Download or read book Charmed Meson Production by Ee Annihilation Branching Ratios Angular Distributions written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Compelling evidence is presented for the production of the lying (D°, D) isodoublet of charmed mesons by ee− annihilation. A study of the recoil mass spectra against these mesons reveals the presence of more massive charmed states, the D*° and D*+, produced in association with the D isodoublet. Mass values and upper limits on the width of the D and D* are established, and the branching fractions for several D* decay modes are obtained. An analysis of the production and decay angular distributions shows that the D is probably a pseudoscalar state and the D* is probably a vector. Finally, upper limits are obtained for D°-antiD° mixing.

Download or read book D Meson Production in E e Annihilation written by Petros-Afentoulis Rapidis and published by . This book was released on 1979 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book D Meson Production in Ee Annihilation 3 7 to 7 0 GeV Total Cross Section Branching Ratio written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The production of D mesons in ee− annihilation for the center-of-mass energy range 3.7 to 7.0 GeV was studied with the MARK I magnetic detector at SPEAR. A resonance was observed in the total cross section for hadron production in ee− annihilation at an energy just above the threshold for charm production. This resonance, which is named psi'', has a mass of 3772 +- 6 MeV/c2, a total width of 28 +- 5 MeV/c2, a partial width to electron pairs of 345 +- 85 eV/c2, and decays almost exclusively into D anti D pairs. The psi'' provides a rich source of background-free and kinematically well defined D mesons for study. From produced in the decay of the psi'' the masses of the D° and D/sup +/ mesons were determined to be 1863.3 +- 0.9 MeV/c2 and 1868.3 +- 0.9 MeV/c2 respectively. Also the branching fractions for D° decay to K−.pi./sup +/, anti K°.pi./sup +/.pi.− and K−.pi./sup +/.pi.−.pi./sup +/ were determined to be (2.2 +- 0.6)%, (4.0 +- 1.3)%, and (3.2 +- 1.1)% and the branching fractions for D/sup +/ decay to anti K°.pi./sup +/ and K−.pi./sup +/.pi./sup +/ to be (1.5 +- 0.60)% and (3.9 +- 1.0)%. The average number of kaons per D decay was found to be 0.52 +- 0.14 K°'s and 0.42 +- 0.12 K/sup +/'s. The rate for inclusive production of D mesons at center-of-mass energies above the psi'' was measured; it is found that it can account for most, if not all, of the observed increase in the total hadronic cross-section for center-of-mass energies above 4 GeV. The inclusive momentum and energy spectra for D's were measured at the highest available center-of-mass energy (7 GeV). The energy spectra are rapidly decreasing functions of energy with a slope similar to the slope of the charged pion spectrum at the same center-of-mass energy. This behavior suggests that the fragmentation function of the charmed quark into charmed mesons is a decreasing function of the scaling variable z = 2E/sub D//E/sub CM/. 81 references.

Download or read book Charmed Meson Production and Decay Properties at the psi 3770 written by Rafe Schindler and published by . This book was released on 1979 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 1684 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Case for Charmed Meson Production in Ee Annihilation at Spear written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence is presented that a new particle, a narrow resonance of mass 1865 MeV/c2, and its associated excited state can be identified with the (D°, D/sup +/) and (D*°, D*/sup +/) doublets of charm theory. The D production in e−e/sup +/ annihilation and various properties of the decay modes are considered. 54 references. (JFP).

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 658 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book INIS Atomindex written by and published by . This book was released on 1984 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976-05 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charmed Meson Production and Decay Properties at the Psi 3770 written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A remeasurement of the resonance near E/sub cm/ = 3.77 GeV in the ee− annihilation is presented. The properties of the resonance are used to deduce branching fractions of charmed mesons into hadronic final states. Several previously unseen decay modes are reported. Decays into Cabibbo suppressed final states are observed. The inclusive properties of D meson decays are studied, including strangeness and charged particle multiplicity. The semileptonic branching fractions for D° and D/sup -+/ are measured, providing a determination of the relative lifetimes of these particles.

Download or read book Charmed Meson Production by Ee Annihilation written by James Ernest Wiss and published by . This book was released on 1977 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration. Technical Information Center and published by . This book was released on 1977 with total page 1680 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Energy Physics Index written by and published by . This book was released on 1993 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charmed Meson Production and Decay written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Charmed meson production through two body processes in ee− annihilation is discussed. Evidence for states of charm excitation beyond the D* is obtained through an analysis of the recoil spectrum against D's produced at Ecm = 4.415 GeV. Direct observation of the reaction D* .-->. .pi.+D° in SPEAR data taken at Ecm exceeding 5 GeV is discussed. This reaction provides an extremely accurate determination of the D*+, D° mass difference (M/sub D*/sup +// -- M/sub D°/ = 145.3 +- 0.5 MeV/c2) and a new upper limit on D° -- anti D° mixing effects. The results of fits to the D°, D/sup +/ recoil spectrum are discussed. These fits provide considerable information on the masses, production mechanisms, and decays of charmed mesons. This is followed by a brief presentation of the known cross sections for charmed meson production and decay and an analysis of possible resonant structure in the decay products of the D° and D/sup +/. Lastly, a bubble chamber D° candidate submitted by Hagopian et al., of Florida State University is discussed.

Download or read book D Meson Production in Ee Annihilation written by Petros-Afentoulis Rapidis and published by . This book was released on 1979 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Charmed Mesons Produced in E e Annihilation written by and published by . This book was released on 1980 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: We shall begin our review by summarizing the first experimental indications for the existence of charm as obtained from experiments in e+e− annihilation. This will include a brief discussion of the role of charm in the understanding of the ? mesons, as well as the unraveling of the intricate structure present in the e+ e− total hadronic cross section. Next we shall discuss the discovery of the D°, and D+, and detail those properties crucial to their identification as charmed particles. Following will be a review of the properties of the D° and D+ learned through studies at the ?(3770) resonance, Compelling evidence will be summarized indicating that this state decays nearly exclusively into D{bar D}, thus making it particularly useful in establishing inclusive and exclusive D branching fractions. Our discussion of branching fractions will include two particularly important D decay modes, D°→?+?− and D°→K+−. These processes are suppressed relative to D°→K−?+ in the standard charm model, and thus serve as a critical test of that theory. This will be followed by a discussion of the D semileptonic decay modes which provide useful information on the D° and D+ lifetimes. Turning our attention to the data collected beyond the ?(3770) we will discuss the properties and production mechanisms of the excited charm mesons, the D*° and the D*+. D production just above the ?(3770) appears to be dominated by the three quasi-two-body processes e+ e− → D{bar D}, D*{bar D} + {bar D}*D, and D*{bar D}*, in accordance with early theoretical predictions. The relative amounts of each process, on the other hand, is somewhat surprising, and has led to considerable theoretical speculation. Finally, we will summarize evidence for the existence of the F meson which is as yet not on as solid a footing as the D°, D+ isodoublet.