A determination of the number of light neutrino families performed by measuring the cross section of single photon production in e(+)e(-) collision near the Z resonance is reported. From an integrated luminosity of 100 pb(-1), collected during the years 1991-94, we have observed 2091 single photon candidates with an energy above 1 GeV in the polar angular region 45 degrees < theta(gamma) < 135 degrees. From a maximum likelihood fit to the single photon cross section, the Z decay width into invisible particles is measured to be Gamma(inv) = 498 +/- 12(stat) +/- 12(sys)MeV. Using the Standard Model couplings of neutrinos to the Z, the number of light neutrino species is determined to be N-v = 2.98 +/- 0.07(stat) +/- 0.07(sys). (C) 1998 Published by Elsevier Science B.V. All rights reserved.
Determination of the number of light neutrino species from single photon production at LEP / M. Acciarri;O. Adriani;M. Aguilar-Benitez;S. Ahlen;J. Alcaraz;G. Alemanni;J. Allaby;A. Aloisio;M. G. Alviggi;G. Ambrosi;H. Anderhub;V. P. Andreev;T. Angelescu;F. Anselmo;A. Arefiev;T. Azemoon;T. Aziz;P. Bagnaia;L. Baksay;R. C. Ball;S. Banerjee;S. Banerjee;K. Banicz;A. Barczyk;R. Barillere;L. Barone;P. Bartalini;A. Baschirotto;M. Basile;R. Battiston;A. Bay;F. Becattini;U. Becker;F. Behner;J. Berdugo;P. Berges;B. Bertucci;B. L. Betev;S. Bhattacharya;M. Biasini;A. Biland;G. M. Bilei;R. Bizzarri;J. J. Blaising;S. C. Blyth;G. J. Bobbink;R. Bock;A. Bohm;L. Boldizsar;B. Borgia;D. Bourilkov;M. Bourquin;D. Boutigny;S. Braccini;J. G. Branson;V. Brigljevic;I. C. Brock;A. Buffini;A. Buijs;J. D. Burger;W. J. Burger;J. Busenitz;X. D. Cai;M. Campanelli;M. Capell;G. C. Romeo;G. Carlino;A. M. Cartacci;J. Casaus;G. Castellini;F. Cavallari;N. Cavallo;C. Cecchi;M. Cerrada;F. Cesaroni;M. Chamizo;Y. H. Chang;U. K. Chaturvedi;S. V. Chekanov;M. Chemarin;A. Chen;G. Chen;G. M. Chen;H. F. Chen;H. S. Chen;M. Chen;G. Chiefari;C. Y. Chien;L. Cifarelli;F. Cindolo;C. Civinini;I. Clare;R. Clare;H. O. Cohn;G. Coignet;A. P. Colijn;N. Colino;S. Costantini;F. Cotorobai;B. d. la;A. Csilling;T. S. Dai;R. D'Alessandro;R. d. Asmundis;A. Degre;K. Deiters;P. Denes;F. DeNotaristefani;D. DiBitonto;M. Diemoz;D. v. Dierendonck;F. D. Lodovico;C. Dionisi;M. Dittmar;A. Dominguez;A. Doria;M. T. Dova;E. Drago;D. Duchesneau;P. Duinker;I. Duran;S. Dutta;S. Easo;Y. Efremenko;H. E. Mamouni;A. Engler;F. J. Eppling;F. C. Erne;J. P. Ernenwein;P. Extermann;M. Fabre;R. Faccini;S. Falciano;A. Favara;J. Fay;O. Fedin;M. Felcini;B. Fenyi;T. Ferguson;F. Ferroni;H. Fesefeldt;E. Fiandrini;J. H. Field;F. Filthaut;P. H. Fisher;I. Fisk;G. Forconi;L. Fredj;K. Freudenreich;C. Furetta;Y. Galaktionov;S. N. Ganguli;P. Garcia-Abia;S. S. Gau;S. Gentile;J. Gerald;N. Gheordanescu;S. Giagu;S. Goldfarb;J. Goldstein;Z. F. Gong;A. Gougas;G. Gratta;M. W. Grunewald;V. K. Gupta;A. Gurtu;L. J. Gutay;D. Haas;B. Hartmann;A. Hasan;D. Hatzifotiadou;T. Hebbeker;A. Herve;J. Hirschfelder;W. C. van;H. Hofer;H. Hoorani;S. R. Hou;G. Hu;V. Innocente;K. Jenkes;B. N. Jin;L. W. Jones;P. d. Jong;I. Josa-Mutuberria;A. Kasser;R. A. Khan;D. Kamrad;Y. Kamyshkov;J. S. Kapustinsky;Y. Karyotakis;M. Kaur;M. N. Kienzle-Focacci;D. Kim;D. H. Kim;J. K. Kim;S. C. Kim;W. W. Kinnison;A. Kirkby;D. Kirkby;J. Kirkby;D. Kiss;W. Kittel;A. Klimentov;A. C. Konig;A. Kopp;I. Korolko;V. Koutsenko;R. W. Kraemer;W. Krenz;A. Kunin;P. Lacentre;P. L. de;G. Landi;C. Lapoint;K. Lassila-Perini;P. Laurikainen;A. Lavorato;M. Lebeau;A. Lebedev;P. Lebrun;P. Lecomte;P. Lecoq;P. L. Coultre;H. J. Lee;C. Leggett