Search for inclusive production of fractionally charged particles produced in electron-positron annihilations at 29 GeV

A search for particles q with charges Q between 0.25e and 0.75e inclusively produced in the reaction e+e-→q anti qX at 29 GeV center of mass energy has been performed. A particle's charge was determined from its ionization energy loss and velocity as measured in scintillation counters and multi-wire proportional chambers. No particle with mass M/sub q/ less than 12 GeV/c2 and Q between 0.25e ad 0.75e was seen in a data sample of 17 events/picobarn. The authors present limits on the total cross section for that process for Q = 1/3e and Q = 2/3e as the ratio R/sub qqx/ = sigma/sub (e+e-→qqX)//sigma/sub (e+e-→μ+μ-)/. These limits are R/sub qqX/(Q = 1/3)<0.01 for M/sub q/ = 1 GeV/c2(0.03 for M/sub q/ = 12 GeV/c2) and R/sub qqX/(Q = 2/3)<0.02 for M/sub q/ = 1 GeV/c2(0.08 for M/sub q/ = 12 GeV/c2)