B. Blumenfeld

We present a new measurement of the inclusive and differential production cross sections of $J/\psi$ mesons and $b$-hadrons in proton-antiproton collisions at $\sqrt{s}=1960$ GeV. The data correspond to an integrated luminosity of 39.7 pb$^{-1}$ collected by the CDF Run II detector. We find the integrated cross section for inclusive $J/\psi$ production for all transverse momenta from 0 to 20 GeV/$c$ in the rapidity range $|y|<0.6$ to be $4.08 \pm 0.02 (stat)^{+0.36}_{-0.33} (syst) \mu {\rm b}$. We separate the fraction of $J/\psi$ events from the decay of the long-lived $b$-hadrons using the lifetime distribution in all events with $p_T(J/\psi) > 1.25$ GeV/$c$. We find the total cross section for $b$-hadrons, including both hadrons and anti-hadrons, decaying to $J/\psi$ with transverse momenta greater than 1.25 GeV/$c$ in the rapidity range $|y(J/\psi)|<0.6$, is $ 0.330 \pm 0.005 (stat) ^{+0.036}_{-0.033} (syst) ~\mu{\rm b}$. Using a Monte Carlo simulation of the decay kinematics of $b$-hadrons to all final states containing a $J/\psi$, we extract the first measurement of the total single $b$-hadron cross section down to zero transverse momentum at $\sqrt{s}=1960$ GeV. We find the total single $b$-hadron cross section integrated over all transverse momenta for $b$-hadrons in the rapidity range $|y|<0.6$ to be $ 17.6 \pm 0.4 (stat)^{+2.5}_{-2.3} (syst) \mu{\rm b}$.

The L3 experiment is one of the six large detectors designed for the new generation of electron-positron accelerators. It is the only detector that concentrates its efforts on limited goals of measuring electrons, muons and photons. By not attempting to identify hadrons, L3 has been able to provide an order of magnitude better resolution for electrons, muons and photons. Vertices and hadron jets are also studied. The construction of L3 has involved much state of the art technology in new principles of vertex detection and in new crystals for large scale electromagnetic shower detection and ultraprecise muon detection. This paper presents a summary of the construction of L3.

We report the observation of a narrow state decaying into $J/\ensuremath{\psi}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ and produced in $220\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ of $\stackrel{\ifmmode \bar{}\else \={}\fi{}}{p}p$ collisions at $\sqrt{s}=1.96\text{ }\mathrm{T}\mathrm{e}\mathrm{V}$ in the CDF II experiment. We observe $730\ifmmode\pm\else\textpm\fi{}90$ decays. The mass is measured to be $3871.3\ifmmode\pm\else\textpm\fi{}0.7(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t})\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\mathrm{M}\mathrm{e}\mathrm{V}/{c}^{2}$, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the $X(3872)$ meson.

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, MW, using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera-electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain [Formula: see text], the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega-electron volts; c, speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

We report the observation of B0s−¯¯¯B0s oscillations from a time-dependent measurement of the B0s−¯¯¯B0s oscillation frequency Δms. Using a data sample of 1 fb−1 of p¯p collisions at √s=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic Bs decays, 3100 partially reconstructed hadronic Bs decays, and 61 500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for B0s−¯¯¯B0s oscillations. The probability that random fluctuations could produce a comparable signal is 8×10−8, which exceeds 5σ significance. We measure Δms=17.77±0.10(stat)±0.07(syst) ps−1 and extract |Vtd/Vts|=0.2060±0.0007(Δms)+0.0081−0.0060(Δmd+theor).Received 18 September 2006DOI:https://doi.org/10.1103/PhysRevLett.97.242003©2006 American Physical Society

We present a new measurement of the inclusive forward-backward $t\overline{t}$ production asymmetry and its rapidity and mass dependence. The measurements are performed with data corresponding to an integrated luminosity of $5.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, recorded with the CDF-II Detector at the Fermilab Tevatron. Significant inclusive asymmetries are observed in both the laboratory frame and the $t\overline{t}$ rest frame, and in both cases are found to be consistent with $CP$ conservation under interchange of $t$ and $\overline{t}$. In the $t\overline{t}$ rest frame, the asymmetry is observed to increase with the $t\overline{t}$ rapidity difference, $\ensuremath{\Delta}y$, and with the invariant mass ${M}_{t\overline{t}}$ of the $t\overline{t}$ system. Fully corrected parton-level asymmetries are derived in two regions of each variable, and the asymmetry is found to be most significant at large $\ensuremath{\Delta}y$ and ${M}_{t\overline{t}}$. For ${M}_{t\overline{t}}\ensuremath{\ge}450\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, the parton-level asymmetry in the $t\overline{t}$ rest frame is ${A}^{t\overline{t}}=0.475\ifmmode\pm\else\textpm\fi{}0.114$ compared to a next-to-leading order QCD prediction of $0.088\ifmmode\pm\else\textpm\fi{}0.013$.

Evidence is reported for a narrow structure near the J/psivarphi threshold in exclusive B;{+} --> J/psivarphiK;{+} decays produced in p[over]p collisions at sqrt[s] = 1.96 TeV. A signal of 14 +/- 5 events, with statistical significance in excess of 3.8 standard deviations, is observed in a data sample corresponding to an integrated luminosity of 2.7 fb;{-1}, collected by the CDF II detector. The mass and natural width of the structure are measured to be 4143.0 +/- 2.9(stat) +/- 1.2(syst) MeV/c;{2} and 11.7_{-5.0};{+8.3}(stat) +/- 3.7(syst) MeV/c;{2}.

We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.

We present a measurement of the $t\overline{t}$ production cross section using events with one charged lepton and jets from $p\overline{p}$ collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From $162\text{ }\text{ }\mathrm{p}{\mathrm{b}}^{\ensuremath{-}1}$ of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where $13.5\ifmmode\pm\else\textpm\fi{}1.8$ events are expected from background contributions. We measure a $t\overline{t}$ production cross section of ${5.6}_{\ensuremath{-}1.1}^{+1.2}(\mathrm{stat}.{)}_{\ensuremath{-}0.6}^{+0.9}(\mathrm{syst}.)\text{ }\text{ }\mathrm{pb}$.

This Letter describes the first determination of bounds on the CP-violation parameter 2βs using B0s decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 B0s→J/ψϕ decays reconstructed in a 1.35 fb−1 data sample collected with the CDF II detector using p¯p collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2βs and the decay-width difference ΔΓ. Assuming the standard model predictions of 2βs and ΔΓ, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.Received 14 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.161802©2008 American Physical Society

We present a search for new particles which produce narrow two-jet (dijet) resonances using proton-antiproton collision data corresponding to an integrated luminosity of $1.13\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude $|y|&lt;1$. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, ${E}_{6}$ diquark, color-octet techni-$\ensuremath{\rho}$, ${W}^{\ensuremath{'}}$, and ${Z}^{\ensuremath{'}}$.

Invariant cross-sections are presented for the inclusive reaction p + p → πo + anything, Measurements of large transverse momentum πo's (2.5 GeV/c<p⊥<9 GeV/c) were made near 90° at the CERN ISR at five centre-of-mass energies (√s = 23.5, 30.6, 44.8, 52.7 and 62.4 GeV. At large p⊥, the invariant cross-sections are seem to vary with s and p⊥, in good agreement with a fit of the form Ap⊥−n F(p⊥/√s), with n≈8 and F(p⊥/√s)≈exp(−26p⊥/√s).

We present measurements of the forward-backward charge asymmetry in top pair production using 1.9 fb;{-1} of pp[over ] collisions at sqrt[s]=1.96 TeV recorded with the Collider Detector at Fermilab II. Correcting for acceptance and measurement dilutions we obtain parton-level asymmetries of A_{FB};{pp[over ]}=0.17+/-0.08 in the pp[over ] frame and A_{FB};{tt[over ]}=0.24+/-0.14 in the tt[over ] frame. The values are consistent with the standard model expectation and disfavor exotic production mechanisms with significant negative values.

