Differential cross sections and spin density matrix elements for gamma p -> phi p from CLAS
Preliminary differential cross-sections and the {rho}{sub MM'}{sup 0} spin density matrix elements (SDME) for the reaction {gamma}p {yields} {phi} for both charged- ({phi} {yields} K{sup +}K{sup -}) and neutral-mode ({phi} {yields} K{sub L}{sup 0}K{sub S}{sup 0}) topologies obtained from CLAS are presented. Our kinematic coverage is from near production threshold ({radical}s {approx} 1.97$$ GeV) to {radical}s = 2.84$$ GeV, with a wide coverage in the production angle. As seen in previous LEPS results, the differential cross-sections show a localized 'bump' between {radical}s {approx} 2 and 2.2 GeV that is not expected from a simple Pomeron exchange picture. Comparisons between the charged- and neutral-mode results and possible effects from the K{sup +} {Lambda}(1520) channel are discussed. Our SDME results confirm the well-known deviations from t-channel helicity conservation (TCHC) for Pomeron exchange, but s-channel helicity conservation (SCHC) is also seen to be broken.
- Research Organization:
- Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- AC05-06OR23177
- OSTI ID:
- 1028813
- Report Number(s):
- JLAB-PHY-10-1294; DOE/OR/23177-1738; arXiv:1103.3821; TRN: US1105506
- Resource Relation:
- Conference: BARYONS'10,Osaka, Japan, Dec. 7-11, 2010
- Country of Publication:
- United States
- Language:
- English
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