Decays that are highly suppressed in the standard model are excellent places to search for effects of new physics. Decays mediated by flavor-changing neutral currents are forbidden at tree level in the SM, and are often further suppressed by helicity and the Glashow-Iliopoulos-Maiani mechanism. Exclusive final states with charged lepton pairs are a particular strength of the CDF experiment due to the large bottom and charm production cross section and the ability to efficiently separate signal from background. CDF has searched for and set the world's best limits on the rare flavor-changing neutral current decays B^0_(s) rightarrow mu^+mu^-, B^0_(s) rightarrow e^+ e^-, and D^0 rightarrow mu^+mu^-, and the lepton flavor violating decay B^0_(s) rightarrow e^+/- μ^-/+.
We present the CDF results using 1.0 fb^{-1} of data on the mixing frequency measurement in the B_s system and the lifetime measurements of several B hadrons. We obtain Δm_s=17.77 +- 0.1 +- 0.07 ps^{-1} and cτ(Λ_b)=473.8 +- 23.1 +- 3.5 μm. The later one is more than 3 sigma above the world average, but in reasonable agreement with HQE calculations.
Using data samples in excess of 1 fb^-1 collected by the CDF II detector we present several world's best measurements of B hadron lifetimes. They include B_s meson lifetime in a flavor-specific decay mode, combining fully and partially reconstructed hadronic decays, B_c^+ meson lifetimes in semileptonic B_c^+ -> J/psi l+ X, l+=mu+,e+ decays and Lambda_b baryon lifetime in Lambda_c^+ pi- fully-reconstructed decays. In addition, we introduce a Monte Carlo independent technique for measuring B hadron lifetimes in data samples biased by displaced vertex triggers.
We present CDF results on the branching fractions and time-integrated direct CP asymmetries for Bd, Bs and Lb decay modes into pairs of charmless charged hadrons (pions, kaons and protons). The data-set for these measurements amounts to 1fb^{-1} of pbar-p collisions at a center of mass energy 1.96TeV. We report on the first observation of the Bs->Kpi, Lb-ppi and Lb->pK decay modes and on the measurement of their branching fractions and direct CP asymmetries.
B-hadron spectroscopy presents an interesting window for the study of QCD. CDF has performed a number of studies involving the production and spectroscopy of B mesons. Among these studies are the first direct observation of the Bc, and the first observation of both narrow states of the Bs**. In addition, measurements are made of the B** masses and widths and the best limit on the production of Eta_b is set.
I report recent measurements in b-hadron decays reconstructed in the full data set of \sqrt{s} = 1.96 TeV proton-antiproton collisions collected by the CDF experiment at the Tevatron. These include the final CDF results on: measurements of CP asymmetries in two-body charmless decays of the Bd, Bs, and Λ^0_b hadrons; bounds on the Bs mixing phase and on the decay width difference of Bs mass eigenstates; and updated measurements of branching ratios of Bs->Jpsi Phi and Bs->Ds(*)Ds(*) decays. All measurements are among the most precise from a single experiment and in agreement with the standard mo…
The CDF experiment at the Tevatron $p\bar{p}$ collider established that extensive and detailed exploration of the $b$--quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from $e^+e^-$ colliders. This provides a rich, and highly rewarding program that has currently reached full maturity. In the following I report some recent results on hadronic decays: the evidence for the charmless annihilation decay mode $B^0_s \to pi^+π^-$, and the first reconstruction in hadron collisions of the suppressed decays $B^- \to D(\to K^+π^-)K^-$ and $B^- \to D(\to…
In the last decade the CDF experiment at the Tevatron clearly demonstrated that it is possible to study extensively heavy flavour physics in hadron collisions and achieve remarkable results, competitive and complementary to $B$-factories. In this paper we report on the indirect searches for physics beyond the standard model via measurements of rare $b$-hadron decays. The final limits, based on the analysis of the full CDF data set, on the branching fraction of the $B^0_{(s)}$ decay into a pair of muons are presented and discussed. Moreover we review the latest measurements, with 6.8 fb$^{-1}$ …
The CDF experiment at the Tevatron p-pbar collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e+e- colliders. This provides an unique, rich, and highly rewarding program that is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in Bs mixing, and b-> s penguin decays.
