Corrected Article: Exclusive electroproduction of φ mesons at 4.2 GeV [Phys. Rev. C<b>63</b>, 065205 (2001)]

K. Lukashin, E. S. Smith, G. S. Adams, E. Anciant, M. Anghinolfi, B. Asavapibhop, G. Audit, T. Auger, H. Avakian, J. Ball,

Physical Review C · 2001 · 10 citations · 30 references

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Abstract

We studied the exclusive reaction $e\stackrel{\ensuremath{\rightarrow}}{p}{e}^{\ensuremath{'}}{p}^{\ensuremath{'}}\ensuremath{\varphi}$ using the $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\varphi}}{K}^{+}{K}^{\ensuremath{-}}$ decay mode. The data were collected using a 4.2 GeV incident electron beam and the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. Our experiment covers the range in ${Q}^{2}$ from 0.7 to 2.2 ${\mathrm{GeV}}^{2},$ and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of $\ensuremath{\varphi}$ production on the proton. Our measurement shows the expected decrease of the t slope with the vector-meson formation time $c\ensuremath{\Delta}\ensuremath{\tau}$ below 2 fm. At $〈c\ensuremath{\Delta}\ensuremath{\tau}〉=0.6$ fm, we measure ${b}_{\ensuremath{\varphi}}=2.27\ifmmode\pm\else\textpm\fi{}0.42$ ${\mathrm{GeV}}^{\ensuremath{-}2}.$ The cross section dependence on W as ${W}^{0.2\ifmmode\pm\else\textpm\fi{}0.1}$ at ${Q}^{2}=1.3$ ${\mathrm{GeV}}^{2}$ was determined by comparison with $\ensuremath{\varphi}$ production at HERA after correcting for threshold effects. This is the same dependence as observed in photoproduction.

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