We report the first measurements of inclusive W and Z boson cross sections times the corresponding leptonic branching ratios for p pbar collisions at sqrt{s} = 1.96 TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 72.0 +/- 4.3 pb-1. We test e-mu lepton universality in W decays by measuring the ratio of the W->mu nu to W->e nu cross sections and determine a value of 0.991 +/- 0.004(stat.) +/- 0.011(syst.) for the ratio of W-l-nu couplings (g_mu/g_e). Since there is no sign of non-universality, we combine our cross section measurements in the different lepton decay modes and obtain sigma*BR(W->lnu) = 2.749 +/- 0.010(stat.) +/- 0.053(syst.) +/- 0.165(lum.) nb and sigma*BR(gamma*/Z->ll)=254.9 +/- 3.3(stat.) +/- 4.6(syst.) +/- 15.2(lum.) pb for dilepton pairs in the mass range between 66 GeV/c^2 and 116 GeV/c^2. We compute the ratio R of the W->lnu to Z->ll cross sections taking all correlations among channels into account and obtain R=10.84 +/- 0.15(stat.) +/- 0.14(syst.) including a correction for the virtual photon exchange component in our measured gamma*/Z->ll cross section. Based on the measured value of R, we extract values for the W leptonic branching ratio, BR(W->lnu) =0.1082 +/- 0.0022; the total width of the W boson, Gamma(W) =2092 +/- 42 MeV; and the ratio of W and Z boson total widths, Gamma(W)/Gamma(Z) = 0.838 +/- 0.017. In addition, we use our extracted value of Gamma(W) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the V_CS CKM matrix element, |V_CS| = 0.976 +/- 0.030.

We have measured the polarization of J/psi and psi(2S) mesons produced in pp collisions at sqrt[s] = 1.8 TeV, using data collected at the Collider Detector at Fermilab during 1992-1995. The polarization of promptly produced J/psi [psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4 [5.5]<P(T)<20 GeV/c and |y|<0.6. For P(T) greater than or approximately equal 12 GeV/c we do not observe significant polarization in the prompt component.

We present an analysis of angular distributions and correlations of the X(3872) particle in the exclusive decay mode X(3872)->J/psi pi+ pi- with J/psi->mu+ mu-. We use 780 pb -1 of data from ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We derive constraints on spin, parity, and charge conjugation parity of the X(3872) particle by comparing measured angular distributions of the decay products with predictions for different JPC hypotheses. The assignments JPC = 1++ and 2-+ are the only ones consistent with the data.

We present the results of a search for neutrino oscillations at the Brookhaven National Laboratory. The experiment searched for the appearance of ${\ensuremath{\nu}}_{\mathit{e}}$ (\ensuremath{\nu}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{e}}$), 1 km from the source of a wide-band ${\ensuremath{\nu}}_{\mathrm{\ensuremath{\mu}}}$ (\ensuremath{\nu}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathrm{\ensuremath{\mu}}}$) beam. The experiment used a total of 3\ifmmode\times\else\texttimes\fi{}${10}^{19}$ protons on target from the Alternating Gradient Synchrotron. The data collecting was split evenly between positive and negative horn polarities, corresponding to neutrino and antineutrino beams. No excess of ${\ensuremath{\nu}}_{\mathit{e}}$ or \ensuremath{\nu}${\mathrm{\ifmmode\bar\else\textasciimacron\fi{}}}_{\mathit{e}}$ over the expected backgorund was detected. The 90%-confidence-level limits obtained are \ensuremath{\Delta}${\mathit{m}}^{2}$\ensuremath{\le}0.075 ${\mathrm{eV}}^{2}$ for maximal mixing, and ${\mathrm{sin}}^{2}$2\ensuremath{\theta}\ensuremath{\le}0.003 for large \ensuremath{\Delta}${\mathit{m}}^{2}$.

We present the results of a search for νμ→νe oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of νe in a predominantly νμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are Δm2<0.4 eV2 for maximal mixing and sin2(2θ)<1.4×10−3 for large Δm2. This result excludes the LSND allowed region of oscillation parameters with Δm2≳10 eV2.

The growth and development of ``charged particle jets'' produced in proton-antiproton collisions at $1.8 \mathrm{TeV} $ are studied over a transverse momentum range from $0.5$ $\mathrm{GeV}/c$ to $50$ $\mathrm{GeV}/c.$ A variety of leading (highest transverse momentum) charged jet observables are compared with the QCD Monte Carlo models HERWIG, ISAJET, and PYTHIA. The models describe fairly well the multiplicity distribution of charged particles within the leading charged jet, the size of the leading charged jet, the radial distribution of charged particles and transverse momentum around the leading charged jet direction, and the momentum distribution of charged particles within the leading charged jet. The direction of the leading ``charged particle jet'' in each event is used to define three regions of $\ensuremath{\eta}\ensuremath{-}\ensuremath{\varphi}$ space. The ``toward'' region contains the leading ``charged particle jet,'' while the ``away'' region, on the average, contains the away-side jet. The ``transverse'' region is perpendicular to the plane of the hard $2$-to-$2$ scattering and is very sensitive to the ``underlying event'' component of the QCD Monte Carlo models. HERWIG, ISAJET, and PYTHIA with their default parameters do not describe correctly all the properties of the ``transverse'' region.

We present the first measurement of the Bs-Bsbar oscillation frequency Delta m_s. We use 1 fb^-1 of data from p-pbar collisions at sqrt{s}=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The sample contains signals of 3,600 fully reconstructed hadronic Bs decays and 37,000 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal consistent with Bs-Bsbar oscillations. The probability that random fluctuations could produce a comparable signal is 0.2%. Under the hypothesis that the signal is due to Bs-Bsbar oscillations, we measure Delta m_s = 17.31^{+0.33}_{-0.18} (stat.) +- 0.07 (syst.) ps^-1 and determine |Vtd/Vts| = 0.208^{+0.001}_{-0.002} (exp.) ^{+0.008}_{-0.006} (theo.).

We have performed a search for B0s→μ+μ− and B0→μ+μ− decays in p¯p collisions at √s=1.96 TeV using 2 fb−1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B0s and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B0s→μ+μ−)<5.8×10−8 and B(B0→μ+μ−)<1.8×10−8 at 95% C.L.Received 12 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.101802©2008 American Physical Society

We report on measurements of differential cross sections dsigma/dp(T) for prompt charm meson production in ppmacr; collisions at sqrt[s]=1.96 TeV using 5.8+/-0.3 pb(-1) of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y|</=1 in four fully reconstructed decay modes: D0-->K-pi(+), D(*+)-->D0pi(+), D+-->K-pi(+)pi(+), D(+)(s)-->phipi(+), and their charge conjugates. The measured cross sections are compared to theoretical calculations.

We present a measurement of the inclusive jet cross section in p¯p collisions at √s=1.96 TeV based on data collected by the CDF II detector with an integrated luminosity of 1.13 fb−1. The measurement was made using the cone-based midpoint jet clustering algorithm in the rapidity region of |y|<2.1. The results are consistent with next-to-leading-order perturbative QCD predictions based on recent parton distribution functions (PDFs), and are expected to provide increased precision in PDFs at high parton momentum fraction x. The results are also compared to the recent inclusive jet cross section measurement using the kT jet clustering algorithm, and we find that the ratio of the cross sections measured with the two algorithms is in agreement with theoretical expectations over a large range of jet transverse momentum and rapidity.10 MoreReceived 14 July 2008DOI:https://doi.org/10.1103/PhysRevD.78.052006©2008 American Physical Society

We present new measurements of the inclusive forward-backward ttbar production asymmetry, AFB, and its dependence on several properties of the ttbar system. The measurements are performed with the full Tevatron data set recorded with the CDF II detector during ppbar collisions at sqrt(s) = 1.96 TeV, corresponding to an integrated luminosity of 9.4 fb^(-1). We measure the asymmetry using the rapidity difference Delta-y=y_(t)-y_(tbar). Parton-level results are derived, yielding an inclusive asymmetry of 0.164+/-0.047 (stat + syst). We observe a linear dependence of AFB on the top-quark pair mass M(ttbar) and the rapidity difference |Delta-y| at detector and parton levels. Assuming the standard model, the probabilities to observe the measured values or larger for the detector-level dependencies are 7.4*10^(-3) and 2.2*10^(-3) for M(ttbar) and |Delta-y| respectively. Lastly, we study the dependence of the asymmetry on the transverse momentum of the ttbar system at the detector level. These results are consistent with previous lower-precision measurements and provide additional quantification of the functional dependencies of the asymmetry.

