Search for decays of the Z0 into a photon and a pseudoscalar meson

6533b82ffe1ef96bd129518b

RESEARCH PRODUCT

Search for decays of the Z0 into a photon and a pseudoscalar meson

D. Decamp B. Deschizeaux C. Goy J.-p. Lees M.-n. Minard J.m. Crespo M. Delfino E. Fernandez M. Martinez R. Miquel Ll.m. Mir S. Orteu A. Pacheco J.a. Perlas E. Tubau M.g. Catanesi M. De Palma A. Farilla G. Iaselli G. Maggi S. Natali S. Nuzzo A. Ranieri G. Raso F. Romano F. Ruggieri G. Selvaggi L. Silvestris P. Tempesta G. Zito Y. Gao H. Hu D. Huang S. Jin J. Lin T. Ruan T. Wang W. Wu Y. Xie D. Xu R. Xu J. Zhang Z. Zhang W. Zhao H. Albrecht W.b. Atwood F. Bird E. Blucher T.h. Burnett T. Charity H. Drevermann Ll. Garrido C. Grab R. Hagelberg S. Haywood B. Jost M. Kaseman G. Kellner J. Knobloch A. Lacourt I. Lehraus T. Lohse D. Lüke A. Marchioro P. Mato J. May A. Minten A. Miotto P. Palazzi M. Pepe-altarelli F. Ranjard A. Roth J. Rothberg H. Rotscheidt W. Von Rüden R. St.denis D. Schlatter M. Takashima M. Talby H. Taureg W. Tejessy H. Wachsmuth S. Wheeler W. Wiedenmann W. Witzeling J. Wotschack Z. Ajaltouni M. Bardadin-otwinowska A. Falvard P. Gay P. Henrard J. Jousset B. Michel J-c. Montret D. Pallin P. Perret J. Proriol F. Prulhière J.d. Hansen J.r. Hansen P.h. Hansen R. Møllerud G. Petersen E. Simopoulou A. Vayaki J. Badier A. Blondel G. Bonneaud J. Bourotte F. Braems J.c. Brient M.a. Ciocci G. Fouque R. Guirlet A. Rougé M. Rumpf R. Tanaka H. Videau I. Videau D.j. Candlin A. Conti G. Parrini M. Corden C. Georgiopoulos J.h. Goldman M. Ikeda J. Lannutti D. Levinthal M. Mermikides L. Sawyer G. Stimpfl A. Antonelli R. Baldini G. Bencivenni G. Bologna F. Bossi P. Campana G. Capon V. Chiarella G. De Ninno B. D'ettorre-piazzoli G. Felici P. Laurelli G. Mannocchi F. Murtas G.p. Murtas G. Nicoletti P. Picchi P. Zografou B. Altoon O. Boyle A.w. Halley I. Ten Have J.l. Hearns J.g. Lynch W.t. Morton C. Raine J.m. Scarr K. Smith A.s. Thompson B. Brandl O. Braun R. Geiges C. Geweniger P. Hanke V. Hepp E.e. Kluge Y. Maumary M. Panter A. Putzer B. Rensch A. Stahl K. Tittel M. Wunsch A.t. Belk R. Beuselinck D.m. Binnie W. Cameron M. Cattaneo P.j. Dornan S. Dugeay R.w. Forty A.m. Greene J.f. Hassard S.j. Patton J.k. Sedgbeer G. Taylor I.r. Tomalin A.g. Wright P. Girtler D. Kuhn G. Rudolph C.k. Bowdery T.j. Brodbeck A.j. Finch F. Foster G. Hughes N.r. Keemer M. Nuttall B.s. Rowlingson T. Sloan S.w. Snow T. Barczewski L.a.t. Bauerdick K. Kleinknecht B. Renk S. Roehn H.-g. Sander M. Schmelling F. Steeg J-p. Albanese J-j. Aubert C. Benchouk A. Bonissent D. Courvoisier F. Etienne E. Matsinos S. Papalexiou P. Payre B. Pietrzyk Z. Qian W. Blum P. Cattaneo G. Cowan B. Dehning H. Dietl M. Fernandez-bosman D. Hauff A. Jahn E. Lange G. Lütjens G. Lutz W. Männer H-g. Moser Y. Pan R. Richter A.s. Schwarz R. Settles U. Stiegler U. Stierlin J. Thomas G. Waltermann V. Bertin G. De Bouard J. Boucrot O. Callot X. Chen A. Cordier M. Davier G. Ganis J.-f. Grivaz Ph. Heusse P. Janot V. Journé D.w. Kim J. Lefrançois A.-m. Lutz J.-j. Veillet F. Zomer S.r. Amendolia G. Bagliesi G. Batignani L. Bosisio U. Bottigli C. Bradaschia I. Ferrante F. Fidecaro L. Foà E. Focardi F. Forti A. Giassi M.a. Giorgi F. Ligabue A. Lusiani E.b. Mannelli P.s. Marrocchesi A. Messineo F. Palla G. Sanguinetti S. Scapellato J. Steinberger R. Tenchini G. Tonelli G. Triggiani J.m. Carter M.g. Green P.v. March T. Medcalf M.r. Saich J.a. Strong R.m. Thomas T. Wildish D.r. Botterill R.w. Clifft T.r. Edgecock M. Edwards S.m. Fisher J. Harvey T.j. Jones P.r. Norton D.p. Salmon J.c. Thompson B. Bloch-devaux P. Colas C. Klopfenstein E. Lançon E. Locci S. Loucatos L. Mirabito E. Monnier P. Perez F. Perrier J. Rander J.-f. Renardy A. Roussarie J.-p. Schuller J.g. Ashman C.n. Booth F. Combley M. Dinsdale J. Martin D. Parker L.f. Thompson S. Brandt H. Burkhardt C. Grupen H. Meinhard E. Neugebauer U. Schäfer H. Seywerd B. Gobbo F. Liello E. Milotti F. Ragusa L. Rolandi L. Bellantoni J.f. Boudreau D. Cinabro J.s. Conway D.f. Cowen Z. Feng J.l. Harton J. Hilgart R.c. Jared R.p. Johnson B.w. Leclaire Y.b. Pan T. Parker J.r. Pater Y. Saadi V. Sharma J.a. Wear F.v. Weber Sau Lan Wu S.t. Xue G. Zobernig

subject

Physics Nuclear physics Nuclear and High Energy Physics Particle physics Photon Secondary education Meson Branching fraction Electron–positron annihilation Pseudoscalar meson Charged particle Particle Physics - Experiment Research method

description

Abstract A search is reported for decays of the Z 0 into π 0 γ , ηγ and η ′ (958) γ in e + e − collisions using data collected during a scan around the Z 0 mass. In order to search for π 0 γ final states, in which the two photons from the π 0 decay are unresolved, the production of pairs of high-energy electromagnetic clusters is studied. The data are compared with the expectations from the pure QED process e + e − → γγ , and a 95% confidence level upper limit on the branching ratio of the Z 0 into π 0 γ of 4.9 × 10 −4 is derived. For η′γ, the decay modes of the mesons that contain two charged particles are largely free from QED background. These modes are used to place upper limits of 4.6 × 10 −4 and 2.2 × 10 −4 on the corresponding branching ratios of the Z 0 .

year	journal	country	edition	language
1990-01-01

10.1016/0370-2693(90)91883-d http://hdl.handle.net/11589/8504