We present results from electroweak precision measurements at CDF. These include the measurement of the Z boson rapidity distribution using di-electron events, the W boson charge asymmetry measurement in the electron-neutrino decay and the direct measurement of the W boson mass and width in both the electron-neutrino and muon-neutrino decay channels.
We present some recent measurements on electroweak physics using data collected by the CDF experiment at the Tevatron proton anti-proton collider ($\sqrt{s}=1.96\mathrm{TeV}$) at Fermilab (Batavia, Ill, USA).
The latest results in electroweak physics from proton anti-proton collisions at the Fermilab Tevatron recorded by the CDF detector are presented. The results provide constraints on parton distribution functions, the mass of the Higgs boson and beyond the Standard Model physics.
A summary of the most up-to-date top quark mass measurements at CDF is presented. These analyses use top-antitop candidate events detected in the CDF experiment at the Tevatron collider with an integrated luminosity of up to ~3/fb. The combination of all those measurements together with the corresponding top mass measurements from the concurrently running D0 experiment at the Tevatron yields a world average of M_t=[173.1+/-0.6(stat.)+/-1.1(syst.)] GeV/c^2.
The Run II physics program of CDF is proceeding with approximately 200 pb-1 of analysis quality data collected at the center-of-mass energy of 1.96 TeV. The Electroweak measurements are among the first and most important benchmarks towards the best understanding of the detector and testing of the Standard Model. We present precision measurements of the W and Z inclusive cross sections and decay asymmetries, recent results in di-boson physics and their sensitivity to new physics, and preliminary studies for the W mass measurement.
These proceedings describe Sleuth, a quasi-model-independent search strategy targeting new electroweak scale physics, and its application to 927 pb^-1 of CDF II data. Exclusive final states are analyzed for an excess of data beyond the Standard Model prediction at large summed scalar transverse momentum. This analysis of high-pT data represents one of the most encompassing searches so far conducted for new physics at the energy frontier.
This letter presents results on the precision measurement of the top quark mass and a combination of the best CDF top mass measurements. A combination by the TevEWWG (Tevatron electroweak working group) of the best top mass results from CDF and D0 in Run 1 and Run 2 of the Tevatron is also presented. This result is the current world average, and offers an uncertainty less than 1%. The new mass value has been included in traditional LEP EWWG fits to precision electroweak data, and implications for the Standard Model Higgs have been derived.
Recent electroweak results from the CDF and D0 Collaborations at the Fermilab Tevatron Collider are presented. After a brief description of the \D0 measurements of W/Z production cross sections, W width, W mass and W \to τνdecays, the CDF result on W(pT) distribution is outlined. The comprehensive search for anomalous gauge couplings by \D0 in 1992-96 data is presented along with a detailed description of the WW/WZ \to μνjj channel.
We report the first observation of single top quark production using ppbar collision data with sqrt{s}=1.96 TeV collected by the CDF II and D0 detectors at Fermilab. The significance of both the observed CDF and D0 data is 5.0 standard deviations, and the expected sensitivity is in excess of 5.9 and equal to 4.5 standard deviations, respectively. The single top production cross section and the CKM matrix element value |V_{tb}| have been measured.
Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predomi…
Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data, and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum, and is particularly sensitive to new electroweak scale physics that appears predomi…
An overview of Tevatron electroweak measurements performed by the CDF and D0 experiments is presented. The current status and future prospects for high precision measurements of electroweak parameters and detailed studies of boson production are highlighted.
I present the recent electroweak measurements related to single W, Z boson and diboson productions from the CDF and D0 experiments at the Fermilab Tevatron collider.
We summarize and combine direct measurements of the width of the W boson in data collected by the Tevatron experiments CDF and D0 at Fermilab. Results from CDF and D0 RunI (1992-1995) have been combined with the CDF 200 pb^-1 results from the first period of RunII (2001-2004) and the recent 1 fb^-1 result in the electron channel from D0 (2002-2006). The results are corrected for any inconsistencies in parton distribution functions and assumptions about electroweak parameters used in the different analyses. The resulting Tevatron average for the width of the W boson is Gamma_W = 2,046 +- 49.