;J. M. Le;R. Leiste;E. Leonardi;P. Levtchenko;C. Li;C. H. Lin;W. T. Lin;F. L. Linde;L. Lista;Z. A. Liu;W. Lohmann;E. Longo;W. Lu;Y. S. Lu;K. Lubelsmeyer;C. Luci;D. Luckey;L. Luminari;W. Lustermann;W. G. Ma;M. Maity;G. Majumder;L. Malgeri;A. Malinin;C. Mana;D. Mangeol;S. Mangla;P. Marchesini;A. Marin;J. P. Martin;F. Marzano;G. G. G.;D. McNally;S. Mele;L. Merola;M. Meschini;W. J. Metzger;M. v. der;Y. Mi;D. Migani;A. Mihul;A. J. W.;H. Milcent;G. Mirabelli;J. Mnich;P. Molnar;B. Monteleoni;R. Moore;T. Moulik;R. Mount;F. Muheim;A. J. M.;S. Nahn;M. Napolitano;F. Nessi-Tedaldi;H. Newman;T. Niessen;A. Nippe;A. Nisati;H. Nowak;Y. D. Oh;H. Opitz;G. Organtini;R. Ostonen;S. Palit;C. Palomares;D. Pandoulas;S. Paoletti;P. Paolucci;H. K. Park;I. H. Park;G. Pascale;G. Passaleva;S. Patricelli;T. Paul;M. Pauluzzi;C. Paus;F. Pauss;D. Peach;Y. J. Pei;S. Pensotti;D. Perret-Gallix;B. Petersen;S. Petrak;A. Pevsner;D. Piccolo;M. Pieri;P. A. Piroue;E. Pistolesi;V. Plyaskin;M. Pohl;V. Pojidaev;H. Postema;N. Produit;D. Prokofiev;J. Quartieri;G. Rahal-Callot;N. Raja;P. G. Rancoita;M. Rattaggi;G. Raven;P. Razis;K. Read;D. Ren;M. Rescigno;S. Reucroft;T. v. Rhee;S. Riemann;K. Riles;O. Rind;A. Robohm;J. Rodin;B. P. Roe;L. Romero;S. Rosier-Lees;P. Rosselet;W. v. Rossum;S. Roth;J. A. Rubio;D. Ruschmeier;H. Rykaczewski;J. Salicio;E. Sanchez;M. P. Sanders;M. E. Sarakinos;S. Sarkar;G. Sauvage;C. Schafer;V. Schegelsky;S. Schmidt-Kaerst;D. Schmitz;M. Schneegans;N. Scholz;H. Schopper;D. J. Schotanus;J. Schwenke;G. Schwering;C. Sciacca;D. Sciarrino;L. Servoli;S. Shevchenko;N. Shivarov;V. Shoutko;J. Shukla;E. Shumilov;A. Shvorob;T. Siedenburg;D. Son;V. Soulimov;B. Smith;P. Spillantini;M. Steuer;D. P. Stickland;H. Stone;B. Stoyanov;A. Straessner;K. Sudhakar;G. Sultanov;L. Z. Sun;G. F. Susinno;H. Suter;J. D. Swain;X. W. Tang;L. Tauscher;L. Taylor;S. C. C.;S. M. Ting;S. C. Tonwar;J. Toth;C. Tully;H. Tuchscherer;K. L. Tung;Y. Uchida;J. Ulbricht;U. Uwer;E. Valente;G. Vesztergombi;I. Vetlitsky;G. Viertel;M. Vivargent;S. Vlachos;R. Volkert;H. Vogel;H. Vogt;I. Vorobiev;A. A. Vorobyov;A. Vorvolakos;M. Wadhwa;W. Wallraff;W. C. Wang;X. L. Wang;Z. M. Wang;A. Weber;S. X. Wu;S. Wynhoff;J. Xu;Z. Z. Xu;B. Z. Yang;C. G. Yang;X. Y. Yao;J. B. Ye;S. C. Yeh;J. M. You;A. Zalite;Y. Zalite;P. Zemp;Y. Zeng;Z. Zhang;Z. P. Zhang;B. Zhou;Y. Zhou;G. Y. Zhu;R. Y. Zhu;A. Zichichi;F. Ziegler. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - ELETTRONICO. - 431:(1998), pp. 199-208. [10.1016/S0370-2693(98)00519-X]
Determination of the number of light neutrino species from single photon production at LEP
ADRIANI, OSCAR;BECATTINI, FRANCESCO;D'ALESSANDRO, RAFFAELLO;
1998
Abstract
A determination of the number of light neutrino families performed by measuring the cross section of single photon production in e(+)e(-) collision near the Z resonance is reported. From an integrated luminosity of 100 pb(-1), collected during the years 1991-94, we have observed 2091 single photon candidates with an energy above 1 GeV in the polar angular region 45 degrees < theta(gamma) < 135 degrees. From a maximum likelihood fit to the single photon cross section, the Z decay width into invisible particles is measured to be Gamma(inv) = 498 +/- 12(stat) +/- 12(sys)MeV. Using the Standard Model couplings of neutrinos to the Z, the number of light neutrino species is determined to be N-v = 2.98 +/- 0.07(stat) +/- 0.07(sys). (C) 1998 Published by Elsevier Science B.V. All rights reserved.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.