ﻻ يوجد ملخص باللغة العربية
Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $pi^0$ electroproduction reaction $gamma^* p to p pi^0$, expanding an analysis of the $gamma^* p to n pi^+$ reaction from the same experiment. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Lab. The kinematic range covered is $1.1<W<3$ GeV and $1<Q^2<6$ GeV$^2$. Results were obtained for about 5700 bins in $W$, $Q^2$, cthcm, and $phi^*$. The beam-target asymmetries were found to generally be greater than zero, with relatively modest phicmsp dependence. The target asymmetries exhibit very strong phicmsp dependence, with a change in sign occurring between results at low $W$ and high $W$, in contrast to $pi^+$ electroproduction. Reasonable agreement is found with phenomenological fits to previous data for $W<1.6$ GeV, but significant differences are seen at higher $W$. When combined with cross section measurements, as well as $pi^+$ observables, the present results will provide powerful constraints on nucleon resonance amplitudes at moderate and large values of $Q^2$, for resonances with masses as high as 2.4 GeV.
Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive $pi^+$ electroproduction reaction $gamma^* p to n pi^+$. The results were obtained from scattering of 6 GeV longitudinally polarized electrons off
Beam-target double spin asymmetries and target single-spin asymmetries in exclusive $pi^+$ and $pi^-$ electroproduction were obtained from scattering of 1.6 to 5.7 GeV longitudinally polarized electrons from longitudinally polarized protons (for $pi^
The observation of beam spin asymmetries in two-pion production in semi-inclusive deep inelastic scattering off an unpolarized proton target is reported. The data presented here were taken in the fall of 2018 with the CLAS12 spectrometer using a 10.6
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
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