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 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 Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 680 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 Inclusive D Meson Production with the Mark II Detector at SPEAR 3 9 to 7 4 GeV c M written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutral and charged D meson production cross sections were measured at center-of-mass energies between 3.9 GeV and 7.4 GeV. The quantity R/sub D/(=(sigma/sub D+D−/ + sigma/sub D°+ anti D°/)/2 sigma/sub ..mu ... mu..−/) is equal to 2 at 4 GeV and 4.4 GeV and about equal to 1 elsewhere. R/sub D/ + 2.5 approximately equals R (sigma/sub hadrons//sigma/sub ..mu..+..mu..−/) at all energies. The exclusive cross sections for e+e− annihilation into D anti D, D* anti D, and D* anti D* were measured at center-of-mass energies between 3.9 GeV and 4.3 GeV. sigma/sub D* anti D*/ decreases with increasing center-of-mass energy from 6.6 +- 1.3 nb near 4 GeV to 3.6 +- 9 nb near 4.3 GeV. sigma/sub D* anti D/ also decreases from 4.2 +- 9 nb to 1.8 +- 6 nb over the same energy region. sigma/sub D anti D/ is less than 0.5 +- 3 nb at all energies. The branching fractions for D*/sup +/ and D* decay were measured. B/sub D*°..-->..D°..pi..°/ = 0.5 +- 09, B/sub D*/sup +/..-->..D°..pi../sup +// = 0.44 +- 10, and B/sub D*/sup +/..-->..D/sup +/..pi..°/ = 0.31 +- 07. At 5.2 GeV, the D meson differential cross section is well described by phase space for e/sup +/e− ..-->.. D anti D..pi pi.. or D* anti D*..pi pi ... Sd sigma/dz was parameterized as A(1-z)/sup n/ with n = 0.9 +- 4. Quasi-two-body production accounts for less than 20% of the total D cross section. No evidence was found for associated charmed baryon-D meson production. An upper limit of 0.4 nb (90% confidence level) was determined for associated production. 41 figures, 12 tables.

Download or read book Soviet Journal of Nuclear Physics written by and published by . This book was released on 1992 with total page 640 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of D and D s Production in E E Annihilation at S 1 2 written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements have been made of the production rates of D[sup +] and D[sub s] mesons via the channels D[sup +]-[bar K]*[sup 0] [ell][sup +][nu][sub [ell]] and D[sub s] [yields] [phi][pi] in e[sup +]e[sup -] annihilation at [radical]s = 29 GeV in 220 pb[sup -1] of data collected by the Mark II detector. The measurements assume the current branching ratios, measured predominantly at [radical]s [approx-equal] 10 GeV and by fixed target experiments. Measurements of the total production cross-sections times the appropriate branching ratios, which are independent of any other measurements, and an upper limit for the ratio of branching ratios, [Lambda](D[sub s] [yields] [phi][ell][bar [nu]][sub [ell]])/[Lambda](D[sub s] [yields] [phi][pi])

Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1146 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 1983 with total page 1290 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Measurement of the Total Cross Section for Hadronic Production by Ee Annihilation at Energies Between 2 5 GeV written by Derrick Kong and published by . This book was released on 2000 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reflections on Experimental Science written by Martin L. Perl and published by World Scientific. This book was released on 1996 with total page 551 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a collection of important lecture and original articles and commentaries by Martin Perl, discoverer of the tau lepton and the third generation of elementary particles, and this year''s Nobel Prize winner. This book contains a fascinating and realistic picture of experimental science based on the high energy physics research work carried out by him. Using reprints of his articles with his commentaries, the author presents the various aspects of experimental research in science: the pleasures and risks of experimental work; the pain and frustration with experiments that are useless or fail; the dreaming about experiments that were not carried out; the constant search for innovation and creativity in the work; and the special joy of discovery. The articles and commentaries range from the early days of bubble chambers and spark chambers in the 1950''s to the author''s present research, experiments at an electron-positron collider and a search for free quarks. The book is for the general reader as well as the scientist.

Download or read book Strange Meson Production in Ee Annihilation at 29 0 GeV written by Steven Oscar Melnikoff and published by . This book was released on 1985 with total page 244 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 Meson Production Interaction And Decay Proceedings Of The Workshop written by Andrzej Magiera and published by World Scientific. This book was released on 1991-10-31 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This workshop proceedings presents interesting lectures on the theoretical and experimental problems which may be studied using the new GeV accelerators. It provides a discussion of ongoing and planned experiments on the CELCIUS, COSY, LEAR, SATURNE and SIS accelerators as well as general descriptions of the experimental techniques applied in these experiments. There is special focus on the meson production mechanism in various reactions, meson spectroscopy and meson decay modes.

Download or read book Measurements of Total Hadronic and Inclusive D star Cross Sections in Electron Positron Annihilation Between 3 87 and 4 5 Giga electron Volts written by Albert Laighton Osterheld and published by . This book was released on 1986 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2001 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book D and D Meson Production in Ee Annihilation at 29 GeV written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent results on D* and D meson production at 29 GeV are presented from the DELCO, HRS, and MARK II collaborations at PEP.