Tue·Dec 9, 2014Tuesday·December 9, 2014

1. 01*

   Elastic breakup cross sections of well-bound nucleons

   K. Wimmer · D. Bazin · A. Gade · J. A. Tostevin · T. Baugher · Z. Chajecki · D. Coupland · M. A. Famiano · T. K. Ghosh · G. F. Grinyer M. E. Howard · M. Kilburn · W. G. Lynch and 12 other authors

   The 9Be(28Mg,27Na) one-proton removal reaction with a large proton separation energy of Sp(28Mg)=16.79 MeV is studied at intermediate beam energy. Coincidences of the bound 27Na residues with protons and other light charged particles are measured. These data are analyzed to determine the percentage contributions to the proton removal cross section from the elastic and inelastic nucleon removal mechanisms. These deduced contributions are compared with the eikonal reaction model predictions and with the previously measured data for reactions involving the re- moval of more weakly-bound protons from lighter nuclei. The role of transitions of the proton between different bound single-particle configurations upon the elastic breakup cross section is also quantified in this well-bound case. The measured and calculated elastic breakup fractions are found to be in good agreement.

   nucl-exPRC(2014)·13 citations
2. 02*

   Zemach moments of 3He and 4He

   Ingo Sick🇨🇭

   We use the world data on elastic electron scattering on 3He and 4He to determine the Zemach moments <r>_(2) and <r^3>_(2). These quantities are required to interpret the Lamb shift and HFS data of muonic Helium presently being measured at PSI by the CREMA collaboration. The rms-radii are determined as well.

   nucl-exnucl-thPRC(2014)·47 citations
3. 03*

   Measurement of beauty-hadron decay electrons in Pb--Pb collisions at sqrt(s_NN) = 2.76 TeV with ALICE

   Martin Völkl (for the ALICE Collaboration)🇩🇪

   The ALICE Collaboration at the LHC studies heavy-ion collisions to investigate the properties of the Quark-Gluon Plasma (QGP). Heavy quarks (charm and beauty) are effective probes for this purpose. Both their energy loss in the medium as well as their possible thermalization yield information about the medium properties. Experimentally, the reconstruction of hadrons with charm valence quarks is possible. For hadrons with beauty valence quarks a promising strategy is the measurement of their decay electrons. To separate these from the background electrons (mainly from charm hadron decays, photon conversions or light-meson decays) the large decay length of beauty hadrons can be utilized. It leads to a relatively large typical impact parameter of the decay electrons. By comparing the impact parameter distribution of the signal electrons with those from the background sources, the signal can be statistically separated from the background. For this purpose a maximum likelihood fit is employed using impact parameter distribution templates from simulations. The resulting nuclear modification factor for electrons from beauty-hadron decays shows a sizeable suppression for p_T > 3 GeV, albeit still with large uncertainties.

   nucl-ex1 citation
4. 04*

   Charged jet reconstruction in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at RHIC

   Jan Rusnak (for the STAR Collaboration)🇨🇿

   Jets represent an important tool to explore the properties of the hot and dense nuclear matter created in heavy-ion collisions. However, full jet reconstruction in such events is a challenging task due to extremely large and fluctuating background, which generates a large population of combinatorial jets that overwhelm the true hard jet population. In order to carry out accurate, data-driven jet measurements over a broad kinematic range in such conditions of small signal to background, we use several novel approaches in order to measure inclusive charged jet distributions and semi-inclusive charged jet distributions recoiling from a high pT hadron trigger in central Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV.

   ↳ hep-exnucl-ex1 citation
5. 05*

   Measurements of non-photonic electrons with the STAR experiment

   Olga Rusňáková (for the STAR Collaboration)🇨🇿

   Non-photonic electrons (NPE), produced by semileptonic decays of D and B mesons, are good probes to study the properties of hot and dense medium created in relativistic heavy ion collisions at RHIC. Studies of heavy quark production in p+p collisions can test the validity of perturbative QCD. They also provide a baseline to study the effects of nuclear matter on the production of heavy quarks in heavy ion collisions. In this paper, we present recent results of NPE spectra measured in p+p collisions at $\sqrt{s}=200$ GeV in mid-rapidity. We also report NPE nuclear modification factor $R_{AA}$ and elliptic flow $v_2$ in Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.

   ↳ hep-exnucl-exJ.Phys.Conf.Ser.(2015)·1 citation

* 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.