Wed·Sep 7, 2011Wednesday·September 7, 2011

1. 01*

   Upper limits for the photoproduction cross section for the Phi--(1860) pentaquark state off the deuteron

   H. Egiyan · J. Langheinrich · R.W. Gothe · L. Graham · M. Holtrop · H. Lu · P. Mattione · G. Mutchler · K. Park · E.S. Smith · S. Stepanyan · Z.W. Zhao · CLAS Collaboration

   We searched for the Phi--(1860) pentaquark in the photoproduction process off the deuteron in the Xi- pi- decay channel using CLAS. The invariant mass spectrum of the Xi- pi- system does not indicate any statistically significant enhancement near the reported mass M = 1.860 GeV. The statistical analysis of the sideband-subtracted mass spectrum yields a 90% confidence level upper limit of 0.7 nb for the photoproduction cross section of Phi--(1860) with a consecutive decay into Xi- pi- in the photon energy range 4.5 GeV < Egamma < 5.5 GeV.

   nucl-exPRC(2012)·4 citations
2. 02*

   Xenon purity analysis for EXO-200 via mass spectrometry

   A. Dobi🇺🇸 · C. Hall🇺🇸 · S. Slutsky🇺🇸 · Y.-R. Yen🇺🇸 · B. Aharmin🇨🇦 · M. Auger🇨🇭 · P.S. Barbeau🇺🇸 · C. Benitez-Medina🇺🇸 · M. Breidenbach🇺🇸 · B. Cleveland🇨🇦 · R. Conley🇺🇸 · J. Cook🇺🇸 and 64 other authors

   We describe purity measurements of the natural and enriched xenon stockpiles used by the EXO-200 double beta decay experiment based on a mass spectrometry technique. The sensitivity of the spectrometer is enhanced by several orders of magnitude by the presence of a liquid nitrogen cold trap, and many impurity species of interest can be detected at the level of one part-per-billion or better. We have used the technique to screen the EXO-200 xenon before, during, and after its use in our detector, and these measurements have proven useful. This is the first application of the cold trap mass spectrometry technique to an operating physics experiment.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2012)·30 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.