136 research outputs found
Search for Pentaquarks at BABAR
The results of searches for the strange pentaquark states, Theta(1540)+,
Xi(1860)-- and Xi(1860)0 in data recorded by the BABAR experiment are
presented. We search for these three states inclusively in 123.4 fb^-1 of e+ e-
annihilation data produced at the PEP-II asymmetric storage rings; we find no
evidence for their production in any physics process, and set limits on their
production rates that are well below the measured rates for conventional
baryons. We also search for Theta(1540)+ produced in interactions of electrons
or hadrons in the material of the inner part of the detector. No evidence for
this state is found in a sample with much higher statistics than similar
electroproduction experiments that claim a signal.Comment: 4 pages, 4 postscript figues, contributed to the Proceedings of QCD
05, Montpellie
Development of a New Clusterization Method for the GEM-TPC Detector
The Facility for Antiproton and Ion Research FAIR, in Darmstadt Germany, will be one of the largest accelerator laboratories worldwide. The Superconducting FRagment Separator (Super-FRS)* is one of its main components. The Super-FRS can produce, separate and deliver high-energy radioactive beams with intensities up to 1e11 ions/s, covering projectiles from protons up to uranium and it can be used as an independent experimental device. The Gas Electron Multiplier-based Time Projection Chambers (GEM-TPC) in twin configuration is a newly developed beam tracking detector capable of providing spatial resolution of less than 1 mm with a tracking efficiency close to 100% at 1 MHz counting rate. The GEM-TPC (HGB4) was tested at the FRagment Separator (FRS), with 238U beam at 850 MeV/u. A new clusterization method was developed, for the first time and used for an analysis. This method allowed to access to waveforms of each strip signal within a single trigger in an event-by-event basis. The procedures involved in this method will be shown in details.Peer reviewe
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