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 boson are: Mw = 80432 +/- 39 MeV and Gamma_W = 2056 +/- 62 MeV. The inclusion of a preliminary Run-II measurement of Gamma_W from D0 gives Gamma_W = 2050 +/- 58 MeV.
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.
The results on the direct measurements of the W-boson width, based on the data collected by the Tevatron experiments CDF and DØat Fermilab during {\RunI} from 1992 to 1996 and {\RunII} since 2001 are summarized. The combination of the published {\RunI} and preliminary {\RunII} results, taking correlated uncertainties properly into account, is presented. The resulting preliminary Tevatron average for the total decay width of the W boson is: $\GW=2078\pm87 \MeV$, where the total error consists of a statistical part of $62 \MeV$ and a systematic part of $60 \MeV$.
The CDF collaboration has analyzed ~200/pb of Tevatron Run II data taken between February 2002 and September 2003 to measure the W boson mass. With a sample of 63964 W->e nu decays and 51128 W->mu nu decays, we measure M_W = 80413+-34(stat)+-34(syst) MeV. The total measurement uncertainty of 48 MeV makes this result the most precise single measurement of the W boson mass to date.
We combine results of CDF and D0 searches for a Standard-Model Higgs boson in data from ppbar collisions at the Fermilab Tevatron with sqrt(s) = 1.96 TeV. With 260-950 pb-1 collected at D0, and 360-1000 pb-1 collected at CDF, the 95%CL upper limits are a factor of 10.4(3.8) higher than the expected cross section for mH =115(160) GeV/c2. This result extends significantly the individual limits of each experiment.
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.
We present combined results on the search for neutral supersymmetric Higgs bosons with data collected at the CDF and D0 experiments. Data were collected in proton-antiproton collisions at sqrt(s) = 1.96 TeV during Run II of the Tevatron. The searches considered cover the main production and decay mechanisms for Higgs bosons in tau lepton and bottom quark final states. The resulting combination is interpreted in the context of different scenarios within the Minimal Supersymmetric Standard Model.
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…
We combine the results of searches by the CDF and D0 collaborations for a fermiophobic Higgs boson (H_f) produced via the processes WH_f, ZH_f, and vector-boson fusion in ppbar collisions at sqrt(s)=1.96 TeV at the Fermilab Tevatron collider. The analyses seek Higgs boson decays to W^+W^- and gamma gamma. With up to 8.2 fb-1 of integrated luminosity analyzed at CDF and up to 8.2 fb-1 at D0, we obtain a 95% CL lower bound on the mass of the Higgs boson in the fermiophobic Higgs model of 119 GeV/c^2.
The results based on 1992-95 data (Run 1) from the CDF and DO experiments on the measurements of the W boson mass and width are presented, along with the combined results. We report a Tevatron collider average M_W = 80.456 +- 0.059 GeV. We also report the Tevatron collider average of the directly measured W boson width Gamma_W = 2.115 +- 0.105 GeV. We describe a new joint analysis of the direct W mass and width measurements. Assuming the validity of the standard model, we combine the directly measured W boson width with the width extracted from the ratio of W and Z boson leptonic partial cross…
We present a search for a Higgs boson decaying to two W bosons in ppbar collisions at sqrt(s)=1.96 TeV center-of-mass energy. The data sample corresponds to an integrated luminosity of 3.0 fb-1 collected with the CDF II detector. We find no evidence for production of a Higgs boson with mass between 110 and 200 GeV/c^2, and determine upper limits on the production cross section. For the mass of 160 GeV/c^2, where the analysis is most sensitive, the observed (expected) limit is 0.7 pb (0.9 pb) at 95% Bayesian credibility level which is 1.7 (2.2) times the standard model cross section.
We present the latest CDF searches for the Standard Model Higgs boson with 1.96 TeV center-of-mass energy collisions produced at the Fermilab Tevatron. The data was collected with the CDF II detector at the Tevatron collider and correspond to an integrated luminosity from 2 to 4.8 1/fb. To achieve maximal sensitivity, many channels are analyzed including final states from gluon fusion, vector boson fusion, and associated production with W and Z bosons.
We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45/fb. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H -> bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c^2 we observe (expect) a limit of 7.1 (3.9) times the standard model value.
