Showing papers by "A. Loginov published in 2005"
TL;DR: In this article, the authors present a new measurement of the inclusive and differential production cross sections of mesons and hadrons in proton-antiproton collisions at the CDF run II detector.
Abstract: We present a new measurement of the inclusive and differential production cross sections of $J/\ensuremath{\psi}$ mesons and $b$ hadrons in proton-antiproton collisions at $\sqrt{s}=1960\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. The data correspond to an integrated luminosity of $39.7\text{ }\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ collected by the CDF run II detector. We find the integrated cross section for inclusive $J/\ensuremath{\psi}$ production for all transverse momenta from 0 to $20\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ in the rapidity range $|y|l0.6$ to be $4.08\ifmmode\pm\else\textpm\fi{}0.02(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}0.33}^{+0.36}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$. We separate the fraction of $J/\ensuremath{\psi}$ events from the decay of the long-lived $b$ hadrons using the lifetime distribution in all events with ${p}_{T}(J/\ensuremath{\psi})g1.25\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$. We find the total cross section for $b$ hadrons, including both hadrons and antihadrons, decaying to $J/\ensuremath{\psi}$ with transverse momenta greater than $1.25\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/c$ in the rapidity range $|y(J/\ensuremath{\psi})|l0.6$ is $0.330\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}0.033}^{+0.036}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$. Using a Monte Carlo simulation of the decay kinematics of $b$ hadrons to all final states containing a $J/\ensuremath{\psi}$, we extract the first measurement of the total single $b$-hadron cross section down to zero transverse momentum at $\sqrt{s}=1960\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$. We find the total single $b$-hadron cross section integrated over all transverse momenta for $b$ hadrons in the rapidity range $|y|l0.6$ to be $17.6\ifmmode\pm\else\textpm\fi{}0.4(\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}{)}_{\ensuremath{-}2.3}^{+2.5}(\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{t})\text{ }\text{ }\ensuremath{\mu}\mathrm{b}$.
336 citations
TL;DR: In this article, 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 is presented.
Abstract: 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. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb{sup -1} of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5{+-}1.8 events are expected from background contributions. We measure a tt production cross section of 5.6{sub -1.1}{sup +1.2}(stat.){sub -0.6}{sup +0.9}(syst.) pb.
119 citations
TL;DR: In this article, the authors report on a study of jet shapes in inclusive jet production in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\mathrm{TeV}$ using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of $170
Abstract: We report on a study of jet shapes in inclusive jet production in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\mathrm{TeV}$ using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of $170\text{ }\mathrm{p}{\mathrm{b}}^{\ensuremath{-}1}$. Measurements are carried out on jets with rapidity $0.1l|{Y}^{\mathrm{jet}}|l0.7$ and transverse momentum $37\text{ }\text{ }\mathrm{GeV}/cl{P}_{T}^{\mathrm{jet}}l380\text{ }\text{ }\mathrm{GeV}/c$. 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.
83 citations
TL;DR: The first measurements of inclusive W and Z cross sections times leptonic branching ratios for pp collisions at square root[s]=1.96 TeV are reported, based on their decays to electrons and muons.
Abstract: We report the first measurements of inclusive W and Z cross sections times leptonic branching ratios for p (p) over bar collisions at 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 -> l nu) can be extracted as well as an indirect value for the total width of the W and the Cabibbo-Kobayashi-Maskawa matrix element, vertical bar V(cs)vertical bar.
66 citations
TL;DR: In this paper, the lifetimes and polarization amplitudes for B(0)(s) and B(d) were measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time.
Abstract: We present measurements of the lifetimes and polarization amplitudes for B(0)(s)-->J/psiphi and B(0)(d)-->J/psiK(*0) decays. Lifetimes of the heavy and light mass eigenstates in the B(0)(s) system are separately measured for the first time by determining the relative contributions of amplitudes with definite CP as a function of the decay time. Using 203+/-15 B(0)(s) decays we obtain tau(L) = (1.05(+0.16)(-0.13) +/- 0.02) ps and tau(H) = (2.07(+0.58)(-0.46) +/- 0.03) ps. Expressed in terms of the difference DeltaGamma(s) and average Gamma(s), of the decay rates of the two eigenstates, the results are DeltaGamma(s)/Gamma(s) = (65(+25)(-33) +/- 1)% and DeltaGamma(s) = (0.47(+0.19)(-0.24) +/- 0.01) ps(-1).