In CDF we have observed the reactions p + p[over] --> p + X + p[over], with X being a centrally produced J/psi, psi(2S), or chi_{c0}, and gammagamma-->micro;{+}micro;{-} in pp[over] collisions at sqrt[s] = 1.96 TeV. The event signature requires two oppositely charged central muons, and either no other particles or one additional photon detected. Exclusive vector meson production is as expected for elastic photoproduction, gamma + p --> J/psi(psi(2S)) + p, observed here for the first time in hadron-hadron collisions. We also observe exclusive chi_{c0} --> J/psi + gamma. The cross sections dsigma/dy|_{y = 0} for J/psi, psi(2S), and chi_{c0} are 3.92 +/- 0.25(stat) +/- 0.52(syst) nb, 0.53 +/- 0.09(stat) +/- 0.10(syst) nb, and 76 +/- 10(stat) +/- 10(syst) nb, respectively, and the continuum is consistent with QED. We put an upper limit on the cross section for Odderon exchange in exclusive J/psi production.

We combine searches by the CDF and D0 collaborations for a Higgs boson decaying to W+W-. The data correspond to an integrated total luminosity of 4.8 (CDF) and 5.4 (D0) fb-1 of p-pbar collisions at sqrt{s}=1.96 TeV at the Fermilab Tevatron collider. No excess is observed above background expectation, and resulting limits on Higgs boson production exclude a standard-model Higgs boson in the mass range 162-166 GeV at the 95% C.L.

We report an indirect search for nonstandard model physics using the flavor-changing neutral current decays B→K(*)μ(+)μ(-). We reconstruct the decays and measure their angular distributions, as a function of q(2)=M(μμ)(2)c(2), where M(μμ) is the dimuon mass, in pp¯ collisions at √s=1.96 TeV using a data sample corresponding to an integrated luminosity of 6.8 fb(-1). The transverse polarization asymmetry A(T)(2) and the time-reversal-odd charge-and-parity asymmetry A(im) are measured for the first time, together with the K* longitudinal polarization fraction F(L) and the muon forward-backward asymmetry A(FB) for the decays B(0)→K(*0)μ(+)μ(-) and B(+)→K(*+)μ(+)μ(-). The B→K*μ(+)μ(-) forward-backward asymmetry in the most sensitive kinematic regime, 1≤q(2)<6 GeV(2)/c(2), is measured to be A(FB)=0.29(-0.23)(+0.20)(stat)±0.07(syst), the most precise result to date. No deviations from the standard model predictions are observed.

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a $W$ boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 Collaborations have measured the top quark's mass in different final states for integrated luminosities of up to $5.8\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes the treatment of the systematic uncertainties and their correlations. The mass value determined is $173.18\ifmmode\pm\else\textpm\fi{}0.56\text{ }(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.75\text{ }(\mathrm{syst})\text{ }\text{ }\mathrm{GeV}$ or $173.18\ifmmode\pm\else\textpm\fi{}0.94\text{ }\text{ }\mathrm{GeV}$, which has a precision of $\ifmmode\pm\else\textpm\fi{}0.54%$, making this the most precise determination of the top-quark mass.

We report a study of the invariant mass distribution of jet pairs produced in association with a W boson using data collected with the CDF detector which correspond to an integrated luminosity of 4.3 fb(-1). The observed distribution has an excess in the 120-160 GeV/c(2) mass range which is not described by current theoretical predictions within the statistical and systematic uncertainties. In this Letter, we report studies of the properties of this excess.

The inclusive production of π and η mesons at 90° from proton-proton collisions has been measured at the CERN ISR at centre-of-mass energies between 23.5 and 62.4 GeV. The momentum correlation of charged particles emitted together with a large transverse momentum pion has also been studied, using two magnetic spectrometers each centred at 90°.

We report the first observation of the baryonic flavor-changing neutral current decay Λ(b)(0)→Λμ(+)μ(-) with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses a pp collisions data sample corresponding to 6.8 fb(-1) at √s = 1.96 TeV collected by the CDF II detector at the Tevatron collider. The total and differential branching ratios for Λ(b)(0)→Λμ(+)μ(-) are measured. We find B(Λ(b)(0)→Λμ(+)μ(-))=[1.73 ± 0.42(stat) ± (syst)] × 10(-6). We also report the first measurement of the differential branching ratio of B(s)(0)→ϕμ(+)μ(-), using 49 signal events. In addition, we report branching ratios for B(+)→K(+)μ(+)μ(-), B(0)→K(0)μ(+)μ(-), and B→K(*)(892)μ(+)μ(-) decays.

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 combine searches by the CDF and D0 Collaborations for the standard model Higgs boson with mass in the range 90–200 GeV/c2 produced in the gluon-gluon fusion, WH, ZH, t¯tH, and vector boson fusion processes, and decaying in the H→b¯b, H→W+W−, H→ZZ, H→τ+τ−, and H→γγ modes. The data correspond to integrated luminosities of up to 10 fb−1 and were collected at the Fermilab Tevatron in p¯p collisions at √s=1.96 TeV. The searches are also interpreted in the context of fermiophobic and fourth generation models. We observe a significant excess of events in the mass range between 115 and 140 GeV/c2. The local significance corresponds to 3.0 standard deviations at mH=125 GeV/c2, consistent with the mass of the Higgs boson observed at the LHC, and we expect a local significance of 1.9 standard deviations. We separately combine searches for H→b¯b, H→W+W−, H→τ+τ−, and H→γγ. The observed signal strengths in all channels are consistent with the presence of a standard model Higgs boson with a mass of 125 GeV/c2.18 MoreReceived 26 March 2013DOI:https://doi.org/10.1103/PhysRevD.88.052014© 2013 American Physical Society

The NOMAD experiment is a short base-line search for νμ − ντ oscillations in the CERN neutrino beam. The ντ's are searched for through their charged current interactions followed by the observation of the resulting τ− through its electronic, muonic or hadronic decays. These decays are recognized using kinematical criteria necessitating the use of a light target which enables the reconstruction of individual particles produced in the neutrino interactions. This paper describes the various components of the NOMAD detector: the target and muon drift chambers, the electromagnetic and hadronic calorimeters, the preshower and transition radiation detectors and the veto and trigger scintillation counters. The beam and data acquisition system are also described. The quality of the reconstruction and individual particles is demonstrated through the ability of NOMAD to observe Ks0's, Λ0's and π0's. Finally, the observation of τ− through its electronic decay being one of the most promising channels in the search, the identification of electrons in NOMAD is discussed.

We report on measurements of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections (d(2)sigma/dp(T)dy)(/y/<0.4), as well as on the Upsilon(1S) polarization in p p macro collisions at square root of s = 1.8 TeV using a sample of 77+/-3 pb(-1) collected by the collider detector at Fermilab. The three resonances were reconstructed through the decay Upsilon-->mu(+)mu(-). The measured angular distribution of the muons in the Upsilon(1S) rest frame is consistent with unpolarized meson production.

This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and anti-protons at Fermilab's Tevatron (sqrt{s}=1.96 TeV) produce top/anti-top pairs, which decay to W^+W^-bbbar; events are selected where one W decays to hadrons, and one W decays to either e or mu plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318 pb^-1. A total of 165 ttbar events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced vertex. In each event, the reconstructed top quark invariant mass is determined by minimizing a chi-squared for the overconstrained kinematic system. At the same time, the mass of the hadronically decaying W boson is measured in the same event sample. The observed W boson mass provides an in situ improvement in the determination of the hadronic jet energy scale, JES. A simultaneous likelihood fit of the reconstructed top quark masses and the W boson invariant masses in the data sample to distributions from simulated signal and background events gives a top quark mass of 173.5 +3.7/-3.6 (stat.+JES) +/- 1.3 (other syst.) GeV/c^2, or 173.5 +3.9/-3.8 GeV/c^2.

We report on measurements of the inclusive jet production cross section as a function of the jet transverse momentum in pp¯ collisions at s=1.96 TeV, using the kT algorithm and a data sample corresponding to 1.0 fb−1 collected with the Collider Detector at Fermilab in run II. The measurements are carried out in five different jet rapidity regions with |yjet|<2.1 and transverse momentum in the range 54<pTjet<700 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.4 MoreReceived 29 January 2007Publisher error corrected 25 May 2007DOI:https://doi.org/10.1103/PhysRevD.75.092006©2007 American Physical Society

We report the first measurements of inclusive W and Z cross sections times leptonic branching ratios for pp collisions at square root[s]=1.96 TeV, based on their decays to electrons and muons. The data correspond to an integrated luminosity of 72 pb(-1) recorded with the CDF detector at the Fermilab Tevatron. We test e-mu universality in W decays, and we measure the ratio of leptonic W and Z rates from which the leptonic branching fraction B(W-->lnu) can be extracted as well as an indirect value for the total width of the W and the Cabibbo-Kobayashi-Maskawa matrix element, |V(cs)|.

