Wed·Oct 25, 2017Wednesday·October 25, 2017

1. 01*

   Charged kaon femtoscopic correlations in p$-$Pb collisions at $\sqrt{{\text{s}}_{\mathrm{NN}}}=5.02$ TeV with ALICE at the LHC

   Elena Rogochaya (for the ALICE Collaboration)🇷🇺

   Particle correlations at small relative momenta can be used to measure the space$-$time characteristics of particle production on the femtoscopic (fm=10${}^{-15}$ m) level in high-energy collisions. Such correlations arise due to quantum statistics and final state interactions. We report correlations of two charged identical kaons measured in p$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV by the ALICE experiment at the LHC. The femtoscopic invariant radii and correlation strengths are extracted from the one-dimensional kaon correlation functions and are compared to those obtained in pp and Pb$-$Pb collisions at $\sqrt{s}=7$ TeV and $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV, respectively. Kaon femtoscopy in p$-$Pb collisions is an important supplement to that in pp and Pb$-$Pb collisions because it allows one to understand the particle production mechanisms in different collision systems. It also complements the existing pion correlation results. The obtained radii increase with increasing multiplicity and decrease with increasing pair transverse momentum. At comparable multiplicity, the radii measured in p$-$Pb collisions are close to those observed in pp collisions, whereas it is difficult to compare them with the results from Pb$-$Pb collisions because of a big multiplicity gap.

   nucl-ex1 citation
2. 02*

   Dawning of the N=32 shell closure seen through precision mass measurements of neutron-rich titanium isotopes

   E. Leistenschneider🇨🇦 · M.P. Reiter🇨🇦 · S. Ayet San Andrés🇩🇪 · B. Kootte🇨🇦 · J.D. Holt🇨🇦 · P. Navrátil🇨🇦 · C. Babcock🇨🇦 · C. Barbieri🇬🇧 · B.R. Barquest🇨🇦 · J. Bergmann🇩🇪 · J. Bollig🇨🇦 · T. Brunner🇨🇦 and 33 other authors

   A precision mass investigation of the neutron-rich titanium isotopes ${}^{51-55}$Ti was performed at TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). The range of the measurements covers the $N=32$ shell closure and the overall uncertainties of the ${}^{52-55}$Ti mass values were significantly reduced. Our results confirm the existence of a weak shell effect at $N=32$, establishing the abrupt onset of this shell closure. Our data were compared with state-of-the-art \textit{ab-initio} shell model calculations which, despite very successfully describing where the $N=32$ shell gap is strong, overpredict its strength and extent in titanium and heavier isotones. These measurements also represent the first scientific results of TITAN using the newly commissioned Multiple-Reflection Time-of-Flight Mass Spectrometer (MR-TOF-MS), substantiated by independent measurements from TITAN's Penning trap mass spectrometer.

   nucl-exnucl-thPRL(2018)·117 citations
3. 03*

   PandaX-III: Searching for Neutrinoless Double Beta Decay with High Pressure Gaseous Time Projection Chambers

   Ke Han (for the PandaX-III Collaboration)🇨🇳

   The PandaX-III (Particle And Astrophysical Xenon Experiment III) experiment will search for Neutrinoless Double Beta Decay (NLDBD) of 136Xe at the China Jin-Ping underground Laboratory II (CJPL-II). In the first phase of the experiment, a high pressure gas Time Projection Chamber (TPC) will contain 200 kg, 90% 136Xe enriched gas operated at 10 bar. Microbulk Micromegas, a fine pitch micro-pattern gas detector, will be used for charge readout and enable us to reconstruct tracks of NLDBD events with good energy and spatial resolution. With simulation, we demonstrate excellent background suppression capability with tracking information. In this proceeding, we will give an overview of recent progress of PandaX-III, including data taking of a 20 kg scale prototype TPC.

   ↳ physics.ins-dethep-exnucl-exJ.Phys.Conf.Ser.(2020)·23 citations
4. 04*

   In-flight energy calibration of the space-borne Compton polarimeter POLAR

   Hualin Xiao🇨🇭 · Wojtek Hajdas🇨🇭 · Bobing Wu🇨🇳 · Nicolas Produit🇺🇸 · Jianchao Sun · Merlin Kole🇸🇪 · Tianwei Bao · Tancredi Bernasconi · Tadeusz Batsch · Franck Cadoux🇨🇭 · Junying Chai🇮🇹 · Yongwei Dong🇨🇳 and 30 other authors

   POLAR is a compact wide-field space-borne detector for precise measurements of the linear polarisation of hard X-rays emitted by transient sources in the energy range from 50 keV to 500 keV. It consists of a 40$\times$40 array of plastic scintillator bars used as a detection material. The bars are grouped in 25 detector modules. The energy range sensitivity of POLAR is optimized to match with the prompt emission photons from the gamma-ray bursts (GRBs). Polarization measurements of the prompt emission would probe source geometries, emission mechanisms and magnetic structures in GRB jets. The instrument can also detect hard X-rays from solar flares and be used for precise measurement of their polarisation. POLAR was launched into a low Earth orbit on-board the Chinese space-lab TG-2 on September 15th, 2016. To achieve high accuracies in polarisation measurements it is essential to assure both before and during the flight a precise energy calibration. Such calibrations are performed with four low activity ${}^{22}$Na radioactive sources placed inside the instrument. Energy conversion factors are related to Compton edge positions from the collinear annihilation photons from the sources. This paper presents main principles of the in-flight calibration, describes studies of the method based on Monte Carlo simulations and its laboratory verification and finally provides some observation results based on the in-flight data analysis.

   ↳ physics.ins-detastro-ph.IMhep-exnucl-exAstropart.Phys.(2018)·8 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.