62 citations
TL;DR: In this article, the forward-backward charge asymmetry of electrons from W boson decays in pp collisions at √s=1.96 TeV using a data sample of 170 pb-1 collected by the Collider Detector at Fermilab.
Abstract: We report a measurement of the forward-backward charge asymmetry of electrons from W boson decays in pp collisions at √s=1.96 TeV using a data sample of 170 pb-1 collected by the Collider Detector at Fermilab. The asymmetry is measured as a function of electron rapidity and transverse energy and provides new input on the momentum fraction dependence of the u and d quark parton distribution functions within the proton. © 2005 The American Physical Society.
60 citations
TL;DR: In this article, the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays were measured using 180 pb{sup -1} of data collected with the CDF II detector at the Tevatron.
Abstract: Using 180 pb{sup -1} of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the non-perturbative Heavy Quark Effective Theory parameters {Lambda} and {lambda}{sub 1} used to relate the B meson semileptonic branching ratio to the CKM matrix element |V{sub cb}|.
60 citations
TL;DR: In this article, a measurement of the ratio of top-quark branching fractions was presented, where q can be a b, s, or a d quark, using lepton-plus-jets and dilepton data sets with an integrated luminosity of approximately 162 pb(-1) collected with the Collider Detector at Fermilab during Run II of the Tevatron.
Abstract: We present a measurement of the ratio of top-quark branching fractions R = B(t --> Wb)/B(t --> Wq), where q can be a b, s, or a d quark, using lepton-plus-jets and dilepton data sets with an integrated luminosity of approximately 162 pb(-1) collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of tt events with different multiplicity of identified secondary vertices. We set a lower limit of R > 0.61 at 95% confidence level.
39 citations
TL;DR: In this article, the authors used an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton+jets events, which have one isolated energetic charged lepton, large missing transverse energy and at least three energetic jets.
Abstract: We present a measurement of the top pair production cross section in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. We collect a data sample with an integrated luminosity of $194\ifmmode\pm\else\textpm\fi{}11\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton+jets events, which have one isolated energetic charged lepton, large missing transverse energy and at least three energetic jets. We measure the top pair production cross section to be ${\ensuremath{\sigma}}_{t\overline{t}}=6.6\ifmmode\pm\else\textpm\fi{}1.1\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{pb}$, where the first uncertainty is statistical and the second is systematic.
36 citations
TL;DR: In this article, a measurement of the mass dependence of the forward-backward charge asymmetry for pairs produced via an intermediate $Z/{\ensuremath{\gamma}}^{*}$ with mass was presented.
Abstract: We present a measurement of the mass dependence of the forward-backward charge asymmetry (${A}_{FB}$) for ${e}^{+}{e}^{\ensuremath{-}}$ pairs produced via an intermediate $Z/{\ensuremath{\gamma}}^{*}$ with mass ${M}_{ee}g40\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}/{c}^{2}$. We study the constraints on the $Z$-quark couplings imposed by our measurement. We analyze an integrated luminosity of $72\text{ }\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ collected by the CDF-II detector in $\overline{p}p$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{T}\mathrm{e}\mathrm{V}$ at the Fermilab Tevatron. A comparison of the uncorrected ${A}_{FB}$ between data and standard model Monte Carlo gives good agreement with a ${\ensuremath{\chi}}^{2}/\mathrm{D}\mathrm{O}\mathrm{F}$ of 15.7/15. The couplings measurements are also consistent with standard model predictions.
32 citations
TL;DR: A search for long-lived doubly charged Higgs bosons (H(+/- +/-)), with signatures of high ionization energy loss and muonlike penetration, finds no evidence of long- lived doubly charge particle production.
