Fri·Dec 18, 2015Friday·December 18, 2015

1. 01*

   Measurements of correlations of anisotropic flow harmonics in Pb--Pb Collisions with ALICE

   You Zhou (ALICE Collaboration)🇩🇰

   We report the first measurements of the correlation strength between various anisotropic flow harmonics, using ALICE data. This correlation strength is characterized with multi-particle cumulants of mixed harmonics, which by construction depend only on the fluctuations of magnitudes of the anisotropic flow vectors. A detailed comparison to theoretical model calculations, including HIJING, Monte Carlo Glauber and hydrodynamics is also presented. These studies further constrain initial conditions, the properties and the evolution of the system to be used in theoretical simulations of heavy-ion collisions.

   nucl-exnucl-thNPA(2016)·11 citations
2. 02*

   Precision Mass Measurements of 129-131Cd and Their Impact on Stellar Nucleosynthesis via the Rapid Neutron Capture Process

   D. Atanasov · P. Ascher · K. Blaum · R. B. Cakirli · T. E. Cocolios · S. George · F. Herfurth · D. Kisler · M. Kowalska · S. Kreim · Yu. A. Litvinov · D. Lunney and 8 other authors

   Masses adjacent to the classical waiting-point nuclide 130Cd have been measured by using the Penning- trap spectrometer ISOLTRAP at ISOLDE/CERN. We find a significant deviation of over 400 keV from earlier values evaluated by using nuclear beta-decay data. The new measurements show the reduction of the N = 82 shell gap below the doubly magic 132Sn. The nucleosynthesis associated with the ejected wind from type-II supernovae as well as from compact object binary mergers is studied, by using state-of-the-art hydrodynamic simulations. We find a consistent and direct impact of the newly measured masses on the calculated abundances in the A = 128 - 132 region and a reduction of the uncertainties from the precision mass input data.

   nucl-exPRL(2015)·63 citations
3. 03*

   A Prototype Combination TPC Cherenkov Detector with GEM Readout for Tracking and Particle Identification and its Potential Use at an Electron Ion Collider

   Craig Woody🇺🇸 · Babak Azmoun🇺🇸 · Richard Majka🇺🇸 · Michael Phipps🇺🇸 · Martin Purschke🇺🇸 · Nikolai Smirnov🇺🇸

   A prototype detector is being developed which combines the functions of a Time Projection Chamber for charged particle tracking and a Cherenkov detector for particle identification. The TPC consists of a 10x10x10 cm3 drift volume where the charge is drifted to a 10x10 cm2 triple GEM detector. The charge is measured on a readout plane consisting of 2x10 mm2 chevron pads which provide a spatial resolution ~ 100 microns per point in the chevron direction along with dE/dx information. The Cherenkov portion of the detector consists of a second 10x10 cm2 triple GEM with a photosensitive CsI photocathode on the top layer. This detector measures Cherenkov light produced in the drift gas of the TPC by high velocity particles which are above threshold. CF4 or CF4 mixtures will be used as the drift gas which are highly transparent to UV light and can provide excellent efficiency for detecting Cherenkov photons. The drift gas is also used as the operating gas for both GEM detectors. The prototype detector has been constructed and is currently being tested in the lab with sources and cosmic rays, and additional tests are planned in the future to study the detector in a test beam.

   ↳ physics.ins-detnucl-exEPJ Web Conf.(2018)·3 citations
4. 04*

   Testing Hydrodynamic Descriptions of of p+p Collisions at \sqrt{s}=7 TeV

   M. Habich🇺🇸 · G.A. Miller🇺🇸 · P. Romatschke🇺🇸 · W. Xiang🇺🇸

   In high energy collisions of heavy-ions, experimental findings of collective flow are customarily associated with the presence of a thermalized medium expanding according to the laws of hydrodynamics. Recently, the ATLAS, CMS and ALICE experiments found signals of the same type and magnitude in ultrarelativistic proton-proton collisions. In this study, the state-of-the-art hydrodynamic model SONIC is used to simulate the systems created in p+p collisions. By varying the size of the second-order transport coefficients, the range of applicability of hydrodynamics itself to the systems created in p+p collisions is quantified. It is found that hydrodynamics can give quantitatively reliable results for the particle spectra and the elliptic momentum anisotropy coefficient $v_2$. Using a simple geometric model of the proton based on the elastic form factor leads to results of similar type and magnitude to those found in experiment when allowing for a small bulk viscosity coefficient.