We present results and prospects for searches for rare B and D meson decays with final state dimuons, including B_s\toμμ, B_d\toμμ, and D\toμμ. Upper limits on the branching fractions are compared to previous CDF measurements, recent results from the B factories and theoretical expectations. We also report on new measurements of production and decay properties of the X(3872) particle, discovered in 2003 by the Belle Collaboration. New results on the measurement of the relative branching fraction for the Cabibbo suppressed decay B^+\to J/ψπ^+ Br(B^+\to J/ψπ^+)/Br(B^+\to J/ψK^+) are presented to…
We present the first exclusive observation of the ttbar to hadronic tau + jets decay channel. Using these events from 1.96 TeV ppbar collisions at CDF, we measure the ttbar cross section as well as the top quark mass. Events require a single hadronic tau, large missing transverse energy, and exactly 4 jets of which at least one must be tagged as a b jet. The cross section measurement is extracted from a Poisson likelihood function based on the observed number of events and the predicted number of signal and background events for a given ttbar cross section. The mass is extracted from a likelih…
I present recent results of measurements of branching fractions and CP-violating asymmetries in B0, Bs, and Lambda_B two-body charmless decays at the upgraded Collider Detector at the Fermilab Tevatron. Measurements of rates of flavor-changing neutral current B0, Bs -->mu+mu- and B+/B0/Bs --> mu+mu- K+/K*0/phi decays are also reported. The results are extracted from samples corresponding to time-intergrated luminosities ranging from 0.78 to 1 fb-1.
The missing transverse energy (MET) plus b-jets signature is very promising for searches for the Higgs boson or new physics. Indeed, MET naturally arises from unidentified particles such as neutrinos, neutralinos, gravitons, etc., and b-quarks are the main decay products of a low mass Higgs boson as well as of several exotic particles. The main challenge is to identify and reject the numerous standard model (SM) backgrounds that mimic this signature. This is especially so for QCD multi-jet production, a large background due to mis-measurement (rather than undetectable particles). We present st…
We present a search for anomalous semileptonic decays of heavy flavor hadrons produced in association with a $W$ boson, in proton-antiproton collisions at sqrt{s}=1.96 TeV. We use 162 pb-1 of data collected with the CDF II detector at the Fermilab Tevatron Collider. We select events with one W boson and at least one jet with an identified secondary vertex. In the jets with a secondary vertex we look for a semileptonic decay to a muon. We compare the number of jets with both a secondary vertex and a semileptonic decay, and the kinematic properties of these jets, with the standard model expectat…
We present a measurement of the top-quark mass, $M_{\mathrm{top}}$, in the all-hadronic decay channel $t\bar{t} \to W^+b W^- \bar{b} \to q_1\bar{q}_2 b q_3 \bar{q}_4 \bar{b}$. The analysis is performed using 310 pb$^{-1}$ of $\sqrt{s}$=1.96 TeV $p\bar{p}$ collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value o…
he CDF experiment at the Fermilab Tevatron p-pbar collider pioneered the exploration of charmless b-hadron decays in hadron collisions. This provided a unique, rich and highly successful program of measurements that is currently reaching its full maturity. I report here results on two-body decays and the new analysis of B0s-->phiphi decays in a event sample corresponding to 2.9 fb-1.
Due to the large b-bbar cross section at 1.96 TeV p-pbar collisions, the Tevatron is currently the most copious source of B hadrons. Recent detector upgrades for Run II have made these more accessible, allowing for a wide range of B and CP violation physics with B hadrons of all flavours. In this paper we present B-physics results, and, using the versatile hadronic Two Track Trigger, a search for Xi(1860), from up to 240/pb of data.
