Search for charginos, neutralinos and gravitinos at LEP

Residual cosmic ray and detector noise backgrounds are measured by selecting events slightly out of time with respect to the beam crossing but which pass all other cuts. No such

The negative results of the searches for charginos and neutralinos described in the previous section can be translated into limits on the gaugino production cross sections and masses

In a model that assumes the usual common gaugino mass at the GUT scale and where, apart from the charginos and neutralinos, all other supersymmetric particles are heavy, we have

The many different selections developed for the chargino and neutralino searches must be combined so that the analysis is sensitive to all possible topologies for a large range of

A search for charginos nearly mass degenerate with the lightest neutralino is performed with the data collected by the ALEPH detector at LEP, at centre-of- mass energies between 189

It resulted in an efficiency of 98% for low x vis , falling to 94% for high x vis , in LCAL tagged events, where x vis is the measured value of x , calculated from the observed

The neural network was trained, with the backward propagation method, using b and non-b jets in radiative returns to the Z from a sample of 400,000 Monte Carlo qq events generated at

This is illustrated in Figure 2, which shows the transverse energy imbalance (E Tvis / E vis ) distribution for the data, the simulated Standard Model background and the signal