SEARCH FOR DECAYS OF THE Z0 INTO A PHOTON AND A PSEUDOSCALAR MESON

被引：7

作者：

DECAMP, D

DESCHIZEAUX, B

GOY, C

LEES, JP

MINARD, MN

CRESPO, JM

DELFINO, M

FERNANDEZ, E

MARTINEZ, M

MIQUEL, R

MIR, LM

ORTEU, S

PACHECO, A

PERLAS, JA

TUBAU, E

CATANESI, MG

DEPALMA, M

FARILLA, A

IASELLI, G

MAGGI, G

NATALI, S

NUZZO, S

RANIERI, A

RASO, G

ROMANO, F

RUGGIERI, F

SELVAGGI, G

SILVESTRIS, L

TEMPESTA, P

ZITO, G

GAO, Y

HU, H

HUANG, D

JIN, S

LIN, J

RUAN, T

WANG, T

WU, W

XIE, Y

XU, D

XU, R

ZHANG, J

ZHANG, Z

ZHAO, W

ALBRECHT, H

ATWOOD, WB

BIRD, F

BLUCHER, E

BURNETT, TH

CHARITY, T

机构：

[1] UNIV AUTONOMA BARCELONA,FIS ALTAS ENERGIAS LAB,E-08193 BARCELONA,SPAIN

[2] UNIV BARI,DEPARTIMENTO APPL PSYCHOL,I-70126 BARI,ITALY

[3] IST NAZL FIS NUCL,BARI,ITALY

[4] CHINESE ACAD SCI,INST HIGH ENERGY PHYS,BEIJING,PEOPLES R CHINA

[5] CERN,EUROPEAN LAB PARTICLE PHYS,CH-1211 GENEVA 23,SWITZERLAND

[6] UNIV CLERMONT FERRAND,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,PHYS CORPUSCULAIRE LAB,F-63177 CLERMONT FERRAND,FRANCE

[7] NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK

[8] DEMOCRITOS NUCL RES CTR,ATHENS,GREECE

[9] ECOLE POLYTECH,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,F-91128 PALAISEAU,FRANCE

[10] UNIV EDINBURGH,DEPT PHYS,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND

[11] UNIV FLORENCE,DEPARTIMENTO FIS,I-50125 FLORENCE,ITALY

[12] FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306

[13] FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306

[14] IST NAZL FIS NUCL,NAZL LAB,I-00044 FRASCATI,ITALY

[15] UNIV GLASGOW,DEPT PHYS & ASTRON,GLASGOW G12 8QQ,SCOTLAND

[16] UNIV HEIDELBERG,INST HOCHENERGIEPHYS,W-6900 HEIDELBERG,GERMANY

[17] UNIV LONDON IMPERIAL COLL SCI & TECHNOL,DEPT PHYS,LONDON SW7 2BZ,ENGLAND

[18] UNIV INNSBRUCK,INST EXPTL PHYS,A-6020 INNSBRUCK,AUSTRIA

[19] UNIV LANCASTER,DEPT PHYS,LANCASTER LA1 4YB,ENGLAND

[20] UNIV MAINZ,INST PHYS,W-6500 MAINZ,GERMANY

[21] FAC SCI LUMINY,INST NATL PHYS NUCL & PHYS PARTICULES,CNRS,CTR PHYS PARTICULES,F-13288 MARSEILLE,FRANCE

[22] WERNER HEISENBERG INST PHYS,MAX PLANCK INST PHYS & ASTROPHYS,W-8000 MUNICH,GERMANY

[23] UNIV PARIS 11,INST NATL PHYS NUCL & PHYS PARTICULES,ACCELEATEUR LINEAIRE LAB,F-91405 ORSAY,FRANCE

[24] IST NAZL PHYS NUCL,DIPARTIMENTO FIS,I-56010 PISA,ITALY

[25] SCUOLA NORMALE SUPER PISA,I-56010 PISA,ITALY

[26] UNIV LONDON,ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT PHYS,SURREY TW20 0EX,ENGLAND

[27] RUTHERFORD APPLETON LAB,DEPT PARTICLE PHYS,DIDCOT OX11 0QX,OXON,ENGLAND

[28] CENS,DEPT PHYS PARTICULES ELEMENTAIRES,F-91191 GIF SUR YVETTE,FRANCE

[29] UNIV SHEFFIELD,DEPT PHYS,SHEFFIELD S3 7RH,S YORKSHIRE,ENGLAND

[30] UNIV SIEGEN,FACHBEREICH PHYS,W-5900 SIEGEN,GERMANY

[31] UNIV TRIESTE,DEPARTIMENTO FIS,I-34127 TRIESTE,ITALY

[32] IST NAZL FIS NUCL,TRIESTE,ITALY

[33] UNIV WISCONSIN,DEPT PHYS,MADISON,WI 53706

来源：

PHYSICS LETTERS B | 1990年 / 241卷 / 04期

基金：

美国国家科学基金会; 中国国家自然科学基金;

关键词：

D O I：

10.1016/0370-2693(90)91883-D

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

A search is reported for decays of the Z0 into π0γ, ηγ and η′ (958)γ in e+e- collisions using data collected during a scan around the Z0 mass. In order to search for π0γ final states, in which the two photons from the π0 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 Z0 into π0γ 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 Z0. © 1990.

引用

页码：635 / 643

页数：9

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