CORE
COnnecting
REpositories

    2,126 research outputs found

    Observation of diffractive J/psi production at the Fermilab Tevatron

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    We report the first observation of diffractive J/psi(--> mu (+)mu (-)) production in collisions at roots = 1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum p(T)(mu) > 2 GeV/c within the pseudorapidity region \ eta \ production rates is found to be R-J/psi = [1.45 +/- 0.25]%. ne ratio R-J/psi(X) is presented as a function of x-Bjorken. By combining it with our previously measured corresponding ratio R-jj(x) for diffractive dijet production, we extract a value of 0.59 +/- 0.15 for the gluon fraction of the diffractive structure function of the proton
    Università degli Studi del Molise: IRIS
    Crossref
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio istituzionale della ricerca - Università degli Studi di Udine
    Archivio Istituzionale della Ricerca - Università degli Studi di Pavia
    UCL Discovery
    OAKTrust Digital Repository (Texas A&M Univ)
    Oxford University Research Archive
    Archivio istituzionale della ricerca - Università di Padova
    Archive ouverte UNIGE

    Reconstruction of B-0->J/psi K-S(0) and measurement of ratios of branching ratios involving B->J/psi K* and B+->J/psi K+

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    We report on the reconstruction of the decay mode B-0 --> J/psi K-S(0) using 19.3 pb(-1) of data collected by the Collider Detector at Fermilab in collisions at root s = 1.8 TeV. A signal of 41.8 +/- 6.9 events, with a signal-to-background ratio of 9:1, is observed. Three additional decay modes B+ --> J/psi K+, B-0 --> J/psi K*(892)(0), and B+ --> J/psi K*(892)(+) are reconstructed. We measure three ratios of branching ratios, each one relative to the B+ --> J/psi K+ mode. We also report the ratio of decay rates, Gamma(B --> J/psi K*)/Gamma(B --> J/psi K), for the vector-vector relative to the vector-pseudoscalar modes, to be 1.32 +/- 0.23(stat) +/- 0.16(syst)
    Università degli Studi del Molise: IRIS
    Crossref
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio della Ricerca - Università di Pisa
    Archivio istituzionale della ricerca - Università di Genova
    Archivio istituzionale della ricerca - Università di Padova

    Measurement of the branching fraction B(Bu+→J/ψπ+) and search for Bc+→J/ψπ+

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    We report on a measured of the branching fraction of the Cabibbo-suppressed decay B-u(+)-->J/psi pi(+), where J/psi-->mu(+)mu(-). The data were collected by the Collider Detector at Fermilab during 1992-1995 and correspond to an integrated luminosity of 110 pb(-1) in (p) over tildep$ collisions at root s=1.8 TeV. A signal of 28(-9)(+10) events is observed and we demonstrate the ratio of branching fractions B(B-u(+)-->J/psi pi)/B(B-u(+)-->J/psi K+) to be [5.0(-1.7)(+1.9) (stat)+/-0.1(syst)]%. Using the world average value for B(B-u(+)-->J/psi K+), we calculate the branching fraction B(B-u(+)-->J/psi pi(+)) to be (5.0(-1.9)(+2.1))x10(-5). We also search for the decay B-c(+)-->J/psi pi(+) and report a 95% confidence level limit on sigma(B-c(+))B(B-c(+)-->J/psi pi(+)/sigma(B-u(+))B(B-u(+)-->J/psi K+) as a function of the B-c(+) lifetime
    Università degli Studi del Molise: IRIS
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio istituzionale della ricerca - Università degli Studi di Udine
    Archivio Istituzionale della Ricerca - Università degli Studi di Pavia
    Archivio della Ricerca - Università di Pisa
    Archivio istituzionale della ricerca - Università di Genova
    Archivio istituzionale della ricerca - Università di Padova

    MEASUREMENT OF THE POLARIZATION IN THE DECAYS B-D-]J/PSI-K-(ASTERISK-0) AND BS-]J/PSI-PHI

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    This Letter reports on measurements of the longitudinal polarization fractions in the decays B-d --> J/psi K*(0) and B-s --> J/psi phi using data collected with the Collider Detector at Fermilab. B-d mesons are reconstructed through the decay chain B-d --> J/psi K*(0), J/psi --> mu(+)mu(-), K*(0) --> K(+)phi(-). A sample of 65 +/- 10 B-d events is used to obtain a longitudinal polarization fraction of T-L/Gamma = 0.65 +/- 0.10(stat) +/- 0.04(syst). B-s mesons are reconstructed through the decay chain B-s --> J/psi phi, J/psi --> mu(+)mu(-), phi --> K+K-. A sample of 19 +/- 5 B-s events is used to obtain the result Gamma(L)/Gamma = 0.56 +/- 0.21(stat)-(+0.02)(0.04)(syst)
    Università degli Studi del Molise: IRIS
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio della Ricerca - Università di Pisa
    Oxford University Research Archive
    Archivio istituzionale della ricerca - Università di Genova
    Archivio istituzionale della ricerca - Università di Padova