We report on the search for $B^0_s\toμ^+μ^-$, $B^0_d\toμ^+μ^-$ decays and $b\to s μ^+μ^-$ transitions in exclusive decays of B mesons using the CDF II detector at the Fermilab Tevatron Collider. Using 2 fb$^{-1}$ of Run II data we find upper limits on the branching fractions $\mathcal{B}(B^0_s\toμ^+μ^-)<5.8\times 10^{-8}$ and $\mathcal{B}(B^0_d\toμ^+μ^-)<1.8\times 10^{-8}$ at 95% confidence level. The results for the branching fractions of the $b\to s μ^+μ^-$ transitions using 924 pb$^{-1}$ of Run II data are $\mathcal{B}(B^+\toμ^+μ^-K^+)=(0.60\pm0.15\pm0.04)\times 10^{-6}$, $\mathcal{B}(B^0_d…
We report on searches for B^0_s to μ^+ μ^-, B^0_d to μ^+ μ^- decays and b to s μ^+μ^- transitions in exclusive decays of B mesons. Using 2 fb^{-1} of data collected by the CDF II detector we find upper limits on the branching fractions B(B^0_s to μ^+ μ^-) < 5.8 x 10^{-8} and B(B^0_d to μ^+ μ^-) < 1.8 x 10^{-8} at 95% confidence level. Using 924 pb^{-1} of data we measure the branching fractions B(B^+ to μ^+ μ^- K^+) = (0.60 \pm 0.15 \pm 0.04) x 10^{-6}, B(B^0_d to μ^+ μ^- K^{*0}) = (0.82 \pm 0.31 \pm 0.10) x 10^{-6} and the limit B(B^0_s to μ^+ μ^- phi)/B(B^0_s to J/ψϕ) < 2.61(2.30) x 10^{-3} …
Using data from proton - antiproton collisions at Ecms = 1.96 TeV recorded by the CDF II and D0 detectors at the Fermilab Tevatron, we present the recent results on charm and bottom hadrons. We report the most recent CDF results on properties of the four bottom baryon resonant states Sigma_b(*)-, Sigma_b(*)+. The new results on exotic Y(4140) state observed by CDF are reported. A precise measurement of production rates of the basic lowest lying bottom baryon Lambda_b produced in the DZero detector is presented.
We measured the ambient energy in jet events using data of the CDF experiment at center-of-mass energies of 1800 and 630 GeV by examining the transverse momentum of charged particles in a region of the detector far away from the two most energetic jets in the event. The energy is compared to that found in minimum bias events. CDF data are compared to Monte Carlo predictions: neither Herwig nor Pythia can reproduce the data in detail.
The latest results in B physics from the CDF and D0 experiments at the Tevatron are presented, including inclusive b lifetime measurement and exclusive lifetime measurement of the B_s. Promising samples collected by CDF with its Secondary Vertex Trigger are shown as well.
This poster, presented at the 2006 Duke Hadron Collider Symposium, presents the results from searches for large extra dimensions, as proposed by Arkani-Hamed, Dimopoulos and Dvali (ADD), and Randall-Sundrum (RS) model warped extra dimensions, at CDF.
We present recent CDF results based on approximately 1 fb$^{-1}$ of $p\bar p$ collisions at $\sqrt s = 1.96$ TeV delivered at Fermilab Tevatron. Results shown include the observation of the $B_s$ oscillation frequency, the first observation of bottom baryon $Σ_b^{(*)\pm}$ states, updates on $B$ hadrons lifetimes, and searches for rare decays in the $b\to sμ^+μ^-$ transition and in charmless two-body B decays.
We present recent CDF results on $B$ lifetimes, $B$ meson mass measurements, ratios of branching ratios, and rare decays. In addition, we present the first measurement of time-dependent $B_d$ mixing at CDF. Several results have been updated and a few new ones included since the workshop.
We search for b to sμ^+μ^- transitions in B meson (B^+, B^0, or B^0_s) decays with 924pb^{-1} of p pbar collisions at sqrt(s)=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We find excesses with significances of 4.5, 2.9, and 2.4 standard deviations in the B^+ to μ^+μ^-K^+, B^0 to μ^+μ^-K^*(892)^0, and B_s^0 to μ^+μ^-ϕdecay modes, respectively. Using B to J/psi h (h = K^+, K^*(892)^0, phi) decays as normalization channels, we report branching fractions for the previously observed B^+ and B^0 decays, BR(B^+ to μ^+μ^-K^+)=(0.59\pm0.15\pm0.04) x 10^{-6}, and BR(B^0 to μ^+μ^…
Measurements of Flavor Changing Neutral Current (FCNC) processes (rare decays, flavor mixing) play a key role to pursue new physics beyond the Standard Model. We present recent analysis results about some FCNC transitions performed by CDF and D0 collaborations, including the first observation of the B_s->phi mu^+mu^- mode, the forward-backward asymmetry measurement in B->K^(*) mu^+mu^-, and updated measurements of B_s (B^0)->mu^+mu^-, using data corresponding to integrated luminosities from 3.7/fb to 5/fb. We also show the CDF/D0 combined measurement of the B_s mixing phase using 2.8/fb of dat…
We present world-leading results on CP-violating asymmetries and branching fractions of several decay modes of B0, B0s, and Λb hadrons into charmless two-body, and of B\pm into charm, final states collected by the CDF detector. We also report a new measurement of CP-violating asymmetries in D\ast\pm-tagged D0 \rightarrow h+h- (h = K or π) decays, where any enhancement from the Standard Model prediction would be unambiguous evidence for New Physics.
