Search for light particles with a charge of 2/3 in e+e- annihilation
Bondar' A. E. , Kuradze L. M., Lel'chuk M. Yu., Panin V. S. , Sidorov V. A. , Chilingarov A. G. , Shvarts B. A. , Eidel'man S. I.
An upper limit has been found on the cross section for the production of particles with a charge of 2/3 and a mass up to 0.4 GeV in the reaction e^e~^qq from measurements by the OLYa detector on the VEPP-2M storage ring: aqq/ σμμ < Ю-4. This limit is two orders of magnitude lower than the results of previous experiments sensitive to quarks of small mass.