Observation of Highly Virtual Photon-Photon Collisions to Hadrons at TRISTAN

Abstract

We have observed highly virtual ($Q^2>1.05 GeV^2$) photon-photon collisions to hadronic final states at $\sqrt{s_{e^+e^-}}=58 GeV$. The integrated luminosity of the data sample was 241pb$^{-1}$. Both scattered beam-electrons and scattered beam-positrons were detected using low-angle calorimeters (i.e., both photons were highly virtual, &#34;double-tag&#34;); we obtained 115 hadronic events with an estimated background of $10.2\pm1.1$. The cross section obtained was $4.11\pm0.66$pb in the $2<W_{γγ}<25$ GeV and $Q^2_{γ, min}>2$ GeV region, while the lowest order quark-parton model predicted 3.00pb.