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 the results of searches for the standard model Higgs boson at CDF in final states with bottom quarks. Results are derived from the complete Tevatron Run II dataset, with a measured integrated luminosity of 9.5 fb$^{-1}$ of proton-antiproton data. The searches are performed for assumed Higgs masses between 90 and 150 GeV, for Higgs bosons produced in association with W or Z bosons. Employing several improved techniques, these are currently the most sensitive searches in the world for these processes, surpassing previous CDF results by 30% beyond what would be expected from the additi…
Results are presented on searches for standard model and non-standard model production of a Higgs boson in pbar-p collisions at sqrt{s}= 1.96 TeV with the CDF II detector at the Fermilab Tevatron. Using data corresponding to 2-3.6 1/fb of integrated luminosity, searches are performed in a number of different production and decay modes. No excess in data above that expected from backgrounds is observed; therefore, we set upper limits on the production cross section times branching fraction as a function of the Higgs boson mass.
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,…
We present a search for standard model (SM) Higgs boson production using ppbar collision data at sqrt(s) = 1.96 TeV, collected with the CDF II detector and corresponding to an integrated luminosity of 4.8 fb-1. We search for Higgs bosons produced in all processes with a significant production rate and decaying to two W bosons. We find no evidence for SM Higgs boson production and place upper limits at the 95% confidence level on the SM production cross section (sigma(H)) for values of the Higgs boson mass (m_H) in the range from 110 to 200 GeV. These limits are the most stringent for m_H > 130…
We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV, focusing on the decay H\rightarrowγγ. We compute upper limits on the Higgs boson production cross section times the decay branching fraction in the range 100<m_H<150 GeV/c^2, and we interpret the results in the context of the standard model. We use the MSTW08 parton distribution functions and the latest theoretical cross section predictions when testing for the presence of a SM Higgs boson. With datasets corresponding to 7.0…
We report on a search for the production of the Higgs boson decaying to two bottom quarks accompanied by two additional quarks. The data sample used corresponds to an integrated luminosity of approximately 4\,\invfb\, of \ppbar\, collisions at $\sqrt{s}=1.96$\,TeV recorded by the CDF II experiment. This search includes twice the integrated luminosity of the previous published result, uses analysis techniques to distinguish jets originating from light flavor quarks and those from gluon radiation, and adds sensitivity to a Higgs boson produced by vector boson fusion. We find no evidence of the H…
We combine results from CDF and D0 searches for a standard model Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. With 1.0-1.9 fb-1 of data collected at CDF, and 0.9-1.7 fb-1 at D0, the 95% C.L. upper limits on Higgs production are a factor of 6.2 (1.4) higher than the SM cross section for a Higgs mass of m_Higgs = 115 (160) GeV/c^2. Based on simulation, the median expected upper limit is 4.3 (1.9). These results extend significantly the individual limits of each experiment.
We present a search for the standard model Higgs boson produced in association with a W boson in sqrt(s) = 1.96 TeV p-pbar collision data collected with the CDF II detector at the Tevatron corresponding to an integrated luminosity of 9.45 fb-1. In events consistent with the decay of the Higgs boson to a bottom-quark pair and the W boson to an electron or muon and a neutrino, we set 95% credibility level upper limits on the WH production cross section times the H->bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125 GeV/c2 we observe (expect) a limit of 4.9 (2.8) t…
We measure the polarization of W bosons from top-quark (t) decays into final states with a charged lepton and jets, tt --> WbWb --> lvbqqb, using the full Run II data set collected by the CDF II detector. A model-independent method simultaneously determines the fraction of longitudinal (f_0) and right-handed (f_+) W bosons to yield f_0 = 0.726 +/- 0.066 (stat) +/- 0.067 (syst) and f_+ = -0.045 +/- 0.044 (stat) +/- 0.058 (syst) with a correlation coefficient of -0.69. Additional results are presented under various standard model assumptions. No significant discrepencies with the standard model …
We combine the results of searches for the standard model Higgs boson based on the full CDF Run II data set obtained from sqrt(s) = 1.96 TeV p-pbar collisions at the Fermilab Tevatron corresponding to an integrated luminosity of 9.45/fb. The searches are conducted for Higgs bosons that are produced in association with a W or Z boson, have masses in the range 90-150 GeV/c^2, and decay into bb pairs. An excess of data is present that is inconsistent with the background prediction at the level of 2.5 standard deviations (the most significant local excess is 2.7 standard deviations).
