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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-09242013-231307


Thesis type
Tesi di dottorato di ricerca
Author
LEO, SABATO
URN
etd-09242013-231307
Thesis title
Measurement of CP violation in Bs--> J/psi Phi decays using the full CDF data set
Academic discipline
FIS/01
Course of study
SCIENZE DI BASE
Supervisors
tutor Punzi, Giovanni
relatore Tonelli, Diego
Keywords
  • CPV mixing phase
Graduation session start date
27/09/2013
Availability
Full
Summary
We report on the final measurement of the \CP-violating \Bs\ mixing phase \betas\ in $\sqrt{s}=$1.96 TeV proton-antiproton
collisions collected with the Collider Detector at the Fermilab Tevatron collider. Using a sample corresponding
to 9.6\,\lumifb\ of integrated luminosity, we fit
the decay-time evolution of $B^0_s \rightarrow J/\psi (\rightarrow \mu^+ \mu^-) \phi (\rightarrow K^+ K^-)$ decays in which the $b$-quark content at production and the \CP\ parity
of the final state are identified.
The interference of decays with and without mixing renders the \Bs\ mixing phase observable.
The phase is determined to be $-0.06<\betas <0.30$ at 68\% confidence level.
The decay-width difference between heavy and light \Bs\ eigenstates, and the average \Bs\ lifetime are also determined to be \DGs $= 0.068 \pm 0.027$ $\rm{ps^{-1}}$ and
$\tau_s\,=1.528 \pm 0.021$ $\rm{ps}$, respectively.
These results are among the world's most precise from a single experiment, and compatible with standard model predictions.
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