Recent results on Bs mixing, lifetime difference and rare decays obtained by the CDF and DO collaborations using the data samples collected at the Tevatron Collider in the period 2002 - 2005 are presented.
This paper describes the determination of the direct CP observables R_cp and A_cp, related to the CKM angle gamma, using B- to D0 K- decays in 1.0 inverse fb of data collected with the CDF II detector. This is the first measurement of these CP observables made at a hadron collider in this decay mode. The results presented are consistent with the measurements of these quantities made by the Belle and BABAR collaborations.
Hadron colliders can be an abundant source of heavy flavor quarks, but pose a challenge to isolate the physics signals from the high backgrounds. The upgraded CDF II detector, with its precise tracking capabilities and powerful trigger system, is well equipped for this task. The detector is described with an emphasis on actual performance and on techniques to maximize the heavy flavor yield. Some first heavy flavor results are summarized.
We present recent measurements by the CDF and D0 Collaborations at the Tevatron Collider on the masses and lifetimes of B hadrons. The results are compared to predictions based on Heavy Quark Effective Theory, lattice gauge theory, and quark models.
We review latest experimental results on the Bs mixing and lifetime difference measurements at CDF. We report on the latest beta_s and dGamma_s results from Bs->J/psi phi. We also discuss flavor specific dGamma_s measurements, including information from hadronic channels, Bs->DsDs and Bs->KK. We describe the new flavor tagging methodology and its calibration using the Bs oscillations.
Results of a search for the Flavor-Changing Neutral Current decay $B^0_{s,d} \to μ^+ μ^-$ using $p\bar{p}$ collision data at $\sqrt{s}=1.96$ TeV collected at Fermilab Tevatron collider by the CDF and DØdetectors are presented. CDF reports upper limits on ${\cal B} (B^0_{s} \to μ^+ μ^-) \leq 7.5 \cdot10^{-7}$ and ${\cal B}(B^0_{d} \to μ^+ μ^-) \leq 1.9 \cdot10^{-7}$ at the 95% C.L. using 171 pb$^{-1}$. The DØCollaboration used 240 pb$^{-1}$ to set an even more stringent limit on the branching ratio for $B^0_{s} \to μ^+ μ^-$ of $5.0\cdot 10^{-7}$ at the 95% C.L.
Last year's X(3872) discovery was confirmed with the CDF II detector in pbarp collisions. We measure its mass to be $3871.3 \pm 0.7 \pm 0.4 MeV/c2$. The source of X-mesons in the large CDF sample is resolved by studying their vertex displacement. We find $16.1 \pm 4.9 \pm 2.0$% of our X-sample comes from decays of b-hadrons, and the remainder from prompt sources: either direct production or by decay of (unknown) short-lived particles. The mix of production sources is similar to that observed for the psi(2S) charmonium state.
We present a measurement of the mass of the top quark from ppbar collisions at 1.96 TeV observed with the Collider Detector at Fermilab (CDF) at the Fermilab Tevatron Run II. The events have the decay signature of ppbar to ttbar in the lepton plus jets channel in which at least one jet is identified as coming from a secondary vertex and therefore a b-hadron. The largest systematic uncertainty, the jet energy scale (JES), is convoluted with the statistical error using an in-situ measurement of the hadronic W boson mass. We calculate a likelihood for each event using leading-order ttbar and W+je…
This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and anti-protons at Fermilab's Tevatron (sqrt{s}=1.96 TeV) produce top/anti-top pairs, which decay to W^+W^-bbbar; events are selected where one W decays to hadrons, and one W decays to either e or mu plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318 pb^-1. A total of 165 ttbar events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced ver…
After an introduction on the peculiarities of flavor-physics measurements at a hadron collider, and on the upgraded Collider Detector at Fermilab (CDF II), I show recent results on two-body B0 and B0s decays into charged, pseudo-scalar, charmless mesons or into muons, to illustrate how the flavor physics program at CDF is competitive with (in B0 decays) and complementary (in B0s decays) to B-factories. Results shown include the new measurement of the CP-violating asymmetry in B0-->K+pi- decays, the first measurement of the time-evolution of B0s-->K+K- decays, and the world best limits on the d…
We present the latest $B$ hadron lifetimes, $B^0_s$ mixing, and $D^0$ mixing measurements using up to 3.0 fb$^{-1}$ of data collected by CDF and D0 experiments at Fermilab. The $B^0_s$ lifetime is measured from both $J/ψϕ$ (CP admixture) and flavor specific channels, and the $B_c$ lifetime is obtained from semileptonic channels. Following the $B^0_s$ oscillation frequency measurement at CDF in 2006, the D0 collaboration now observes $B^0_s$ oscillation at a significance of about 3$σ$. Since the first $D^0$ mixing evidence established at $B$ factories in 2007, CDF has observed $D^0$ mixing at a…
A summary of the results of several recent studies of charm mixing is presented. A number of different methods were used, including the measurement of lifetime ratios for final states of different CP, time dependence of wrong-sign hadronic decays, fits to time-dependent Dalitz plots, and searches for wrong-sign semi-leptonic decays. Taken together, they suggest mixing is of order 1%. The status of searches for indirect CP violation is also reported.
