Tue·Sep 20, 2011Tuesday·September 20, 2011

1. 01*

   Comparison of Lithium Gadolinium Borate Crystal Shards in Scintillating and Nonscintillating Plastic Matrices

   Kareem Kazkaz🇺🇸 · Nathaniel S. Bowden🇺🇸 · Marisa Pedretti🇺🇸

   We present a method for detecting neutrons using scintillating lithium gadolinium borate crystal shards in a plastic matrix while maintaining high gamma rejection. We have procured two cylindrical detectors, 5"\times5", containing 1% crystal by mass. Crystal shards have a typical dimension of 1 mm. One detector was made with scintillating plastic, and one with nonscintillating plastic. Pulse shape analysis was used to reject gamma ray backgrounds. The scintillating detector was measured to have an intrinsic fast fission neutron efficiency of 0.4% and a gamma sensitivity of less than 2.3 \times 10-9, while the nonscintillating detector had a neutron efficiency of 0.7% and gamma sensitivity of (4.75\pm3.94)\times10-9. We determine that increasing the neutron detection efficiency by a factor of 2 will make the detector competitive with moderated 3He tubes, and we discuss several simple and straightforward methods for obtaining or surpassing such an improvement. We end with a discussion of possible applications, both for the scintillating-plastic and nonscintillating-plastic detectors.

   nucl-exIEEE Trans.Nucl.Sci.(2013)·1 citation
2. 02*

   Measuring the JPsi-Nucleon dissociation cross section with PANDA

   Paul Bühler🇦🇹

   With the PANDA detector at the HESR at FAIR it will be possible to study the production and absorption of charmed hadrons in nuclear targets. Of special interest in this context is the determination of the JPsi-nucleon dissociation cross section. This can be determined with measurements of the JPsi yield in antiproton-nucleus reactions using different target materials. The experiment is described and numerical simulations are presented.

   nucl-ex0 citations
3. 03*

   Measuring the Upsilon Nuclear Modification Factor at STAR

   Rosi Reed (for the STAR Collaboration)🇺🇸

   Suppression of quarkonia in heavy ion collisions with respect to proton-proton collisions due to the Debye screening of the potential between the heavy quarks was hypothesized to be a signature of the Quark Gluon Plasma (QGP). However, other effects besides Debye screening, such as the statistical recombination of quark anti-quark heavy flavor pairs, or co-mover absorption can also affect quarkonia production in heavy ion collisions. Quantifying the suppression of an entire family of quarkonium mesons can give us a model dependent constraint on the temperature. The suppression of Upsilon can be quantified by calculating the Nuclear Modification factor, RAA, which is the ratio of the production in Au+Au collisions to the production in p+p scaled by the number of binary collisions. We present our results for mid-rapidity Upsilon(1S+2S+3S) production in p+p and Au+Au collisions at sqrt(sNN) = 200 GeV. The centrality dependence of RAA will be shown for the combined Upsilon(1S+2S+3S) yield.

   nucl-exJ.Phys.G(2011)·36 citations
4. 04*

   Measurement of the double polarisation observable E in single pseudoscalar meson production

   Jonas Müller🇩🇪 · Manuela Gottschall🇩🇪

   Polarisation observables are measured with the Crystal Barrel/TAPS experiment at ELSA for photoproduction reactions with various final states, using a circularly or linearly polarised photon beam and a longitudinally or transversely polarised frozen spin butanol target. The Crystal Barrel/TAPS setup provides a nearly 4$\pi$ angular coverage, a good energy resolution and a high detection efficiency for photons, and is therefore ideally suited to study final states comprising neutral mesons. Results for the measurement of the double polarisation observable E for pion and eta photoproduction off the proton are presented.

   nucl-ex1 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.