Wed·Mar 8, 2017Wednesday·March 8, 2017

1. 01*

   A new measurement of electron transverse polarization in polarized nuclear beta decay

   H. Kawamura🇯🇵 · T. Akiyama🇯🇵 · M. Hata🇯🇵 · Y. Hirayama🇯🇵 · M. Ikeda🇯🇵 · Y. Ikeda🇯🇵 · T. Ishii🇯🇵 · D. Kameda🇯🇵 · S. Mitsuoka🇯🇵 · H. Miyatake🇯🇵 · D. Nagae🇯🇵 · Y. Nakaya🇯🇵 and 11 other authors

   The Mott polarimetry for T -Violation (MTV) experiment tests time-reversal symmetry in polarized nuclear beta decay by measuring an electron's transverse polarization as a form of angular asymmetry in Mott scattering using a thin metal foil. A Mott scattering analyzer system developed using a tracking detector to measure scattering angles offers better event selectivity than conventional counter experiments. In this paper, we describe a pilot experiment conducted at KEK-TRIAC using a prototype system with a polarized 8Li beam. The experiment confirmed the sound performance of our Mott analyzer system to measure T-violating triple correlation (R correlation), and therefore recommends its use in higher-precision experiments at the TRIUMF-ISAC.

   nucl-exMod.Phys.Lett.A(2017)·0 citations
2. 02*

   QCD mechanisms for accessing the nucleon GPDs with the exclusive pion-induced Drell-Yan process at J-PARC

   Kazuhiro Tanaka (Juntendo Univ.)🇯🇵

   Generalized parton distributions (GPDs) encoding multidimensional information of hadron partonic structure appear as the building blocks in a factorized description of hard exclusive reactions. The nucleon GPDs have been accessed by deeply virtual Compton scattering and deeply virtual meson production with lepton beam. A complementary probe with hadron beam is the exclusive pion-induced Drell-Yan process. We discuss recent theoretical advances on describing this process in terms of the partonic subprocess convoluted with the nucleon GPDs and the pion distribution amplitudes. Furthermore, we mention the feasibility study for measuring the exclusive pion-induced Drell-Yan process, ${\pi }^{-}p\to {\mu }^{+}{\mu }^{-}n$, via a spectrometer at the High Momentum Beamline being constructed at J-PARC in Japan. We also point out the possible soft partonic mechanisms beyond the QCD factorization framework, which could give important contributions at J-PARC kinematics, and present an estimate of the soft mechanisms making use of dispersion relations and quark-hadron duality. Realization of the measurement of the exclusive pion-induced Drell-Yan process at J-PARC will provide a new test of QCD descriptions of a novel class of hard exclusive reactions. It will also offer the possibility of experimentally accessing nucleon GPDs at large timelike virtuality.

   ↳ hep-phhep-exnucl-exnucl-th3 citations
3. 03*

   Measurements of the suppression and anisotropy of heavy-flavour particles in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$= 2.76 TeV with ALICE

   A. Dubla (for the ALICE Collaboration)🇩🇪

   Heavy quarks, i.e. charm and beauty, are produced on a shorter time scale with respect to the strongly-interacting matter produced in high-energy heavy-ion collisions. Therefore, they are unique probes to study the mechanisms of parton energy loss, hadronisation and thermalization in the hot and dense state of matter. The nuclear modification factor ($R_{\mathrm{AA}}$) and the elliptic flow ($v_2$) are two of the main experimental observables that allow us to investigate the interaction strength of heavy quarks with the medium. The most recent results on heavy-flavour production and elliptic flow measured by the ALICE collaboration in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV will be discussed.

   ↳ hep-exnucl-exNucl.Part.Phys.Proc.(2017)·0 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.