Abstract: We present a search for long-lived doubly charged Higgs bosons (H(+/- +/-)), with signatures of high ionization energy loss and muonlike penetration We use 292 pb(-1) of data collected in pp collisions at sqrt[s] = 196 TeV by the CDF II detector at the Fermilab Tevatron Observing no evidence of long-lived doubly charged particle production, we exclude H(+/- +/-)(L) and H(+/- +/-)(R) bosons with masses below 133 GeV/c(2) and 109 GeV/c(2), respectively In the degenerate case we exclude H(+/- +/-) mass below 146 GeV/c(2) All limits are quoted at the 95% confidence level
TL;DR: In this paper, a measurement of the rate of prompt diphoton production in pp collisions at 1.96 TeV using a data sample of 207 pb 1 collected with the upgraded Collider Detector at Fermilab is reported.
Abstract: We report a measurement of the rate of prompt diphoton production in pp collisions at 1.96 TeV using a data sample of 207 pb 1 collected with the upgraded Collider Detector at Fermilab. The background from nonprompt sources is determined using a statistical method based on differences in the electromagnetic showers. The cross section is measured as a function of the diphoton mass, the transverse momentum of the diphoton system, and the azimuthal angle between the two photons and is found to be consistent with perturbative QCD predictions. © 2005 The American Physical Society.
TL;DR: A measurement of relative partial widths and decay rate CP asymmetries in K-K+ and pi(-)pi(+) decays of D0 mesons produced in pp collisions at sqrt[s]=1.96 TeV is presented.
Abstract: We present a measurement of relative partial widths and decay rate CP asymmetries in K- K+ and π-π+ decays of D0 mesons produced in pp collisions at,√s = 1.96 TeV. We use a sample of 2 × 105 D*+ →D0π+ (and charge conjugate) decays with the D0 decaying to K-π+, K-K +, and π-π+, corresponding to 123 pb -1 of data collected by the Collider Detector at Fermilab II experiment at the Fermilab Tevatron collider. No significant direct CP violation is observed. We measure γ(D0→ K- K +)/γ(D0-→K-π+) = 0.0992 ±0.0992 ±0.0012, γ(D0→K -π+)/γ(D0→K -π+) = 0.03594 ± 0.00054 ±0.00040, A CP(K- K+) = (2.0 ±1.2 ±0.6)%, and ACP(π-π+) = (1.0 ±1.3 ±0.6)%, where, in all cases, the first uncertainty is statistical and the second is systematic. © 2005 The American Physical Society.
TL;DR: In this article, a study of the production of K{sub S}{sup 0} and ε-sup 0 in inelastic pp collisions at {radical}(s)=1800 and 630 GeV using data collected by the CDF experiment at the Fermilab Tevatron is presented.
Abstract: We present a study of the production of K{sub S}{sup 0} and {lambda}{sup 0} in inelastic pp collisions at {radical}(s)=1800 and 630 GeV using data collected by the CDF experiment at the Fermilab Tevatron. Analyses of K{sub S}{sup 0} and {lambda}{sup 0} multiplicity and transverse momentum distributions, as well as of the dependencies of the average number and of K{sub S}{sup 0} and {lambda}{sup 0} on charged particle multiplicity, are reported. Systematic comparisons are performed for the full sample of inelastic collisions, and for the low and high momentum transfer subsamples, at the two energies. The p{sub T} distributions extend above 8 GeV/c, showing a higher than previous measurements. The dependence of the mean K{sub S}{sup 0}({lambda}{sup 0}) p{sub T} on the charged particle multiplicity for the three samples shows a behavior analogous to that of charged primary tracks.
TL;DR: In this paper, a search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb{sup -1} of pp collision data at {radical}(s)=1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron.
Abstract: A search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb{sup -1} of pp collision data at {radical}(s)=1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron. Limits on {sigma}(pp{yields}X)BR(X{yields}ll) are presented as a function of dilepton invariant mass m{sub ll}>150 GeV/c{sup 2}, for different spin hypotheses (0, 1, or 2). The limits are approximately 25 fb for m{sub ll}>600 GeV/c{sup 2}. Lower mass bounds for X from representative models beyond the standard model including heavy neutral gauge bosons are presented.