    Study of Bc+→J/ψDs+ and Bc+→J/ψDs∗+ decays in pp collisions at √s = 13 TeV with the ATLAS detector

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    A study of Bc+→J/ψDs+ and Bc+→J/ψDs∗+ decays using 139 fb−1 of integrated luminosity collected with the ATLAS detector from s = 13 TeV pp collisions at the LHC is presented. The ratios of the branching fractions of the two decays to the branching fraction of the Bc+→ J/ψπ+ decay are measured: B(Bc+→J/ψDs+)/B(Bc+→J/ψπ+) = 2.76 ± 0.47 and B(Bc+→J/ψDs∗+)/B(Bc+→J/ψπ+) = 5.33 ± 0.96. The ratio of the branching fractions of the two decays is found to be B(Bc+→J/ψDs∗+)/B(Bc+→J/ψDs∗+) = 1.93 ± 0.26. For the Bc+→J/ψDs∗+ decay, the transverse polarization fraction, Γ±±/Γ, is measured to be 0.70 ± 0.11. The reported uncertainties include both the statistical and systematic components added in quadrature. The precision of the measurements exceeds that in all previous studies of these decays. These results supersede those obtained in the earlier ATLAS study of the same decays with s = 7 and 8 TeV pp collision data. A comparison with available theoretical predictions for the measured quantities is presented. [Figure not available: see fulltext.]
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio istituzionale della ricerca - Università degli Studi di Udine
    Archivio della Ricerca - Università di Pisa
    Archivio della Ricerca - Università di Roma 3
    ePubs: the open archive for STFC research publications

    A Remarkable Orbital Apex Mass in a Young Man

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    Stiff neck, DiplopiaA 29-year old male with stiff neck and intermittent diplopia.VA: 20/20 OUCTCellular mass composed of oval, spindle-shaped polyhedral cells containing acidophilic cytoplasm consistent with malignant granular cell myoblastoma.Corticosteroids; Surgery; XRT1. Al-Sarraf M, Lo\u27Jd AV, Vaitkevioius KV: Malignant granular cell tumor. Arch. Pathol. 91:550-553, 1971. 2. Adaracio SR, Lumsden CE: Light and electron microscopic studies on the granular cell myoblastoma of the tongue. J. Pathol. 97:339-55, 1969. 3. Armin A, Connelly EM, Rowden G: An immunoperoxidase investigation of S-100 protein in granular cell myoblastomas: evidence for Schwann cell derivation. Am. J. Clin. Pathol. 79:37-44, 1983. 4.Azzopardi JG: Histogenesis of the granular cell \u27myoblastoma.\u27 J. Pathol. Bact. 71:85-94, 1956. 5. Bunt AH and Bensinger, RE. Alveolar soft-part sarcoma of the orbit. Ophthalmology 88:1339-1346, 1981. 6. Fishe ER, Wechsler H: Granular cell myoblastoma - misnomer. Cancer 15:936-954, 1962. 7. Garancis JC, Komorowski RA, Kuzma JF: Granular cell myoblastoma. Cancer 25:542-550, 1970. 8. Nakazato Y, Ishizeki J, Takahashi K, Yamaguchi H: Immunohisto-chemical localization of S-100 protein in granular cell myoblastoma. Cancer 49:1624-1628, 1982. 9. Ravich A, Stout AP, and Ravich RA: Malignant granular cell myoblastoma involving the urinary bladder. Ann. Surg. 121:361-372, 1945. 10. Sobel HJ, Schwarz R, Marquet E: Light and electron-microscope study of the origin of granular-cell myoblastoma. J. Pathol. 109: 101-111, 1973. 11. Sobel HJ, Marquet E and Schwartz R: Is schwannoma related to granular cell myoblastoma? Arch. Pathol. 95:396-401, 1973. 12. Stefansson K, Wollmann RL: S-100 protein in granular cell tumors (granular cell myoblastomas). Cancer 49:1834-1838, 1982. 13. Von Bahr G: A case of myoblastic myoma of the lacrimal sac. Acta Ophthalmol. 16:109, 1938
    The University of Utah: J. Willard Marriott Digital Library

