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Register a new userSearch for neutral Higgs bosons decaying into four taus at LEP2
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A search for the production and non-standard decay of a Higgs boson, h, into four taus through intermediate pseudoscalars, a, is conducted on 683 pb-1 of data collected by the ALEPH experiment at centre-of-mass energies from 183 to 209 GeV. No excess of events above background is observed, and exclusion limits are placed on the combined production cross section times branching ratio, xi^2 = sigma(e+e- --> Zh)/sigma_{SM}(e+e- --> Zh) x B(h --> aa)x B(a --> tau^+tau^-)^2. For mh < 107 GeV/c2 and 4 < ma < 10 GeV/c2, xi^2 > 1 is excluded at the 95% confidence level.
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A search is presented for massive long-lived particles, in the 20-60 GeV mass range with lifetimes between 5 and 100 ps. The dataset used corresponds to 0.62 1fb of proton-proton collision data collected by the LHCb detector at sqrt(s)=7 TeV. The particles are assumed to be pair-produced by the decay of a Higgs-like boson with mass between 80 and 140 GeV. No excess above the background expectation is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime and of the Higgs-like boson mass.
We report the results of a search for a light pseudoscalar particle $a$ that couples to electrons and decays to $e^+e^-$ performed using the high-energy CERN SPS H4 electron beam. If such pseudoscalar with a mass $simeq 17$ MeV exists, it could explain the ATOMKI anomaly. We used the NA64 data samples collected in the visible mode configuration with total statistics corresponding to $8.4times 10^{10}$ electrons on target (EOT) in 2017 and 2018. In order to increase sensitivity to small coupling parameter $epsilon$ we used also the data collected in 2016-2018 in the invisible mode configuration of NA64 with a total statistics corresponding to $2.84times 10^{11}$ EOT. A thorough analysis of both these data samples in the sense of background and efficiency estimations was already performed and reported in our previous papers devoted to the search for light vector particles and axion-like particles (ALP). In this work we recalculate the signal yields, which are different due to different cross section and life time of a pseudoscalar particle $a$, and perform a new statistical analysis. As a result, the region of the two dimensional parameter space $m_a - epsilon$ in the mass range from 1 to 17.1 MeV is excluded. At the mass of the ATOMKI anomaly the values of $epsilon$ in the range $2.1 times 10^{-4} < epsilon < 3.2 times 10^{-4}$ are excluded.
Talk given at PIC2013 summarizing the results of CMS-PAS-HIG-13-004.
The LEP collaborations ALEPH, DELPHI, L3 and OPAL have searched for the neutral Higgs bosons which are predicted within the framework of the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and show no signicant excess of events which would indicate the production of Higgs bosons. The search results are thus used to set upper bounds on the cross sections of various Higgs-like event topologies and limits on MSSM benchmark models, including CP-conserving and CP-violating scenarios. Here, the limits on the model parameters of the CP-violating benchmark scenario CPX and derivates of this scenario are shown.
A search for the non-resonant decays $B^0_s rightarrow mu^{+}mu^{-}mu^{+}mu^{-}$ and $B^0 rightarrow mu^{+}mu^{-}mu^{+}mu^{-}$ is presented. The measurement is performed using the full Run 1 data set collected in proton-proton collisions by the LHCb experiment at the LHC. The data correspond to integrated luminosities of $1$ and $2~mathrm{fb}^{-1}$ collected at centre-of-mass energies of $7$ and $8~mathrm{TeV}$, respectively. No signal is observed and upper limits on the branching fractions of the non-resonant decays at $95%$ confidence level are determined to be mathcal{B}(B^0_s rightarrow mu^{+}mu^{-}mu^{+}mu^{-}) & < 2.5 times 10^{-9} mathcal{B}(B^0 rightarrow mu^{+}mu^{-}mu^{+}mu^{-}) & < 6.9 times 10^{-10}.
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