7,734 research outputs found

    Exotic charmonium spectroscopy with CMS

    Full text link
    The latest results of CMS in the area of exotic quarkonium decays will be presented: observation of a peaking structure in J/ψΦJ/\psi\Phi mass spectrum in the decay B±J/ψΦK±B^\pm \rightarrow J/\psi \Phi K^\pm, search for new bottomonium states in Υ(1S)π+π\Upsilon(1\mathrm{S})\pi^+\pi^- mass spectrum, measurement of prompt J/ψJ/\psi pair production.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 6 pdf figure

    Measurement of the CP violating phase Φs\Phi_s with CMS and ATLAS

    Full text link
    The phase Φs\Phi_s is the key parameter for the CP-violation of the Bs0B^0_s-Bs0ˉ\bar{B^0_s} system. An angular and proper decay time analysis is applied to the Bs0J/ψΦB^0_s \rightarrow J/\psi \Phi events. Using a data sample collected by the CMS and ATLAS experiments in LHC Run1, the Bs0B^0_s signal candidates are reconstructed and are used to extract the phase Φs\Phi_s. We present the latest update on the results in this decay channel.Comment: Talk presented CIPANP2015. 8 pages, LaTeX, 7 pdf figure

    Noise reduction in muon tomography for detecting high density objects

    Get PDF
    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented

    CP asymmetry in BϕKSB \to \phi K_S in a general two-Higgs-doublet model with fourth-generation quarks

    Full text link
    We discuss the time-dependent CP asymmetry of decay BϕKSB \to \phi K_S in an extension of the Standard Model with both two Higgs doublets and additional fourth-generation quarks. We show that although the Standard Model with two-Higgs-doublet and the Standard model with fourth generation quarks alone are not likely to largely change the effective sin2β\sin 2 \beta from the decay of BϕKSB \to \phi K_S , the model with both additional Higgs doublet and fourth-generation quarks can easily account for the possible large negative value of sin2β\sin 2 \beta without conflicting with other experimental constraints. In this model, additional large CP violating effects may arise from the flavor changing Yukawa interactions between neutral Higgs bosons and the heavy fourth generation down type quark, which can modify the QCD penguin contributions. With the constraints obtained from bssˉsb \to s \bar{s} s processes such as BXsγB \to X_s \gamma and ΔmBs0\Delta m_{B_s^0}, this model can lead to the effective sin2β\sin 2 \beta to be as large as 0.4- 0.4 in the CP asymmetry of BϕKSB \to \phi K_S.Comment: 13 pages, 5 figures, references added, to appear in Eur.Phys.J.

    Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0

    Full text link
    Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.

    Search for composite and exotic fermions at LEP 2

    Get PDF
    A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

    Search for the standard model Higgs boson at LEP

    Get PDF
    corecore