Speaker
Prof.
Xerxes Tata
(University of Hawaii)
Description
We describe work-in-progress that attempts to extract model-independent
information about neutralino properties from LHC data, assuming only the
particle content of the MSSM, that all two-body neutralino decays are
kinematically forbidden and that neutralino inclusive production has a
sufficient cross section. We show that the Lorentz invariant dilepton
mass distribution, which will be well-determined at the LHC if squarks
and/or gluinos are light enough, encodes clear information about
the relative sign of the mass eigenvalues of the parent and daughter
neutralinos. Somewhat surprisingly, we find that in the limit that the
neutralino mass gap is significantly smaller than the mass of the Z
boson and slepton that mediate neutralino decays, it will be impossible
to tell Z-mediated decays from slepton-mediated decays. Finally, we
study a complicated case where two different neutralinos
$\tilde{Z}_{2,3}$ both contribute to this mass distibution, and show
that in the ideal situation it may be possible to extract information
about $M_{1,2}$, $\mu$ and even the slepton mass, although with
quasi-realistic cuts on lepton momenta, the precision with which this is
possible is considerably degraded, at least in our preliminary study.