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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 tbar{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. This conjecture allows a determination of the heavy superpartner mass scale (as a function of the LSP mass) in a completely general and model-independent way, and without the need for any exclusive event reconstruction. In our SUSY examples of several multijet plus missing energy signals, the accuracy of the mass measurement based on sqrt{s}_{min} is typically at the percent level, and never worse than 10%. After including the effects of initial state radiation and multiple parton interactions, the precision gets worse, but for heavy SUSY mass spectra remains 10%.
We propose to use the MT2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of MT2 and define a new MT2(n,p,c) variable, which can be applied to v
We study methods for reconstructing the momenta of invisible particles in cascade decay chains at hadron colliders. We focus on scenarios, such as SUSY and UED, in which new physics particles are pair produced. Their subsequent decays lead to two dec
In LHC searches for new and rare phenomena the top-associated channel $pp to toverline{t}W^pm +X$ is a challenging background that multilepton analyses must overcome. Motivated by sustained measurements of enhanced rates of same-sign and multi-lepton
In multiscale and topcolor-assisted models of walking technicolor, relatively light spin-one technihadrons $rho_T$ and $omega_T$ exist and are expected to decay as $rho_T to W pi_T, Z pi_T$ and $omega_T to gamma pi_T$. For $M_{rho_T} simeq 200 GeV$ a
The PADME experiment is searching for the Dark Photon $A$ in the $e^{+}e^{-} to gamma A$ process, assuming a $A$ decay into invisible particles. In extended Dark Sector models, a Dark Higgs $h$ can be produced alongside $A$ in the process $e^{+}e^{-}