M. Derrick et al., SEARCH FOR LEPTON FLAVOR VIOLATION IN EP COLLISIONS AT 300 GEV CENTER-OF-MASS ENERGY, Zeitschrift fur Physik. C, Particles and fields, 73(4), 1997, pp. 613-628
Using the ZEUS detector at the HERA electron-proton collider, we have
searched for lepton flavor violation in ep collisions at a center-of-m
ass energy (root s) of 300 GeV. Events of the type e + p --> l + X wit
h a final-state lepton of high transverse momentum, l = mu or tau, wer
e sought. No evidence was found for lepton flavor violation in the com
bined 1993 and 1994 data samples, for which the integrated luminositie
s were 0.84 pb(-1) for e(-)p collisions and 2.94 pb(-1) for e(+)p coll
isions. Limits on coupling vs. mass are provided for leptoquarks and R
-parity violating squarks, For flavor violating couplings of electroma
gnetic strength, we set 95% confidence level lower limits on leptoquar
k masses between 207 GeV and 272 GeV, depending on the leptoquark spec
ies and final-state lepton. For leptoquark,masses larger than 300 GeV,
limits on flavor-changing couplings are determined, many of which sup
ersede prior limits from rare decay processes.