Constraining the minimal supergravity model parameter tan beta by measuring the dilepton mass distribution at CERN LHC

We study the dependence on tan beta of the event kinematics of final states with e/sup +/e/sup -// mu /sup +/ mu /sup -//e/sup +or-/ mu /sup -or+/+E/sub T//sup miss/+jets, as expected in pp collisions at CERN LHC, within the framework of the minimal supergravity model. With an increase of tan beta , the third generation sparticle masses m/sub tau 1/ and m/sub b1/ decrease due to the increase of the tau and bottom Yukawa couplings. As a result, the gluino, top squark, sbottom, chargino, and neutralino decays to third generation particles and sparticles are enhanced. With tan beta rising, we observe a characteristic change in the shape of the dilepton mass spectra in e/sup +/e/sup -// mu /sup +/ mu /sup -/+E/sub T//sup miss /+jets versus e/sup +or-/ mu /sup -or+/+E/sub T//sup miss/+jets final states, reflecting the presence of the decays chi /sub 2//sup 0/ to l /sub L, R//sup +or-/l/sup -or+/ to chi /sub 1//sup 0/l/sup +/l/sup - /, chi /sub 2//sup 0/ to chi /sub 1//sup 0/l/sup +/ l/sup -/, and chi /sub 2//sup 0/ to tau /sub 1//sup +or-/ tau /sup -or+/ to chi /sub 1 //sup 0/ tau /sup +/ tau /sup -/, chi /sub 2//sup 0/ to tau /sup +/ tau /sup -/ chi /sub 1//sup 0/, respectively. We exploit this effect for constraining the value of tan beta. (16 refs).