We measure the dipion mass spectrum in X(3872)--> J/psipi(+) pi(-) decays using 360 pb(-1) of pp collisions at square root s= 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity ((3)S(1), (1)P(1), and (3)D(J)) charmonia decaying to J/psipi(+) pi(-), as well as even C-parity states in which the pions are from rho(0) decay. The latter case also encompasses exotic interpretations, such as a D(0)D(*0) molecule. Only the (3)S(1) and J/psirho hypotheses are compatible with our data. Since (3)S(1) is untenable on other grounds, decay via J/psirho is favored, which implies C= +1 for the X(3872). Models for J/psi - rho different angular momenta L are considered. Flexibility in the models, especially the introduction of rho - omega interference, enables good descriptions of our data for both L = 0 and 1.

We present a measurement of the tt[over ] differential cross section with respect to the tt[over ] invariant mass, dsigma/dM_{tt[over ]}, in pp[over ] collisions at sqrt[s]=1.96 TeV using an integrated luminosity of 2.7 fb;{-1} collected by the CDF II experiment. The tt[over ] invariant mass spectrum is sensitive to a variety of exotic particles decaying into tt[over ] pairs. The result is consistent with the standard model expectation, as modeled by PYTHIA with CTEQ5L parton distribution functions.

We measure the time dependence of the ratio of decay rates for the rare decay D{0}-->K{+}pi{-} to the Cabibbo-favored decay D{0}-->K{-}pi;{+}. A signal of 12.7x10;{3} D{0}-->K{+}pi{-} decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb;{-1}. We measure the D0-D[over ]{0} mixing parameters (R_{D},y{'},x{'2}), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian standard deviations.

We report the results of a search for a charged Higgs boson in the decays of top quarks produced in pp collisions at a center-of-mass energy of 1.96 TeV. We use a data sample corresponding to an integrated luminosity of 193 pb-1 collected by the upgraded Collider Detector at Fermilab. No evidence for charged Higgs production is found, allowing 95% C.L. upper limits to be placed on BR(t-->H+b) for different charged Higgs decay scenarios. In addition, we present in the minimal supersymmetric standard model (mH+/-, tanbeta) plane the first exclusion regions with radiative and Yukawa coupling corrections.

We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.

The Bc+/- meson is observed through the decay Bc+/--->J/psipi+/-, in data corresponding to an integrated luminosity of 2.4 fb(-1) recorded by the Collider Detector at Fermilab II detector at the Fermilab Tevatron. A signal of 108+/-15 candidates is observed, with a significance that exceeds 8sigma. The mass of the Bc+/- meson is measured to be 6275.6+/-2.9(stat)+/-2.5(syst) MeV/c2.

We report on the first direct search for charged Higgs bosons decaying into c¯s in t¯t events produced by p¯p collisions at √s=1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb−1 collected by the CDF II detector at Fermilab and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t¯t candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at B(t→H+b)< 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c2 assuming B(H+→c¯s)=1.0. The upper limits on B(t→H+b) are also used as model-independent limits on the decay branching ratio of top quarks to generic scalar charged bosons beyond the standard model.Received 8 July 2009DOI:https://doi.org/10.1103/PhysRevLett.103.101803©2009 American Physical Society

We present a search for high-mass neutral resonances using dimuon data corresponding to an integrated luminosity of 2.3 fb(-1) collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at the Fermilab Tevatron. No significant excess above the standard model expectation is observed in the dimuon invariant-mass spectrum. We set 95% confidence level upper limits on sigmaBR(pp-->X-->micromicro), where X is a boson with spin-0, 1, or 2. Using these cross section limits, we determine lower mass limits on sneutrinos in R-parity-violating supersymmetric models, Z' bosons, and Kaluza-Klein gravitons in the Randall-Sundrum model.

We report the observation of electroweak single top quark production in $3.2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collision data collected by the Collider Detector at Fermilab at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. Candidate events in the $W+\mathrm{\text{jets}}$ topology with a leptonically decaying $W$ boson are classified as signal-like by four parallel analyses based on likelihood functions, matrix elements, neural networks, and boosted decision trees. These results are combined using a super discriminant analysis based on genetically evolved neural networks in order to improve the sensitivity. This combined result is further combined with that of a search for a single top quark signal in an orthogonal sample of events with missing transverse energy plus jets and no charged lepton. We observe a signal consistent with the standard model prediction but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations. We measure a production cross section of ${2.3}_{\ensuremath{-}0.5}^{+0.6}(\mathrm{stat}+\mathrm{sys})\text{ }\text{ }\mathrm{pb}$, extract the value of the Cabibbo-Kobayashi-Maskawa matrix element $|{V}_{tb}|={0.91}_{\ensuremath{-}0.11}^{+0.11}(\mathrm{stat}+\mathrm{sys})\ifmmode\pm\else\textpm\fi{}0.07\text{ }\text{ }(\mathrm{\text{theory}})$, and set a lower limit $|{V}_{tb}|&gt;0.71$ at the 95% C.L., assuming ${m}_{t}=175\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

We present the first direct measurement of the W production charge asymmetry as a function of the W boson rapidity yW in p¯p collisions at √s=1.96 TeV. We use a sample of W→eν events in data from 1 fb−1 of integrated luminosity collected using the CDF II detector. In the region |yW|<3.0, this measurement is capable of constraining the ratio of up- and down-quark momentum distributions in the proton more directly than in previous measurements of the asymmetry that are functions of the charged-lepton pseudorapidity.Received 15 January 2009DOI:https://doi.org/10.1103/PhysRevLett.102.181801©2009 American Physical Society

We report the observation and measurement of the mass of the bottom, strange baryon $\Xi^-_b$ through the decay chain $\Xi^-_b \to J/\psi \Xi^-$, where $J/\psi \to \mu^+ \mu^-$, $\Xi^- \to \Lambda \pi^-$, and $\Lambda \to p \pi^-$. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The $\Xi^-_b$ mass is measured to be $5792.9\pm 2.5$ (stat.) $\pm 1.7$ (syst.) MeV/$c^2$.

We present an analysis of the mass of the X(3872) reconstructed via its decay to J/psi pi+ pi- using 2.4 fb^-1 of integrated luminosity from ppbar collisions at sqrt(s) = 1.96 TeV, collected with the CDF II detector at the Fermilab Tevatron. The possible existence of two nearby mass states is investigated. Within the limits of our experimental resolution the data are consistent with a single state, and having no evidence for two states we set upper limits on the mass difference between two hypothetical states for different assumed ratios of contributions to the observed peak. For equal contributions, the 95% confidence level upper limit on the mass difference is 3.6 MeV/c^2. Under the single-state model the X(3872) mass is measured to be 3871.61 +- 0.16 (stat) +- 0.19 (syst) MeV/c^2, which is the most precise determination to date.

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.

Inclusive jet cross sections in Z/γ∗ events, with Z/γ∗ decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in p¯p collisions at √s=1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb−1. The measurements cover the rapidity region |yjet|<2.1 and the transverse momentum range pjetT>30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.Received 23 November 2007DOI:https://doi.org/10.1103/PhysRevLett.100.102001©2008 American Physical Society

We summarize and combine direct measurements of the mass of the W boson in √s=1.96 TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2 fb−1 of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3 fb−1 of integrated luminosity. The resulting Tevatron average for the mass of the W boson is MW=80387±16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of MW=80385±15 MeV.Received 29 July 2013DOI:https://doi.org/10.1103/PhysRevD.88.052018© 2013 American Physical Society

We present the results of searches for large extra dimensions in samples of events with large missing transverse energy ${\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$ and either a photon or a jet produced in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ collected with the Collider Detector at Fermilab II. For $\ensuremath{\gamma}+{\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$ and $\mathrm{\text{jet}}+{\mathrm{E\ensuremath{\llap{\not\;}}}}_{T}$ candidate samples corresponding to 2.0 and $1.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity, respectively, we observe good agreement with standard model expectations and obtain a combined lower limit on the fundamental parameter of the large extra dimensions model ${M}_{D}$ as a function of the number of extra dimensions in the model.

