A comparison of neutral and charged current deep inelastic neutrino interactions is made in an ex... more A comparison of neutral and charged current deep inelastic neutrino interactions is made in an experiment utilizing the Fermilab 15 ft. bubble chamber. The ratio of neutral current events (NC) to charged current events (CC)'is 0.35 ± .06 when the visible hadronic energy • is greater than 10 GeV. The distributions of NC and CC in a new variable called us. which depends only on the observed hadrons, are given. From these distributions and the assumption that the x distribution is the same for NC and CC, it is concluded that for a ' NC y distribution of the form (l-'j ^ 3n(l-y) Z , n = .12 + .32. The ratio p NC (p cc)of neutron to proton cross sections in NC (CC) is studied and the quotient p Nr /p rr = °-7 *-0-2. The distribution of hadroiv, in z. , the scaled hadronic momentum, is given. The CC hadrons fit the predictions of the quark fragmentation functions D" (Z) and D" (Z) as given by Field and Feynman. The neutral current events fit the form • (1-A) D* (z) + .X D* (z) for positives and (1-X) D*(z) + X D] (Z) for • negatives with X = 0.56 ± 0.10 and a fit confidence level of K. :
A measurement is presented of the cross section for the production of a W boson with one or two j... more A measurement is presented of the cross section for the production of a W boson with one or two jets, of which at least one must be a b-jet, in pp collisions at √ s = 7 TeV. Production via top decay is not included in the signal definition. The measurement is based on 35 pb −1 of data collected with the ATLAS detector at the LHC. The W + b-jet cross section is defined for jets reconstructed with the antik t clustering algorithm with transverse momentum above 25 GeV and rapidity within ±2.1. The b-jets are identified by reconstructing secondary vertices. The fiducial cross section is measured both for the electron and muon decay channel of the W boson and is found to be 10.2 ± 1.9(stat) ± 2.6(syst) pb for one lepton flavour. The results are compared with next-to-leading order QCD calculations, which predict a cross section smaller than, though consistent with, the measured value.
We have observed bottom-charm mesons B c via the decay mode B ± c → J/ψ ℓ ± ν in 1.8 TeV pp colli... more We have observed bottom-charm mesons B c via the decay mode B ± c → J/ψ ℓ ± ν in 1.8 TeV pp collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/ψ ℓ mass distribution yielded 20.4 +6.2 −5.5 events from B c mesons. A fit to the same distribution with background alone was rejected at the level of 4.8 standard
We present a search for like-sign dielectron plus multijet events using 107 pb −1 of data in pp c... more We present a search for like-sign dielectron plus multijet events using 107 pb −1 of data in pp collisions at √ s = 1.8 TeV collected in 1992-95 by the CDF experiment. Finding no events that pass our selection, we set σ • Br limits on two SUSY processes that can produce this experimental signature: gluino-gluino or squark-antisquark production with R-parity violating decays of the charm squark or lightest neutralino via a non-zero λ ′ 121 coupling. We compare our results to NLO calculations for gluino and squark production cross sections and set lower limits on M (g), M (t 1), and M (q).
We present a measurement of the top quark mass using a sample of tt decays into an electron or a ... more We present a measurement of the top quark mass using a sample of tt decays into an electron or a muon, a neutrino, and four jets. The data were collected in pp collisions at √ s = 1.8 TeV with the Collider Detector at Fermilab and correspond to an integrated luminosity of 109 pb −1. We measure the top quark mass to be 175.9 ± 4.8(stat.) ± 4.9(syst.) GeV/c 2 .
We observe hadronic W decays in tt → W (→ ℓν) + ≥ 4 jet events using a 109 pb −1 data sample of p... more We observe hadronic W decays in tt → W (→ ℓν) + ≥ 4 jet events using a 109 pb −1 data sample of pp collisions at √ s = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). A peak in the dijet invariant mass distribution is obtained that is consistent with W decay and inconsistent with the background prediction by 3.3σ. From this peak we measure the W mass to be 77.2 ± 4.6 (stat+syst) GeV/c 2. This result demonstrates the presence of two W bosons in tt candidates in the W (→ ℓν)+ ≥ 4 jet channel.
We present a search for the associated production of charginos and neutralinos in pp collisions a... more We present a search for the associated production of charginos and neutralinos in pp collisions at √ s = 1.96 TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0 fb −1. We look for final states with one high-pT electron or muon, and two additional leptons. Our results are consistent with the standard model expectations, and we set limits on the cross section as a function of the chargino mass in three different supersymmetric scenarios. For a specific MSSM scenario with no slepton mixing we set a 95% C.L. limit at 151 GeV/c 2 .
