BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

   Dushmanta Sahu🇮🇳 · Sushanta Tripathy🇮🇳 · Girija Sankar Pradhan🇮🇳 · Raghunath Sahoo🇮🇳

   Hadronic resonances, having very short lifetime, like ${\mathrm{K}}^{\ast 0}$, can act as useful probes to understand and estimate lifetime of hadronic phase in ultra-relativistic proton-proton, p--Pb and heavy-ion collisions. Resonances with relatively longer lifetime, like $\varphi$ meson, can serve as a tool to locate the QGP phase boundary. We estimate a lower limit of hadronic phase lifetime in Cu--Cu and Au--Au collisions at RHIC, and in pp, p--Pb and Pb--Pb collisions at different LHC collision energies. Also, we obtain the effective temperature of $\varphi$ meson using Boltzmann-Gibbs Blast-Wave function, which gives an insight to locate the QGP phase boundary. We observe that the hadronic phase lifetime strongly depends on final state charged-particle multiplicity, whereas the QGP phase and hence the QCD phase boundary shows a very weak multiplicity dependence. This suggests that the hadronisation from a QGP state starts at a similar temperature irrespective of charged-particle multiplicity, collision system and collision energy, while the endurance of hadronic phase is strongly dependent on final state charge-particle multiplicity, system size and collision energy.

   ↳ hep-phhep-exnucl-exnucl-thPRC(2020)·29 citations
2. 02*

   Impact of Charge Trapping on the Energy Resolution of Ge Detectors for Rare-Event Physics Searches

   D.-M. Mei🇺🇸 · R.B Mukund🇮🇳 · W.-Z. Wei🇺🇸 · R. Panth🇺🇸 · J. Liu🇺🇸 · H. Mei🇺🇸 · Y.-Y. Li🇺🇸 · P. Acharya🇺🇸 · S. Bhattarai🇺🇸 · K. Kooi🇺🇸 · M-S. Raut🇺🇸 · X.-S. Sun🇨🇳 and 5 other authors

   Charge trapping degrades the energy resolution of germanium (Ge) detectors, which require to have increased experimental sensitivity in searching for dark matter and neutrinoless double-beta decay. We investigate the charge trapping processes utilizing nine planar detectors fabricated from USD-grown crystals with well-known net impurity levels. The charge collection efficiency as a function of charge trapping length is derived from the Shockley-Ramo theorem. Furthermore, we develop a model that correlates the energy resolution with the charge collection efficiency. This model is then applied to the experimental data. As a result, charge collection efficiency and charge trapping length are determined accordingly. Utilizing the Lax model (further developed by CDMS collaborators), the absolute impurity levels are determined for nine detectors. The knowledge of these parameters when combined with other traits such as the Fano factor serve as a reliable indicator of the intrinsic nature of charge trapping within the crystals. We demonstrate that electron trapping is more severe than hole trapping in a p-type detector and the charge collection efficiency depends on the absolute impurity level of the Ge crystal when an adequate bias voltage is applied to the detector. Negligible charge trapping is found when the absolute impurity level is less than 1.0$\times$10${}^{11}/$cm${}^3$ for collecting electrons and 2.0$\times$10${}^{11}/$cm${}^3$ for collecting holes.

   ↳ physics.ins-dethep-exnucl-exJ.Phys.G(2020)·23 citations
3. 03*

   Radio Frequency and DC High Voltage Breakdown of High Pressure Helium, Argon, and Xenon

   K. Woodruff🇺🇸 · J. Baeza-Rubio🇺🇸 · D. Huerta🇺🇸 · B. J. P. Jones🇺🇸 · A. D. McDonald🇺🇸 · L. Norman🇺🇸 · D.R. Nygren🇺🇸 · C. Adams🇺🇸 · V. Álvarez🇪🇸 · L. Arazi🇮🇱 · I.J. Arnquist🇺🇸 · C.D.R Azevedo🇵🇹 and 82 other authors

   Motivated by the possibility of guiding daughter ions from double beta decay events to single-ion sensors for barium tagging, the NEXT collaboration is developing a program of R&D to test radio frequency (RF) carpets for ion transport in high pressure xenon gas. This would require carpet functionality in regimes at higher pressures than have been previously reported, implying correspondingly larger electrode voltages than in existing systems. This mode of operation appears plausible for contemporary RF-carpet geometries due to the higher predicted breakdown strength of high pressure xenon relative to low pressure helium, the working medium in most existing RF carpet devices. In this paper we present the first measurements of the high voltage dielectric strength of xenon gas at high pressure and at the relevant RF frequencies for ion transport (in the 10 MHz range), as well as new DC and RF measurements of the dielectric strengths of high pressure argon and helium gases at small gap sizes. We find breakdown voltages that are compatible with stable RF carpet operation given the gas, pressure, voltage, materials and geometry of interest.

   ↳ physics.ins-detnucl-exJINST(2020)·5 citations
4. 04*

   Pseudoscalar glueball mass: a window on three-gluon interactions

   E. V. Souza🇧🇷 · M. N. Ferreira🇧🇷 · A. C. Aguilar🇧🇷 · J. Papavassiliou🇪🇸 · C. D. Roberts🇨🇳 · S.-S. Xu🇨🇳

   In pure-glue QCD, gluon-gluon scattering in the $J^{PC}=0^{-+}$ channel is described by a very simple equation, especially if one considers just the leading contribution to the scattering kernel. Of all components in this kernel, only the three-gluon vertex, $V_{\mu \nu \rho }$, is poorly constrained by contemporary analyses; hence, calculations of $0^{-+}$ glueball properties serve as a clear window onto the character and form of $V_{\mu \nu \rho }$. This is important given that many modern calculations of $V_{\mu \nu \rho }$ predict the appearance of an infrared suppression in the scalar function which comes to modulate the bare vertex after the nonperturbative resummation of interactions. Such behaviour is a peculiar prediction; but we find that such suppression is essential if one is to achieve agreement with lattice-QCD predictions for the $0^{-+}$ glueball mass. It is likely, therefore, that this novel feature of $V_{\mu \nu \rho }$ is real and has observable implications for the spectrum, decays and interactions of all QCD bound-states.

   ↳ nucl-thhep-lathep-phnucl-exEPJA(2020)·47 citations
5. 05*

   Shell Model Symmetries-Honoring Franco Iachello

   Levering Wolfe🇺🇸 · Larry Zamick🇺🇸

   We discuss L=0 vs L=2 couplings, symmetries of the pairing interaction for neutrons and protons, and the J_{max} interaction. We show that certain schematic interactions yield exponentially decreasing transition strengths.We compare shell model calculations of B(E2)'s and quadrupole moments in the p-f shell with collective model results.

   ↳ nucl-thnucl-exquant-phAIP Conf.Proc.(2019)·0 citations
6. 06*

   A superfluid liquid helium target for low-momentum electron scattering experiments at the S-DALINAC

   Michaela Hilcker · Jonny Birkhan · Antonio D'Alessio · Lars Jürgensen · Tobias Klaus · Peter von Neumann-Cosel · Norbert Pietralla · Philipp Christian Ries · Maxim Singer · Gerhart Steinhilber (Institut für Kernphysik, Technische Universität Darmstadt, Germany)

   The superconducting electron accelerator S-DALINAC enables electron scattering experiments with low momentum transfer and high energy resolution. In order to perform experiments on helium with high precision and high luminosity, a superfluid liquid helium target with good temperature stability was developed. The functionality of this target could be confirmed and its properties were characterized in a commissioning experiment.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2020)·2 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.