EVENTS WITH ISOLATED LEPTONS AND MISSING TRANSVERSEMOMENTUM AT HERA

摘要

Events with isolated leptons and missing transverse momentum are searched for in electron— orpositron—proton collisions at HERA by the H1 and ZEUS experiments. Such events may beexplained within the Standard Model by W boson production, followed by leptonic decay. Theanalysis performed including HERA I and the recently collected data at HERA II results in clearevidence of W production. However, H1 collaboration observes an excess of events in e~+p collisions,not supported so far by ZEUS. If the difference between the H1 and ZEUS observations is attributedto a statistical fluctuation, the combined result exceeds the Standard Model prediction at 2.6alevel. A search for events with r leptons and missing transverse momentum is also presented.