427 research outputs found
All Possible Lightest Supersymmetric Particles in R-Parity Violating mSUGRA Models and their Signals at the LHC
We consider minimal supergravity (mSUGRA) models with an additional R-parity
violating operator at the grand unification scale. This can change the
supersymmetric spectrum leading on the one hand to a sneutrino, smuon or squark
as the lightest supersymmetric particle (LSP). On the other hand, a wide
parameter region is reopened, where the scalar tau is the LSP. It is vital to
know the nature of the LSP, because supersymmetric particles normally cascade
decay down to the LSP at collider experiments. We investigate in detail the
conditions leading to non-neutralino LSP scenarios. We also present some
typical LHC signatures.Comment: 4 pages, 4 figures, submitted for the proceedings of the SUSY09
conferenc
Bounds on R-parity Violation from Resonant Slepton Production at the LHC
We consider the ATLAS and CMS searches for dijet resonances, as well as the
ATLAS search for like-sign dimuon pairs at the LHC with 7 TeV center of mass
energy. We interpret their exclusions in terms of bounds on the supersymmetric
R-parity violating parameter space. For this we focus on resonant slepton
production followed by the corresponding decay.Comment: 17 pages, 11 figures, 3 table
The R-Parity Violating Minimal Supergravity Model
We present the minimal supersymmetric standard model with general broken
R-parity, focusing on minimal supergravity (mSUGRA). We discuss the origins of
lepton number violation in supersymmetry. We have computed the full set of
coupled one-loop renormalization group equations for the gauge couplings, the
superpotential parameters and for all the soft supersymmetry breaking
parameters. We provide analytic formule for the scalar potential minimization
conditions which may be iterated to arbitrary precision. We compute the
low-energy spectrum of the superparticles and the neutrinos as a function of
the small set of parameters at the unification scale in the general basis.
Specializing to mSUGRA, we use the neutrino masses to set new bounds on the
R-parity violating couplings. These bounds are up-to five orders of magnitude
stricter than the previously existing ones. In addition, new bounds on the
R-parity violating couplings are also derived demanding a non-tachyonic
sneutrino spectrum. We investigate the nature of the lightest supersymmetric
particle and find extensive regions in parameter space, where it is not the
neutralino. This leads to a novel set of supersymmetric signatures, which we
classify.Comment: 42 pages, revtex4, 8 figures. Revised version corrects a factor of 2
in Eq. (86) with associated numerical corrections to Tables III,IV and Fig.
I. Conclusions left unchange
General MSSM signatures at the LHC with and without R-parity
We present the possible signatures appearing in general realizations of the
MSSM based on 14 unrelated mass parameters at the SUSY scale. The parameters of
the general MSSM are reduced by assuming a degeneracy of the sfermions of the
first two generations with the same quantum numbers. We also assume no
mass-splitting between neutral and charged Higgsinos. We do allow for separate
soft breaking terms for the third generation sfermons. We consider all possible
resulting relevant mass orderings and check for
the dominant decay cascades and the corresponding collider signatures. In
determining the dominant decay modes we assume that mixing between sparticles
is sub-dominant. As preferred signatures, we consider charged leptons, missing
transverse momentum, jets, and or Higgs bosons. We include also the
cases of bi- and trilinear R-parity violation and show that specific signatures
can be used to distinguish the different scenarios.Comment: 18 pages, 14 tables. v2: Minor changes to improve readability of the
result
General NMSSM signatures at the LHC
Peer reviewe
SUSY R parity violation and CP asymmetry in semi-leptonic tau-decays
We analyze the CP violation in the semileptonic | \Delta S|=1 tau-decays in
supersymmetric extensions of the standard model (SM) with R parity violating
term. We show that the CP asymmetry of tau-decay is enhanced significantly and
the current experimental limits obtained by CLEO collaborations can be easily
accommodated. We argue that observing CP violation in semi leptonic tau-decay
would be a clear evidence for R-parity violating SUSY extension of the SM.Comment: 5 pages, 2 figure
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