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Featured researches published by S. Sarwar.
Physics Letters B | 1994
P.L. Frabetti; H.W.K. Cheung; Jp Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; William E. Johns; Matthew S. Nehring; J. N. Butler; S. Cihangir; I. Gaines; P. H. Garbincius; L. Garren; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrum; S. Shukla; M. Vittone; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R.W. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini
Abstract Analysis of three D → Kππ Dalitz plots is presented using data collected by the Fermilab high energy photoproduction experiment E687. Our data are fit to a model consisting of a sum of Breit-Wigner amplitudes for the intermediate two-body resonant decay modes and a constant term for the nonresonant contribution. We extract branching fractions and relative phases and compare them to the results obtained in other experiments. Although this model qualitatively reproduces many features of our data, statistically significant discrepancies are observed in some of our fits.
Physics Letters B | 1995
P.L. Frabetti; G. Grim; V.S. Paolone; P. M. Yager; C.W. Bogart; H.W.K. Cheung; S. Culy; J. P. Cumalat; C. Dallapicola; J. F. Ginkel; S. V. Greene; William E. Johns; Matthew S. Nehring; J. N. Butler; S. Cihangir; I. Gaines; P. H. Garbincius; L. Garren; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; H. Mendez; S. Shukla; S. Bianco; F. Fabbri; S. Sarwar; A. Spallone; A. Zallo
Abstract Fermilab high-energy photoproduction experiment E687 provides a high statistics sample of the decay mode D + → K ∗0 μ + ν (charge conjugates are implied). Our analysis yields a branching ratio of Γ (D + → K ∗0 μ + ν) Γ (D + → K − π + π + ) = 0.56±0.04±0.06 . The ratios of the form factors governing the decay are measured to be R ν = 1.74 ±0.27±0.28 and R 2 = 0.78±0.18±0.10, implying a polarization of Γ l Γ t = 1.20±0.13 ±0.13 for the electron decay. Finally, we report new limits on the decay modes D + → K − π + μ + ν (nonresonent) and D + → K ∗0 π 0 μ + ν .
Physics Letters B | 1993
P.L. Frabetti; H. W. K. Cheung; J. P. Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; W. Johns; M. Nehring; J. N. Butler; S. Cihangir; I. Gaines; L. Garren; P. H. Garbincius; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; S. Shukla; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini; B. Caccianiga
Abstract We report evidence of a narrow resonance at a mass of 2705.9 ± 3.3 ± 2.0 MeV/c2 in the final state Ω−π+ and the charge conjugate. The mass and width support the interpretation of a weakly decaying doubly strange charmed baryon, the Ω c 0 . Limits on the relative branching ratios for Ω c 0 →Ω − K − π + π + and Ω c 0 →Ω − π − π + π + are also presented.
Physics Letters B | 1995
P.L. Frabetti; H.W.K. Cheung; J. P. Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; William E. Johns; Matthew S. Nehring; J. N. Butler; S. Cihangir; I. Gaines; P. H. Garbincius; L. Garren; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; S. Shukla; M. Vittone; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R.W. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini
Abstract Amplitude analyses of the D + and D s + → K + K − π + Dalitz plots are presented using data collected by the Fermilab high energy photoproduction experiment E687. Our data are fit to a model consisting of a sum of Breit-Wigner amplitudes for the intermediate two-body resonant decay modes. We extract decay fractions and relative phases. These results are used to infer new branching ratios for D + → K + K − π + inclusive as well as the Φπ + and K ∗ (892) 0 K + channels.
Physics Letters B | 1993
P.L. Frabetti; G. Grim; J. F. Filasetta; T. Handler; A. Spallone; D. Menasce; R. Ruchti; E.J. Mannel; J. Wiss; B. G. Cheon; G. Jaross; C.J. Kennedy; S. Sala; L. Moroni; G. Boca; M. Giammarchi; D. Claes; C.W. Bogart; P. Inzani; J. F. Ginkel; P. Vitulo; J.K. Busenitz; A. Zallo; D.J. Harding; R.J. Mountain; K. Lingel; R. Diaferia; I. Gaines; S. A. Gourlay; N. M. Cason
Abstract Fermilab high-energy photoproduction experiment E687 provides a high statistics sample of the decay mode D + → K ∗0 μ + ν (charge conjugates are implied). Our analysis yields a branching ratio of Γ (D + → K ∗0 μ + ν) Γ (D + → K − π + π + ) = 0.56±0.04±0.06 . The ratios of the form factors governing the decay are measured to be R ν = 1.74 ±0.27±0.28 and R 2 = 0.78±0.18±0.10, implying a polarization of Γ l Γ t = 1.20±0.13 ±0.13 for the electron decay. Finally, we report new limits on the decay modes D + → K − π + μ + ν (nonresonent) and D + → K ∗0 π 0 μ + ν .
