Exclusive electroproduction of phi mesons at 4.2 GeV
Abstract
We studied the exclusive reaction e p --> e' p' phi using the phi --> K^+ K^- decay mode. The data were collected using a 4.2 GeV incident electron beam and the CLAS detector at Jefferson Lab. Our experiment covers the range in Q^2 from 0.7 to 2.2 GeV^2, and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of phi production on the proton. Our measurement shows the expected decrease of the t-slope with the vector meson formation time c Delta tau below 2 fm. At = 0.6 fm, we measure b_phi = 2.27 +- 0.42 GeV^-2. The cross section dependence on W as W^{0.2+-0.1} at Q^2 = 1.3 GeV^2 was determined by comparison with phi production at HERA after correcting for threshold effects. This is the same dependence as observed in photoproduction.
Cite
@article{arxiv.hep-ex/0101030,
title = {Exclusive electroproduction of phi mesons at 4.2 GeV},
author = {CLAS Collaboration and K. Lukashin and E. S. Smith},
journal= {arXiv preprint arXiv:hep-ex/0101030},
year = {2010}
}
Comments
13 pages, LaTeX, 16 eps figures, 3 tables, submitted to Phys Rev C; revised Fig 9 and Subsec "Differential Cross Section"