The inclusive cross section for larger pTπ0 production near 90° in p-p collisions at the CERN ISR is presented for centre-of-mass energies 30.7, 53.1 and 62.4 GeV. The data are inconsistent with scaling of the form pT−nF(xT), with constant n or with n allowed to depend on xT = 2pT/s. For s = 53.1 and 62.4 GeV, the value of n found for 3.5 < pT < 7.0 GeV/c is n = 8.0 ± 0.5, in agreement with previous experiments. However, for 7.5 < pT < 14.0 GeV/c the value becomes n = 5.1 ± 0.4.

We present a measurement of the cross section for W-boson production in association with jets in p¯p collisions at √s=1.96 TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb−1 collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W+≥n−jet sample (n=1−4) we measure the differential cross section dσ(p¯p→W+≥n−jet)/dEnth−jetT×B(W→eν) with respect to the transverse energy ET of the nth-highest ET jet above 20 GeV, and the total cross section σ(p¯p→W+≥n−jet;Enth−jetT>25 GeV)×B(W→eν), for a restricted W→eν decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level W+jet(s) predictions. We present here comparisons to leading order and next-to-leading order predictions.Received 26 November 2007DOI:https://doi.org/10.1103/PhysRevD.77.011108©2008 American Physical Society

We report a measurement of the difference (Delta Acp) between time-integrated CP--violating asymmetries in D0-> K+ K- and D0-> pi+pi- decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7 fb-1 of integrated luminosity. The strong decay D*+->D0 pi+ is used to identify the charm meson at production as D0 or anti-D0. We measure Delta Acp = [-0.62 +- 0.21 (stat) +- 0.10 (syst)] %, which differs from zero by 2.7 Gaussian standard deviations.This result supports similar evidence for CP violation in charm-quark decays obtained in proton-proton collisions.

A search has been performed for B(s)(0) → μ+ μ- and B(0) → μ+ μ- decays using 7 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B(0) candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of B(B(0) → μ+ μ-) < 6.0 × 10(-9) at 95% confidence level. We observe an excess of B(s)(0) candidates. The probability that the background processes alone could produce such an excess or larger is 0.27%. The probability that the combination of background and the expected standard model rate of B(s)(0) → μ+ μ- could produce such an excess or larger is 1.9%. These data are used to determine B(B(s)(0)→ μ+ μ-) = (1.8(-0.9) (+1.1)) × 10(-8) and provide an upper limit of B(B(s)(0) → μ+ μ-) < 4.0 × 10(-8) at 95% confidence level.

We combine six measurements of the inclusive top-quark pair (ttbar) production cross section (sigma_ttbar) from data collected with the CDF and D0 detectors at the Fermilab Tevatron with proton anti-proton collisions at sqrt{s} = 1.96 TeV. The data correspond to integrated luminosities of up to 8.8 fb^{-1}. We obtain a value of sigma_ttbar = 7.60 \pm 0.41 pb for a top-quark mass of m_t=172.5 GeV. The contributions to the uncertainty are 0.20 pb from statistical sources, 0.29 pb from systematic sources, and 0.21 pb from the uncertainty on the integrated luminosity. The result is in good agreement with the standard model expectation of 7.35^{+0.28}_{-0.33} pb at NNLO+NNLL in pertubative QCD.

We report on a measurement of CP-violating asymmetries (Acp) in the Cabibbo-suppressed D0 --> pi+ pi- and D0 --> K+K- decays reconstructed in a data sample corresponding to 5.9 fb-1 of integrated luminosity collected by the upgraded Collider Detector at Fermilab. We use the strong decay D*+ --> D0 pi+ to identify the flavor of the charmed meson at production and exploit CP-conserving strong c-cbar pair-production in p-pbar collisions. High-statistics samples of Cabibbo-favored D0 --> K- p+ decays with and without a D* tag are used to correct for instrumental effects and significantly reduce systematic uncertainties. We measure Acp(D0 --> pi+ pi-) = (+0.22 +- 0.24 (stat) +- 0.11 (syst))% and Acp(D 0 --> K+ K-) = (-0.24 +- 0.22 (stat) +- 0.09 (syst))%, in agreement with CP conservation. These are the most precise determinations from a single experiment to date. Under the assumption of negligible direct CP violation in D0 --> pi+ pi- and D0 --> K+K- decays, the results provide an upper limit to the CP-violating asymmetry in D0 mixing, |Acp^{ind}(D0)|< 0.13% at the 90% confidence level.

A search for high transverse momentum electrons directly produced in proton-proton collisions has been performed at the CERN ISR. The apparatus included a magnetic spectrometer with wire spark chambers, a lead-glass counter array, and a threshold gas Čerenkov counter. At a centre-of-mass energy √s = 52.7 GeV, a signal has been observed in the range 1.6<pT∗<4.7 GeV/c. The signal occurs at a level of approximately 10−4 of the inclusive pion cross-section.

We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ corresponding to an integrated luminosity of $6.7\text{ }\text{ }\mathrm{f}{\mathrm{b}}^{\ensuremath{-}1}$ recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of $5\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, and on spin-dependent interactions up to masses of $200\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb−1 per experiment. The measured cross section is σs=1.29+0.26−0.24 pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8×10−10, corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks.Received 21 February 2014DOI:https://doi.org/10.1103/PhysRevLett.112.231803© 2014 American Physical Society

Using the full CDF Run II data sample, we report evidence for a new resonance, which we refer to as $B(5970)$, found simultaneously in the ${B}^{0}{\ensuremath{\pi}}^{+}$ and ${B}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ mass distributions with a significance of 4.4 standard deviations. We further report the first study of resonances consistent with orbitally excited ${B}^{+}$ mesons and an updated measurement of the properties of orbitally excited ${B}^{0}$ and ${B}_{s}^{0}$ mesons. We measure the masses and widths of all states, as well as the relative production rates of the ${B}_{1}$, ${B}_{2}^{*}$, and $B(5970)$ states and the branching fraction of the ${B}_{s2}^{*0}$ state to either ${B}^{*+}{K}^{\ensuremath{-}}$ and ${B}^{+}{K}^{\ensuremath{-}}$. Furthermore, we measure the production rates of the orbitally excited ${B}^{0,+}$ states relative to the ${B}^{0,+}$ ground state. The masses of the new $B(5970)$ resonances are $5978\ifmmode\pm\else\textpm\fi{}5(\text{stat})\ifmmode\pm\else\textpm\fi{}12(\text{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ for the neutral state and $5961\ifmmode\pm\else\textpm\fi{}5(\text{stat})\ifmmode\pm\else\textpm\fi{}12(\text{syst})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$ for the charged state, assuming that the resonance decays into $B\ensuremath{\pi}$ final states. The properties of the orbitally excited and the new $B(5970{)}^{0,+}$ states are compatible with isospin symmetry.

We present the final combination of CDF and D0 measurements of cross sections for single-top-quark production in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7 fb^{-1} per experiment. The t-channel cross section is measured to be σ_{t}=2.25_{-0.31}^{+0.29} pb. We also present the combinations of the two-dimensional measurements of the s- vs t-channel cross section. In addition, we give the combination of the s+t channel cross section measurement resulting in σ_{s+t}=3.30_{-0.40}^{+0.52} pb, without assuming the standard model value for the ratio σ_{s}/σ_{t}. The resulting value of the magnitude of the top-to-bottom quark coupling is |V_{tb}|=1.02_{-0.05}^{+0.06}, corresponding to |V_{tb}|>0.92 at the 95% C.L.

The observation of the [Formula: see text] structure in [Formula: see text] decays produced in [Formula: see text] collisions at [Formula: see text] TeV is reported with a statistical significance greater than 5 standard deviations. A fit to the [Formula: see text] mass spectrum is performed assuming the presence of a Breit–Wigner resonance. The fit yields a signal of [Formula: see text] resonance events, and resonance mass and width of [Formula: see text] and [Formula: see text], respectively. The parameters of this resonance-like structure are consistent with values reported from an earlier CDF analysis.

We report results from a study of events with a leading antiproton of beam momentum fraction 0.905<x(F)<0.965 and 4-momentum transfer squared |t|<3 GeV2 produced in &pmacr;p collisions at sqrt[s] = 1800 GeV at the Fermilab Tevatron collider. Approximately 2% of the events contain two jets of transverse energy E(jet)(T)>7 GeV. Using the dijet events, we evaluate the diffractive structure function of the antiproton and compare it with expectations based on results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA.

