Constraining the minimal supergravity model parameter tan beta by measuring the dilepton mass distribution at CERN LHC - art. no. 035008.

We study the dependence on tan beta of the event kinematics of final states with e(+)e(-)/mu(+)mu(-)/e(+/-)mu(-/+) + E-T(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(tau 1)(-) and m(b1)(-) decrease due to the increase of the tau and botto m Yukawa couplings. As a result, the gluino, top squark, sbottom, chargino, and neutralino decays to third generation particles and sparticles are enh anced. With tan beta rising, we observe: a characteristic change in the sha pe of the dilepton mass spectra in e(+)e(-)/mu(+)mu(-) + E-T(miss) + jets v ersus e(+/-)mu(-/+) + E-T(miss) + jets final states, reflecting the presenc e of the decays <(chi)over tilde>(0)(2) --> (l) over tilde(L,R)(-/+) --> <( chi)over tilde>(0)(1)l(+)l(-), <(chi)over tilde>(0)(2) --> <(chi)over tilde >(0)(1)l(+)l(-), and <(chi)over tilde>(0)(2) --> <(tau)over tilde>(+/-)(1) tau(-/+) --> <(chi)over tilde>(0)(1) tau+tau-, <(chi)over tilde>(0)(2) --> tau(+)tau(-) <(chi)over tilde>(0)(1), respectively. We exploit this effect for constraining the value of tan beta. [S0556-2821(99)06913-1].