Fri·Sep 23, 2011Friday·September 23, 2011

1. 01*

   Heavy-flavor production in pp and Pb-Pb collisions at LHC with ALICE

   Kai Schweda (for the ALICE Collaboration)🇩🇪

   We report recent results from the ALICE experiment the Large Hadron Collider on open charmed hadron production in pp collisions at $\sqrt{s}=2.76$ and 7 TeV, and Pb-Pb collisions at $\sqrt{{\mathrm{s}}_{{}_{\mathrm{NN}}}}=2.76$ TeV. Open charmed hadrons are kinematically fully reconstructed in the hadronic decay channels \DtoKpi, \DtoKpipi, and \DstartoDpi %$D^0\to K^{-}{\pi }^{+}$, $D^{+}\to K^{-}{\pi }^{+}{\pi }^{+}$, and $D^{\ast +}\to D^0(K^{-}{\pi }^{+})+{\pi }^{+}$ and identified through their invariant mass. Combinatorial background is minimized by selecting a displaced vertex topology. Inclusive charm and beauty production is measured by detecting electrons (muons) from semi-leptonic decays of open charmed and beauty hadrons in the central (forward) region. Comparison to results from state-of-the-art QCD calculations is given. First results on nuclear modifications factors in Pb--Pb collisions from hadronic and semi-leptonic decays are presented.

   nucl-exhep-ex1 citation
2. 02*

   Polarization components in ${\pi }^0$ photoproduction at photon energies up to 5.6 GeV

   W. Luo🇨🇳 · E. J. Brash🇺🇸 · R. Gilman🇺🇸 · M. K. Jones🇺🇸 · M. Meziane🇺🇸 · L. Pentchev🇺🇸 · C. F. Perdrisat🇺🇸 · A. J. R. Puckett🇺🇸 · V. Punjabi🇺🇸 · F. R. Wesselmann🇺🇸 · A. Ahmidouch🇺🇸 · I. Albayrak🇺🇸 and 98 other authors

   We present new data for the polarization observables of the final state proton in the ${}^{1}H(\vec{\gamma },\vec{p}){\pi }^0$ reaction. These data can be used to test predictions based on hadron helicity conservation (HHC) and perturbative QCD (pQCD). These data have both small statistical and systematic uncertainties, and were obtained with beam energies between 1.8 and 5.6 GeV and for ${\pi }^0$ scattering angles larger than 75${}^{\circ }$ in center-of-mass (c.m.) frame. The data extend the polarization measurements data base for neutral pion photoproduction up to $E_{\gamma }=5.6GeV$. The results show non-zero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and ${\pi }^0$ scattering angle in c.m. frame. This indicates that HHC does not hold and that the pQCD limit is still not reached in the energy regime of this experiment.

   nucl-exPRL(2012)·13 citations
3. 03*

   Neutron Nuclear Data Evaluation of Actinoid Nuclei for CENDL-3.1

   Chen Guo-Chang🇨🇳 · Cao Wen-Tian🇨🇳 · Yu Bao-Sheng🇨🇳 · Tang Guo-You🇨🇳 · Shi Zhao-Min🇨🇳 · Tao Xi🇨🇳

   New evaluations for several actinoids of the third version of China Evaluated Nuclear Data Library (CENDL-3.1) have been completed during the period between 2000 and 2005. The evaluations are for all neutron induced reactions with Uranium, Neptunium, Plutonium and Americium in the mass range A=232-241, 236-239, 236-246 and 240-244, respectively, and cover the incident neutron energy up to 20 MeV. In present evaluation, much more efforts were devoted to improve reliability of nuclide for available new measured data, especially scarce experimental data. A general description for the evaluation of several actinoids data were presented.

   nucl-ex0 citations
4. 04*

   The MAJORANA Experiment

   The MAJORANA Collaboration

   The MAJORANA collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay) experiment. The current, primary focus is the construction of the MAJORANA DEMONSTRATOR experiment, an R&D effort that will field approximately 40kg of germanium detectors with mixed enrichment levels. This article provides a status update on the construction of the DEMONSTRATOR.

   nucl-ex3 citations
5. 05*

   Measurement of the double polarisation observable G in single pseudoscalar meson photoproduction

   Marcus Grüner🇩🇪

   The excitation spectrum of the nucleon consists of several overlapping resonances. To identify these resonances and their contributions to the measured cross sections, a partial wave analysis is used. A set of at least eight, well chosen, single and double polarisation observables is needed to derive an unambiguous solution. With the Crystal Barrel/TAPS setup at ELSA, single and double polarisation observables can be measured in different reaction channels, by using the combination of a linearly or circularly polarised photon beam and a longitudinally or transversely polarised butanol frozen spin target. Results of the G asymmetry measurement, using linearly polarised photons and longitudinally polarised protons, for pion and eta photoproduction are presented. This project is supported by the DFG (SFB/TR16).

   nucl-ex1 citation
6. 06*

   Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC

   N. Sharma (for the ALICE Collaboration)🇮🇳

   We present first results on the production of nuclei and antinuclei such as (anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at $\text{s}$ = 7 TeV and Pb-Pb collisions at $\text{sNN}$ = 2.76 TeV. These particles are identified using their energy loss (dE/dx) information in the Time Projection Chamber of the ALICE experiment. The Inner Tracking System gives a precise determination of the event vertex, by which primary and secondary particles are separated. The high statistics of over 360 million events for pp and 16 million events for Pb-Pb collisions give a significant number of light nuclei and antinuclei (Pb-Pb collisions: \sim30,000 anti-deuterons($\bar{d}$) and \sim4 anti-alpha($\overline{{}^{4}He}$)). The predictions of various particle ratios from the THERMUS model is also discussed.

   nucl-exJ.Phys.G(2011)·22 citations
7. 07*

   K0s and \Lambda\ production in Pb--Pb collisions with the ALICE experiment

   Iouri Belikov (for the ALICE Collaboration)🇫🇷

   We present the study of K0s and Lambda production performed with the ALICE experiment at the LHC in Pb--Pb collisions at \sqrt{s_NN}=2.76 TeV and pp collisions at \sqrt{s}=0.9 and 7 TeV. The K0s and Lambda particles are reconstructed via their V0 decay topology allowing their identification up to high transverse momenta. The corresponding baryon/meson ratios as a function of transverse momentum are extracted for Pb--Pb collisions in centrality bins and in the transverse momentum range from 1 to 6 GeV/c. They are also compared with those measured in pp events at the LHC energies of 0.9 and 7 TeV as well as in Au--Au collisions at \sqrt{s_NN} = 62.4 and 200 GeV from RHIC.

   ↳ hep-exnucl-exJ.Phys.G(2011)·22 citations
8. 08*

   Charge-dependent Azimuthal Correlations in Relativistic Heavy-ion Collisions and Electromagnetic Effects

   K. F. Liu🇺🇸

   We propose a scenario where the pattern of the recently observed charge-dependent azimuthal correlations can be understood qualitatively. This is based on the cluster picture and the assumption that the charged hadrons that flow outward from the surface of the overlapping region of the colliding nuclei move primarily parallel to the reaction plane. We also point out the there is a strong electric field induced by the transient magnetic field during the parton production in the initial phase of the relativistic heavy-ion collision and discuss its possible relevance to the scenario.

   ↳ nucl-thhep-exhep-phnucl-exPRC(2012)·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.