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 data per experiment.
Recent measurements of branching fractions and CP-violating partial-rate asymmetries for rare hadronic B-meson decays by the asymmetric-energy B-factory experiments, Belle and BaBar, are reviewed.
The K_S \to pi+/- e+ e- decay mode has been investigated using the data collected in 2002 by the NA48/1 collaboration. With about 23k signal events and 59k K_L \to pi+ pi- pi0_D normalization decays, the K_S \to pi+ pi- e+ e- branching ratio was determined. This result is also used to set an upper limit on the presence of E1 direct emission in the decay amplitude. The CP-violating asymmetry has been also measured. We report on measurements of the rare decays K +/- \to pi+/- e+ e- and K+/- \to pi+/- mu+ mu- . The full NA48/2 data set was analyzed, leading to more than 7200 reconstructed events …
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.
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.
Both CDF and DØexperiments have been searching for evidence of physics beyond the standard model (SM) using the Tevatron $p\bar{p}$ collider at Fermilab. We report on recent searches in the $B$ flavor sector, especially decays via flavor changing neutral current processes (FCNC), $B^0_{(s)} \to e^+μ^-$ and $B^0_{s} to μ^+ μ^-$, at the Tevatron.
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.
The Tevatron experiments CDF and D0 investigated the top quark decay in search of deviations from the Standard Model. Rare processes expected in the Standard Model as well as decays including hypothetical particles of models beyond the Standard Model were investigated. This contribution gives an overview of the studies that were performed with datasets of up to 7.5fb^-1 of integrated luminosity.
A summary of recent results on B rare decays from the CDF and D0 experiments operating in Run II of the Fermilab Tevatron is given; analyzed decay modes are B_{d,s}--> hh, B_{d,s}--> mu^{+}mu^{-}, and B--> mu^{+} mu^{-}h. Data samples are relative to 1 fb^{-1} or more integrated luminosity of p-pbar collisions at sqrt(s) = 1.96 TeV. All reported results are in agreement with Standard Model predictions and consistent with B-Factories analyzes.
The top quark is the most recently discovered quark. Relatively little is known about its properties so far. Due to its very large mass of about $175 \rm GeV/c^2$, the top quark behaves differently from all other quarks and provides a unique environment for tests of the Standard Model. Furthermore, it is believed to yield sensitivity to physics beyond the Standard Model. This report discusses the latest measurements and studies of top quark properties and rare decays from the Tevatron in Run II.
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-.
The measurements of rare decays are highly sensitive to physics beyond the standard model. In this article limits on the branching ratios of the decays B0s -> mu+mu-, D0 -> mu+mu- and D+ -> pi+mu+mu- are presented. Furthermore the first measurement of the branching fraction and CP asymmetry of Lambda_b -> p pi- and Lambda_b -> p K- decays is described. Data samples with an integrated luminosity of up to 2/fb collected at the Tevatron ppbar-collider at sqrt(s)=1.96 TeV were used in these analyses. The results are consistent with the standard model predictions and tighten the constraints on new …
Studying flavor changing neutral current transitions provides important information that helps searches for physics beyond the standard model. In this paper we report on recent measurements of these transitions using data collected by the CDF and D0 experiments at the Tevatron $p\bar{p}$ collider, including world-leading limits on the branching fraction of the decay $B^0_{(s)} \to μ^+ μ^-$, a forward-backward asymmetry measurement in $B^0 \to K^{*0} μ^+ μ^-$ and $B^+ \to K^+ μ^+ μ^-$ decays which is consistent and competitive with best $B$-factories results, and the first observation of the de…
In this report I review recent results in the field of rare decays at the Tevatron CDF II and D0 experiments. The presentation is focused on rare decays of charm and bottom mesons with two muons in the final state. This includes improvements over the previously available limits on the following branching ratios: $B(D^+ \to π^+ μ^+ μ^-)< 4.7 \times 10^{-6}$, B(B_s^0 \to ϕμ^+ μ^-)< 3.2\times 10^{-6}$, $B(B_s^0 \to μ^+ μ^-)< 1 \times 10^{-7}$, and $B(B_d^0)< 3 \times 10{-8}$ all at the 90% confidence level. Also reported are the first direct observation of $D_s^+ \to ϕπ^+ \to μ^+ μ^- π^+$ with a …
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.