Results from the ντ appearance search in a neutrino beam using the full NOMAD data sample are reported. A new analysis unifies all the hadronic τ decays, significantly improving the overall sensitivity of the experiment to oscillations. The “blind analysis” of all topologies yields no evidence for an oscillation signal. In the two-family oscillation scenario, this sets a 90% CL allowed region in the sin22θμτ–Δm2 plane which includes sin22θμτ<3.3×10−4 at large Δm2 and Δm2< 0.7 eV2/c4 at sin22θμτ=1. The corresponding contour in the νe→ντ oscillation hypothesis results in sin22θeτ<1.5×10−2 at large Δm2 and Δm2<5.9 eV2/c4 at sin22θeτ=1. We also derive limits on effective couplings of the τ lepton to νμ or νe.

We present the results of a search for doubly charged Higgs bosons (H+/-+/-) decaying to dileptons (ll(')) using approximately 240 pb(-1) of pp collision data collected by the CDF II experiment at the Fermilab Tevatron. In our search region, given by same-sign ll(') mass m(ll('))>80 GeV/c(2) (100 GeV/c(2) for ee channel), we observe no evidence for H+/-+/- production. We set limits on sigma(pp -->H++H---->l(+)l('+)l(-)l('-)) as a function of the mass of the H+/-+/- and the chirality of its couplings. Assuming exclusive same-sign dilepton decays, we derive lower mass limits on H(+/-+/-)(L) of 133, 136, and 115 GeV/c(2) in the ee, mumu, and emu channels, respectively, and a lower mass limit of 113 GeV/c(2) on H(+/-+/-)(R) in the mumu channel, all at the 95% confidence level.

We report the first evidence for a fully reconstructed decay mode of the B±c meson in the channel B±c→J/ψπ±, with J/ψ→μ+μ−. The analysis is based on an integrated luminosity of 360 pb−1 in p¯p collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6±4.6 signal events with a background of 7.1±0.9 events, and a fit to the J/ψπ± mass spectrum yields a B±c mass of 6285.7±5.3(stat)±1.2(syst) MeV/c2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%.Received 23 May 2005DOI:https://doi.org/10.1103/PhysRevLett.96.082002©2006 American Physical Society

For comparison of inclusive jet cross sections measured at hadron-hadron colliders to next-to-leading order (NLO) parton-level calculations, the energy deposited in the jet cone by spectator parton interactions must first be subtracted. The assumption made at the Tevatron is that the spectator parton interaction energy is similar to the ambient level measured in minimum bias events. In this paper, we test this assumption by measuring the ambient charged track momentum in events containing large transverse energy jets at $\sqrt{s}=1800$ GeV and $\sqrt{s}=630$ GeV and comparing this ambient momentum with that observed both in minimum bias events and with that predicted by two Monte Carlo models. Two cones in $\eta$--$\phi$ space are defined, at the same pseudo-rapidity, $\eta$, as the jet with the highest transverse energy ($E_T^{(1)}$), and at $\pm 90^o$ in the azimuthal direction, $\phi$. The total charged track momentum inside each of the two cones is measured. The minimum momentum in the two cones is almost independent of $E_T^{(1)}$ and is similar to the momentum observed in minimum bias events, whereas the maximum momentum increases roughly linearly with the jet $E_T^{(1)}$ over most of the measured range. This study will help improve the precision of comparisons of jet cross section data and NLO perturbative QCD predictions. %this is new The distribution of the sum of the track momenta in the two cones is also examined for five different $E_T^{(1)}$ bins. The HERWIG and PYTHIA Monte Carlos are reasonably successful in describing the data, but neither can describe completely all of the event properties.

We present the first observation of exclusive e+e− production in hadron-hadron collisions, using p¯p collision data at √s=1.96 TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb−1. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy ET>5 GeV and pseudorapidity |η|<2. With these criteria, 16 events are observed compared to a background expectation of 1.9±0.3 events. These events are consistent in cross section and properties with the QED process p¯p→p+e+e−+¯p through two-photon exchange. The measured cross section is 1.6+0.5−0.3(stat)±0.3(syst) pb. This agrees with the theoretical prediction of 1.71±0.01 pb.Received 27 November 2006DOI:https://doi.org/10.1103/PhysRevLett.98.112001©2007 American Physical Society

We present a measurement of the muon neutrino–nucleon inclusive charged current cross section, off an isoscalar target, in the neutrino energy range 2.5⩽Eν⩽40GeV. The significance of this measurement is its precision, ±4% in 2.5⩽Eν⩽10GeV, and ±2.6% in 10⩽Eν⩽40GeV regions, where significant uncertainties in previous experiments still exist, and its importance to the current and proposed long baseline neutrino oscillation experiments.

We report on a search for inclusive production of squarks and gluinos in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, in events with large missing transverse energy and multiple jets of hadrons in the final state. The study uses a CDF Run II data sample corresponding to $2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity. The data are in good agreement with the standard model predictions, giving no evidence for any squark or gluino component. In an $R$-parity conserving minimal supergravity scenario with ${A}_{0}=0$, $\ensuremath{\mu}&lt;0$, and $\mathrm{tan}\ensuremath{\beta}=5$, 95% C.L. upper limits on the production cross sections in the range between 0.1 and 1 pb are obtained, depending on the squark and gluino masses considered. For gluino masses below $280\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, arbitrarily large squark masses are excluded at the 95% C.L., while for mass degenerate gluinos and squarks, masses below $392\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ are excluded at the 95% C.L.

We present a measurement of the tt¯ production cross section using events with one charged lepton and jets from pp¯ collisions at a center-of-mass energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced tracks coming from the event interaction vertex is applied to identify b quarks from top decay. Using 318 pb−1 of data collected with the CDF II detector, we measure the tt¯ production cross section in events with at least one restrictive (tight) b-tagged jet and obtain 8.9−1.0+1.0(stat)−1.0+1.1(syst) pb. The cross section value assumes a top quark mass of mt=178 GeV/c2 in the acceptance corrections. The dependence of the cross section on mt is presented in the paper. This result is consistent with other CDF measurements of the tt¯ cross section using different samples and analysis techniques, and has similar systematic uncertainties. We have also performed consistency checks by using the b-tagging probability function to vary the signal-to-background ratio and also using events that have at least two b-tagged jets.20 MoreReceived 21 July 2006DOI:https://doi.org/10.1103/PhysRevD.74.072006©2006 American Physical Society

We report the most restrictive direct limits on masses of fourth-generation down-type quarks b′, and quarklike composite fermions (B or T5/3), decaying promptly to tW∓. We search for a significant excess of events with two same-charge leptons (e, μ), several hadronic jets, and missing transverse energy. An analysis of data from p¯p collisions with an integrated luminosity of 2.7 fb−1 collected with the CDF II detector at Fermilab yields no evidence for such a signal, setting mass limits mb′, mB>338 GeV/c2 and mT5/3>365 GeV/c2 at 95% confidence level.Received 5 December 2009DOI:https://doi.org/10.1103/PhysRevLett.104.091801©2010 American Physical Society

We present a measurement of the Bc+ meson lifetime in the decay mode Bc+ --> J/Psie+nue using the Collider Detector at Fermilab II detector at the Fermilab Tevatron Collider. From a sample of about of 360 pb(-1) of pp collisions at square root of s = 1.96 TeV, we reconstruct J/Psie+ pairs with invariant mass in the kinematically allowed range 4< M(J/Psie) < 6 GeV/c2. A fit to the decay-length distribution of 238 signal events yields a measured Bc+ meson lifetime of 0.463(-0.065)(+0.073)(stat) +/- 0.036(syst) ps.

We present a measurement of the top quark pair production cross section in p¯p collisions at √s=1.96 TeV using 318 pb−1 of data collected with the Collider Detector at Fermilab. We select t¯t decays into the final states eν+jets and μν+jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c2, we measure a cross section of 8.7±0.9(stat)+1.1−0.9(syst) pb. We also report the first observation of t¯t with significance greater than 5σ in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1+1.6−1.4(stat)+2.0−1.3(syst) pb.Received 6 June 2006DOI:https://doi.org/10.1103/PhysRevLett.97.082004©2006 American Physical Society

We present the first observation and cross section measurement of exclusive dijet production in $\overline{p}p$ interactions, $\overline{p}p\ensuremath{\rightarrow}\overline{p}+\mathrm{dijet}+p$. Using a data sample of $310\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ collected by the Run II Collider Detector at Fermilab at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, exclusive cross sections for events with two jets of transverse energy ${E}_{T}^{\mathrm{jet}}\ensuremath{\ge}10\text{ }\text{ }\mathrm{GeV}$ have been measured as a function of minimum ${E}_{T}^{\mathrm{jet}}$. The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of $200\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of $b$-tagged jet events, where exclusive dijet production is expected to be suppressed by the ${J}_{z}=0$ total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the $pp$ Large Hadron Collider at $\sqrt{s}=14\text{ }\text{ }\mathrm{TeV}$ are discussed.

