Author/Authors :
TOPAZ Collaboration، نويسنده , , M. Iwasaki، نويسنده , , R. Enomoto، نويسنده , , H. Hayashii، نويسنده , , E. Nakano، نويسنده , , K. Abe، نويسنده , , T. Abe، نويسنده , , José I. Adachi and Anthony P. Peirce ، نويسنده , , K. Adachi، نويسنده , , M. Aoki، نويسنده , , S. Awa، نويسنده , , K. Emi، نويسنده , , H. Fujii، نويسنده , , K. Fujii، نويسنده , , T. Fujii، نويسنده , , J. Fujimoto، نويسنده , , K. Fujita، نويسنده , , N. Fujiwara، نويسنده , , B. Howell، نويسنده , , N. Iida، نويسنده , , et al.، نويسنده ,
Abstract :
We have studied open charm production in γγ collisions with the TOPAZ detector at the TRISTAN e+e− collider. In this study, charm quarks were identified by electrons (and positrons) from semi-leptonic decays of charmed hadrons. The data corresponded to an integrated luminosity of 95.3 pb−1 at a center-of-mass energy of 58 GeV. The results are presented as the cross sections of inclusive electron production in γγ collisions with an anti-tag condition, as well as the subprocess cross sections, which correspond to resolved-photon processes. The latter were measured by using a sub-sample with remnant jets. A comparison with various theoretical predictions based on direct and resolved-photon processes showed that our data prefer that with relatively large gluon contents in a photon at small x(x≤0.1), with the next-to-leading order correction, and with a charm-quark mass of 1.3 GeV.