Penguin transitions play a key role in the search of New Physics hints in the heavy flavor sector. During the last decade CDF has been exploring this opportunity with a rich study of two--body charmless decays of neutral B mesons into charged final--state particles. After briefly introducing the aspects of this physics peculiar to the hadron collision environment, I report on two interesting results: the first polarization measurement of the B^0_s --> phi phi decay and the update of the B^0(_s) --> h^+h'^- decays analysis.
In this contribution to the panel discussion on ``The Future of Hadron B Experiments'' held at the 8th International Conference on B Physics at Hadron Machines (Beauty 2002) at Santiago de Compostela, Spain, we explore the physics potential for B physics at CDF and DO in five years and beyond. After a brief introduction to precision flavour physics, we concentrate our discussion on the future of CP violation by evaluating the prospects for measuring the CKM angles beta, gamma and alpha at the Tevatron Collider experiments CDF and DO by the end of Run II.
The study of the charm quark continues to have wide interest as a possible avenue for the discovery of physics beyond the Standard Model and can as well be used as a tool for understanding the non-perturbative aspects of the strong interactions. Owning to the large production cross-section available at the Tevatron collider and to the flexibility of a trigger on fully hadronic final states, the CDF experiment, in a decade of successful operations, collected millions of charmed mesons decays which can be used to investigate the details of the physics of the production and decay processes of the…
For data collected with the CDF Run II detector, measurements of the charm and bottom production cross-sections are presented. The results are based both on large samples of fully reconstructed hadron decay products of charm and bottom made available by the tracking triggers and on a calorimeter jet triggered sample tagged by the presence of a secondary vertex. The experimental data are compared with theoretical predictions from recent next-to-leading order (NLO) QCD calculations.
We present new CDF results on the branching fractions and time-integrated direct CP asymmetries for $B^0$ and $B^0_s$ decay modes into pairs of charmless charged hadrons (pions or kaons). The data-set for this update amounts to 1 $\mathrm{fb}^{-1}$ of $p\bar p$ collisions at a center of mass energy 1.96 $\mathrm{TeV}$. We report the first observation of the $B_s \to K^- π^+$ mode and a measurement of its branching fraction and direct CP asymmetry. We also observe for the first time two charmless decays of the $Λ_b^0$-baryon: $Λ_b^0 \to pπ^-$ and $Λ_b^0 \to pK^-$.
The D0 and CDF detectors at the Fermilab Tevatron have each accumulated more that 9/fb of integrated luminosity. The corresponding large datasets enable the two experiments to perform unprecedented studies of heavy flavor hadron properties. We present recent D0 and CDF measurements, focusing on rare decays and CP violation in B-meson decays.
The CDF experiment at the Tevatron $p\bar{p}$ collider has pioneered and established the role of hadron collisions in exploring flavor physics through a broad program that is now at its full maturity. We report new results sensitive to physics beyond the standard model, obtained using the whole CDF data set; including new bounds on the \Bs\ mixing phase and the decay width difference of \Bs\ mass-eigenstates and a measurement of the difference of CP asymmetries in $K^+K^-$ and $π^+π^-$ decays of $D^0$ mesons. We also present a new measurement of the $\Bs \rightarrow D^{(*)+}_s D^{(*)-}_s$ bran…
Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the b -> s mu^+ mu^- and B0 -> mu^+ mu^- decays. We report recent results at a center of mass energy of sqrt(s) = 1.96 TeV from CDF II using 7/fb at the Fermilab Tevatron Collider.
