Tue·Jun 30, 2015Tuesday·June 30, 2015

1. 01*

   $\varphi$ meson production in $d$$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV

   PHENIX Collaboration: A. Adare · C. Aidala · N.N. Ajitanand · Y. Akiba · H. Al-Bataineh · J. Alexander · M. Alfred · A. Angerami · K. Aoki · N. Apadula · Y. Aramaki · H. Asano and 473 other authors

   The PHENIX experiment has measured $\varphi$ meson production in $d$$+$Au collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV using the dimuon and dielectron decay channels. The $\varphi$ meson is measured in the forward (backward) $d$-going (Au-going) direction, $1.2<y<2.2$ ($-2.2<y<-1.2$) in the transverse-momentum ($p_T$) range from 1--7 GeV/$c$, and at midrapidity $|y|<0.35$ in the $p_T$ range below 7 GeV/$c$. The $\varphi$ meson invariant yields and nuclear-modification factors as a function of $p_T$, rapidity, and centrality are reported. An enhancement of $\varphi$ meson production is observed in the Au-going direction, while suppression is seen in the $d$-going direction, and no modification is observed at midrapidity relative to the yield in $p$$+$$p$ collisions scaled by the number of binary collisions. Similar behavior was previously observed for inclusive charged hadrons and open heavy flavor indicating similar cold-nuclear-matter effects.

   nucl-exPRC(2015)·22 citations
2. 02*

   K*0(892) and phi(1020) resonance production at RHIC

   Lokesh Kumar (for STAR Collaboration)🇮🇳

   The measurement of resonance production in ultrarelativistic heavy-ion collisions provides a glimpse of the hadronic medium properties and its evolution at different stages. Resonances decaying into hadrons are used to estimate the time span and hadronic interaction cross section in the hadronic phase between chemical and kinetic freeze-out. Specifically, the comparison of K*0(892) and phi(1020) resonances is interesting as the lifetimes of these particles differ by about a factor of 10. Moreover, the nuclear modification factor and azimuthal anisotropy measurements of mesonic resonances, which measure parton energy loss in medium and reflect partonic collectivity, can also probe particle-species and mass ordering. The K*0(892) and phi(1020) resonance production at mid-rapidity (|y|<0.5), measured in high energy (Au+Au, Cu+Cu, d+Au and p+p) collisions at RHIC with STAR experiment, reconstructed by their hadronic decay in Kpi and KK, respectively, are discussed. Mesons' spectra, yields, mean transverse momentum, nuclear modification factor, and azimuthal anisotropy are discussed as a function of centrality and collision energy.

   nucl-exEPJ Web Conf.(2015)·12 citations
3. 03*

   ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\bar{\Lambda }}^3\overline{\mathrm{H}}$ production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV

   ALICE Collaboration

   The production of the hypertriton nuclei ${}_{\Lambda }^3\mathrm{H}$ and ${}_{\bar{\Lambda }}^3\overline{\mathrm{H}}$ has been measured for the first time in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV with the ALICE experiment at LHC energies. The total yield, d$N$/d$y$ $\times {B.R.}_{\left({}_{\Lambda }^3\mathrm{H}{\to }^3\mathrm{He},{\pi }^{-}\right)}=\left(3.86\pm 0.77(stat.)\pm 0.68(syst.)\right)\times 10^{-5}$ in the 0-10% most central collisions, is consistent with the predictions from a statistical thermal model using the same temperature as for the light hadrons. The coalescence parameter $B_3$ shows a dependence on the transverse momentum, similar to the $B_2$ of deuterons and the $B_3$ of ${}^3\mathrm{He}$ nuclei. The ratio of yields $S_3$ = ${}_{\Lambda }^3\mathrm{H}$/(${}^3\mathrm{He}$ $\times \Lambda /\mathrm{p}$) was measured to be $S_3$ = 0.60 $\pm$ 0.13 (stat.) $\pm$ 0.21 (syst.) in 0-10% centrality events; this value is compared to different theoretical models. The measured $S_3$ is fully compatible with thermal model predictions. The measured ${}_{\Lambda }^3\mathrm{H}$ lifetime, $\tau =181_{-39}^{+54}(stat.)\pm 33(syst.)\mathrm{ps}$ is compatible within 1$\sigma$ with the world average value.

   nucl-exPLB(2016)·266 citations
4. 04*

   Centrality, rapidity and transverse momentum dependence of isolated prompt photon production in lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV measured with the ATLAS detector

   ATLAS Collaboration

   Prompt photon production in $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV Pb+Pb collisions has been measured by the ATLAS experiment at the Large Hadron Collider using data collected in 2011 with an integrated luminosity of 0.14 nb${}^{-1}$. Inclusive photon yields, scaled by the mean nuclear thickness function, are presented as a function of collision centrality and transverse momentum in two pseudorapidity intervals, $|\eta |<1.37$ and $1.52<|\eta |<2.37$. The scaled yields in the two pseudorapidity intervals, as well as the ratios of the forward yields to those at midrapidity, are compared to the expectations from next-to-leading order perturbative QCD calculations from JETPHOX. The measured cross sections agree well with the predictions for proton-proton collisions within statistical and systematic uncertainties. Both the yields and ratios are also compared to two other pQCD calculations, one which uses the isospin content appropriate to colliding lead nuclei, and another which includes the EPS09 nuclear modifications to the nucleon parton distribution functions.

   ↳ hep-exnucl-exPRC(2016)·118 citations
5. 05*

   Measurement of the production of neighbouring jets in lead-lead collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the ATLAS detector

   ATLAS Collaboration

   This Letter presents measurements of correlated production of nearby jets in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV using the ATLAS detector at the Large Hadron Collider. The measurement was performed using 0.14 ${\mathrm{nb}}^{-1}$ of data recorded in 2011. The production of correlated jet pairs was quantified using the rate, $R_{\Delta R}$, of "neighbouring" jets that accompany "test" jets within a given range of angular distance, $\Delta R$, in the pseudorapidity--azimuthal angle plane. The jets were measured in the ATLAS calorimeter and were reconstructed using the anti-$k_t$ algorithm with radius parameters $d=0.2$, $0.3$, and $0.4$. $R_{\Delta R}$ was measured in different Pb+Pb collision centrality bins, characterized by the total transverse energy measured in the forward calorimeters. A centrality dependence of $R_{\Delta R}$ is observed for all three jet radii with $R_{\Delta R}$ found to be lower in central collisions than in peripheral collisions. The ratios formed by the $R_{\Delta R}$ values in different centrality bins and the values in the 40-80 % centrality bin are presented.

   ↳ hep-exnucl-exPLB(2015)·33 citations
6. 06*

   A Scintillator Purification Plant and Fluid Handling System for SNO+

   Richard J. Ford (for the SNO+ Collaboration)🇨🇦

   A large capacity purification plant and fluid handling system has been constructed for the SNO+ neutrino and double-beta decay experiment, located 6800 feet underground at SNOLAB, Canada. SNO+ is a refurbishment of the SNO detector to fill the acrylic vessel with liquid scintillator based on Linear Alkylbenzene (LAB) and 2 g/L PPO, and also has a phase to load natural tellurium into the scintillator for a double-beta decay experiment with 130Te. The plant includes processes multi-stage dual-stream distillation, column water extraction, steam stripping, and functionalized silica gel adsorption columns. The plant also includes systems for preparing the scintillator with PPO and metal-loading the scintillator for double-beta decay exposure. We review the basis of design, the purification principles, specifications for the plant, and the construction and installations. The construction and commissioning status is updated.

   ↳ physics.ins-detnucl-exAIP Conf.Proc.(2015)·22 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.