Tue·Jul 14, 2009Tuesday·July 14, 2009

1. 01*

   Bulk Properties in Au+Au Collisions at $\sqrt{s_{NN}}$ = 9.2 GeV in STAR Experiment at RHIC

   Lokesh Kumar (for the STAR Collaboration)🇺🇸

   One of the primary goals of high-energy heavy-ion collisions is to establish the QCD phase diagram and search for possible phase boundaries. The planned RHIC energy scan program will explore this exciting physics topic using heavy-ion collisions at various center of mass energies. The first test run with Au+Au collisions at $\sqrt{s_{NN}}$ = 9.2 GeV took place in early 2008. We present the results on identified particle ratios, azimuthal anisotropy parameters (v1 and v2) and HBT at midrapidity using data from this run. These results are compared to data for both lower and higher center of mass energies at the AGS, SPS and RHIC. These new data demonstrate the capabilities of the STAR detector for exploring the QCD phase diagram.

   nucl-exNPA(2009)·16 citations
2. 02*

   Open Charm Mesons at the LHC with ALICE

   Renu Bala🇮🇹

   The ALICE experiment will be able to detect hadrons containing charm and beauty quarks in proton-proton and heavy ion collisions in the new energy regime of the CERN Large Hadron Collider (LHC). Open charmed mesons are a powerful tool to study the medium produced in heavy ion collisions, since charm quarks are produced on a very short time scale and they experience the whole history of the collision. In addition, the measurements of heavy flavour yield provide a natural normalization for those of charmonia and bottomonia production at LHC. In this talk, after a general overview of ALICE perspectives for heavy flavour physics, we will report some study of D-meson reconstruction through their hadronic decay channels with Monte Carlo simulated data.

   nucl-ex0 citations
3. 03*

   Discovery of the Vanadium Isotopes

   A. Shore🇺🇸 · A. Fritsch🇺🇸 · M. Heim🇺🇸 · A. Schuh🇺🇸 · M. Thoennessen🇺🇸

   Twenty-four vanadium isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

   nucl-exAtom.Data Nucl.Data Tabl.(2010)·5 citations
4. 04*

   The Compressed Baryonic Matter Experiment at FAIR: Progress with feasibility studies and detector developments

   Johann M. Heuser (for the CBM collaboration)🇯🇵

   The Compressed Baryonic Matter (CBM) experiment is being planned at the international research center FAIR, under realization next to the GSI laboratory in Darmstadt, Germany. Its physics programme addresses the QCD phase diagram in the region of highest net baryon densities. Of particular interest are the expected first order phase transition from partonic to hadronic matter, ending in a critical point, and modifications of hadron properties in the dense medium as a signal of chiral symmetry restoration. Laid out as a fixed-target experiment at the heavy-ion synchrotrons SIS-100/300, the detector will record both proton-nucleus and nucleus-nucleus collisions at beam energies between 10 and 45$A$ GeV. Hadronic, leptonic and photonic observables have to be measured with large acceptance. The interaction rates will reach 10 MHz to measure extremely rare probes like charm near threshold. Two versions of the experiment are being studied, optimized for either electron-hadron or muon identification, combined with silicon detector based charged-particle tracking and micro-vertex detection. The CBM physics requires the development of novel detector sytems, trigger and data acquisition concepts as well as innovative real-time reconstruction techniques. Progress with feasibility studies of the CBM experiment and the development of its detector systems are reported.

   nucl-exNPA(2009)·18 citations
5. 05*

   Experimental study of local strong parity violation in relativistic nuclear collisions

   Sergei A. Voloshin · the STAR Collaboration

   Parity-odd domains, corresponding to non-trivial topological solutions of the QCD vacuum, might be created in relativistic heavy ions collisions. These domains are predicted to lead to charge separation along the system orbital momentum of the system created in non-central collisions. Three-particle mixed harmonics azimuthal correlator is a \P even observable but directly sensitive to the charge separation effect. Using this observable to analyze Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}}=200$ and 62 GeV, STAR detects a signal consistent with several of the theoretical expectations. Possible contributions from effects not related to parity violation are studied with existing event generators, which fail to describe the data. Future directions in studying the effect are discussed.

   nucl-exNPA(2009)·35 citations
6. 06*

   Theory Support for the Excited Baryon Program at the Jlab 12 GeV Upgrade

   I. Aznauryan🇺🇸 · V. Braun🇩🇪 · V. Burkert🇺🇸 · S. Capstick🇺🇸 · R. Edwards🇺🇸 · I.C. Cloet🇺🇸 · M. Giannini🇮🇹 · T.-S. H. Lee🇺🇸 · H.-W. Lin🇺🇸 · V. Mokeev🇺🇸 · C.D. Roberts🇺🇸 · E. Santopinto🇮🇹 and 3 other authors

