Wed·Apr 6, 2016Wednesday·April 6, 2016

1. 01*

   Jet-like Correlations with Direct-Photon and Neutral-Pion Triggers at $\sqrt{s_{{}_{NN}}}=200$ GeV

   STAR Collaboration

   Azimuthal correlations of charged hadrons with direct-photon (${\gamma }_{dir}$) and neutral-pion (${\pi }^0$) trigger particles are analyzed in central Au+Au and minimum-bias $p+p$ collisions at $\sqrt{s_{{}_{NN}}}=200$ GeV in the STAR experiment. The charged-hadron per-trigger yields at mid-rapidity from central Au+Au collisions are compared with $p+p$ collisions to quantify the suppression in Au+Au collisions. The suppression of the away-side associated-particle yields per ${\gamma }_{dir}$ trigger is independent of the transverse momentum of the trigger particle ($p_T^{\mathrm{trig}}$), whereas the suppression is smaller at low transverse momentum of the associated charged hadrons ($p_T^{\mathrm{assoc}}$). Within uncertainty, similar levels of suppression are observed for ${\gamma }_{dir}$ and ${\pi }^0$ triggers as a function of $z_T$ ($\equiv p_T^{\mathrm{assoc}}/p_T^{\mathrm{trig}}$). The results are compared with energy-loss-inspired theoretical model predictions. Our studies support previous conclusions that the lost energy reappears predominantly at low transverse momentum, regardless of the trigger energy.

   nucl-exhep-exhep-phnucl-thPLB(2016)·91 citations
2. 02*

   Complete kinematical study of the 3$\alpha$ breakup of the 16.11 MeV state in ${}^{12}$C

   K. L. Laursen · H. O. U. Fynbo🇩🇰 · O. S. Kirsebom🇩🇰 · K. O. Madsbøl · K. Riisager🇩🇰

   The reaction ${}^{11}B+p$ has been used to populate the $(J^{\pi },T)=(2^{+},1)$ state at an excitation energy of 16.11 MeV in ${}^{12}$C, and the breakup of the state into three $\alpha$ particles has been studied in complete kinematics. A two-step breakup model which includes interference effects is found to provide the most accurate description of the experimental data. The branching ratio to the ground state of ${}^8$Be is determined to be 5.1(5)% in agreement with previous findings, but more precise by a factor of two, while the decay to the first-excited state in ${}^8$Be is found to be dominated by $d$-wave emission.

   nucl-exEPJA(2016)·11 citations
3. 03*

   Detectability of galactic supernova neutrinos coherently scattered on xenon nuclei in XMASS

   XMASS Collaboration

   The coherent elastic neutrino-nucleus scattering (CEvNS) plays a crucial role at the final evolution of stars. The detection of it would be of importance in astroparticle physics. Among all available neutrino sources, galactic supernovae give the highest neutrino flux in the MeV range. Among all liquid xenon dark matter experiments, XMASS has the largest sensitive volume and light yield. The possibility to detect galactic supernova via the CEvNS-process on xenon nuclei in the current XMASS detector was investigated. The total number of events integrated in about 18 seconds after the explosion of a supernova 10~kpc away from the Earth was expected to be from 3.5 to 21.1, depending on the supernova model used to predict the neutrino flux, while the number of background events in the same time window was measured to be negligible. All lead to very high possibility to detect CEvNS experimentally for the first time utilizing the combination of galactic supernovae and the XMASS detector. In case of a supernova explosion as close as Betelgeuse, the total observable events can be more than ten thousand, making it possible to distinguish different supernova models by examining the evolution of neutrino event rate in XMASS.

   ↳ physics.ins-detastro-ph.HEastro-ph.IMhep-ex+1Astropart.Phys.(2017)·31 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.