PaperPanorama

Nuclear Experiment·nucl-ex

Tue·Jul 21, 2009

8 papers—6 primary·2 cross-listed·reconstructed*

All8Primary6Cross-lists2
  1. 01*

    Resonance production from jet fragmentation

    Christina Markert · (for the) STAR Collaboration

    Short lived resonances are sensitive to the medium properties in heavy-ion collisions. Heavy hadrons have larger probability to be produced within the quark gluon plasma phase due to their short formation times. Therefore heavy mass resonances are more likely to be affected by the medium, and the identification of early produced resonances from jet fragmentation might be a viable option to study chirality. The high momentum resonances on the away-side of a triggered di-jet are likely to be the most modified by the partonic or early hadronic medium. We will discuss first results of triggered hadron-resonance correlations in Cu+Cu heavy ion collisions.

    nucl-exEPJC(2009)·0 citations
  2. 02*

    The Transition Radiation Detector for ALICE at LHC

    M.J. Kweon (for the ALICE TRD Collaboration)🇰🇷

    The Transition Radiation Detector (TRD) for the ALICE experiment at the Large Hadron Collider (LHC) identifies electrons in p+p and in the challenging high multiplicity environment of heavy-ion collisions and provides fast online tracking for the ALICE Level1 trigger. The TRD is designed to have excellent position resolution and pion rejection capability. Presently, six of the 18 TRD supermodules are installed in the ALICE central barrel. In 2008, four supermodules were installed and commissioning of the detector using cosmic ray tracks was successfully performed. We briefly describe the design of the detector and report on the performance and current understanding of the detector based on these data.

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

    Photodisintegration of He into p+t

    R. Nasseripour · B.L. Berman · N. Benmouna · Y. Ilieva · J.-M. Laget

    The two-body photodisintegration of He into a proton and a triton has been studied using the CEBAF Large-Acceptance Spectrometer (CLAS) at Jefferson Laboratory. Real photons produced with the Hall-B bremsstrahlung-tagging system in the energy range from 0.35 to 1.55 GeV were incident on a liquid He target. This is the first measurement of the photodisintegration of He above 0.4 GeV. The differential cross sections for the He reaction have been measured as a function of photon-beam energy and proton-scattering angle, and are compared with the latest model calculations by J.-M. Laget. At 0.6-1.2 GeV, our data are in good agreement only with the calculations that include three-body mechanisms, thus confirming their importance. These results reinforce the conclusion of our previous study of the three-body breakup of He that demonstrated the great importance of three-body mechanisms in the energy region 0.5-0.8 GeV .

    nucl-exPRC(2009)·6 citations
  7. 07*

    Reaction-in-Flight Neutrons as a Signature for Shell Mixing in NIF capsules

    A.C. Hayes🇺🇸 · P.A. Bradley🇺🇸 · G.P. Grim🇺🇸 · Gerard Jungman🇺🇸 · J.B. Wilhelmy🇺🇸

    We present analytic calculations and results from computational simulations showing that reaction-in-flight (RIF) neutrons act as a robust indicator for mixing of the ablator shell material into the fuel in DT capsules designed for the National Ignition Facility. The sensitivity of RIF neutrons to hydrodynamical mixing arises through the dependence of RIF production on charged-particle stopping lengths in the mixture of DT fuel and ablator material. Since the stopping power in the plasma is a sensitive function of the electron temperature and density, it is also sensitive to mix. RIF production scales approximately inversely with the degree of mixing taking place, and the ratio of RIF to downscattered neutrons provides a measure of the mix fraction and/or the mixing length. For sufficiently high-yield capsules, where spatially resolved RIF images may be possible, neutron imaging could be used to map RIF images into detailed mix images.

    ↳ physics.plasm-phnucl-exnucl-thPhys.Plasmas(2010)·7 citations
  8. 08*

    Size fluctuations of the initial source and the event-by-event transverse momentum fluctuations in relativistic heavy-ion collisions

    Wojciech Broniowski🇵🇱 · Mikolaj Chojnacki🇵🇱 · Lukasz Obara🇵🇱

    We show that the event-by-event fluctuations of the transverse size of the initial source, which follow directly from the Glauber treatment of the earliest stage of relativistic heavy-ion collisions, cause, after hydrodynamic evolution, fluctuations of the transverse flow velocity at hadronic freeze-out. This in turn leads to event-by-event fluctuations of the average transverse momentum, p_T. Simulations with GLISSANDO for the Glauber phase, followed by a realistic hydrodynamic evolution and statistical hadronization carried out with THERMINATOR, lead to agreement with the RHIC data. In particular, the magnitude of the effect, its centrality dependence, and the weak dependence on the incident energy are properly reproduced. Our results show that bulk of the observed event-by-event p_T fluctuations may be explained by the fluctuations of the size of the initial source.

    ↳ nucl-thhep-phnucl-exPRC(2009)·75 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.