Electroproduction of exclusive $\phi$ vector mesons has been studied with the CLAS detector in the kinematical range $1.6\leq Q^2\leq 3.8$ GeV$^{2}$, $0.0\leq t^{\prime}\leq 3.6$ GeV$^{2}$, and $2.0\leq W\leq 3.0$ GeV. The scaling exponent for the total cross section as $1/(Q^2+M_{\phi}^2)^n$ was determined to be $n=2.49\pm 0.33$. The slope of the four-momentum transfer $t'$ distribution is $b_{\phi}=0.98 \pm 0.17$ GeV$^{-2}$. The data are consistent with the assumption of s-channel helicity conservation (SCHC). Under this assumption, we determine the ratio of longitudinal to transverse cross sections to be $R=0.86 \pm 0.24$. A 2-gluon exchange model is able to reproduce the main features of the data.
Axis error includes +- 18.6/18.6 contribution.
Axis error includes +- 18.6/18.6 contribution.
Axis error includes +- 18.6/18.6 contribution.
A systematic study of p p and p d reactions producing strange particles between 1.09 and 3.45 GeV/ c has been completed. Reaction and resonance cross-section data are presented at 11 p p and 13 p d momentum settings. Evidence for a broad shoulder in the K K 3π final state near 1.8 GeV/ c is presented and contrasted to previously published work on a portion of the final data sample. No evidence for a p n → K 0 K − ω effect near 1.3 GeV/ c is found, ruling out an association of K K ω effects with the nearby isospin one enhancement in the total cross section. Finally, we find no evidence for a p p → K K ω enhancement near 1.8 GeV/ c .
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Measurements have been made of the total charge-exchange cross section π − p to π 0 n over the laboratory kinetic energy range 90 to 290 MeV. The data have an absolute accuracy of typically 1%, and have here been used to determine the pion-nucleon P 13 phase shift.
QUADRATIC INTERPOLATION.
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