The Higgs boson is the only elementary particle predicted by the Standard Model (SM) that has neither been confirmed nor refuted. The CDF collaboration has performed SM Higgs searches in many channels using $p\pbar$ collisions at a centre-of-mass energy $\sqrt{s}=1.96\tev$. We present the latest combined Higgs boson search at CDF. Since the previous year's combination, the sensitivity is increased through the addition of new channels, the improvement of existing channels and the addition of new data samples. We also use the latest parton distribution functions and $gg \rightarrow H$ theoretica…
We present a search for standard model Higgs boson production in association with a W boson in proton-antiproton collisions ($p\bar{p}\to W^\pm H \to \ellνb\bar{b}$) at a center of mass energy of 1.96 TeV. The search employs data collected with the CDF II detector which correspond to an integrated luminosity of approximately 1 fb-1. We select events consistent with a signature of a single lepton ($e^\pm/μ^\pm$), missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with a secondary vertex tagging method and a neural network filter technique. The observed n…
We combine results from CDF and D0 searches for a standard model Higgs boson in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. With 1.0-2.4 fb-1 of data collected at CDF, and 1.1-2.3 fb-1 at D0, the 95 % C.L. upper limits on Higgs boson production are a factor of 3.7 (1.1) higher than the SM cross section for a Higgs boson mass of m_{H}=115 (160) GeV. Based on simulation, the median expected upper limit should be 3.3 (1.6). Standard Model branching ratios, calculated as functions of the Higgs boson mass, are assumed. Compared to the previous Higgs Tevatron combination, more dat…
We present the development and validation of the Higgs Optimized b Identification Tagger (HOBIT), a multivariate b-jet identification algorithm optimized for Higgs boson searches at the CDF experiment at the Fermilab Tevatron. At collider experiments, b taggers allow one to distinguish particle jets containing B hadrons from other jets; these algorithms have been used for many years with great success at CDF. HOBIT has been designed specifically for use in searches for light Higgs bosons decaying via H ! b\bar{b}. This fact combined with the extent to which HOBIT synthesizes and extends the be…
We combine results from CDF and DO searches for a standard model Higgs boson in ppbar collisions at the Fermilab Tevatron, at sqrt{s}=1.96 TeV. With 3.0 fb-1 of data analyzed at CDF, and at DO, the 95% C.L. upper limits on Higgs boson production are a factor of 1.2, 1.0 and 1.3 higher than the SM cross section for a Higgs boson mass of m_{H}=$165, 170 and 175 GeV, respectively. We exclude at 95% C.L. a standard model Higgs boson of m_H=170 GeV. Based on simulation, the ratios of the corresponding median expected upper limit to the Standard Model cross section are 1.2, 1.4 and 1.7. Compared to …
We present a search for standard model Higgs boson to WW(*) production in dilepton plus missing transverse energy final states in data collected by the CDF II detector corresponding to 4.8/fb of integrated luminosity. To maximize sensitivity, the multivariate discriminants used to separate signal from background in the opposite-sign dilepton event sample are independently optimized for final states with zero, one, or two or more identified jets. All significant Higgs boson production modes (gluon fusion, associated production with either a W or Z boson, and vector boson fusion) are considered …
We present a search for associated production of the standard model (SM) Higgs boson and a $Z$ boson where the $Z$ boson decays to two leptons and the Higgs decays to a pair of $b$ quarks in $p\bar{p}$ collisions at the Fermilab Tevatron. We use event probabilities based on SM matrix elements to construct a likelihood function of the Higgs content of the data sample. In a CDF data sample corresponding to an integrated luminosity of 2.7 fb$^{-1}$ we see no evidence of a Higgs boson with a mass between 100 GeV$/c^2$ and 150 GeV$/c^2$. We set 95% confidence level (C.L.) upper limits on the cross-…
A search for a narrow Higgs boson resonance in the diphoton mass spectrum is presented based on data corresponding to 10 fb-1 of integrated luminosity from proton-antiproton collisions at \surds = 1.96 TeV collected by the CDF experiment. In addition to searching for a resonance in the diphoton mass spectrum, we employ a multivariate discriminant technique for the first time in this channel at CDF. No evidence of signal is observed, and upper limits are set on the cross section times branching ratio of the resonant state as a function of Higgs boson mass. The limits are interpreted in the cont…
