arXiv subjects

R. De Vita

Publications and source records attributed to R. De Vita.

128 records · Page 8Linked to original sources

arXiv2002

Photoproduction of the $ω$ meson on the proton at large momentum transfer

The differential cross section, $dσ/dt$ for $ω$ meson exclusive photoproduction on the proton above the resonance region ($2.6<W<2.9$ GeV) was measured up to a momentum transfer $-t = 5$ GeV$^2$ using the CLAS detector at Jefferson Laboratory. The $ω$ channel was identified by detecting a proton and $π^+$ in the final state and using the missing mass technique. While the low momentum transfer region shows the typical diffractive pattern expected from Pomeron and Reggeon exchange, at large $-t$ the differential cross section has a flat behavior. This feature can be explained by introducing quark interchange processes in addition to the QCD-inspired two-gluon exchange.

hep-ex↗

arXiv2002

First Measurement of the Double Spin Asymmetry in $\vec{e}\vec{p}\to e' π^+ n$ in the Resonance Region

The double spin asymmetry in the $\vec{e}\vec{p}\to e' π^+ n$ reaction has been measured for the first time in the resonance region for four-momentum transfer $Q^2=0.35-1.5$ GeV$^2$. Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH$_3$ target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with $Q^2$ of the helicity asymmetry $A_1$ for the $F_{15}(1680)$ resonance than expected from the analysis of the unpolarized data.

hep-ex↗