   This document outlines major directions in theoretical support for the measurement of nucleon resonance transition form factors at the JLab 12 GeV upgrade with the CLAS12 detector. Using single and double meson production, prominent resonances in the mass range up to 2 GeV will be studied in the range of photon virtuality $Q^2$ up to 12 GeV${}^2$ where quark degrees of freedom are expected to dominate. High level theoretical analysis of these data will open up opportunities to understand how the interactions of dressed quarks create the ground and excited nucleon states and how these interactions emerge from QCD. The paper reviews the current status and the prospects of QCD based model approaches that relate phenomenological information on transition form factors to the non-perturbative strong interaction mechanisms, that are responsible for resonance formation.

   ↳ nucl-thhep-latnucl-ex45 citations
7. 07*

   QED vacuum fluctuations and induced electric dipole moment of the neutron

   C.A. Dominguez🇿🇦 · H. Falomir🇦🇷 · M. Ipinza🇨🇱 · S. Kohler🇺🇸 · M. Loewe🇨🇱 · J.C. Rojas🇨🇱

   Quantum fluctuations in the QED vacuum generate non-linear effects, such as peculiar induced electromagnetic fields. In particular, we show here that an electrically neutral particle, possessing a magnetic dipole moment, develops an induced electric dipole-type moment with unusual angular dependence, when immersed in a quasistatic, constant external electric field. The calculation of this effect is done in the framework of the Euler-Heisenberg effective QED Lagrangian, corresponding to the weak field asymptotic expansion of the effective action to one-loop order. It is argued that the neutron might be a good candidate to probe this signal of non-linearity in QED.

   ↳ hep-phhep-exhep-lathep-th+1PRD(2009)·3 citations
8. 08*

   A Xenon Condenser with a Remote Liquid Storage Vessel

   S. Slutsky🇺🇸 · Y.-R. Yen🇺🇸 · H. Breuer🇺🇸 · A. Dobi🇺🇸 · C. Hall🇺🇸 · T. Langford🇺🇸 · D. S. Leonard🇺🇸 · L. J. Kaufman🇺🇸 · V. Strickland🇨🇦 · N. Voskanian🇺🇸

   We describe the design and operation of a system for xenon liquefaction in which the condenser is separated from the liquid storage vessel. The condenser is cooled by a pulse tube cryocooler, while the vessel is cooled only by the liquid xenon itself. This arrangement facilitates liquid particle detector research by allowing easy access to the upper and lower flanges of the vessel. We find that an external xenon gas pump is useful for increasing the rate at which cooling power is delivered to the vessel, and we present measurements of the power and efficiency of the apparatus.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2009)·4 citations
9. 09*

   Will jets reduce the elliptic flow at LHC, while decays of resonances restore the constituent quark scaling?

   G. Eyyubova (1,2)🇳🇴 · L. Bravina (1)🇳🇴 · V.L. Korotkih (2)🇷🇺 · I.P. Lokhtin (2)🇷🇺 · L.V. Malinina (1,2,3)🇷🇺 · S.V. Petrushanko (2)🇷🇺 · A.M. Snigirev (2)🇷🇺 · E. Zabrodin (1,2) (1 - Department of Physics, University of Oslo, Norway; 2 - Skobeltsyn Institute of Nuclear Physics, Moscow State University, Russia; 3 - Joint Institute for Nuclear Researches, Dubna, Russia)🇳🇴

   Formation and evolution of the elliptic flow pattern in Pb+Pb collisions at sqrt{s}=5.5 ATeV and in Au+Au collisions at sqrt{s}=200 AGeV are analyzed for different hadron species within the framework of HYDJET++ Monte-Carlo model. The model contains both hydrodynamic state and jets, thus allowing for a study of the interplay between the soft and hard processes. It is found that jets are terminating the rise of the elliptic flow with increasing transverse momentum. Since jets are more influential at LHC compared to RHIC, the elliptic flow at LHC should be weaker than that at RHIC. The influence of resonance decays on particle elliptic flow is investigated also. These final state interactions enhance the low-p_T part of the v_2 of pions and light baryons, and work towards the fulfilment of idealized constituent quark scaling.

   ↳ hep-phnucl-exnucl-thPRC(2009)·36 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.