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 measurement of the CP violation in the b-meson system and of b-meson rare decays provides information about the electroweak symmetry breaking in terms of flavour structure of the CKM matrix and flavour changing neutral currents. The deviation of the experimental observations from the Standard Model predictions allows to constrain new physics. In this paper recent results from Tevatron are reported.
This review summarizes the most important results in B physics obtained at the Tevatron. They include the discovery of the new B hadrons, the measurement of their masses and lifetimes, the measurement of the oscillation frequency of $\Bs$ meson, the search for its rare decay $\Bs \to μ^+ μ^-$, and the study of the CP asymmetry in decays and mixing of $B$ mesons.
We present the B physics results from the CDF and DØ experiments at the Tevatron Run II at Fermilab and their future prospect. This includes various B mass and lifetime measurements, B mixing, the confirmation of the discovery of the X particle, rare decays, CP violation and spectroscopy.
The CDF and D0 experiments 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 B-factories. In this paper we review the current state of Tevatron's heavy flavor measurements considering two main categories: searches for non standard model physics (results on rare decays and CP-violation) and determinations of standard model parameters (annihilation in $B \to h^+ h^-$ decays and $γ$ angle measurement through $B\to DK$ modes).
We report on recent B-Physics results from the Tevatron. The topics covered include measurement of the polarization amplitudes in $B_s^0 \to ϕϕ$, the search for rare flavor-changing neutral-current decays, CP violation in $B_s^0 \to J/ψϕ$ and semileptonic $B_s^0$ decays, and a new measurement of the like-sign asymmetry in dimuon events.
We present a summary of recent WW, WZ, and ZZ measurements carried out in $\sqrt{s} = 1.96$ TeV at the Tevatron. The observation of rare ZZ events and the precise measurement of the WW cross section in fully leptonic decay modes are described. Results in semi-leptonic decay modes where one boson decays to two quarks are also presented. The measurements described are all in good agreement with the Standard Model and are relevant to searches for the Higgs boson at the Tevatron.
Successful operation of the Large Hadron Collider has led to more than 1 fb^-1 of data recorded with both ATLAS and CMS detectors by summer of 2011. This large amount of data has allowed to perform numerous searches for rare processes beyond the Standard Model, many of which are competitive with previous searches performed with the CDF and D0 detectors at the Tevatron. In this talk the most recent searches at the hadron colliders are reviewed.
The CDF and DØ experiments 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 is currently reaching full maturity. I report a few recent world-leading results on rare decays, CP-violation in $B^0_s$ mixing, $b\to s$ penguin decays, and charm physics.
Recent results on $B_d$, $B_u^{\pm}$, $B_s$, $Λ_b$ and Charm hadrons are reported from $\approx$ 75pb$^{-1}$ and $\approx$ 40 pb$^{-1}$ of data accumulated at the upgraded CDF and D0 experiments at the Fermilab Tevatron $\bar{p}-p$ collider, during Run-II. These include lifetime and mass measurements of $B$ and Charm hadrons, searches for rare decays in charm and $B$ hadrons and CP-violation in Charm decays. Results relevant to CP-violation in B-decays are also reported.
The recent Tevatron result on the top quark forward-backward asymmetry, which deviates from its standard model prediction by 3.4$σ$, has prompted many authors to build new models to account for this anomaly. Among the various proposals, we find that those mechanisms which produce $t\bar t$ via $t$- or $u$-channel can have a strong correlation to the rare B decays. We demonstrate this link by studying a model with a new charged gauge boson, $W'$. In terms of the current measurements on $B\to πK$ decays, we conclude that the branching ratio for $B^-\to π^- \bar K^0$ is affected most by the new e…
We report on recent Z (+jets) measurements from the Fermilab Tevatron proton anti-proton collider. A new D0 measurement of the transverse momentum of Z bosons yields the best measurement to date of the non-perturbative form factor, g2. The production of Z+jets is an major background to many rare signals, and is a vital testing ground for theoretical predictions. Measurements from CDF and D0 of differential cross sections in Z+jet production test NLO pQCD, and in the case of D0, the latest tree-level matrix element with matched parton shower calculations. Improving modelling of this signal will…
We summarize recent measurements made at the Tevatron Collider using top event candidates. Cross section and mass measurements are discussed in a separate contribution to these Proceedings. Here we report on studies of the top P$_T$ distribution in $\ttbar$ production and studies of single top production. Properties of top decays examined are: BF($t \into Wb$)/BF($t \into Wq$), helicity amplitudes of W's from top decays and correlations of $\ttbar$ decay products. Searches for new physics in rare top decays and a search for a state X $\into \ttbar$ are also reported.