We perform a global fit of electroweak data, finding that the anomaly in the $W$ mass claimed by the CDF collaboration can be reproduced as a universal new-physics correction to the $T$ parameter or $| H^\dagger D_μH|^2$ operator. Contributions at tree-level from multi-TeV new physics can fit the anomaly compatibly with collider bounds: we explore which scalar vacuum expectation values (such as a triplet with zero hypercharge), $Z'$ vectors (such as a $Z'$ coupled to the Higgs only), little-Higgs models or higher-dimensional geometries provide good global fits. On the other hand, new physics t…
We report a preliminary measurement of the CP violating asymmetry in D0->pi+pi- using approximately 215,000 decays reconstructed in about 5.94/fb of CDF data. We use the strong D*+->D0pi+ decay ("D* tag") to identify the flavor of the charmed meson at production time and exploit CP-conserving strong c-cbar pair-production in p-pbar collisions. Higher statistic samples of Cabibbo-favored D0->K-pi+ decays with and without D* tag are used to highly suppress systematic uncertainties due to detector effects. The result is the world's most precise measurement to date.
We present the most recent CDF results in the measurements of the decay and production vertex of the top-quark. New results on forward-backward asymmetry in top-antitop events are presented. Also, recent measurements of the branching fractions of top-quark are discussed. Finally, measurements in single top events, where top-quark is produced through electroweak processes, are presented. Despite the much larger number of top events collected at the LHC, due to the symmetric initial state and the better signal-to-background ratio in specific channels, some results will be lasting heritage of the…
We summarize and combine the results on the direct measurements of the mass of the W boson in data collected by the Tevatron experiments CDF and D0 at Fermilab. Results from CDF Run-0 (1988-1889) and Run-I (1992-1995) have been combined with D0 results from Run-I, the CDF 200 pb^(-1) published results from the first period of Run-II (2001-2004) and the recent 1 fb^(-1) result in the electron channel from D0 (2002-2006). The results are corrected for any inconsistencies in parton distribution functions and assumptions about electroweak parameters used in the different analyses. The resulting Te…
Recent measurements of processes involving the electroweak bosons, Z and W, performed at the Fermilab Tevatron Collider are summarized. The large integrated luminosities collected by both the D0 and CDF Collaborations enable precise measurements of differential single boson production cross sections, the determination of the W mass with unprecedented precision, and the observation of diboson production including ZZ.
The forward-backward charge asymmetry ($A_{FB}$) of $\ppbar \to e^{+}e^{-} X$ is sensitive to the vector and axial-vector couplings of the initial state quarks and final state leptons. Based on the measurement in $72 pb^{-1}$ of CDF Run II data, we measure the coupling constants of the $Z$ boson to quarks and electron. The electroweak mixing angle, $\sin^2θ_{W}$, is also measured through its relation to the coupling constants.
The results on the direct measurements of the W-boson mass and width, based on the data collected by the Tevatron experiments CDF and D0 at Fermilab are summarised and combined. The CDF Run-0 (1988-1889) and Run-I (1992-1995) results have been re-averaged using the BLUE method and combined with Run-I D0 results and the latest published results from CDF taken from the first period of Run-II (2001-2004). The results are corrected to have consistency between the parton distribution functions and electroweak parameters. The resulting Tevatron averages for the mass and total decay width of the W bo…
We report a measurement of the top quark mass, M_t, in the dilepton decay channel of $t\bar{t}\to b\ell'^{+}ν_{\ell'}\bar{b}\ell^{-}\barν_{\ell}$ using an integrated luminosity of 1.0 fb^{-1} of p\bar{p} collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a mea…
We present the most recent precision electroweak measurements of single $W$ and $Z$ boson cross section and properties from the LHC and Tevatron colliders, analyzing data collected by ATLAS, CDF, CMS, D0, and LHCb detectors. The results include the measurement of the single $W$ and $Z$ boson cross section at LHC, the differential cross section measurements, the measurement of $W$ boson mass, the measurement of $W$ and $Z$ charge asymmetry. These measurements provide precision tests on the electroweak theory, high order predictions and the information can be used to constraint parton distributi…
The mass of the top quark M_top is interesting both as a fundamental parameter of the standard model and as an important input to precision electroweak tests. The Collider Detector at Fermilab (CDF) has a robust program of top quark mass analyses, including the most precise single measurement, M_top = 173.4 +/- 2.8 GeV/c^2, using 680 pb^-1 of ppbar collision data. A combination of current results from CDF gives M_top = 172.0 +/- 2.7 GeV/c^2, surpassing the stated goal of 3 GeV/c^2 precision using 2 fb^-1 of data. Finally, a combination with current D0 results gives a world average top quark ma…
The Tevatron Run-II program has been in progress since 2001, and the CDF and D0 experiments have been operational with upgraded detectors. Coupled with recent improvements in the Tevatron accelerator performance, the experiments have started producing important physics results and measurements. We report these measurements as well as prospects in the near future.