TL;DR: In this article, the authors report on a search for B⁰s → μ+ μ- and Bµd → mu+mu- decays in p anti-p collisions at √s = 1.96 TeV using 364.4 pb -1 of data collected by the CDF II dectector at Fermilab Tevatron Collider.
Abstract: We report on a search for B⁰s → μ+ μ- and B⁰d → mu+mu- decays in p anti-p collisions at √s = 1.96 TeV using 364.4 pb -1 of data collected by the CDF II dectector at Fermilab Tevatron Collider. After applying all selection requirements, we observe no candidates inside the B⁰s or B⁰d mass windows. The resulting upper limits on the branching fractions are β(B⁰s → μ+μ-) < 1.5 x 10-7 and β(B⁰d → μ+μ-) < 3.9 x 10-8 at 90 % confidence level. (auth)
TL;DR: In this article, the azimuthal angular correlation of b{bar b} production was measured using 86.5 pb{sup -1} of data collected by Collider Detector at Fermilab (CDF) in p{bar p} collisions at {radical}s = 1.8 TeV during 1994-1995.
Abstract: The authors have measured the azimuthal angular correlation of b{bar b} production, using 86.5 pb{sup -1} of data collected by Collider Detector at Fermilab (CDF) in p{bar p} collisions at {radical}s = 1.8 TeV during 1994-1995. In high-energy p{bar p} collisions, such as at the Tevatron, b{bar b} production can be schematically categorized into three mechanisms. The leading-order (LO) process is ''flavor creation'', where both b and {bar b} quarks substantially participate in the hard scattering and result in a distinct back-to-back signal in final state. The ''flavor excitation'' and the ''gluon splitting'' processes, which appear at next-leading-order (NLO), are known to make a comparable contribution to total b{bar b} cross section, while providing very different opening angle distributions from the LO process. An azimuthal opening angle between bottom and anti-bottom, {Delta}{phi}, has been used for the correlation measurement to probe the interaction creating b{bar b} pairs. The {Delta}{phi} distribution has been obtained from two different methods. one method measures the {Delta}{phi} between bottom hadrons using events with two reconstructed secondary vertex tags. The other method uses b{bar b} {yields} (J/{psi}X)({ell}X') events, where the charged lepton ({ell}) is an electron (e) or a muon ({mu}), to measure {Delta}{phi} between bottommore » quarks. The b{bar b} purity is determined as a function of {Delta}{phi} by fitting the decay length of the J/{psi} and the impact parameter of the {ell}. Both methods quantify the contribution from higher-order production mechanisms by the fraction of the b{bar b} pairs produced in the same azimuthal hemisphere, f{sub toward}. The measured f{sub toward} values are consistent with both parton shower Monte Carlo and NLO QCD predictions.« less
TL;DR: In this article, a search for excited and exotic electrons (e*) decaying to an electron and a photon, both with high transverse momentum, was presented, but no signal above standard model expectation is seen for associated ee(*) production.
Abstract: We present a search for excited and exotic electrons (e(*)) decaying to an electron and a photon, both with high transverse momentum. We use 202 pb(-1) of data collected in pp collisions at sqrt[s] = 1.96 TeV with the Collider Detector at Fermilab II detector. No signal above standard model expectation is seen for associated ee(*) production. We discuss the e(*) sensitivity in the parameter space of the excited electron mass M(e(*)) and the compositeness energy scale Lambda. In the contact interaction model, we exclude 132 GeV/c(2)
TL;DR: In this article, a search for pair production of first-generation scalar leptoquarks (LQ) in p (p) over bar collisions at root s=1.96 TeV using an integrated luminosity of 252 pb(-1) collected at the Fermilab Tevatron collider by the D0 detector was conducted.
Abstract: We report on a search for pair production of first-generation scalar leptoquarks (LQ) in p (p) over bar collisions at root s=1.96 TeV using an integrated luminosity of 252 pb(-1) collected at the Fermilab Tevatron collider by the D0 detector. We observe no evidence for LQ production in the topologies arising from LQ(LQ) over bar -> eqeq and LQ(LQ) over bar -> eq nu q, and derive 95% C.L. lower limits on the LQ mass as a function of beta, where beta is the branching fraction for LQ -> eq. The limits are 241 and 218 GeV/c(2) for beta=1 and 0.5, respectively. These results are combined with those obtained by D0 at root s=1.8 TeV, which increases these LQ mass limits to 256 and 234 GeV/c(2).