The CDF II detector has the capability of triggering on displaced tracks. Because of this ability, CDF II has accrued large samples of charmed meson decays to fully hadronic final states in 64 pb^-1 of ppbar collision data gathered at sqrt(s) = 1.96 TeV. Using initial Run II data samples, the production cross sections for J/psi, D0, D+, D*+ and Ds+ mesons have been measured. Ratios of branching ratios for Cabibbo suppressed final states and CP asymmetries in D0 meson decays have been studied. A measurement of the mass difference m(Ds+) - m(D+) has been done, and a limit for the branching fract…
We combine the results of CDF and DO searches for the rare decays B_s to mu+ mu- and B_d to mu+ mu-. The experiments use 364 pb-1 and 300 pb-1 of data respectively. The limits on the branching ratios are obtained by normalizing the estimated sensitivity to the decay B+ to J/psi K+, taking into account the fragmentation ratios f_u/f_s(d). The combined results exclude branching ratios of BR(B_s to mu+ mu-) > 1.5x10-7 and BR(B_d to mu+ mu- > 4.0x10-8 at 95% confidence level. These are the most stringent limits on these decays at the present time.
Exploiting the full Run II data sample collected by the CDF trigger on displaced vertices, we present a search for CP violation in neutral D mesons decays to hadronic final states. We use the strong D^{*+}\to D^{0}π^{+} (and c.c.) decay to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c\bar{c} pair-production in p\bar{p} collisions. The results are the world's most precise measurements to date and confirm the presence of sizable CP-violating effects in the charm sector as recently observed by the LHCb Collaboration
We report on mass and mean life measurements of several ground state $b-$baryons, using 9.6 $\textrm{fb}^{-1}$ of data from $p\bar p$ collisions at $\sqrt{s}=1.96$ TeV, and recorded with the Collider Detector at Fermilab. Data collected with triggers designed to collect events with $J/ψ\rightarrow μ^+ \, μ^-$ candidates and events with hadrons displaced from the beamline are used to measure the masses and lifetimes of $Λ_b, Ξ_b^-, Ξ_b^0$, and $Ω_b^-$. The first evidence for the process $Ω_b^- \rightarrow Ω_c^0 \, π^-$ is also shown. The results supersede our previous measurements of these quan…
We present a measurement of R_B, the ratio of the branching fraction for the rare decay D0 -> K+ pi- to that for the Cabibbo-favored decay D0 -> K- pi+. Charge conjugate decays are implicitly included. A signal of 2005 +/- 104 events for the decay D0 -> K+ pi- is obtained using the CDF II detector at the Fermilab Tevatron collider. The data set corresponds to an integrated luminosity of 0.35 1/fb produced in p-bar/p collisions at sqrt{s}=1.96 TeV. Assuming no mixing, we find R_B = [ 4.05 +/- 0.21 (stat) +/- 0.11 (syst) ] x 10(-3). This measurement is consistent with the world average, and comp…
We present a measurement of the top-quark width using $t\bar{t}$ events produced in $p\bar{p}$ collisions at Fermilab's Tevatron collider and collected by the CDF II detector. In the mode where the top quark decays to a $W$ boson and a bottom quark, we select events in which one $W$ decays leptonically and the other hadronically~(lepton + jets channel) . From a data sample corresponding to 4.3~fb$^{-1}$ of integrated luminosity, we identify 756 candidate events. The top-quark mass and the mass of $W$ boson that decays hadronically are reconstructed for each event and compared with templates of…
Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the Bs(d) -> μ^{+} μ^{-} and b -> sμ^{+}μ^{-} decays. We report recent results at a center of mass energy of sqrt{s} = 1.96 TeV from the CDF and D0 collaborations using between 3.7 fb^{-1} and 6.9 fb^{-1} taken during Run II of the Fermilab Tevatron Collider.
Rare hadronic B-meson decays allow us to study CP violation. The class of B decays final states containing two vector mesons provides a rich set of angular correlation observables to study. This article reviews some of the recent experimental results from the BaBar and Belle collaborations.
We report on searches for Flavor-Changing Neutral Current (FCNC) decays in ppbar collisions at a center of mass energy of 1.96 TeV using up to 0.78 fb-1 of data, collected at the CDF and DO detectors respectively. The rare FCNC decays presented here are the searches for Bs-> Mu+Mu- and Bs -> phi mu+mu-.
