ﻻ يوجد ملخص باللغة العربية
This paper reports on the most comprehensive data set obtained on differential and fully integrated cross sections for the process $e p to e p pi^{+} pi^{-} $. The data were collected with the CLAS detector at Jefferson Laboratory. Measurements were carried out in the so-far unexplored kinematic region of photon virtuality 0.2 $<$ $Q^{2}$ $<$ 0.6 GeV$^{2}$ and invariant mass of the final hadron system $W$ from 1.3 to 1.57 GeV. For the first time, nine independent 1-fold differential cross sections were determined in each bin of $W$ and $Q^{2}$ covered by the measurements. A phenomenological analysis of the data allowed us to establish the most significant mechanisms contributing to the reaction. The non-resonant mechanisms account for a major part of cross-sections. However, we find sensitivity to s-channel excitations of low-mass nucleon resonances, especially to the $N(1440)P_{11}$ and $N(1520)D_{13}$ states in kinematical dependencies of the 1-fold differential cross-sections.
Exclusive neutral-pion electroproduction ($epto e^prime p^prime pi^0$) was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4sigma/dtdQ^2dx_Bdphi_pi$ and structure functions $sigma_T+epsilo
New results on the single-differential and fully-integrated cross sections for the process $gamma_{v} p rightarrow p pi^{+} pi^{-}$ are presented. The experimental data were collected with the CLAS detector at Jefferson Laboratory. Measurements were
The exclusive electroproduction process $ep rightarrow eppi^{0}$ was measured in the range of photon virtualities $Q^{2} = 0.4 - 1.0$~GeV$^{2}$ and the invariant mass range of the $ppi^{0}$ system of $W = 1.1 - 1.8$~GeV. These kinematics are covered
The differential cross sections sigma_0=sigma_T+epsilon sigma_L, sigma_{LT}, and sigma_{TT} of pi^0 electroproduction from the proton were measured from threshold up to an additional center of mass energy of 40 MeV, at a value of the photon four-mome
The cross section of the exclusive $eta$ electroproduction reaction $epto e^prime p^prime eta$ was measured at Jefferson Lab with a 5.75-GeV electron beam and the CLAS detector. Differential cross sections $d^4sigma/dtdQ^2dx_Bdphi_eta$ and structure