Showing papers by "Marumi Kado published in 2000"
TL;DR: In this article, a search for the Standard Model Higgs boson in the data sample collected with the ALEPH detector at LEP, at centre-of-mass energies up to 209 GeV, was performed.
157 citations
TL;DR: In this article, a search for charged Higgs bosons produced in pairs is performed with data collected at centre-of-mass energies ranging from 189 to 209 GeV by ALEPH at LEP, corresponding to a total luminosity of 629 invpb.
86 citations
TL;DR: In this paper, the cross sections and forward-backward asymmetries of hadronic and leptonic events produced in e+e- collisions at centre-of-mass energies of 130-183 GeV are presented.
Abstract: The cross sections and forward-backward asymmetries of hadronic and leptonic events produced in e+e- collisions at centre-of-mass energies of 130-183 GeV are presented. Results for ee, mumu, tautau, qq, bb and cc production show no significant deviation from the Standard Model predictions. This enable constraints to be set upon physics beyond the Standard Model such as four-fermion contact interactions, leptoquarks, Z' bosons and R-parity violating squarks and sneutrinos. Limits on the energy scale Lambda of eeff contact interactions are typically in the range from 2-10 TeV. Limits on R-parity violating sneutrinos reach masses of a few hundred GeV for large values of their Yukawa couplings.
62 citations
TL;DR: The Instituto de Fisica Teorica Universidade Estadual Paulista, Rua Pamplona 145, 01405-900, Sao Paulo, Brazil as discussed by the authors.
29 citations
TL;DR: In this paper, the authors measured the decay branching fraction of the W boson into hadrons at lower center-of-mass energies and showed that B(W → hadrons) = 66.97 ± 0.65(stat.) ± 0.32(syst.)%, allowing a determination of the CKM matrix element |Vcs| = 0.951 ± 0.,
18 citations
TL;DR: In this article, a scan of a minimal GMSB parameter space is performed and model dependent lower limits of about 45 GeV/c^2 on the next-to-lightest supersymmetric particle (NLSP) mass and of about 9 TeV on the mass scale parameter Lambda are derived, independently of the NLSP lifetime.
Abstract: Searches for topologies characteristic of Gauge Mediated SUSY Breaking models (GMSB) are performed by analysing 173.6 pb^-1 of data collected at Ecm = 188.6~GeV with the ALEPH detector.These topologies include acoplanar photons, non-pointing single photon, acoplanar leptons, large impact parameter leptons, detached slepton decay vertices, heavy stable charged sleptons and four leptons plus missing energy final states.No evidence for these new phenomena is observed and limits on production cross sections and sparticle masses are derived. A scan of a minimal GMSB parameter space is performed and model dependent lower limits of about 45 GeV/c^2 on the next-to-lightest supersymmetric particle (NLSP) mass and of about 9 TeV on the mass scale parameter Lambda are derived, independently of the NLSP lifetime.
18 citations
TL;DR: In this paper, the ALEPH detector at LEP collected at center-of-mass energies from 189 GeV to 202 GeV, corresponding to an integrated luminosity of 411 pb-1, are analysed in a search for the scalar top in the decay channels'stop -> c/u neutralino' for small mass differences between the stop and the lightest neutralino.
14 citations
TL;DR: In this paper, a search for gamma-gamma decays of a Higgs boson is performed in the data sample collected at LEP with the ALEPH detector between 1991 and 1999.
11 citations
TL;DR: In this article, single top production via flavour changing neutral currents in the reactions e + e − → t c / u is searched for in approximately 411 −pb −1 of data collected by ALEPH at center-of-mass energies in the range between 189 and 202 −GeV.
6 citations