Skip to content

Measurement of elastic electroproduction of phi mesons at HERA

H1 Collaboration, C. Adloff

hep-exarXiv:hep-ex/0005010

Abstract

The elastic electroproduction of phi mesons is studied at HERA with the H1 detector for photon virtualities 1 < Q2 < 15 GeV2 and hadronic centre of mass energies 40 < W < 130 GeV. The Q2 and t dependences of the cross section are extracted (t being the square of the four-momentum transfer to the target proton). When plotted as function of (Q2 + MV2) and scaled by the appropriate SU(5) quark charge factor, the phi meson cross section agrees within errors with the cross sections of the vector mesons V = rho, omega and J/psi. A detailed analysis is performed of the phi meson polarisation state and the ratio of the production cross sections for longitudinally and transversely polarised phi mesons is determined. A small but significant violation of s-channel helicity conservation (SCHC) is observed.

Create a lesson