Wed·May 27, 2015Wednesday·May 27, 2015

1. 01*

   Nucleon-Gold Collisions at 200 AGeV Using Tagged d+Au Interactions in PHOBOS

   B. B. Back🇺🇸 · M. D. Baker🇺🇸 · M. Ballintijn🇺🇸 · D. S. Barton🇺🇸 · B. Becker🇺🇸 · R. R. Betts🇺🇸 · A. A. Bickley🇺🇸 · R. Bindel🇺🇸 · W. Busza🇺🇸 · A. Carroll🇺🇸 · M. P. Decowski🇳🇱 · E. García🇺🇸 and 49 other authors

   Forward calorimetry in the PHOBOS detector has been used to study charged hadron production in d+Au, p+Au and n+Au collisions at sqrt(s_nn) = 200 GeV. The forward proton calorimeter detectors are described and a procedure for determining collision centrality with these detectors is detailed. The deposition of energy by deuteron spectator nucleons in the forward calorimeters is used to identify p+Au and n+Au collisions in the data. A weighted combination of the yield of p+Au and n+Au is constructed to build a reference for Au+Au collisions that better matches the isospin composition of the gold nucleus. The p_T and centrality dependence of the yield of this improved reference system is found to match that of d+Au. The shape of the charged particle transverse momentum distribution is observed to extrapolate smoothly from pbar+p to central d+Au as a function of the charged particle pseudorapidity density. The asymmetry of positively- and negatively-charged hadron production in p+Au is compared to that of n+Au. No significant asymmetry is observed at mid-rapidity. These studies augment recent results from experiments at the LHC and RHIC facilities to give a more complete description of particle production in p+A and d+A collisions, essential for the understanding the medium produced in high energy nucleus-nucleus collisions.

   nucl-exPRC(2015)·0 citations
2. 02*

   Toward the Limits of Matter: Ultra-relativistic nuclear collisions at CERN

   Jurgen Schukraft🇨🇭 · Reinhard Stock🇩🇪

   Strongly interacting matter as described by the thermodynamics of QCD undergoes a phase transition, from a low temperature hadronic medium to a high temperature quark-gluon plasma state. In the early universe this transition occurred during the early microsecond era. It can be investigated in the laboratory, in collisions of nuclei at relativistic energy, which create "fireballs" of sufficient energy density to cross the QCD Phase boundary. We describe 3 decades of work at CERN, devoted to the study of the QCD plasma and the phase transition. From modest beginnings at the SPS, ultra-relativistic heavy ion physics has evolved today into a central pillar of contemporary nuclear physics and forms a significant part of the LHC program.

   nucl-exhep-exAdv.Ser.Direct.High Energy Phys.(2015)·16 citations
3. 03*

   Form factors and radii of light nuclei

   Ingo Sick🇨🇭

   We discuss the determination of electromagnetic form factors from the {\em world} data on electron-nucleus scattering for nuclei $Z\le 3$, with particular emphasis on the derivation of the moments required for comparison with measurements from electronic/muonic atoms and isotope shifts.

   nucl-exnucl-th10 citations
4. 04*

   A new tool in nuclear physics: Nuclear lattice simulations

   Ulf-G. Meißner🇩🇪

   In the last years, chiral effective field theory has been successfully developed for and applied to systems with few nucleons. Here, I present a new approach for ab initio calculations of nuclei that combines these precise and systematic forces with Monte Carlo simulation techniques that allow for exact solutions of the nuclear A-body problem. A short introduction of this method is given and a few assorted results concerning the spectrum and structure of 12C and 16O are presented. The framework further allows one to study the properties of nuclei in worlds that have fundamental parameters different from the ones in Nature. This allows for a physics test of the anthropic principle by addressing the question how strongly the generation of the life-relevant elements depends on the light quark masses and the electromagnetic fine structure constant.

   ↳ nucl-thhep-lathep-phnucl-exNucl.Phys.News.(2014)·17 citations
5. 05*

   Radon and material radiopurity assessment for the NEXT double beta decay experiment

   S. Cebrián · J. Pérez · I. Bandac · L. Labarga · V. Álvarez · A.I. Barrado · A. Bettini · F.I.G.M. Borges · M. Camargo · S. Cárcel · A. Cervera · C.A.N. Conde and 59 other authors

   The Neutrino Experiment with a Xenon TPC (NEXT), intended to investigate the neutrinoless double beta decay using a high-pressure xenon gas TPC filled with Xe enriched in 136Xe at the Canfranc Underground Laboratory in Spain, requires ultra-low background conditions demanding an exhaustive control of material radiopurity and environmental radon levels. An extensive material screening process is underway for several years based mainly on gamma-ray spectroscopy using ultra-low background germanium detectors in Canfranc but also on mass spectrometry techniques like GDMS and ICPMS. Components from shielding, pressure vessel, electroluminescence and high voltage elements and energy and tracking readout planes have been analyzed, helping in the final design of the experiment and in the construction of the background model. The latest measurements carried out will be presented and the implication on NEXT of their results will be discussed. The commissioning of the NEW detector, as a first step towards NEXT, has started in Canfranc; in-situ measurements of airborne radon levels were taken there to optimize the system for radon mitigation and will be shown too.

   ↳ physics.ins-dethep-exnucl-exAIP Conf.Proc.(2015)·16 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.