First Results of the Search for Neutrinoless Double-Beta Decay with the NEMO 3 Detector

The NEMO 3 detector, which has been operating in the Frejus underground laboratory since February 2003, is devoted to the search for neutrinoless double beta decay (bb0nu). Half-lives of the two neutrino double beta decays (bb2nu) have been measured for 100Mo and 82Se. After 389 effective days of data collection from February 2003 until September 2004 (Phase I), no evidence for neutrinoless double beta decay was found from ~7kg of 100Mo and ~1 kg of 82Se. The corresponding lower limits for the half-lives are 4.6 x 10^23 years for 100Mo and 1.0 x10^23 years for 82Se (90% C.L.). Depending on the nuclear matrix elements calculation, limits for the effective Majorana neutrino mass are < 1.7-4.9 eV for 82Se

Study of the electron trigger efficiency of the CMS Experiment using test beam data

A study of the electron identification and selection efficiency of the L1 Trigger algorithm has been performed using the combined ECAL/HCAL test beam data. A detailed discussion of the electron isolation and its impact on the selection efficiency is presented. The L1 electron algorithm is studied for different beam energies and the results indicate that efficiencies of 98% or more can be achieved for electrons with energies between 15 and 100 GeV. The fraction of charged hadrons with energies from 3 up to 100 GeV rejected by the L1 electron trigger algorithm is estimated to be larger than 93%.Comment: 22 pages, 14 figure