In this paper we study the gluino dijet mass edge measurement at the LHC in a realistic situation including both SUSY and combinatorical backgrounds together with effects of initial and final state radiation as well as a finite detector resolution. T
hree benchmark scenarios are examined in which the dominant SUSY production process and also the decay modes are different. Several new kinematical variables are proposed to minimize the impact of SUSY and combinatorial backgrounds in the measurement. By selecting events with a particular number of jets and leptons, we attempt to measure two distinct gluino dijet mass edges originating from wino $tilde g to jj tilde W$ and bino $tilde g to jj tilde B$ decay modes, separately. We determine the endpoints of distributions of proposed and existing variables and show that those two edges can be disentangled and measured within good accuracy, irrespective of the presence of ISR, FSR, and detector effects.
We describe the universal Monte-Carlo event generator WHIZARD. The program automatically computes complete tree-level matrix elements, integrates them over phase space, evaluates distributions of observables, and generates unweighted event samples
that can be used directly in detector simulation. There is no principal limit on the process complexity; using current hardware, the program has successfully been applied to hard scattering processes with up to eight particles in the final state. Matrix elements are computed as helicity amplitudes, so spin and color correlations are retained. The Standard Model, the MSSM, and many alternative models such as Little Higgs, anomalous couplings, or effects of extra dimensions or noncommutative SM extensions have been implemented. Using standard interfaces to PDF, beamstrahlung, parton shower and hadronization programs, WHIZARD generates complete physical events and covers physics at hadron, lepton, and photon colliders.
Supersymmetric (SUSY) grand unified theories based on exceptional gauge groups such as E6 have recently triggered a lot of interest. Aside from top-down motivations, they contain phenomenologically interesting states with leptoquark quantum numbers.
Their SUSY partners, leptoquarkinos, will appear similar to all R-odd particles in decay cascades, but mass edges in kinematic distributions- originating from the same semiexclusive final states-will however have major differences to the corresponding edges of ordinary squarks. This distortion of standard observables bears the opportunity to detect them at the LHC, but may also pose significant confusion of underlying model assumptions, which should be handled with care and, if interpreted falsely, might even prevent a possible discovery.
