Search for the Standard Model Higgs boson at the LEP2 collider near sqrt(S) = 183GeV

Abstract

During 1997 the ALEPH experiment at LEP gathered 57pb^-1 of data at centre-of- mass energies near 183 GeV. These data are used to look for possible signals from the production of the Standard Model Higgs boson in the reaction e+e- -> HZ. No evidence of a signal is found in the data; seven events are selected, in agreement with the expectation of 7.2 events from background processes. This observation results in an improved lower limit on the mass of the Higgs boson: m_H > 87.9GeV/c^2 at 95% confidence level.