Download or read book Analysis of the P P bar Mass Spectrum in J Psi written by A. W. Thomas and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The near-threshold enhancement in the p p-bar invariant mass spectrum of the reaction J/Psi --> gamma p p-bar, observed in an experiment by the BES Collaboration, is analysed. It is shown, within the Watson-Migdal approach to final state interactions, that the mass dependence of the p p-bar spectrum close to the threshold can be reproduced by the S-wave p p-bar interaction of the Jülich N N-bar model in the isospin I=1 state. Difficulties in the consistent interpretation of the p invariant mass spectrum of the reaction J/Psi --> pi^0 p p-bar, where there are no obvious signs for a final state interaction, are discussed.

Download or read book Analysis of the P P bar Mass Spectrum in J written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The near-threshold enhancement in the p p-bar invariant mass spectrum of the reaction J/Psi --> gamma p p-bar, observed in an experiment by the BES Collaboration, is analysed. It is shown, within the Watson-Migdal approach to final state interactions, that the mass dependence of the p p-bar spectrum close to the threshold can be reproduced by the S-wave p p-bar interaction of the Jülich N N-bar model in the isospin I=1 state. Difficulties in the consistent interpretation of the p invariant mass spectrum of the reaction J/Psi --> pi^0 p p-bar, where there are no obvious signs for a final state interaction, are discussed.

Download or read book Near Threshold Enhancement of the P P bar Mass Spectrum in J Psi Decay written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We investigate the nature of the near-threshold enhancement in the p {bar p} invariant mass spectrum of the reaction J/[Psi] → [gamma] p {bar p} reported recently by the BES Collaboration. Using the Juelich N {bar N} model we show that the mass dependence of the p {bar p} spectrum close to the threshold can be reproduced by the S-wave p {bar p} final state interaction in the isospin I=1 state within the Watson-Migdal approach. However, because of our poor knowledge of the N {bar N} interaction near threshold and of the J/[Psi] → [gamma] p {bar p} reaction mechanism and in view of the controversial situation in the decay J/[Psi] → [pi]° p {bar p}, where no obvious signs of a p {bar p} final state interaction are seen, explanations other than final state interactions cannot be ruled out at the present stage.

Download or read book Observation of a Near Threshold Enhancement in the P anti p Mass Spectrum from Radiative J psi Gamma p anti p Decays written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We observe a narrow enhancement near 2m[sub p] in the invariant mass spectrum of p[bar p] pairs from radiative J/[psi][yields][gamma]p[bar p] decays. No similar structure is seen in J/[psi][yields][pi][sup 0] p[bar p] decays. The results are based on an analysis of a 58 million event sample of J/[psi] decays accumulated with the BESII detector at the Beijing electron-positron collider. The enhancement can be fit with either an S- or P-wave Breit Wigner resonance function. In the case of the S-wave fit, the peak mass is below 2m[sup p] at M= 1859[sub -10][sup+3] (stat)[sub -25][sup+5] (sys) MeV/c[sup 2] and the total width is[Lambda]

Download or read book B Physics Evidence for the Exclusive Decay B c J psi Pi and Measurement of the Mass of the B c Meson written by and published by . This book was released on 2005 with total page 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 1993 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of the Pi pi J psi Mass Spectrum Via Initial State Radiation at BaBar written by and published by . This book was released on 2008 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present an update of the study of the Y(4260) resonance, produced in the process ee− →?{sub ISR}?+?− J/? using initial-state radiation events at the PEP-II e+e− storage rings. This study is based on 454 fb−1 of data recorded with the BABAR detector at a center-of-mass energy in the?(4S) resonance region. From a fit with a single non-relativistic Breit-Wigner shape we obtain updated parameters for the Y(4260) resonance which are m{sub Y} = 4252 ± 6−3{sup +2} MeV/c2 and?{sub Y} = 105 ± 18−6{sup +4} MeV/c2; we also measure?(?+?− J/?)?{sub e{sup +}e−} = (7.5 ± 0.9 ± 0.8) eV. We cannot confirm the recent BELLE observation of a broad structure around 4.05GeV/c2 in this decay mode.

Download or read book Study of the Exclusive Initial State RadiationProduction of the D bar D System written by B. Aubert and published by . This book was released on 2006 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study of exclusive production of the D{bar D} system through initial-state radiation is performed in a search for charmonium states, where D = D{sup 0} or D{sup +}. The D{sup 0} mesons are reconstructed in the D{sup 0} {yields} K{sup -}{pi}{sup +}, D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup 0}, and D{sup 0} {yields} K{sup -}{pi}{sup +}{pi}{sup +}{pi}{sup -} decay modes. The D{sup +} is reconstructed through the D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} decay mode. The analysis makes use of an integrated luminosity of 288.5 fb{sup -1} collected by the BABAR experiment. The D{bar D} mass spectrum shows a clear {psi}(3770) signal. Further structures appear in the 3.9 and 4.1 GeV/c{sup 2} regions. No evidence is found for Y(4260) decays to D{bar D}, implying an upper limit {Beta}(Y(4260) {yields} D{bar D})/{Beta}(Y(4260) {yields} J/{psi}{pi}{sup +}{pi}{sup -})

Download or read book Measurement of Prompt and Nonprompt J psi Production in Pp and PPb Collisions at Sqrt s NN written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reports the measurement of J/psi meson production in proton-proton (pp) and proton-lead (pPb) collisions at a center-of-mass energy per nucleon pair of 5.02 TeV by the CMS experiment at the LHC. The data samples used in the analysis correspond to integrated luminosities of 28 inverse picobarns and 35 inverse nanobarns for pp and pPb collisions, respectively. Prompt and nonprompt J/psi mesons, the latter issuing from the decay of B mesons, are measured in their dimuon decay channels. Differential cross sections are measured in the transverse momentum range of 2

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ERDA Energy Research Abstracts written by and published by . This book was released on 1983 with total page 1028 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 1977 with total page 818 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 1988 with total page 948 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 1994 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Measurement of the Polarization of J Psi Mesons Produced in High energy Proton antiproton Collisions written by Robert J. Cropp and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation presents an analysis of the polarization of ' J'/ y mesons produced in 'pp¢' collisions at a centre-of-mass energy of 1.8 TeV. The collisions were produced by the Fermilab Tevatron collider, the world's highest energy particle accelerator. The data were recorded by the Collider Detector at Fermilab during Run 1 of the Tevatron in 1992-1995. The 'J'/ y meson consists of a charm quark and its antiquark, and is the best-known type of quarkonium, the bound state of a heavy quark-antiquark pair. The measurement of the production polarization of 'J'/ y mesons and other quarkonia provides a test of quarkonium production models. The study of quarkonium production is important for understanding the strong nuclear force between quarks. The strong force is one of the four known fundamental forces, being responsible for binding quarks into hadrons and holding atomic nuclei together. The polarization of centrally produced 'J'/ y mesons has been measured over the transverse momentum range 4-20 GeV/'c', using an analysis of the angular distribution of their decays to [mu]+[mu]-. Decay length measurements made by CDF's silicon vertex detector allowed the promptly produced ' J'/ y mesons to be separated from those produced in ' B'-hadron decays. The prompt and 'B'-decay polarization parameters, Ã'P' and Ã' B', have both been measured. The measured value of Ã' P' is positive at intermediate 'PT', but is consistent with zero above 12 GeV/'c', in apparent disagreement with predictions of the NRQCD factorization formalism.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992-08 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: