High-Resolution Search for Pentaquark Partners in Hall A at Jefferson Lab
We have carried out a high-resolution search ({sigma} = 1.5 MeV) for narrow exotic resonances ({Gamma} < 10 MeV) in the mass range M {approx} 1500-1850 MeV in ep {yields} e'K{sup +}X, ep {yields} e'K{sup -}X and ep {yields} e'{pi}{sup +}X electroproduction at forward angles ({theta}{sup CM} {approx} 6-7 degrees). Such narrow resonances would be candidates for partner states of the speculative {Theta}{sup +}(1540) pentaquark. The experiment employed a 5 GeV CW electron beam incident on a liquid hydrogen target and two high-resolution magnetic spectrometers covering a total center-of-mass solid angle of {Delta}{Omega} {approx} 30-40 msr. We do not observe a statistically significant signal in any of the three reaction channels. Upper limits on the production cross sections were determined to be between 3 and 16 nb/sr, depending on the channel and the assumed width of the state. In addition, precise electroproduction data of the {Lambda}(1116), {Sigma}(1193) and {Lambda}(1520) resonances were obtained for calibration purposes.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-84ER40150
- OSTI ID:
- 859285
- Report Number(s):
- JLAB-PHY-06-1; DOE/ER/40150-3625; TRN: US200520%%138
- Resource Relation:
- Conference: 11th International Conference On Hadron Spectroscopy (Hadron05), 21-26 Aug 2005, Rio de Janeiro, Brazil
- Country of Publication:
- United States
- Language:
- English
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