We report a set of measurements of particle production in inelastic p¯p collisions collected with a minimum-bias trigger at the Tevatron Collider with the CDF II experiment. The inclusive charged particle transverse momentum differential cross section is measured, with improved precision, over a range about ten times wider than in previous measurements. The former modeling of the spectrum appears to be incompatible with the high particle momenta observed. The dependence of the charged particle transverse momentum on the event particle multiplicity is analyzed to study the various components of hadron interactions. This is one of the observable variables most poorly reproduced by the available Monte Carlo generators. A first measurement of the event transverse energy sum differential cross section is also reported. A comparison with a pythia prediction at the hadron level is performed. The inclusive charged-particle differential production cross section is fairly well reproduced only in the transverse momentum range available from previous measurements. At higher momentum the agreement is poor. The transverse energy sum is poorly reproduced over the whole spectrum. The dependence of the charged particle transverse momentum on the particle multiplicity needs the introduction of more sophisticated particle production mechanisms, such as multiple parton interactions, in order to be better explained.3 MoreReceived 8 April 2009DOI:https://doi.org/10.1103/PhysRevD.79.112005©2009 American Physical Society

We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c^2 using 1.3 fb^-1 of ppbar collision data at sqrt(s) = 1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard model-like Z' with a mass below 923 GeV/c^2 and the Randall-Sundrum graviton with a mass below 807 GeV/c^2 for k/M_pl=0.1, both at the 95% confidence level. Combining with di-photon data excludes the Randall-Sundrum graviton for masses below 889 GeV/c^2 for k/M_pl=0.1.

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 the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for ``bumps'' that could indicate resonant production of new particles, and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in $2.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ reveals no indication of physics beyond the standard model.

As part of a study of large pT phenomena in photon-proton collisions at the CERN ISR, a search for direct single photon production has been performed. A statistical division of the data sample into the fraction consistent with single photon and the fraction due to multiphoton decays of neutral hadrons is accomplished by measuring the average conversion probability for the sample in a one radiation length thick converter. The fraction of the sample attributable to direct single photon production is 〈γ/all〉 = 0.074 ± 0.012 for 6 GeV/c < pT 10 GeV/c, and 〈γ/all〉 = 0.26 ± 0.04 for pT > 10 GeV/c, with an additional systematic uncertainty of ±0.05 for both values.

A search for high-mass resonances in the ${e}^{+}{e}^{\ensuremath{-}}$ final state is presented based on $2.5\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ $p\overline{p}$ collision data from the CDF II detector at the Fermilab Tevatron. The largest excess over the standard model prediction is at an ${e}^{+}{e}^{\ensuremath{-}}$ invariant mass of $240\text{ }\text{ }\mathrm{GeV}/{c}^{2}$. The probability of observing such an excess arising from fluctuations in the standard model anywhere in the mass range of $150--1000\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ is 0.6% (equivalent to $2.5\ensuremath{\sigma}$). We exclude the standard model coupling ${Z}^{\ensuremath{'}}$ and the Randall-Sundrum graviton for $k/{\overline{M}}_{\mathrm{Pl}}=0.1$ with masses below 963 and $848\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ at the 95% credibility level, respectively.

We report a search for the flavor changing neutral current (FCNC) decay of the top quark \tZq ($q=u,c$) in \ppbar collisions at $\sqrt{s} = 1.96\tev$ using a data sample corresponding to an integrated luminosity of 1.9\invfb collected by the CDF II detector. This decay is strongly suppressed in the standard model (SM) and an observation of a signal at the Tevatron would be an indication of physics beyond the SM. Using $Z+\ge4$ jet final state candidate events, both with and without an identified bottom quark jet, we discriminate signal from background by exploiting kinematic constraints present in FCNC events and obtain an upper limit of $\btZq < 3.7%$ at 95% C.L.

We report the most sensitive direct search for pair production of fourth-generation bottomlike chiral quarks (b') each decaying promptly to tW. We search for an excess of events with an electron or muon, at least five jets (one identified as due to a b or c quark), and an imbalance of transverse momentum by using data from pp collisions collected by the CDF II detector at Fermilab with an integrated luminosity of 4.8 fb(-1). We observe events consistent with background expectation, calculate upper limits on the b' pair-production cross section (σ(bb')) ≲30 fb for m(b') > 375 GeV/c2), and exclude m(b') < 372 GeV/c2 at 95% confidence level assuming a 100% branching ratio of b' to tW.

We report the observation of the bottom, doubly-strange baryon Omega^-_b through the decay chain Omega^-_b -> J/psi Omega^-, where J/psi -> mu^+ mu^-, Omega^- -> Lambda K^-, and Lambda -> p pi^-, using 4.2 fb^{-1} of data from p\bar p collisions at sqrt{s}=1.96 TeV, and recorded with the Collider Detector at Fermilab. A signal is observed whose probability of arising from a background fluctuation is 4.0 * 10^{-8}, or 5.5 Gaussian standard deviations. The Omega^-_b mass is measured to be 6054.4 +/- 6.8 (stat.) +/- 0.9 (syst.) MeV/c^2. The lifetime of the Omega^-_b baryon is measured to be 1.13^{+0.53}_{-0.40}(stat.) +/- 0.02(syst.)$ ps. In addition, for the \Xi^-_b baryon we measure a mass of 5790.9 +/- 2.6(stat.) +/- 0.8(syst.) MeV/c^2 and a lifetime of 1.56^{+0.27}_{-0.25}(stat.) +/-0.02(syst.) ps. Under the assumption that the \Xi_b^- and \Omega_b^- are produced with similar kinematic distributions to the \Lambda^0_b baryon, we find sigma(Xi_b^-) B(Xi_b^- -> J/psi Xi^-)}/ sigma(Lambda^0_b) B(Lambda^0_b -> J/psi Lambda)} = 0.167^{+0.037}_{-0.025}(stat.) +/-0.012(syst.) and sigma(Omega_b^-) B(Omega_b^- -> J/psi Omega^-)/ sigma(Lambda^0_b) B(Lambda^0_b -> J/psi Lambda)} = 0.045^{+0.017}_{-0.012}(stat.) +/- 0.004(syst.) for baryons produced with transverse momentum in the range of 6-20 GeV/c.

We report a measurement of the ratio of the tt to Z/γ{*} production cross sections in sqrt[s]=1.96 TeV pp collisions using data corresponding to an integrated luminosity of up to 4.6 fb{-1}, collected by the CDF II detector. The tt cross section ratio is measured using two complementary methods, a b-jet tagging measurement and a topological approach. By multiplying the ratios by the well-known theoretical Z/γ{*}→ll cross section predicted by the standard model, the extracted tt cross sections are effectively insensitive to the uncertainty on luminosity. A best linear unbiased estimate is used to combine both measurements with the result σ{tt}=7.70±0.52 pb, for a top-quark mass of 172.5 GeV/c{2}.

We study the underlying event in proton-antiproton collisions by examining the behavior of charged particles produced in association with a large transverse momentum jet ($\ensuremath{\sim}2.2\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$) or with a Drell-Yan lepton pair ($\ensuremath{\sim}2.7\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$) in the $Z$-boson mass region [$70&lt;M(\mathrm{\text{pair}})&lt;110\text{ }\text{ }\mathrm{GeV}/{c}^{2}$] as measured by CDF at 1.96 TeV center-of-mass energy. We use the direction of the lepton pair or the leading jet in each event to define regions of $\ensuremath{\eta}\mathrm{\text{\ensuremath{-}}}\ensuremath{\phi}$ space that are sensitive to the modeling of the underlying event. The data are corrected to the particle level to remove detector effects and are then compared with several QCD Monte Carlo models.

