Events at Physics
I shall discuss how certain Lorentz _variant_ quantities such as the Energy of one of the decay product encodes Lorentz _invariant_ quantities of the decay in a simple and measurable way. I will describe a method to access these invariants that allow to determine the mass of the decaying particle by observing only one of the two decay products. Not requiring the observation of both decay products, the described method can be applied when traditional quantities as the invariant mass cannot be used. I shall show concrete results about mass measurements for the leptonic decay of the top quark and supersymmetric decay chains of the gluino. Possible uses of this observation to study the stabilization symmetry of the Dark Matter at colliders will be discussed as well.