    Ratios of bottom meson branching fractions involving J/psi mesons and determination of b quark fragmentation fractions

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    We report a measurement of the ratios of the decay rates of the B+, B0, and Bs 0 mesons into exclusive final states containing a J/ψ meson. The final states were selected from 19.6 pb-1 of pp̄ collisions recorded by the Collider Detector at Fermilab. These data are interpreted to determine the b quark fragmentation fractions fu, fd, and fs. We also determine the branching fractions for the decay modes B+ → J/ψK+, B+ → J/ψK*(892)+, B0 → J/ψK0, B0 → J/ψK*(892)0, and Bs 0 → J/ψφ(1020). We discuss the implications of these measurements to B meson decay models. © 1996 The American Physical Society
    Università degli Studi del Molise: IRIS
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio istituzionale della ricerca - Università degli Studi di Udine
    Archivio Istituzionale della Ricerca - Università degli Studi di Pavia
    Archivio della Ricerca - Università di Pisa
    Oxford University Research Archive
    Archivio istituzionale della ricerca - Università di Genova
    Archivio istituzionale della ricerca - Università di Padova

    INCLUSIVE J/OMEGA, OMEGA(2S), AND B-QUARK PRODUCTION IN (P)OVER-BAR-P COLLISIONS AT ROOT-S = 1.8 TEV

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    Inclusive J/psi and psi(2S) production has been studied in ppBAR collisions at square-root s = 1.8 TeV using 2.6+/-0.2 pb-1 of data taken with the Collider Detector at Fermilab. The products of production cross section times branching fraction were measured as functions of P(T) for J/psi --> mu+mu- and psi(2S) --> mu+mu-. In the kinematic range P(T)>6 GeV/c and Absolute value of eta less-than-or-equal-to 0.5 we get sigma(ppBAR --> J/psiX)B(J/psi --> mu+mu-) = 6.88+/-0.23(stat)-1.08(+0.93)(syst) nb, and sigma(ppBAR --> psi(2S)X)B(psi(2S) --> mu+mu-) = 0.232+/-0.251(stat)-0.032(+0.029)(syst) nb. From these values we calculate the inclusive b-quark production cross section
    Crossref
    Archivio della Ricerca - Università degli Studi di Siena
    Oxford University Research Archive
    Archivio istituzionale della ricerca - Università di Padova

    Measurement of the Beta-meson and B-quark Cross-sections At Root-s = 1.8 Tev Using the Exclusive Decay Beta+/--]j/psi-kappa+/-

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    This Letter reports the full reconstruction of B mesons through the decay chain B +/- --> J/psi-K +/-, J/psi --> mu+-mu-, using data obtained at thc Collider Detector at Fermilab in ppBAR collisions at square-root s = 1.8 TeV. This exclusive sample, the first observed at a hadron collider, is then used to measure the B-meson cross section, from which we extract the b-quark cross section. We obtain sigma = 2.8 +/- 0.9(stat) +/- 1.1 (syst) mu-b for B- mesons with P(T) > 9.0 GeV/c and rapidity \y\ 11.5 GeV/c and rapidity \y\ < 1.0
    Archivio della Ricerca - Università degli Studi di Siena
    Archivio istituzionale della ricerca - Università di Padova

    Observation of Lambda(b)(0)-&gt;J/psi Lambda at the Fermilab proton-antiproton collider

    Author
    Publication venue
    Publication date
    Field of study
    No full text
    The decay Lambda(b)(0) --> J/psi Lambda is observed in 110 pb(-1) of p (p) over bar collisions taken at root s = 1.8 TeV. These data are used to measure a Lambda(b)(0) mass of 5621+/-4(stat)+/-3(syst) MeV/c(2), and a mass difference between the Lambda(b)(0) and the B-0 of 340+/-5(stat)+/-1(syst) MeV/c(2). The production cross-section times branching fraction for the decay Lambda(b)(0) --> J/psi Lambda relative to that for the decay B-0 --> J/psi K-S(0) has been measured to be 0.27+/-0.12(stat)+/-0.05(syst)
    Università degli Studi del Molise: IRIS
    Archivio Istituzionale della Ricerca - Università degli Studi di Pavia
    Oxford University Research Archive
    Archivio istituzionale della ricerca - Università di Genova
    Archivio istituzionale della ricerca - Università di Padova
    • …
    corecore