We combine results from CDF and D0's direct searches for the standard model (SM) Higgs boson (H) produced in p-pbar collisions at the Fermilab Tevatron at sqrt(s)=1.96 TeV. The results presented here include those channels which are most sensitive to Higgs bosons with mass between 130 and 200 GeV/c^2, namely searches targeted at Higgs boson decays to W+W-, although acceptance for decays into tau+tau- and gamma gamma is included. Compared to the previous Tevatron Higgs search combination, more data have been added and the analyses have been improved to gain sensitivity. We use the MSTW08 parton…
Combined results are presented on the search for a neutral Higgs boson in the di-tau final state using 1.8fb-1 and 2.2fb-1 of integrated luminosity collected at the CDF and D0 experiments respectively. Data were collected in ppbar collisions at a centre of mass energy of 1.96TeV during RunII of the Tevatron. Limits are set on the cross section times branching ratio ranging from 13.6pb to 0.653pb for Higgs masses from 90GeV to 200GeV respectively. The results are then interpreted as limits in four different benchmark scenarios within the framework of the MSSM.
We combine results from searches by the CDF and D0 Collaborations for a standard model Higgs boson (H) in the processes gg->H->W+W- and gg->H->ZZ in p-pbar collisions at the Fermilab Tevatron Collider at sqrt(s)=1.96 TeV. With 8.2 fb-1 of integrated luminosity analyzed at CDF and 8.1 fb-1 at D0, the 95% C.L. upper limit on sigma(gg->H)xBr(H->W+W-) is 1.01 pb at m_H=120 GeV, 0.40 pb at m_H=165 GeV, and 0.47 pb at m_H=200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass…
We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at $\sqrt{s} = 1.96$ TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb$^{-1}$. We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a $b$ quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction f…
We combine results from CDF and D0 on direct searches for the standard model (SM) Higgs boson H in ppbar collisions at the Fermilab Tevatron at sqrt(s)=1.96 TeV. Compared to the previous Tevatron Higgs search combination more data have been added, additional new channels have been incorporated, and some previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg to H theoretical cross sections when comparing our limits to the SM predictions. With up to 5.9 fb-1 of data analyzed at CDF, and up to 6.7 fb-1 at D0, the 95% C.L. upper li…
A search is presented for the standard model Higgs boson produced in association with top quarks using the full Run II proton-antiproton collision data set, corresponding to 9.45 inverse fb, collected by the Collider Detector at Fermilab. No significant excess over the expected background is observed, and 95% credibility-level upper bounds are placed on the cross section sigma(t\bar{t}H --> lepton + missing transverse energy + jets). For a Higgs boson mass of 125 GeV, we expect to set a limit of 12.6, and observe a limit of 20.5 times the standard model rate. This represents the most sensitive…
We present a measurement of $W$ boson polarization in top-quark decays in $t\bar{t}$ events with decays to dilepton final states using $5.1 {\rm fb^{-1}}$ of integrated luminosity in $p\bar{p}$ collisions collected by the CDF II detector at the Tevatron. A simultaneous measurement of the fractions of longitudinal ($f_0$) and right-handed ($f_+$) $W$ bosons yields the results $f_0 = 0.71 ^{+0.18}_{-0.17} {\rm (stat)} \pm 0.06 {\rm (syst)}$ and $f_+ = -0.07 \pm 0.09 {\rm (stat)} \pm 0.03 {\rm (syst)}$. Combining this measurement with our previous result based on single lepton final states, we ob…
We combine results from CDF and D0 on direct searches for a standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt(s)=1.96 TeV. Compared to the previous Tevatron Higgs search combination more data have been added and some previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg->H theoretical cross sections when comparing our limits to the SM predictions. With 2.0-4.8 fb-1 of data analyzed at CDF, and 2.1-5.4 fb-1 at D0, the 95% C.L. upper limits on Higgs boson production are a factor of 2.70 (0.…
We present the results on the searches for the SM and the non-SM Higgs boson production in ppbar collisions at sqrt(s)=1.96 TeV with the CDF detector at the Fermilab Tevatron. Using data corresponding to 300--700pb-1, we search for the Higgs boson in various production and decay channels. No signal is observed, therefore, we set upper limits on the production cross-section times branching fraction as a function of the Higgs boson mass.