We report on measurements of differential µ − b cross sections, where the muon is from a semi-lep... more We report on measurements of differential µ − b cross sections, where the muon is from a semi-leptonic b decay and the b is identified using precision track reconstruction in jets.
We report the observation of bottom-charmed mesons B c in 1.8 TeV pp collisions using the CDF det... more We report the observation of bottom-charmed mesons B c in 1.8 TeV pp collisions using the CDF detector at the Fermilab Tevatron. The B c mesons were found through their semileptonic decays, B c Ϯ →J/l Ϯ X. A fit to the J/l mass distribution yielded 20.4 Ϫ5.5 ϩ6.2 events from B c mesons. A test of the null hypothesis, i.e., an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed B c mass, we determined M (B c)ϭ6.40 Ϯ0.39 ͑stat.͒Ϯ0.13 ͑syst͒ GeV/c 2. From the distribution of trilepton intersection points in the plane transverse to the beam direction we measured the B c lifetime to be (B c)ϭ0.46 Ϫ0.16 ϩ0.18 ͑stat͒Ϯ0.03 ͑syst͒ ps. We also measured the ratio of production cross section times branching fraction for B c ϩ →J/l ϩ relative to that for B ϩ →J/K ϩ to be ͑B c ͒ϫB͑B c →J/l͒ ͑B͒ϫB͑B→J/K͒ ϭ0.132 Ϫ0.037 ϩ0.041 ͑stat͒Ϯ0.031 ͑syst͒ Ϫ0.020 ϩ0.032 ͑lifetime͒.
We present a measurement of the W boson mass using data collected by the DØ experiment at the Fer... more We present a measurement of the W boson mass using data collected by the DØ experiment at the Fermilab Tevatron during 1994-1995. We identify W bosons by their decays to eν final states. We extract the W mass, MW , by fitting the transverse mass and transverse electron momentum spectra from a sample of 28,323 W → eν decay candidates. We use a sample of 3,563 dielectron events, mostly due to Z → ee decays, to constrain our model of the detector response. From the transverse mass fit we measure MW = 80.44 ± 0.10(stat) ± 0.07(syst) GeV. Combining this with our previously published result from data taken in 1992-1993, we obtain MW = 80.43 ± 0.11 GeV.
A comparison of neutral and charged current deep inelastic neutrino interactions is made in an ex... more A comparison of neutral and charged current deep inelastic neutrino interactions is made in an experiment utilizing the Fermilab 15 ft. bubble chamber. The ratio of neutral current events (NC) to charged current events (CC)'is 0.35 ± .06 when the visible hadronic energy • is greater than 10 GeV. The distributions of NC and CC in a new variable called us. which depends only on the observed hadrons, are given. From these distributions and the assumption that the x distribution is the same for NC and CC, it is concluded that for a ' NC y distribution of the form (l-'j ^ 3n(l-y) Z , n = .12 + .32. The ratio p NC (p cc)of neutron to proton cross sections in NC (CC) is studied and the quotient p Nr /p rr = °-7 *-0-2. The distribution of hadroiv, in z. , the scaled hadronic momentum, is given. The CC hadrons fit the predictions of the quark fragmentation functions D" (Z) and D" (Z) as given by Field and Feynman. The neutral current events fit the form • (1-A) D* (z) + .X D* (z) for positives and (1-X) D*(z) + X D] (Z) for • negatives with X = 0.56 ± 0.10 and a fit confidence level of K. :
A measurement is presented of the cross section for the production of a W boson with one or two j... more A measurement is presented of the cross section for the production of a W boson with one or two jets, of which at least one must be a b-jet, in pp collisions at √ s = 7 TeV. Production via top decay is not included in the signal definition. The measurement is based on 35 pb −1 of data collected with the ATLAS detector at the LHC. The W + b-jet cross section is defined for jets reconstructed with the antik t clustering algorithm with transverse momentum above 25 GeV and rapidity within ±2.1. The b-jets are identified by reconstructing secondary vertices. The fiducial cross section is measured both for the electron and muon decay channel of the W boson and is found to be 10.2 ± 1.9(stat) ± 2.6(syst) pb for one lepton flavour. The results are compared with next-to-leading order QCD calculations, which predict a cross section smaller than, though consistent with, the measured value.
