Superpartner Mass Measurement Technique using 1D Orthogonal Decompositions of the Cambridge Transverse Mass Variable MT2

We propose a new model-independent technique for mass measurements in missing energy events at hadron colliders. We illustrate our method with the most challenging case of a single-step decay chain. We consider inclusive same-sign chargino pair production in supersymmetry, followed by leptonic decays to sneutrinos chi(+)chi(+) -> l(+)l'(+)(nu) over tildel (nu) over tilde and invisible decays (nu) over tilde -> nu l (chi) over tilde (0)(1). We introduce two one-dimensional decompositions of the Cambridge M-T2 variable: M-T2 parallel to and M-T2 perpendicular to, on the direction of the upstream transverse momentum P-T and the direction orthogonal to it, respectively. We show that the sneutrino mass M-c can be measured directly by minimizing the number of events N((M) over tilde (c)) in which M-T2 exceeds a certain threshold, conveniently measured from the end point M-T2 perpendicular to(max)((M) over tilde (c)).