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

Abstract

We have observed highly virtual ($Q^2>1.05Ge{V}^2$) photon-photon collisions to hadronic final states at $\sqrt{s_{e^{+}{e}^{-}}}=58GeV$. 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, "double-tag"); we obtained 115 hadronic events with an estimated background of $10.2\pm 1.1$. The cross section obtained was $4.11\pm 0.66$pb in the $2<W_{\gamma \gamma }<25$ GeV and $Q_{\gamma ,min}^2>2$ GeV region, while the lowest order quark-parton model predicted 3.00pb.

14 pages, latex (revtex), 2 figures, available at http://topsun1.kek.jp/~enomoto/dtag.ps