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 combine results from CDF and D0 on direct searches for a standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. Compared to the previous Higgs Tevatron combination, more data and new channels (WH to tau nu b bbar, VH to tau tau b bbar/jj tau tau,VH to jj b bbar, t tbar H to t tbar b bbar) have been added. Most previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg to H theoretical cross sections when comparing our limits to the SM predictions. With 2.0-3.6 fb-1 of data analyzed …
A search for particles with the same mass and couplings as those of the standard model Higgs boson but different spin and parity quantum numbers is presented. We test two specific non-standard Higgs boson hypotheses: a pseudoscalar Higgs boson with spin-parity $J^P$ = $0^-$ and a graviton-like Higgs boson with $J^P$ = $2^+$, assuming for both a mass of 125 GeV/$c^2$. We search for these exotic states produced in association with a vector boson and decaying into a bottom-antibottom quark pair. The vector boson is reconstructed through its decay into an electron or muon pair, or an electron or m…
We present a measurement of the fractions F_0 and F_+ of longitudinally polarized and right-handed W bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 955 pb-1. We select top-antitop candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle theta*, which is defined as the angle between the momentum of the charged lepton in the W boson rest-frame and the W momentum in the top-quark rest-frame. The cos(theta*) …
We combine results from CDF and D0 on direct searches for the standard model (SM) Higgs boson (H) in ppbar collisions at the Fermilab Tevatron at sqrt{s}=1.96 TeV. Compared to the previous Tevatron Higgs boson search combination more data have been added, additional channels have been incorporated, and some previously used channels have been reanalyzed to gain sensitivity. We use the MSTW08 parton distribution functions and the latest theoretical cross sections when comparing our limits to the SM predictions. With up to 8.2 fb-1 of data analyzed at CDF and up to 8.6 fb-1 at D0, the 95% C.L. ou…
We report on a study of the dijet invariant-mass distribution in events with one identified lepton, a significant imbalance in the total event transverse momentum, and two jets. This distribution is sensitive to the possible production of a new particle in association with a $W$ boson, where the boson decays leptonically. We use the full data set of proton-antiproton collisions at 1.96 TeV center-of-mass energy collected by the Collider Detector at the Fermilab Tevatron and corresponding to an integrated luminosity of 8.9 fb$^{-1}$. The data are found to be consistent with standard-model expec…
We present a measurement of the fractions F_0 and F_+ of longitudinally polarized and right-handed W bosons in top quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately 318 pb -1. We select ttbar candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle theta*, which is defined as the angle between the momentum of the charged lepton in the W boson rest frame and the W momentum in the top quark rest frame. The cos(theta*) distr…
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.
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…
We present a search for technicolor particles decaying into $b\bar b$, $b\bar c$ or $b\bar u$ and produced in association with $W$ bosons in $p\bar p$ collisions at $\sqrt{s}= 1.96 \mathrm{TeV}$. The search uses approximately $1.9 \mathrm{fb}^{-1}$ of the dataset accumulated in the CDF II detector at the Fermilab Tevatron. We select events matching the $W$ + 2-jets signature and require at least one jets to be identified as $b$-quark jets. In the case of exactly one vertex $b$-tagged events, we apply a neural network flavor separator to reject contamination from charm and light quark jets. The…
I present measurements of the W boson charge asymmetry and the W boson width G_W using 350 pb-1 of CDF Run II data. The charge asymmetry is the first direct measurement, which uses a new technique to reconstruct the W rapidity by constraining its mass; the result will further constrain Parton Distribution Functions in future fits. The width measurement relies on a fit to the W transverse mass distribution. We measure G_W = 2032 +/- 71 MeV which is in good agreement with the Standard Model prediction.
