Final measurement of Bs0B^0_s mixing phase in the full CDF Run II data set

We report the final CDF measurement of the $B^0_s$ mixing phase, mean lifetime, and decay-width difference through the fit of the time evolution of flavor-tagged $B^0_s \rightarrow J/\psi \phi$ decays. The measurement is based on the full data set of 1.96 TeV $p\bar{p}$ collisions collected between February 2002 and September 2011 by the CDF experiment. The results are consistent with the standard model and other experimental determinations and are amongst the most precise to date.Comment: 3 pages, 2 figures, conference IFAE 201

On the resolution in a measurement of dijet invariant mass when searching for associated WZ production with CDF

We report on a number of simulation studies on how to improve the invariant mass resolution of a particle decaying into two large energy hadron jets. This is a preliminary step of an effort to observe associated WZ production. This process is extremely rare and competes with a large background, and any minor improvement in resolution deserves great attention. These tools would be of interest in the study of many rare multi-jet processes. They are implemented here in a simulated measurement of $Z\rightarrow q\bar{q}$ decay (aiming eventually at a $H\rightarrow b\bar{b}$ decay), in associated WZ (WH) production in \proton \antiproton\ collisions at \ecm = 1.96 TeV recorded by the CDF II experiment at the Fermilab Tevatron Collider. We generate WZ events with an identified charged lepton, a large imbalance in transverse momentum, and at least two large transverse energy jets. We determine the sample selection cuts by studying jet energy dependence of signal and background. The main backgrounds, noticeably W+jets production, are modeled based on experimental data whenever possible. We first try to optimize the sensitivity to a jet-jet invariant mass peak by complementing the information provided by the CDF calorimeter with that of the tracker. For mis-measured calorimeter jets, and for jets fragmenting with a large charged-to-neutral ratio, the jet axis could be better measured in the tracker. As a consequence the dijet invariant mass could be better measured. The study starts by checking the best ever achievable improvement by adopting the primary parton direction as jet axis. This study is performed on a $WZ\rightarrow l \nu q\bar{q}$ PHYTIA Monte Carlo in the simpler case of light decay quarks. Improvements in dijet mass resolution of the order of a few \% are obtained in a number of cases. Next we try to develop event-specific energy corrections for calorimeter jets. Again, improvements of the order of a few \% are obtained in a number of cases. The combination of these two methods indicates possible improvements in dijet mass resolution up to $\sim$5\%., \par When the study is extended to using, rather than primary quark directions, tracker jet axes which are experimental observables, no real progress is predicted. However, the study is extended to event specific corrections to calorimeter jets based on information carried by observables in the event, including tracking. This study gives very interesting and promising indications: Resolution improves by $\sim4\%$. Criteria by which we select and merge jets due to final state radiation (FSR) are discussed, and the impact on dijet mass resolution of merging three jets to reconstruct W or Z in $q\bar{q}$ decay is studied

A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states

A first study of CP violation in the decay modes $B^\pm\to [K^0_{\rm S} K^\pm \pi^\mp]_D h^\pm$ and $B^\pm\to [K^0_{\rm S} K^\mp \pi^\pm]_D h^\pm$, where $h$ labels a $K$ or $\pi$ meson and $D$ labels a $D^0$ or $\overline{D}^0$ meson, is performed. The analysis uses the LHCb data set collected in $pp$ collisions, corresponding to an integrated luminosity of 3 fb$^{-1}$. The analysis is sensitive to the CP-violating CKM phase $\gamma$ through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of $\gamma$ using other decay modes

Measurement of Upsilon production in collisions at root s=2.76 TeV

The production of $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S)$ mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3 $pb^{-1}$ collected in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=2.76$ TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the $\Upsilon$ transverse momentum and rapidity, over the ranges $p_{\rm T} Upsilon(1S) X) x B(Upsilon(1S) -> mu+mu-) = 1.111 +/- 0.043 +/- 0.044 nb, sigma(pp -> Upsilon(2S) X) x B(Upsilon(2S) -> mu+mu-) = 0.264 +/- 0.023 +/- 0.011 nb, sigma(pp -> Upsilon(3S) X) x B(Upsilon(3S) -> mu+mu-) = 0.159 +/- 0.020 +/- 0.007 nb, where the first uncertainty is statistical and the second systematic