A PRECISE DETERMINATION OF THE NUMBER OF FAMILIES WITH LIGHT NEUTRINOS AND OF THE Z BOSON PARTIAL WIDTHS

被引:135
作者
DECAMP, D
DESCHIZEAUX, B
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
HU, H
HUANG, D
LIN, J
RUAN, T
WANG, T
WU, W
XIE, Y
XU, D
XU, R
ZHANG, J
ZHAO, W
ALBRECHT, H
ATWOOD, WB
BIRD, F
BLUCHER, E
BURNETT, TH
CHARITY, T
DREVERMANN, H
GARRIDO, L
GRAB, C
HAGELBERG, R
机构
[1] UNIV AUTONOMA BARCELONA,FIS ALTAS ENERGIAS LAB,E-08193 BARCELONA,SPAIN
[2] IST NAZL FIS NUCL,I-70126 BARI,ITALY
[3] UNIV BARI,DEPARTIMENTO FIS,I-70126 BARI,ITALY
[4] CHINESE ACAD SCI,INST HIGH ENERGY PHYS,BEIJING,PEOPLES R CHINA
[5] CERN,CH-1211 GENEVA 23,SWITZERLAND
[6] NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK
[7] DEMOCRITOS NUCL RES CTR,ATHENS,GREECE
[8] UNIV CLERMONT FERRAND,INST NATL PHYS NUCL & PHYS PARTICLES,CNRS,PHYS CORPUSCULAIRE LAB,F-63177 CLERMONT FERRAND,FRANCE
[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,IST NAZL FIZ NUCL,DIPARTIMENTO FIS,I-50125 FLORENCE,ITALY
[12] FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306
[13] FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306
[14] IST NAZL FIS NUCL,LAB NAZL,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,CNRS,F-91405 ORSAY,FRANCE
[24] IST NAZL FIS NUCL,DEPARTIMENTO FIS,PISA,ITALY
[25] SCUOLA NORMALE SUPER PISA,I-56010 PISA,ITALY
[26] UNIV LONDON,ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT PHYS,EGHAM TW20 0EX,SURREY,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
[34] CNR,IST COSMO GEOFIS,TURIN,ITALY
[35] UNIV TURIN,IST FIS GEN,I-10124 TURIN,ITALY
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)91984-J
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
More extensive and precise results are reported on the parameters of Z decay. On the basis of 20 000 Z decays collected with the ALEPH detector at LEP we find Mz=91.182±0.026 (exp.) ±0.030 (beam) GeV, Γz=2.541±0.056 GeV and σhad 0=41.4±0.8 nb. The partial widths for the hadronic and leptonic channels are Γhad=1804±44 MeV, Γe=82.1±3.4 MeV, Γμ=87.9±6.0 MeV and Γτ=86.1±5.6 MeV, in good agreement with the standard model. On the basis of the average leptonic width Γℓ=83.9±2.2 MeV, the effective weak mixing angle is found to be sin2θw(Mz)=0.231±0.008. Usin g the partial widths calculated in the standard model, the number of light neutrino families is Nν=3.01±0.15 (exp.)±0.05 (theor.). © 1990.
引用
收藏
页码:399 / 411
页数:13
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