Search for R-parity violating supersymmetry in multilepton final states with the DŸ detector

Results obtained from a search for the trilepton signature mu-mu-l (with l=e, or mu) are combined with two complementary searches for the trilepton signatures e-e-l and e-e-tau and interpreted in the framework of R-parity violating Supersymmetry. Pairwise, R-parity conserving production of the supersymmetric particles is assumed, followed by R-parity violating decays via an LLE-operator with one dominant coupling lambda_122. An LLE-operator couples two weak isospin doublet and one singlet (s)lepton fields and thus violates lepton number conservation. The data, collected with the D0 detector at the Fermilab proton-antiproton collider Tevatron, corresponds to an integrated luminosity of L = 360 +/- 23 /pb. No event is observed, while 0.41 +/- 0.11 (stat) +/- 0.07(sys) events are expected from Standard Model processes. The resulting 95 % confidence level cross section limits on new physics producing a mu-mu-l signature in the detector are of the order of 0.020 to 0.136 pb. They are interpreted in two different supersymmetry scenarios: the mSUGRA and the MSSM model. The corresponding lower limits on the masses of the lightest neutralino (N1) and the lightest chargino (C1) in case of the mSUGRA model are found to be in the range of: mSUGRA, mu > 0: M(N1) >~ 115-128 GeV and M(C1) >~ 215-241 GeVmsugra, mu < 0: M(N1) >~ 101-114 GeV and M(C1) >~ 194-230 GeV, depending on the actual values of the model parameters: mzero, mhalf, Azero, anb, and $mu$. The first and second parameters provide the boundary conditions for the masses of the supersymmetric spin-0 and spin-1/2 particles, respectively, while A_0 gives the universal value for the trilinear couplings at the GUT scale. The parameter tan(beta) denotes the ratio of the vacuum expectation values of the two Higgs fields and mu, finally, represents the Higgs mixing parameter. In the MSSM scenario the lower bound on the mass of the lightest chargino (for fixed neutralino mass) is found to be in the range of: M(C1) >~ 205 GeV, für M(N1) = 30 GeVM(C1) >~ 232 GeV, für M(N1) = 200 GeV.The parameters of the considered MSSM model are: M_1, M_2, M_3, A_0, tan(beta), mu, and m_A. The first three parameters define the common masses of the superpartners of the U(1)_Y, SU(2)_L, and SU(3)_C bosons at the electroweak scale, respectively. The following three parameters are identical to those defined in the mSUGRA model above, while m_A denotes the mass of the pseudoscalar Higgs boson, present in the supersymmetric extension of the Standard Model. In addition all sfermion masses are set to 1000 GeV.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2006

Author dc:creator

• Käfer, Daniela

Contributors dc:contributor

• Hebbeker, Thomas

• info:eu-repo/classification/ddc/530
• Physik
• Supersymmetrie
• Supergravitation
• Speicherring
• Tevatron
• Datenanalyse
• Supersymmetry
• mSUGRA
• MSSM
• Multilepton Final States
• D0 Detector

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123201%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61546