We discuss the physics goals and rationale for a detector to study Beauty and Charm decays in the forward direction at the Fermilab Tevatron Collider. We then describe the BTeV detector which has been designed to achieve these goals and present its physics reach based on extensive simulation. We conclude by comparing BTeV to other experiments designed to explore similar topics.
We discuss several recent measurements of rare charmed hadron decays. Focus is placed on radiative and annihilation topologies highlighting their sensitivity to new physics and pointing out the strengths and weaknesses of different channels. We compare the different measurement techniques employed at fixed target and $e^+e^-$ dedicated charm experiments, B-factories, and the Tevatron experiments. Comparisons are also made to similar topologies in the beauty, strange, and top systems where appropriate.
I present a review of using rare B decays to search for physics beyond the Standard Model. B decays that proceed either through annihilation or loop topologies at leading order in the Standard Model provide unique probes in the search for new physics. The latest experimental results from the B factories (Babar and Belle) and the Tevatron experiments (CDF and D0) on rare decays and their impact on various scenarios for new physics will be presented.
The CDF and D0 experiments finalize the analysis of their full statistics collected in the $p \bar p$ collisions at a center-of-mass energy of $\sqrt{s} = 1.96$ TeV at the Fermilab Tevatron collider. This paper presents several new results on the properties of hadrons containing heavy $b$- and $c$-quarks obtained by both collaborations. These results include the search for the rare decays $B^0, B^0_s \to μ^+ μ^-$ (CDF), the study of CP asymmetry in $B_s \to Jψϕ$ decay (CDF, D0), the measurement of the like-sign dimuon charge asymmetry (D0), the measurement of CP asymmetry in $D^0 \to K^+K^-$ a…
We perform a search for the rare decay Bs->mumu using data collected by the D0 experiment at the Fermilab Tevatron Collider. This result is based on the full D0 Run II dataset corresponding to 10.4 fb^(-1) of ppbar collisions at sqrt(s) = 1.96 TeV. We use a multivariate analysis to increase the sensitivity of the search. In the absence of an observed number of events above the expected background, we set an upper limit on the decay branching fraction of BR(Bs->mumu) < 15x10^(-9) at the 95% C.L.
Between 1992 to 1996, the CDF and D0 detectors each collected data samples exceeding 100 pb^{-1} of p\bar{p} collisions at sqrt{s}=1.8 TeV at the Fermilab Tevatron. These data sets led to a large number of precision measurements of the properties of B hadrons including lifetimes, masses, neutral B meson flavor oscillations, and relative branching fractions, and to the discovery of the B_c meson. Perhaps the most exciting result was the first look at the CP violation parameter sin(2beta) using the world's largest sample of fully reconstructed B^0/bar{B}^0 -> J/psi K^0_S decays. A summary of thi…
This report summarizes the latest experimental results on radiative and electroweak rare B meson decays. These rare decay processes proceed through the flavor changing neutral current processes, and thus sensitive to the postulated new particles in the theories beyond the Standard Model. Experiments at e+ e- colliders, Belle, BaBar and CLEO, have been playing the dominant role, while the CDF and D0 experiments have just started to provide new results from Tevatron Run-II. The most significant achievement is the first observation of the decay B --> K* l+ l-, which opens a new window to search f…
Rare B hadron decays provide an excellent test bench for the Standard Model and can probe new physics models. We review the experimental progress of the searches for rare leptonic B decays ($b\rightarrow \ell^+ \ell^-$ and $b\rightarrow s \ell^+ \ell^-$) at LHC and Tevatron experiments.
We present the results of a search for the flavor changing neutral current decay B_s^0->mu^+mu^- using 6.1 fb^-1 of ppbar collisions at sqrt(s) = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B_s^0 candidates is consistent with background expectations. The resulting upper limit on the branching fraction is BR(B_s^0->mu^+mu^-) < 5.1 x 10^-8 at the 95% C.L. This limit is a factor of 2.4 better than that of the previous D0 analysis and the best limit to date.