We propose to add high precision track detectors 55m downstream on both (E&W) sides of CDF, to measure high Feynman-x protons and antiprotons in association with central states. A primary motivation is to search for the Higgs boson, and if it is seen to measure its mass precisely. The track detectors will be silicon strip telescopes backed up by high resolution time-of-flight counters. The addition of these small detectors effectively converts the Tevatron into a gluon-gluon collider with sqrt{s} from 0 to ~ 200 GeV. This experiment will also measure millions/year clean high-|t| elastic scatte…
We present a combination of searches for the standard model Higgs boson using the full CDF Run II data set, which corresponds to an integrated luminosity of 9.45--10.0 fb$^{-1}$ collected from $\sqrt{s}=1.96$ TeV $p{\bar{p}}$ collisions at the Fermilab Tevatron. The searches consider Higgs boson production from gluon-gluon fusion, vector-boson fusion, and associated production with either a $W$ or $Z$ boson or a $t{\bar{t}}$ pair. Depending on the production mode, Higgs boson decays to $W^+W^-$, $ZZ$, $b{\bar{b}}$, $τ^+τ^-$, and $γγ$ are examined. We search for a Higgs boson with masses ($m_H$…
Production of the Upsilon(1S) meson in association with a vector boson is a rare process in the standard model with a cross section predicted to be below the sensitivity of the Tevatron. Observation of this process could signify contributions not described by the standard model or reveal limitations with the current non-relativistic quantum-chromodynamic models used to calculate the cross section. We perform a search for this process using the full Run II data set collected by the CDF II detector corresponding to an integrated luminosity of 9.4/fb. The search considers the Upsilon(1S) to di-mu…
We present a search for the standard model Higgs boson produced in association with a $W^{\pm}$ boson. This search uses data corresponding to an integrated luminosity of 7.5 fb$^{-1}$ collected by the CDF detector at the Tevatron. We select $WH \to \ellνb \bar{b}$ candidate events with two jets, large missing transverse energy, and exactly one charged lepton. We further require that at least one jet be identified to originate from a bottom quark. Discrimination between the signal and the large background is achieved through the use of a Bayesian artificial neural network. The number of tagged …
This Letter reports a search for a narrow resonant state decaying into two $W$ bosons and a bottom-antibottom quark pair where one $W$ boson decays leptonically and the other decays into a quark-antiquark pair. The search is particularly sensitive to top-antitop resonant production. We use the full data sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 9.45 fb$^{-1}$. No evidence for resonant production is found and upper limits on the production cross section tim…
Motivated by recent anomalous CDF data on $Wjj$ events, we study a possible explanation within the framework of the two-Higgs doublet model. We find that a charged Higgs boson of mass $\sim$ 140 GeV with appropriate couplings can account for the observed excess. In addition, we consider the flavor-changing neutral current effects induced at loop level by the charged Higgs boson on the $B$ meson system to further constrain the model. Our study shows that the like-sign charge asymmetry $A_{s\ell}^b$ can be of ${\cal O}(10^{-3})$ in this scenario.
The polarization of the $W$ boson in $t \to W b$ decay is unambiguously predicted by the Standard Model of weak interactions and is a powerful test of our understanding of the $tbW$ vertex. The subsequent $W \to l ν$ decay serves as a polarimeter for the $W$, and the invariant mass of the lepton and $b$ quark in top decay provides a measurement of the $W$ decay angle. In this paper we present a measurement of the decay rate of the W produced from the decay of the top quark in the hypothesis of V+A structure of the tWb vertex. We find no evidence for the non-standard V+A vertex and set a limit …
Due to an excellent mass resolution and a large amount of available data, the CDF experiment, located at the Tevatron proton-antiproton accelerator, allows the precise measurement of spectroscopic properties, like mass and decay width, of a variety of states. This was exploited to examine the first orbital excitations of the Lambdac baryon, the resonances Lambdac(2595) and Lambdac(2625), in the decay channel Lambdac+ pi+ pi-, as well as the Lambdac spin excitations Sigmac(2455) and Sigmac(2520) in its decays to Lambdac+ pi- and Lambdac+ pi+ final states in a data sample corresponding to an int…
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…
