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 χ⁺χ⁺→^{+ ′+}ν ν^′ and invisible decays ν →ν χ 10. We introduce two one-dimensional decompositions of the Cambridge MT2 variable: MT2 and MT2, on the direction of the upstream transverse momentum P→T and the direction orthogonal to it, respectively. We show that the sneutrino mass Mc can be measured directly by minimizing the number of events N(Mc) in which MT2 exceeds a certain threshold, conveniently measured from the end point MT2 ax (Mc).