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak measurements from other experiments, notably CDF and DØat the Tevatron. Constraints on the input parameters of the Standard Model are derived from the results obtained in high-$Q^2$ interactions, and used to predict results in low-$Q^2$ experiments, such as atomic parity violation, Møller scattering, and neutrino-nucleon scattering.
The W Mass determination at the Tevatron CDF experiment reported a deviation from the SM expectation at 7$σ$ level. We discuss a few possible interpretations and their collider implications. We perform electroweak global fits under various frameworks and assumptions. We consider three types of electroweak global fits in the effective-field-theory framework: the $S$-$T$, the $S$-$T$-$δG_F$, and the eight-parameter flavor-universal one. We discuss the amounts of tensions between different $m_W$ measurements reflected in these fits and the corresponding shifts in central values of these parameter…
Recent CDF and D0 measurements of the top quark forward-backward asymmetry at the Tevatron present deviations between 1-sigma and 2-sigma from QCD predictions and a cut M_inv > 450 GeV on the events increases this deviation to 3.4 sigma in the CDF measurement. The inclusion of electroweak contributions of order alpha^2 and order alpha alphas^2 enlarges the theoretical prediction from QCD by a factor ~ 1.2 and diminishes the observed deviations. The calculation method is shortly discussed and numerical results are compared to the experimental data.
We summarize and combine the results on the direct measurements of the mass of the W boson in data collected by the Tevatron experiments CDF and D0 at Fermilab. Earlier results from CDF Run-0 (1988--1989), D0 and CDF Run-I (1992--1995) and D0 results from 1/fb (2002--2006) of Run-II data are now combined with two new, high statistics Run-II measurements: a CDF measurement in both electron and muon channels using 2.2/fb of integrated luminosity collected between 2002 and 2007, and a D0 measurement in the electron channel using 4.3/fb collected between 2006 and 2009. As in previous combinations,…
Recent Run 2 experimental results on electroweak physics from the CDF and D0 collaborations at Tevatron are reviewed. We present measurements of the inclusive W and Z boson cross-sections times leptonic branching ratio as well as the Z/gamma forward-backward asymmetry and the W charge asymmetry for p-pbar collisions at sqrt{s}=1.96 TeV. The first Run 2 studies for the W width and W mass measurements are also reported. The di-boson production results are presented elsewhere.
The status of W and Z cross-section and width measurements from the CDF and D0 experiments is reviewed. Recent results that are discussed: the cross-section for Z production times the branching ratio to tau pairs, the rapidity and transverse momentum distributions of Z production in the electron channel, and the direct measurements of the W width and the Z invisible width; the latter from an analysis of events with large missing transverse energy and one or more energetic jets.
Recent rate measurements of B_s mesons and Lambda_b baryons produced in sqrt{s} = 1.96 TeV proton-antiproton and Upsilon(5S) electron-positron collisions are reviewed, including the first observations of six new decay modes: B_s -> D_s^+ K^- (CDF), B_s -> D_s^- D_s^+ (CDF), B_s -> D_{s1}^-(2536) mu^+ nu_mu X (DZero), B_s -> phi gamma (Belle), Lambda_b -> p pi^- (CDF), and Lambda_b -> p K^- (CDF). Also examined are branching-fraction measurements or limits for the B_s -> D_s^{(*)} D_s^{(*)} modes (Belle, CDF, and DZero), the B_s -> gamma gamma radiative penguin decay (Belle), and three two-body…
The top quark is by far the most massive fundamental particle observed so far, and the study of its properties is interesting for several reasons ranging from its possible special role in electroweak symmetry breaking to its sensitivity to physics beyond the Standard Model. We present recent top physics results from CDF based on 160-320 inverse pb of ppbar collision data at a center-of-mass energy of 1.96 TeV. The ttbar cross section and the top mass have been measured in different decay channels and using different methods. We have searched for evidence of single top production, setting upper…
Preliminary SLD electroweak results based on essentially the complete 550K Z dataset are presented and interpreted, and some historical background is provided.