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$^{-1}$ …
Top quarks are produced at the Tevatron proton-antiproton collider at Fermilab and at the Large Hadron (proton-proton) Collider at CERN in two ways: as quark-antiquark pairs, and singly. For each mode, the cross sections and future experimental yields are presented. I then discuss some precision measurements that can be made using the anticipated large data sets. These measurements include the top quark mass, width and branching fractions, the electroweak Wtb coupling, and the CKM matrix element Vtb. Detailed studies of the top quark polarization and gluon radiation will also be possible, in a…
We review the salient features of $B$-meson physics, with particular emphasis on the measurements carried out at the $B$-factories and Tevatron, theoretical progress in understanding these measurements in the context of the standard model, and anticipation at the LHC. Topics discussed specifically are the current status of the Cabibbo-Kobayashi-Maskawa matrix, the CP-violating phases, rare radiative and semileptonic decays, and some selected non-leptonic two-body decays of the $B$ mesons.
We present a search for the flavor-changing neutral current decay B0_s -> phi mu+ mu- using about 0.45 fb^-1 of data collected in p \bar p collisions at sqrt{s} =1.96 TeV with the DØdetector at the Fermilab Tevatron Collider. We find an upper limit on the branching ratio of this decay normalized to B0_s -> J/psi phi of B(B0_s -> phi mu+ mu-)/B(B0_s -> J/psi phi) < 4.4\times 10^{-3} at the 95% C.L. Using the central value of the world average branching fraction of B0_s -> J/psi phi, the limit corresponds to B(B0_s -> phi mu+ mu-) < 4.1 \times 10^{-6} at the 95% C.L., the most stringent upper bo…
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…
The forward-backward asymmetry A_{FB}^t in top quark production at the Tevatron has been seen to be anomalously large both by CDF and D0. Parton-level asymmetries as large as 50%, with a large error bar, have been extracted from the data. It is important to measure other quark asymmetries if possible, as these would help clarify the source of any new physics behind A_{FB}^t. In this note it is argued that asymmetries in b\bar b and c\bar c should be accessible to the Tevatron experiments, using the full data sets. A crude study suggests that muon asymmetries in high-p_T dijet events, with suit…
The discovery potential of the Tevatron CDF for the rare B-decay B_s --> mu^+ mu^- is analysed. We find that with an integrated luminosity of 2 fb^(-1), and using CDF as the example detector, a 5 sigma combined discovery reach of the Tevatron is possible if the Branching ratio for B_s --> mu^+ mu^- is (1.7 +- 0.46) \times 10^(-7). Such a possible signal for the decay B_s --> mu^+ mu^- will invite large tan(beta) values and set an upper bound on the heaviest mass of the MSSM Higgs sector in a complete analogy to the upper bound of the lightest observable supersymmetric particle set from the exc…
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 $\mathcal{B}(B^+\toμ^+μ^-K^+)=(0.60\pm0.15\pm0.04)\times 10^{-6}$, $\mathcal{B}(B^0_d…
We present recent CDF results based on approximately 1 fb$^{-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.
Precision studies of top quark properties are currently underway at the LHC and Tevatron colliders with the prospect of probing anomalous t-W -b interactions. In the mean time, recent experimental results for the B_{d,s} - \bar{B}_{d,s} oscillation observables, the branching ratio B_s->μ^+μ^-, as well as the forward - backward asymmetry in B->K\starl^+l^-, accompanied by the accurate theoretical predictions for the relevant observables obtained within the SM motivate a combined study of these observables in the presence of anomalous t - W - b vertices. We investigate contributions of such anom…
This review summarizes the current experimental results on rare B0_(s) -> mu+mu- decays of the Tevatron experiments CDF and D0, and the LHC experiments ATLAS, CMS and LHCb. The experimental branching fraction upper limits for the B0_s -> mu+mu- are already quite close to the branching fraction predicted by the Standard Model, and the first observation of the B0_s -> mu+mu- decay is expected soon. The rare decays B0_(s) -> mu+mu- are highly suppressed in the Standard Model, and therefore accurate measurements of these branching fractions provide complementary constraints to the free parameters …
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 currently live in the age of the CKM paradigm. The $3\times 3$ matrix that links $(d,\ s,\ b)$ quarks to $(u,\ c,\ t)$ in the charged current weak interaction, being complex and nominally with 18 parameters, can be accounted for by just 3 rotation angles and one $CP$ violating (CPV) phase, with unitarity and the CKM phases triumphantly tested at the B factories. But the CKM picture is unsatisfactory and has too many parameters. The main aim of Flavor Physics and $CP$ violation (FPCP) studies is the pursuit to uncover New Physics beyond the Standard Model (SM). Two highlights of LHC Run~1 pe…