We have observed bottom-charm mesons B c via the decay mode B ± c → J/ψ ℓ ± ν in 1.8 TeV pp colli... more We have observed bottom-charm mesons B c via the decay mode B ± c → J/ψ ℓ ± ν in 1.8 TeV pp collisions using the CDF detector at the Fermilab Tevatron. A fit of background and signal contributions to the J/ψ ℓ mass distribution yielded 20.4 +6.2 −5.5 events from B c mesons. A fit to the same distribution with background alone was rejected at the level of 4.8 standard
We present a search for like-sign dielectron plus multijet events using 107 pb −1 of data in pp c... more We present a search for like-sign dielectron plus multijet events using 107 pb −1 of data in pp collisions at √ s = 1.8 TeV collected in 1992-95 by the CDF experiment. Finding no events that pass our selection, we set σ • Br limits on two SUSY processes that can produce this experimental signature: gluino-gluino or squark-antisquark production with R-parity violating decays of the charm squark or lightest neutralino via a non-zero λ ′ 121 coupling. We compare our results to NLO calculations for gluino and squark production cross sections and set lower limits on M (g), M (t 1), and M (q).
We present a measurement of the top quark mass using a sample of tt decays into an electron or a ... more We present a measurement of the top quark mass using a sample of tt decays into an electron or a muon, a neutrino, and four jets. The data were collected in pp collisions at √ s = 1.8 TeV with the Collider Detector at Fermilab and correspond to an integrated luminosity of 109 pb −1. We measure the top quark mass to be 175.9 ± 4.8(stat.) ± 4.9(syst.) GeV/c 2 .
We observe hadronic W decays in tt → W (→ ℓν) + ≥ 4 jet events using a 109 pb −1 data sample of p... more We observe hadronic W decays in tt → W (→ ℓν) + ≥ 4 jet events using a 109 pb −1 data sample of pp collisions at √ s = 1.8 TeV collected with the Collider Detector at Fermilab (CDF). A peak in the dijet invariant mass distribution is obtained that is consistent with W decay and inconsistent with the background prediction by 3.3σ. From this peak we measure the W mass to be 77.2 ± 4.6 (stat+syst) GeV/c 2. This result demonstrates the presence of two W bosons in tt candidates in the W (→ ℓν)+ ≥ 4 jet channel.
We present a search for the associated production of charginos and neutralinos in pp collisions a... more We present a search for the associated production of charginos and neutralinos in pp collisions at √ s = 1.96 TeV. The data were collected at the Collider Detector at Fermilab (CDF II) and correspond to integrated luminosities between 0.7 and 1.0 fb −1. We look for final states with one high-pT electron or muon, and two additional leptons. Our results are consistent with the standard model expectations, and we set limits on the cross section as a function of the chargino mass in three different supersymmetric scenarios. For a specific MSSM scenario with no slepton mixing we set a 95% C.L. limit at 151 GeV/c 2 .
We report on measurements of differential µ − b cross sections, where the muon is from a semi-lep... more We report on measurements of differential µ − b cross sections, where the muon is from a semi-leptonic b decay and the b is identified using precision track reconstruction in jets.
We report the observation of bottom-charmed mesons B c in 1.8 TeV pp collisions using the CDF det... more We report the observation of bottom-charmed mesons B c in 1.8 TeV pp collisions using the CDF detector at the Fermilab Tevatron. The B c mesons were found through their semileptonic decays, B c Ϯ →J/l Ϯ X. A fit to the J/l mass distribution yielded 20.4 Ϫ5.5 ϩ6.2 events from B c mesons. A test of the null hypothesis, i.e., an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed B c mass, we determined M (B c)ϭ6.40 Ϯ0.39 ͑stat.͒Ϯ0.13 ͑syst͒ GeV/c 2. From the distribution of trilepton intersection points in the plane transverse to the beam direction we measured the B c lifetime to be (B c)ϭ0.46 Ϫ0.16 ϩ0.18 ͑stat͒Ϯ0.03 ͑syst͒ ps. We also measured the ratio of production cross section times branching fraction for B c ϩ →J/l ϩ relative to that for B ϩ →J/K ϩ to be ͑B c ͒ϫB͑B c →J/l͒ ͑B͒ϫB͑B→J/K͒ ϭ0.132 Ϫ0.037 ϩ0.041 ͑stat͒Ϯ0.031 ͑syst͒ Ϫ0.020 ϩ0.032 ͑lifetime͒.
We present a measurement of the W boson mass using data collected by the DØ experiment at the Fer... more We present a measurement of the W boson mass using data collected by the DØ experiment at the Fermilab Tevatron during 1994-1995. We identify W bosons by their decays to eν final states. We extract the W mass, MW , by fitting the transverse mass and transverse electron momentum spectra from a sample of 28,323 W → eν decay candidates. We use a sample of 3,563 dielectron events, mostly due to Z → ee decays, to constrain our model of the detector response. From the transverse mass fit we measure MW = 80.44 ± 0.10(stat) ± 0.07(syst) GeV. Combining this with our previously published result from data taken in 1992-1993, we obtain MW = 80.43 ± 0.11 GeV.
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Papers by John Marriner