We propose an explanation to the new W mass measurement recently reported by the CDF collaboration, which is larger than the standard model expectation by about 7 standard deviations. To alleviate the tensions that are imposed on the electroweak sector by the new W mass measurement, we carry out an analysis in the Stueckelberg extended standard model where a new neutral gauge boson appears which mixes with the two neutral gauge bosons in the electroweak sector both via the Stueckelberg mass terms and via the gauge invariant Stueckelberg-Higgs portal interaction and spoils the custodial symmetr…
The mass of the W boson is one of the least precisely measured parameters of the electroweak interaction. Confronted with other measurements of standard model parameters it can test the internal consistency of the Standard Model and can constrain the possible mass of the standard model Higgs boson. The CDF collaboration has published the current single most precise measurement of the W boson mass using 200 pb-1 of CDF Run II p-pbar data, and an improved measurement with 2.4 fb-1 of CDF Run II data is underway. Both measurements are described in detail in these proceedings.
The CDF Collaboration has analyzed 955/pb of CDF II data to search for electroweak single top quark production at the Tevatron. We employ three different analysis techniques to search for a single top signal: multivariate likelihood functions; neural networks; the matrix element analysis technique. The sensitivities to a single top signal at the rate predicted by the Standard Model are 2.1 - 2.6 sigma. The first two analyses observe a deficit of single top-like events and set upper limits on the production cross section. The matrix element analysis observes a 2.3 sigma single top excess and me…
We have measured the W-boson mass MW using data corresponding to 2.2/fb of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470126 W->enu candidates and 624708 W->munu candidates yield the measurement MW = 80387 +- 12 (stat) +- 15 (syst) = 80387 +- 19 MeV. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined.
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…
We present a search for chargino-neutralino associated production using like electric charge dilepton events collected by the CDF II detector at the Fermilab Tevatron in proton-antiproton collisions at $\sqrt{s} = 1.96$ TeV. One lepton is identified as the hadronic decay of a tau lepton, while the other is an electron or muon. In data corresponding to 6.0 fb$^{-1}$ of integrated luminosity, we obtain good agreement with standard model predictions, and set limits on the chargino-neutralino production cross section for simplified gravity- and gauge-mediated models. As an example, assuming that t…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak measurements from other experiments, notably CDF and DØat the Tevatron. Constraints on the input parameters of the Standard Model are derived from the results obtained in high-$Q^2$ interactions, and used to predict results in low-$Q^2$ experiments, such as atomic parity violation, Møller scattering, and neutrino-nucleon scattering. The main changes with respect to the…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak measurements from other experiments, notably CDF and DØat the Tevatron. Constraints on the input parameters of the Standard Model are derived from the combined set of results obtained in high-$Q^2$ interactions, and used to predict results in low-$Q^2$ experiments, such as atomic parity violation, Møller scattering, and neutrino-nucleon scattering. The main changes wit…
The increasing size of the data samples recorded by the CDF and DO experiments at the Tevatron enables studies of a wide range of processes involving the electroweak bosons W and Z. Single boson production is now looked at in terms of differential cross sections such as rapidity or transverse momentum dependence. Diboson production cross-sections are several orders of magnitude smaller than single boson production cross-sections, but all combinations Wgamma, Zgamma, WW and WZ have been observed. ZZ production is expected at a rate just below the observation threshold with current data sample s…
I present measurements by the CDF collaboration of the Standard Model three generation CKM matrix element Vtb and of a special case extension with additional assumptions, using current Tevatron ttbar data. I then show how we can significantly improve the precision on Vtb and at the same time extend the measurement so it is not constrained by Standard Model assumptions, using single top production at the upgraded Tevatron.
With the start of Run II at the Fermilab Tevatron a host of new physics opportunities are opened. In this paper we will review the prospects for physics at the CDF and \Dzero experiments. Topics ranging from QCD, to electro-weak precision measurements, to top-quark physics, to searches for the Higgs boson and signals of physics beyond the Standard Model will be discussed. B-Physics at the Tevatron is covered in a separate contribution to these proceedings. We will outline how upgrades to the accelerator and the detectors make these studies possible with precisions higher than ever achieved pre…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results obtained at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak measurements from other experiments, notably CDF and DØ at the Tevatron. Constraints on the input parameters of the Standard Model are derived from the combined set of results obtained in high-$Q^2$ interactions, and used to predict results in low-$Q^2$ experiments, such as atomic parity violation, Møller scattering, and neutrino-nucleon scattering. The main changes wi…
This talk describes some of the precision electroweak measurements from around the world, namely those related to the Z and W bosons, the top quark mass, sin2 theta_ W at NuTeV, and three other fundamental measurements: alpha-1 m2_ Z, (g-2)_mu at the E821 BNL experiment as well as the atomic parity violation (APV) measurement for the Cesium atom. These and other measurements are set in the context of the Standard Model (SM) and of the electroweak fit predictions. Future prospects for forthcoming experiments are briefly discussed.
