Measurement of Exclusive rho+rho- Production in Mid-Virtuality Two-Photon Interactions and Study of the gamma gamma* -> rho rho Process at LEP

TL;DR

This paper measures the cross section of exclusive rho+rho- production in two-photon collisions at LEP, analyzing its dependence on photon virtuality and energy, and compares it with previous rho0 rho0 results to study the process over a broad Q^2 range.

Contribution

It provides new measurements of the gamma gamma* -> rho+ rho- cross section as a function of Q^2 and W_gg at LEP, extending the understanding of rho rho production in two-photon interactions.

Findings

Cross section measured within specified Q^2 and W_gg ranges.

Results enable comparison with previous rho0 rho0 measurements.

Study covers Q^2 from 0.2 GeV^2 to 30 GeV^2.

Abstract

Exclusive rho+rho- production in two-photon collisions between a quasi-real photon, gamma, and a mid-virtuality photon, gamma*, is studied with data collected at LEP at centre-of-mass energies root(s)=183-209GeV with a total integrated luminosity of 684.8pb^-1. The cross section of the gamma gamma* -> rho+ rho- process is determined as a function of the photon virtuality, Q^2, and the two-photon centre-of-mass energy, W_gg, in the kinematic region: 0.2GeV^2 < Q^2 <0.85GeV^2 and 1.1GeV < W_gg < 3GeV. These results, together with previous L3 measurements of rho0 rho0 and rho+ rho- production, allow a study of the gamma gamma* -> rho rho process over the Q^2-region 0.2GeV^2 < Q^2 < 30 GeV^2.