TL;DR: In this article, the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab were presented.
Abstract: We present the results of a search for anomalous production of diphoton events with large missing transverse energy using the Collider Detector at Fermilab. In 202 pb(-1) of p (p) over bar collisions at s=1.96 TeV we observe no candidate events, with an expected standard model background of 0.27+/-0.07(stat)+/-0.10(syst) events. The results exclude a lightest chargino of mass less than 167 GeV/c(2), and lightest neutralino of mass less than 93 GeV/c(2) at 95% C.L. in a gauge-mediated supersymmetry-breaking model with a light gravitino.
TL;DR: In this article, the authors report on a search for the branching fractions in the CDF II detector at the Fermilab Tevatron Collider and observe no candidates inside the mass windows.
Abstract: We report on a search for ${B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ and ${B}_{d}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ decays in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ using $364\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data collected by the CDF II detector at the Fermilab Tevatron Collider. After applying all selection requirements, we observe no candidates inside the ${B}_{s}^{0}$ or ${B}_{d}^{0}$ mass windows. The resulting upper limits on the branching fractions are $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})l1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}7}$ and $\mathcal{B}({B}_{d}^{0}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})l3.9\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$ at 90% confidence level.
TL;DR: In this paper, the decay rate of the W boson produced from the decay of the top quark in the hypothesis of V+A structure of the tWb vertex is measured from the invariant mass of the b quark from t{yields}Wb and the lepton from W{y yields}l{nu} whose momenta measure the W decay angle and direction of motion, respectively.
Abstract: The polarization of the W boson in t{yields}Wb decay is unambiguously predicted by the standard model of electroweak interactions and is a powerful test of our understanding of the tbW vertex. We measure this polarization from the invariant mass of the b quark from t{yields}Wb and the lepton from W{yields}l{nu} whose momenta measure the W decay angle and direction of motion, respectively. In this paper we present a measurement of the decay rate (f{sub V+A}) 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 nonstandard V+A vertex and set a limit on f{sub V+A} < 0.80 at 95% confidence level. By combining this result with a complementary observable in the same data, we assign a limit on f{sub V+A} < 0.61 at 95% CL. This corresponds to a constraint on the right-handed helicity component of the W polarization of f{sub +}<0.18 at 95% CL. This limit is the first significant direct constraint on f{sub V+A} in top decay.
TL;DR: In this paper, a measurement of the tt production cross section using the CDF II detector at the Fermilab Tevatron is reported, which is consistent with the standard model prediction.
Abstract: We report a measurement of the tt production cross section using the CDF II detector at the Fermilab Tevatron. The data consist of events with an energetic electron or muon, missing transverse energy, and three or more hadronic jets, at least one of which is identified as a b-quark jet by reconstructing a secondary vertex. The background fraction is determined from a fit of the transverse energy of the leading jet. Using 162 ± 10 pb -1 of data, the total cross section is found to be 6.0 ± 1.6(stat.) ± 1.2(syst.) pb, which is consistent with the standard model prediction. © 2005 The American Physical Society.
TL;DR: In this paper, the standard model predictions for W γ and Z γ production were tested using an integrated luminosity of 200 pb -1 of pp collision data collected at the Collider Detector at Fermilab.
Abstract: The standard model predictions for W γ and Z γ production are tested using an integrated luminosity of 200 pb -1 of pp collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the W and Z bosons, and photons with transverse energy E T > 7 GeV that are well separated from leptons. The production cross sections and kinematic distributions for the W γ and Z γ data are compared to SM predictions. © 2005 The American Physical Society.
TL;DR: In this paper, a measurement of the W{sup +}W{sup -} production cross section using 184 pb{sup 1} of pp collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab was presented.