The precision measurements of lepton electroweak parameters at SLD and LEP are reviewed and discussed. The updated SLD weak mixing angle measurement from $A_{LR}$ and the lepton left-right forward-backward asymmetries is $\sin^2θ_W^{eff} = 0.23099 \pm 0.00026$, and the combined SLD/LEP lepton-based value is $0.23119 \pm 0.00020$. This value differs by over $3σ$ from the comparable quark-based value.
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…
Recent electroweak precision measurements from e+e- and pbarp colliders are presented. Some emphasis is placed on the recent developments in the heavy flavor sector. The measurements are compared to predictions from the Standard Model of electroweak interactions. All results are found to be consistent with the Standard Model. The indirect constraint on the top quark mass from all measurements is in excellent agreement with the direct Mt measurements. Using the world's electroweak data in conjunction with the current measurement of the top quark mass, the constraints on the Higgs mass are discu…
Future high energy linear electron positron colliders with centre-of-mass enegies between 90 and 1000 GeV offer a unique opportunity to study precisely the Standard Model and phenomena from new physics. Most important, the mechanism of electroweak symmetry breaking can be established in full depth if one or more Higgs bosons are observed. Precision measurements of electroweak processes open a window into the multi-TeV energy range for searching for new physics, which is of particular importance if no light Higgs boson is observed.
We report a selection of the most recent CDF and D0 results on top quark and W and Z boson properties, based on Tevatron Run 2 data. The large datasets of W and Z bosons allow a very precise measurement of the W mass and detailed studies of vector boson production and asymmetries. Associated production of vector boson pairs has been observed and cross sections have been measured. The top quark is being studied in great detail, and a precision of 1.1 % in the measurement of its mass has been achieved. The precise knowledge of top and W masses are constraining the allowed mass range of a standar…
An overview of recent results on electroweak precision measurements from the CMS Collaboration is presented. Studies of the weak boson differential transverse momentum spectra, Z boson angular coefficients, forward-backward asymmetry of Drell-Yan lepton pairs and charge asymmetry of W boson production are made in comparison to the state-of-the-art Monte Carlo generators and theoretical predictions. The results show a good agreement with the Standard Model. As a proof of principle for future W mass measurements, a W-like analysis of the Z boson mass is performed.
During the first three years of low luminosity operation, the LHC will facilitate a number of precision tests of the Electroweak sector of the Standard Model. The prospects for measuring the W boson and top quark masses and for probing the charged triple gauge boson couplings at ATLAS are presented here. In each case the most likely analysis methods are described and the statistical and systematic uncertainties which can be expected are reported.
We present the recent results of top-quark physics using up to 6 fb$^{-1}$ of $p \bar p$ collisions at a center of mass energy of $\sqrt s$ = 1.96 TeV analyzed by the CDF collaboration. Thanks to this large data sample, precision top quark measurements are now a reality at the Tevatron. Further, several new physics signals could appear in this large dataset. We will present the latest measurements of top quark intrinsic properties as well as direct searches for new physics in the top sector.
Recently the CDF collaboration at the Tevatron reported a significant discrepancy between the direct measurement of the $W$-boson mass and its Standard Model (SM) prediction based on electroweak precision tests (EWPTs). In this paper we explore the potential origin of this discrepancy from physics beyond the SM. Explicitly, we work on a set of six-dimensional operators in the SM effective field theory (SMEFT) which are relevant to the EWPTs. By fitting to the data, we demonstrate that an upward shift in $m_W$ is driven by the operator $\mathcal{O}_{T}=\frac{1}{2}(H^{\dagger}\overset{\text{$\le…
We report on the extraction of $\sin^2θ^{\rm lept}_{\rm eff}(M_Z)$ and an indirect measurement of the mass of the W boson from the forward-backward asymmetry of dilepton events in the $Z$ boson mass region at the Tevatron. The data samples of $e^+e^-$ and $μ^+μ^-$ events collected by the CDF detector correspond to the full 9.4 fb$^{-1}$ run II sample and yield an effective electroweak mixing angle $\sin^2θ^{\rm lept}_{\rm eff}(M_Z) = 0.23222 \pm 0.00046$. The corresponding result reported by the D0 collaboration with the full 9.4 fb$^{-1}$ $e^+e-$ sample is $\sin^2θ^{\rm lept}_{\rm eff}(M_Z) =…