Fermilab operates the world's most intense antiproton source. Newly proposed experiments can use those antiprotons either parasitically during Tevatron Collider running or after the end of the Tevatron Collider program. For example, the annihilation of 5 to 8 GeV antiprotons is expected to yield world-leading sensitivities to hyperon rare decays and CP violation. It could also provide the world's most intense source of tagged D^0 mesons, and thus the best near-term opportunity to study charm mixing and, via CP violation, to search for new physics. Other measurements that could be made include …
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^…
Fermilab operates the world's most intense antiproton source. Newly proposed experiments can use those antiprotons either parasitically during Tevatron Collider running or after the Tevatron Collider finishes. For example, the annihilation of 8 GeV antiprotons is expected to yield world-leading sensitivities to hyperon rare decays and CP violation. It could also provide the world's most intense source of tagged D^0 mesons, and thus the best near-term opportunity to study charm mixing and, via CP violation, to search for new physics. Other precision measurements that could be made include prope…
The Fermilab Tevatron (p pbar), operating at sqrt(s)=1.96 TeV, is a rich source of B hadrons. The large acceptance in terms of rapidity and transverse momentum of the charged particle tracking system and the muon system make the upgraded Run II D0 detector an excellent tool for B physics. In this article, we report on selected physics results based on the first 250 pb^-1 of Run II data. This includes results on the X(3872) state, semileptonic B decays, B hadron lifetimes, flavour oscillations, and the rare decay B_s -> mu^+ mu^-.
We report on a search for Bs->mu+mu- and Bd->mu+mu- decays in ppbar collisions at sqrt(s)=1.96 TeV using 171 pb-1 of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are sensitive to contributions from physics beyond the Standard Model. One event survives all our selection requirements,consistent with the background expectation. We derive branching ratio limits of BR(Bs->mu+mu-) < 5.8 x 10^-7 and BR(Bd->mu+mu-) < 1.5 x 10^-7 at 90% confidence level.
We investigate the bounds on the mass of the lightest neutralino from rare meson decays within the MSSM with and without minimal flavor violation. We present explicit formulae for the two-body decays of mesons into light neutralinos and perform the first complete calculation of the loop-induced decays of kaons to pions and light neutralinos and B mesons to kaons and light neutralinos. We find that the supersymmetric branching ratios are strongly suppressed within the MSSM with minimal flavor violation, and that no bounds on the neutralino mass can be inferred from experimental data, i.e. a mas…
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…
The measured forward-backward asymmetry in the t tbar production at the Tevatron might be explained by the additional exchange of a colored weak singlet scalar. Such state appears in some of the grand unified theories and its interactions with the up-quarks are purely antisymmetric in flavor space. We systematically investigate the resulting impact on charm and top quark physics. The constraints on the relevant Yukawa couplings come from the experimentally measured observables related to D0--D0bar oscillations, as well as di-jet and single top production measurements at the Tevatron. After ful…
We reconstruct the rare decays $B^+ \to K^+μ^+μ^-$, $B^0 \to K^{*}(892)^0μ^+μ^-$, and $B^0_s \to ϕ(1020)μ^+μ^-$ in a data sample corresponding to $4.4 {\rm fb^{-1}}$ collected in $p\bar{p}$ collisions at $\sqrt{s}=1.96 {\rm TeV}$ by the CDF II detector at the Fermilab Tevatron Collider. Using $121 \pm 16$ $B^+ \to K^+μ^+μ^-$ and $101 \pm 12$ $B^0 \to K^{*0}μ^+μ^-$ decays we report the branching ratios. In addition, we report the measurement of the differential branching ratio and the muon forward-backward asymmetry in the $B^+$ and $B^0$ decay modes, and the $K^{*0}$ longitudinal polarization …
We measure the time dependence of the ratio of decay rates for the rare decay D0->K+pi- to the Cabibbo-favored decay D0->K-pi+. We use a signal of 12.7 x10^3 D0->K+pi decays with proper decay times between 0.75 and 10 mean D0 lifetimes. The data sample was recorded with the CDF II detector at the Fermilab Tevatron and corresponds to an integrated luminosity of 1.5 fb-1 of p-pbar collisions at sqrt(s) = 1.96 TeV. We search for D0-D0bar mixing and measure the mixing parameters to be Rd = (3.04 +/- 0.55) x10^{-3}, y' = (8.5 +/- 7.6) x10^{-3}, and x'^2 = (-0.12 +/- 0.35) x10^{-3}. We report Bayesi…
