Lepton energy asymmetry and precision supersymmetry study at hadron colliders - art. no. 075009

We study the distribution of lepton pairs from the second lightest neutrali no decay <(chi)over tilde>20-(l) over tilde l followed by (l) over tilde -- > <(chi)over tilde>(0)(1)l. The distribution of the ratio of lepton transve rse momenta A(T) shows a peak structure if m(ll)less than or similar to m(l l)(max)/2 is required. The peak position A(T)(peak) is described by a simpl e function of the gaugino and slepton masses in the m(ll)similar to 0 limit . When a moderate m(ll) cut is applied, the A(T)(peak) depends on the <(chi )over tilde>(0)(2) velocity distribution, but the dependence would be corre cted by studying the lepton P-T distribution. A(T)(peak) and the edge of m( ll) distributions are used to determine the mass parameters involved in the decay for parameters of interest to CERN Large Hadron Collider experiments . For some cases the gaugino and slepton masses may be determined within 10 % by the lepton distribution only independent of model assumptions. Correct combinations of A(T)(peak) and m(ll)(edge) would be identified even if dif ferent <(chi)over tilde>(0)(2) decay chains are coexisting. The analysis co uld be extended to the Fermilab Tevatron energy scale or other cascade deca ys.