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment | 1995
A. Antonelli; Massimo Antonelli; G. Barbiellini; M Barone; S. Bertolucci; S. Bianco; C. Bini; C. Bloise; V. Bolognesi; F. Bossi; P. Campana; F. Cervelli; R. Caloi; M Cordelli; G. De Zorzi; G. Di Cosimo; A. Di Domenico; O. Erriquez; F. Fabbri; A Farilla; A Ferrari; P. Franzini; F. Garufi; P. Gauzzi; E Gero; S Giovannella; R Haydar; M. Incagli; L Keeble; W. Kim
The KLOE detector is designed primarily for the study of direct CP violation in K0 decays. The electromagnetic calorimeter, EmC, is a most demanding element of the detector. Two prototypes of the EmC (one for the barrel and one for the end-cap region) have been built at Frascati and tested at PSI (Switzerland) using beams of electrons, muons and pions of 40 to 290 MeV/c momentum, and at the Frascati LADON facility using photons of 20 to 80 MeV. We observe excellent linearity from 20 to 290 MeV. The energy resolution is σ(E)/E ∼ 4.4% / ”E(GeV) and the time resolution is ∼ 34 ps/”E(GeV). We found little dependence on incidence angle and entry position. We also determined that some πμ identification is possible.
Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment | 1996
A. Antonelli; Massimo Antonelli; G. Barbiellini; M Barone; S. Bertolucci; S. Bianco; C. Bini; C. Bloise; V. Bolognesi; F. Bossi; R. Caloi; P. Campana; F. Cervelli; M Cordelli; G. De Zorzi; G. Di Cosimo; A. Di Domenico; O. Erriquez; F. Fabbri; A Farilla; A Ferrari; P. Franzini; F. Garufi; P. Gauzzi; E Gero; S Giovannella; R Haydar; M. Incagli; L Keeble; W. Kim
Abstract In connection with the design of the electromagnetic calorimeter of the KLOE detector, we have studied the performance of several samples of commercially available plastic scintillating fibers with a particle beam at the CERN PS. Results on light yield, attenuation length and time resolution measurements concerning 2–4.5 m long samples of those fibers are presented.
Physics Letters B | 1993
P.L. Frabetti; H.W.K. Cheung; J. P. Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; William E. Johns; Matthew S. Nehring; J. N. Butler; S. Cihangir; I. Gaines; L. Garren; P. H. Garbincius; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; S. Shukla; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R.W. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini; B. Caccianiga
Abstract We report evidence of a narrow resonance at a mass of 2705.9 ± 3.3 ± 2.0 MeV/c2 in the final state Ω−π+ and the charge conjugate. The mass and width support the interpretation of a weakly decaying doubly strange charmed baryon, the Ω c 0 . Limits on the relative branching ratios for Ω c 0 →Ω − K − π + π + and Ω c 0 →Ω − π − π + π + are also presented.
Physics Letters B | 1995
P.L. Frabetti; H.W.K. Cheung; J. P. Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; William E. Johns; Matthew S. Nehring; J. N. Butler; S. Cihangir; I. Gaines; P. H. Garbincius; L. Garren; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; S. Shukla; M. Vittone; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R.W. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini
Abstract We present the first measurement of the lifetime of the Ω c 0 baryon. The data were collected in the Fermilab high energy photoproduction experiment E687. The measured lifetime is τ = 86−20+27(stat.) ± 28(syst.) fr. Thus the Ω c 0 has one of the shorter lifetimes among the weakly decaying singly charmed baryons.
Physical Review Letters | 1993
P.L. Frabetti; H. W. K. Cheung; J. P. Cumalat; C. Dallapiccola; J. F. Ginkel; S. V. Greene; W. Johns; M. Nehring; J. N. Butler; S. Cihangir; Gaines I I; L. Garren; P. H. Garbincius; S. A. Gourlay; D.J. Harding; P. Kasper; A. Kreymer; P. Lebrun; S. Shukla; S. Bianco; F. Fabbri; S. Sarwar; A. Zallo; R. Culbertson; R. Gardner; R. Greene; J. Wiss; G. Alimonti; G. Bellini; B. Caccianiga
A measurement of the lifetime of the charmed strange baryon [Xi][sub [ital c]][sup 0] is presented. The data were accumulated by the Fermilab high energy photoproduction experiment E687. The measurement has been made using 42[plus minus]10 [Xi][sub [ital c]][sup 0][r arrow][Xi][sup [minus]][pi][sup +] decays. The lifetime of the [Xi][sub [ital c]][sup 0] is measured to be 0.101[sub [minus]0.017][sup +0.025][plus minus]0.005 ps and its mass is measured to be 2462.1[plus minus]3.1[plus minus]1.4 MeV/[ital c][sup 2].