589 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
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
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
Stau as the Lightest Supersymmetric Particle in R-Parity Violating SUSY Models: Discovery Potential with Early LHC Data
We investigate the discovery potential of the LHC experiments for R-parity
violating supersymmetric models with a stau as the lightest supersymmetric
particle (LSP) in the framework of minimal supergravity. We classify the final
states according to their phenomenology for different R-parity violating decays
of the LSP. We then develop event selection cuts for a specific benchmark
scenario with promising signatures for the first beyond the Standard Model
discoveries at the LHC. For the first time in this model, we perform a detailed
signal over background analysis. We use fast detector simulations to estimate
the discovery significance taking the most important Standard Model backgrounds
into account. Assuming an integrated luminosity of 1 inverse femtobarn at a
center-of-mass energy of 7 TeV, we perform scans in the parameter space around
the benchmark scenario we consider. We then study the feasibility to estimate
the mass of the stau-LSP. We briefly discuss difficulties, which arise in the
identification of hadronic tau decays due to small tau momenta and large
particle multiplicities in our scenarios.Comment: 26 pages, 18 figures, LaTeX; minor changes, final version published
in PR
What is the Discrete Gauge Symmetry of the MSSM?
We systematically study the extension of the Supersymmetric Standard Model
(SSM) by an anomaly-free discrete gauge symmetry Z_N. We extend the work of
Ibanez and Ross with N=2,3 to arbitrary values of N. As new fundamental
symmetries, we find four Z_6, nine Z_9 and nine Z_18. We then place three
phenomenological demands upon the low-energy effective SSM: (i) the presence of
the mu-term in the superpotential, (ii) baryon-number conservation upto
dimension-five operators, and (iii) the presence of the see-saw neutrino mass
term LHLH. We are then left with only two anomaly-free discrete gauge
symmetries: baryon-triality, B_3, and a new Z_6, which we call proton-hexality,
P_6. Unlike B_3, P_6 prohibits the dimension-four lepton-number violating
operators. This we propose as the discrete gauge symmetry of the Minimal SSM,
instead of R-parity.Comment: Typo in item 2 below Eq.(6.9) corrected (wrong factor of "3"); 27
pages, 5 table
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