We present a precision measurement of the top-quark mass using the full sample of Tevatron $\sqrt{s}=1.96$ TeV proton-antiproton collisions collected by the CDF II detector, corresponding to an integrated luminosity of 8.7 $fb^{-1}$. Using a sample of $t\bar{t}$ candidate events decaying into the lepton+jets channel, we obtain distributions of the top-quark masses and the invariant mass of two jets from the $W$ boson decays from data. We then compare these distributions to templates derived from signal and background samples to extract the top-quark mass and the energy scale of the calorimeter jets with {\it in situ} calibration. The likelihood fit of the templates from signal and background events to the data yields the single most-precise measurement of the top-quark mass, $\mtop = 172.85 $\pm$ 0.71 (stat) $\pm$ 0.85 (syst) GeV/c^{2}.$

This Letter describes the current most precise measurement of the $W$ boson pair production cross section and most sensitive test of anomalous $WW\ensuremath{\gamma}$ and $WWZ$ couplings in $p\overline{p}$ collisions at a center-of-mass energy of 1.96 TeV. The $WW$ candidates are reconstructed from decays containing two charged leptons and two neutrinos. Using data collected by the CDF II detector from $3.6\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity, a total of 654 candidate events are observed with an expected background of $320\ifmmode\pm\else\textpm\fi{}47$ events. The measured cross section is $\ensuremath{\sigma}(p\overline{p}\ensuremath{\rightarrow}{W}^{+}{W}^{\ensuremath{-}}+X)=12.1\ifmmode\pm\else\textpm\fi{}0.9(\mathrm{stat}{)}_{\ensuremath{-}1.4}^{+1.6}(\mathrm{syst})\text{ }\text{ }\mathrm{pb}$, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous $WW\ensuremath{\gamma}$ and $WWZ$ couplings.

The cross section for jets from b quarks produced with a W boson has been measured in pp collision data from 1.9 fb(-1) of integrated luminosity recorded by the CDF II detector at the Tevatron. The W+b-jets process poses a significant background in measurements of top quark production and prominent searches for the Higgs boson. We measure a b-jet cross section of 2.74+/-0.27(stat)+/-0.42(syst) pb in association with a single flavor of leptonic W boson decay over a limited kinematic phase space. This measured result cannot be accommodated in several available theoretical predictions.

We present our new measurement of the cross-section for charm dimuon production in neutrino–iron interactions based upon the full statistics collected by the NOMAD experiment. After background subtraction we observe 15 344 charm dimuon events, providing the largest sample currently available. The analysis exploits the large inclusive charged current sample – about 9×106 events after all analysis cuts – and the high resolution NOMAD detector to constrain the total systematic uncertainty on the ratio of charm dimuon to inclusive Charged Current (CC) cross-sections to ∼2%. We also perform a fit to the NOMAD data to extract the charm production parameters and the strange quark sea content of the nucleon within the NLO QCD approximation. We obtain a value of mc(mc)=1.159±0.075 GeV/c2 for the running mass of the charm quark in the MS¯ scheme and a strange quark sea suppression factor of κs=0.591±0.019 at Q2=20 GeV2/c2.

We report measurements of direct CP-violating asymmetries in charmless decays of neutral bottom hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb-1 of integrated luminosity, we obtain the first measurements of direct CP violation in bottom strange mesons, A_CP(BsKpi) = +0.39 +- 0.15 stat +- 0.08 syst, and bottom baryons, A_CP(Lb->ppi) = +0.03 +- 0.17 stat +- 0.05 syst and A_CP(Lb->pK) = +0.37 +- 0.17 +- 0.03 syst. In addition, we measure CP violation in Bd-->Kpi decays with 3.5sigma significance, A_CP(B->Kpi) = -0.086 +- 0.023 stat +- 0.009 syst, in agreement with the current world average. Measurements of branching fractions of Bs-->K+K- and B0-->pi+pi- decays are also updated.

Drell-Yan lepton pairs produced in the process $p\overline{p}\ensuremath{\rightarrow}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}+X$ through an intermediate ${\ensuremath{\gamma}}^{*}/Z$ boson have an asymmetry in their angular distribution related to the spontaneous symmetry breaking of the electroweak force and the associated mixing of its neutral gauge bosons. The CDF and D0 experiments have measured the effective-leptonic electroweak mixing parameter ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{\mathrm{eff}}^{\mathrm{lept}}$ using electron and muon pairs selected from the full Tevatron proton-antiproton data sets collected in 2001-2011, corresponding to $9--10\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity. The combination of these measurements yields the most precise result from hadron colliders, ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{\mathrm{eff}}^{\mathrm{lept}}=0.23148\ifmmode\pm\else\textpm\fi{}0.00033$. This result is consistent with, and approaches in precision, the best measurements from electron-positron colliders. The standard model inference of the on-shell electroweak mixing parameter ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}$, or equivalently the $W$-boson mass ${M}_{W}$, using the zfitter software package yields ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{W}=0.22324\ifmmode\pm\else\textpm\fi{}0.00033$ or equivalently, ${M}_{W}=80.367\ifmmode\pm\else\textpm\fi{}0.017\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

We have performed a search for gluinos (g) and scalar quarks (q) in a data sample of 84 pb(-1) of pp collisions at square root[s] = 1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and three or more jets, a characteristic signature in R-parity-conserving supersymmetric models. The analysis has been performed "blind," in that the inspection of the signal region is made only after the predictions from standard model backgrounds have been calculated. Comparing the data with predictions of constrained supersymmetric models, we exclude gluino masses below 195 GeV/c2 (95% C.L.), independent of the squark mass. For the case m(q) approximately m(g), gluino masses below 300 GeV/c2 are excluded.

We present results from the measurement of the inclusive jet cross section for jet transverse energies from 40 to 465 GeV in the pseudorapidity range $0.1&lt;|\ensuremath{\eta}|&lt;0.7.$ The results are based on 87 ${\mathrm{pb}}^{\ensuremath{-}1}$ of data collected by the CDF Collaboration at the Fermilab Tevatron collider. The data are consistent with previously published results. The data are also consistent with QCD predictions given the flexibility allowed from current knowledge of the proton parton distributions. We develop a new procedure for ranking the agreement of the parton distributions with data and find that the data are best described by QCD predictions using the parton distribution functions which have a large gluon contribution at high ${E}_{T}$ (CTEQ4HJ).

We report on a study of jet shapes in inclusive jet production in p¯p collisions at √s=1.96 TeV using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of 170 pb−1. Measurements are carried out on jets with rapidity 0.1<|Yjet|<0.7 and transverse momentum 37 GeV/c<PjetT<380 GeV/c. The jets have been corrected to the hadron level. The measured jet shapes are compared to leading-order QCD parton-shower Monte Carlo predictions as implemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the underlying event as measured in CDF Run I, provides a better description of the measured jet shapes than does PYTHIA or HERWIG with their default parameters.2 MoreReceived 9 May 2005DOI:https://doi.org/10.1103/PhysRevD.71.112002©2005 American Physical Society

The structure of hadronic events fromZ 0 decay is studied by measuring event shape variables, factorial moments, and the energy flow distribution. The distributions, after correction for detector effects and initial and final state radiation, are compared with the predictions of different QCD Monte Carlo programs with optimized parameter values. These Monte Carlo programs use either the second order matrix element or the parton shower evolution for the perturbative QCD calculations and use the string, the cluster, or the independent fragmentation model for hadronization. Both parton shower andO(α 2 s matrix element based models with string fragmentation describe the data well. The predictions of the model based on parton shower and cluster fragmentation are also in good agreement with the data. The model with independent fragmentation gives a poor description of the energy flow distribution. The predicted energy evolutions for the mean values of thrust, sphericity, aplanarity, and charge multiplicity are compared with the data measured at different center-of-mass energies. The parton shower based models with string or cluster fragmentation are found to describe the energy dependences well while the model based on theO(α 2 s calculation fails to reproduce the energy dependences of these mean values.

The Λ polarization in νμ charged current interactions has been measured in the NOMAD experiment. The event sample (8087 reconstructed Λ 's) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is comparable. We observe negative polarization along the W -boson direction which is enhanced in the target fragmentation region: Px(xF<0)=−0.21±0.04(stat)±0.02(sys) . In the current fragmentation region we find Px(xF>0)=−0.09±0.06(stat)±0.03(sys) . These results provide a test of different models describing the nucleon spin composition and the spin transfer mechanisms. A significant transverse polarization (in the direction orthogonal to the Λ production plane) has been observed for the first time in a neutrino experiment: Py=−0.22±0.03(stat)±0.01(sys) . The dependence of the absolute value of Py on the Λ transverse momentum with respect to the hadronic jet direction is in qualitative agreement with the results from unpolarized hadron–hadron experiments.