• Search for New Physics in the Bs -> J/psi phi and Bs -> phi phi decays at CDF
  • Dorigo, Mirco

Subject

  • CDF experiment
  • B physics
  • CP violation
  • Tevatron collider
  • Bs meson
  • SCUOLA DI DOTTORATO DI RICERCA IN FISICA
  • FIS/04 FISICA NUCLEARE E SUBNUCLEARE

Description

  • 2011/2012
  • We present a search for physics beyond the standard model (SM) through a measurement of the violation of the charge-parity (CP) symmetry in two decays of the Bs meson using data collected by the Collider Detector at Fermilab (CDF) in proton-antiproton collisions at the center-of-mass energy of 1.96 Tev. We exploit the decays Bs->Jpsi (->mu mu) phi(-> KK) and Bs -> phi(-> KK) phi(-> KK), for which the SM accurately predicts very small or vanishing CP violation; both decay modes are very sensitive to new sources of CP violation expected in a broad class of SM extensions. We analyze the time-dependent CP asymmetry of the Bs->Jpsi phi decays collected in the full CDF Run II dataset for providing the final measurement of the Bs-antiBs mixing phase, 2*betas, and we present the first measurement of CP violation in Bs -> Phi Phi decays, through the determination of two time-integrated CP asymmetries, Av and Au, using an original method developed in this work. We find: -0.06< betas<0.30 at the 68% confidence level; Av=(-12.0 +/-6.4(stat) +/- 1.6(syst))%; and Au=(-0.7 +/-6.4(stat) +/- 1.8(syst))%. In addition, we provide measurements of the decay width difference between the light and heavy mass eigenstates of the Bs meson, DeltaGamma_s=0.068 +/- 0.026(stat) +/- 0.009(syst) ps^{-1}; and of their mean lifetime, tau_s=1.528 +/- 0.019(stat) +/- 0.009(syst) ps. All results are among the most precise determinations from a single experiment and exhibit an excellent agreement with the SM predictions. They have been published in two letters in Physical Review.
  • XXV Ciclo
  • 1985

Date

  • 2013-04-16T08:17:34Z
  • 2013-04-16T08:17:34Z
  • 2013-04-11

Type

  • Doctoral Thesis

Format

  • application/pdf

Identifier