\sqrt{s}_min: a global inclusive variable for determining the mass scale of new physics in events with missing energy at hadron colliders

Understand

We propose a new global and fully inclusive variable \sqrt{s}_{min} for determining the mass scale of new particles in events with missing energy at hadron colliders.

• We define \sqrt{s}_{min} as the minimum center-of-mass parton level energy consistent with the measured values of the total calorimeter energy E and the total visible momentum \vec{P}.
• We prove that for an arbitrary event, \sqrt{s}_{min} is simply given by the formula \sqrt{s}_{min}=\sqrt{E^2-P_z^2}+\sqrt{\met^2+M_{inv}^2}, where M_{inv} is the total mass of all invisible particles produced in the event.
• We use t\bar{t} production and several supersymmetry examples to argue that the peak in the \sqrt{s}_{min} distribution is correlated with the mass threshold of the parent particles originally produced in the event.