Abstract: We present a measurement of the W{sup +}W{sup -} production cross section using 184 pb{sup -1} of pp collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W{sup +}W{sup -}{yields}l{sup +}{nu}l{sup -}{nu}, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0{sub -0.8}{sup +2.2} events. The resulting W{sup +}W{sup -} production cross-section measurement of {sigma}(pp{yields}W{sup +}W{sup -})=14.6{sub -5.1}{sup +5.8}(stat){sub -3.0}{sup +1.8}(syst){+-}0.9(= lum) pb agrees well with the standard model expectation.
TL;DR: A search for the direct production of Higgs bosons in the di-tau decay mode is performed with 86.3 +/- 3.5 pb(-1) of data collected with the Collider Detector at Fermilab during the 1994-1995 data taking period of the Tevatron.
Abstract: A search for the direct production of Higgs bosons in the di-tau decay mode is performed with 86.3 +/- 3.5 pb(-1) of data collected with the Collider Detector at Fermilab during the 1994-1995 data taking period of the Tevatron. We search for events where one tau decays to an electron plus neutrinos and the other tau decays hadronically. We perform a counting experiment and set limits on the cross section for supersymmetric Higgs boson production where tan beta is large and m(A) is small. For a benchmark parameter space point where m(A)(0)=100 GeV/c(2) and tan beta=50, we limit the production cross section multiplied by the branching ratio to be less than 77.9 pb at the 95% confidence level compared to the theoretically predicted value of 11.0 pb. This is the first search for Higgs bosons decaying to tau pairs at a hadron collider.
TL;DR: In this article, the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, N-q and N-g, produced at the Fermilab Tevatron in p (p) over bar collisions with a center-of-mass energy of 1.8 TeV, was reported.
Abstract: We report the first largely model independent measurement of charged particle multiplicities in quark and gluon jets, N-q and N-g, produced at the Fermilab Tevatron in p (p) over bar collisions with a center-of-mass energy of 1.8 TeV and recorded by the Collider Detector at Fermilab. The measurements are made for jets with average energies of 41 and 53 GeV by counting charged particle tracks in cones with opening angles of theta(c)=0.28, 0.36, and 0.47 rad around the jet axis. The corresponding jet hardness Q=E-jet theta(c) varies in the range from 12 to 25 GeV. At Q=19.2 GeV, the ratio of multiplicities r=N-g/N-q is found to be 1.64 +/- 0.17, where statistical and systematic uncertainties are added in quadrature. The results are in agreement with resummed perturbative QCD calculations.
TL;DR: A new a priori technique is developed designed to isolate the subset in a data sample revealing the largest deviation from standard model (SM) expectations and to quantify the significance of this departure.
Abstract: We report on a search for anomalous kinematics of t (t) over bar dilepton events in p (p) over bar collisions at root s = 1: 96 TeV using 193 pb(-1) of data collected with the CDF II detector. We developed a new a priori technique designed to isolate the subset in a data sample revealing the largest deviation from standard model (SM) expectations and to quantify the significance of this departure. In the four-variable space considered, no particular subset shows a significant discrepancy, and we find that the probability of obtaining a data sample less consistent with the SM than what is observed is 1.0%-4.5%.
TL;DR: In this paper, the standard model predictions for $W\ensuremath{\gamma}$ and $Z\enuremath{-1}$ production are tested using an integrated luminosity of $200\text{ }{\mathrm{p}\mathrm {b}}^{\ensurem{-} 1}$ of collision data collected at the Collider Detector at Fermilab.
Abstract: The standard model predictions for $W\ensuremath{\gamma}$ and $Z\ensuremath{\gamma}$ production are tested using an integrated luminosity of $200\text{ }{\mathrm{p}\mathrm{b}}^{\ensuremath{-}1}$ of $p\overline{p}$ collision data collected at the Collider Detector at Fermilab. The cross sections are measured by selecting leptonic decays of the $W$ and $Z$ bosons, and photons with transverse energy ${E}_{T}g7\text{ }\text{ }\mathrm{G}\mathrm{e}\mathrm{V}$ that are well separated from leptons. The production cross sections and kinematic distributions for the $W\ensuremath{\gamma}$ and $Z\ensuremath{\gamma}$ data are compared to SM predictions.