   ↳ nucl-thhep-phnucl-exEPJC(2016)·42 citations
5. 05*

   Gluon Polarization in Longitudinally Polarized $pp$ Collisions at STAR

   Zilong Chang (for the STAR Collaboration)🇺🇸

   The STAR Collaboration is performing a wide range of measurements to determine the gluon helicity distribution in the proton. Gluon-gluon and quark-gluon scattering dominate jet production in proton-proton collisions at RHIC, so the longitudinal double-spin asymmetry, $A_{LL}$, for jet production places significant constraints on the gluon polarization in the proton. In recent years STAR has recorded large longitudinally polarized $pp$ data sets at both $\sqrt{s}=200$ GeV and $510$ GeV. The 2009 STAR inclusive jet $A_{LL}$ measurements at $\sqrt{s}=200$ GeV show the first experimental evidence of non-zero gluon polarization over the Bjorken-$x$ range, $x>0.05$. Furthermore, data collected at $\sqrt{s}=510$ GeV during the 2012 and 2013 RHIC runs allow access to the gluon polarization at lower $x$. In this talk, I will present the final results of the 2009 inclusive jet $A_{LL}$ measurement at $200$ GeV, the analysis status of the 2012 inclusive jet $A_{LL}$ measurement at $510$ GeV, and the status of di-jet and other STAR measurements that are sensitive to gluon polarization.

   ↳ hep-exnucl-exInt.J.Mod.Phys.Conf.Ser.(2016)·12 citations
6. 06*

   Searching for charmoniumlike states with hidden $s\bar{s}$

   Xiao-Hai Liu🇯🇵 · Makoto Oka🇯🇵

   We investigate the processes $e^{+}{e}^{-}$$\to$$\gamma J/\psi \varphi$, $\gamma J/\psi \omega$ and ${\pi }^{0}J/\psi \eta$ to search for the charmnium-like states with hidden $s\bar{s}$, such as $Y(4140)$, $Y(4274)$, $X(4350)$ and $X(3915)$. These processes will receive contributions from the charmed-strange meson rescatterings. When the center-of-mass energies of the $e^{+}{e}^{-}$ scatterings are taken around the $D_{s0}(2317)D_s^{\ast }$, $D_{s1}(2460)D_s$ or $D_{s1}(2460)D_s^{\ast }$ threshold, the anomalous triangle singularities can be present in the rescattering amplitudes, which implies a non-resonance explanation about the resonance-like structures. The positions of the anomalous triangle singularities are sensitive to the kinematics, which offers us a criterion to distinguish the kinematic singularities from genuine particles.

   ↳ hep-phhep-exnucl-exnucl-thPRD(2016)·21 citations
7. 07*

   Test of the $X(3872)$ Structure in Antiproton-Nucleus Collisions

   Alexei Larionov🇩🇪 · Mark Strikman🇺🇸 · Marcus Bleicher🇩🇪

   The present day experimental data on the $X(3872)$ decays do not allow to make clear conclusions on the dominating structure of this state. We discuss here an alternative way to study its structure by means of the two-step ${\bar{D}}^{\ast }$ (or $D$) production in $\bar{p}A$ reactions. If this process is mediated by $X(3872)$, the characteristic narrow peaks of the ${\bar{D}}^{\ast }$ (or $D$) distributions in the light cone momentum fraction at small transverse momenta will appear. This would unambiguously signal the $D{\bar{D}}^{\ast }$ + c.c. molecular composition of the $X(3872)$ state.

   ↳ nucl-thhep-exhep-phnucl-exAIP Conf.Proc.(2016)·1 citation
8. 08*

   Hadron Structure and Spectrum from the Lattice

   C. B. Lang🇦🇹

   Lattice calculations for hadrons are now entering the domain of resonances and scattering, necessitating a better understanding of the observed discrete energy spectrum. This is a reviewing survey about recent lattice QCD results, with some emphasis on spectrum and scattering.

   ↳ nucl-thhep-lathep-phnucl-exAIP Conf.Proc.(2016)·7 citations
9. 09*

   Influence of kinematic cuts on the net charge distribution

   Hannah Petersen🇩🇪 · Dmytro Oliinychenko🇺🇦 · Jan Steinheimer🇩🇪 · Marcus Bleicher🇩🇪

   The higher moments of the net charge distributions, e.g. the skewness and kurtosis, are studied within an infinite hadronic matter calculation in a transport approach. By dividing the box into several parts, the volume dependence of the fluctuations is investigated. After confirming that the initial distributions follow the expectations from a binomial distribution, the influence of quantum number conservation in this case the net charge in the system on the higher moments is evaluated. For this purpose, the composition of the hadron gas is adjusted and only pions and $\rho$ mesons are simulated to investigate the charge conservation effect. In addition, the effect of imposing kinematic cuts in momentum space is analysed. The role of resonance excitations and decays on the higher moments can also be studied within this model. This work is highly relevant to understand the experimental measurements of higher moments obtained in the RHIC beam energy scan and their comparison to lattice results and other theoretical calculations assuming infinite matter.

   ↳ nucl-thhep-phnucl-exNPA(2016)·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.