Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks

K. Ackerstaff, G. Alexander, J. Allison, N. Altekamp, K. J. Anderson, S. Anderson, S. Arcelli, S. Asai, D. Axen, G. Azuelos, A. H. Ball, E. Barberio, R. J. Barlow, R. Bartoldus, J. R. Batley, S. Baumann, J. Bechtluft, C. Beeston, T. Behnke, A. N. BellK. W. Bell, G. Bella, S. Bentvelsen, P. Berlich, S. Bethke, O. Biebel, A. Biguzzi, S. D. Bird, V. Blobel, I. J. Bloodworth, J. E. Bloomer, M. Bobinski, P. Bock, D. Bonacorsi, M. Boutemeur, B. T. Bouwens, S. Braibant, L. Brigliadori, R. M. Brown, H. J. Burckhart, C. Burgard, R. Bürgin, P. Capiluppi, R. K. Carnegie, A. A. Carter, J. R. Carter, C. Y. Chang, D. G. Charlton, D. Chrisman, S. Komamiya

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Using approximately 4.3 million hadronic Z0 decays collected with the OPAL detector at LEP between 1990 and 1995, we measure the branching fractions of the Z0 into up-type and down-type light quarks, Rq, and the forward-backward asymmetries, AFB(q), using high-momentum stable particles as a tag. Adopting a method that employs double tagged events to determine the flavour tagging efficiencies, and assuming the flavour independence of strong interactions and SU(2) isospin symmetry, we measure: Rd,s/(Rd + Ru + Rs) = 0.371 ±0.016 (stat.) ±0.016 (syst.) and AFB(d, s) = 0.068 ±0.035 (stat.) ±0.011 (syst.) , assuming the branching fractions and forward-backward asymmetries of down and strange quarks to be equal. The results are essentially free of assumptions based on hadronisation models. These results are in agreement with the Standard Model expectations and are used to infer the left and right handed couplings of strange/down quarks to the Z0, yielding gL d,s = -0.44-0.09 +0.13 and gR d,s = +0.13-0.17 +0.15. The results for the up quark, Ru/(Rd + Ru + Rs) = 0.258 ± 0.031 (stat.) ± 0.032 (syst.) and AFB(u) = 0.040 ±0.067 (stat.) ±0.028 (syst.), are fully negatively correlated and almost completely positively correlated, respectively, with the corresponding down-type results.

Original languageEnglish
Pages (from-to)387-400
Number of pages14
JournalZeitschrift fur Physik C-Particles and Fields
Volume76
Issue number3
Publication statusPublished - 1997 Jan 1
Externally publishedYes

Fingerprint

Flavors
asymmetry
quarks
Momentum
Detectors
marking
momentum
detectors
symmetry
decay

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

Cite this

Ackerstaff, K., Alexander, G., Allison, J., Altekamp, N., Anderson, K. J., Anderson, S., ... Komamiya, S. (1997). Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks. Zeitschrift fur Physik C-Particles and Fields, 76(3), 387-400.

Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks. / Ackerstaff, K.; Alexander, G.; Allison, J.; Altekamp, N.; Anderson, K. J.; Anderson, S.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Ball, A. H.; Barberio, E.; Barlow, R. J.; Bartoldus, R.; Batley, J. R.; Baumann, S.; Bechtluft, J.; Beeston, C.; Behnke, T.; Bell, A. N.; Bell, K. W.; Bella, G.; Bentvelsen, S.; Berlich, P.; Bethke, S.; Biebel, O.; Biguzzi, A.; Bird, S. D.; Blobel, V.; Bloodworth, I. J.; Bloomer, J. E.; Bobinski, M.; Bock, P.; Bonacorsi, D.; Boutemeur, M.; Bouwens, B. T.; Braibant, S.; Brigliadori, L.; Brown, R. M.; Burckhart, H. J.; Burgard, C.; Bürgin, R.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Chrisman, D.; Komamiya, S.

In: Zeitschrift fur Physik C-Particles and Fields, Vol. 76, No. 3, 01.01.1997, p. 387-400.

Research output: Contribution to journalArticle

Ackerstaff, K, Alexander, G, Allison, J, Altekamp, N, Anderson, KJ, Anderson, S, Arcelli, S, Asai, S, Axen, D, Azuelos, G, Ball, AH, Barberio, E, Barlow, RJ, Bartoldus, R, Batley, JR, Baumann, S, Bechtluft, J, Beeston, C, Behnke, T, Bell, AN, Bell, KW, Bella, G, Bentvelsen, S, Berlich, P, Bethke, S, Biebel, O, Biguzzi, A, Bird, SD, Blobel, V, Bloodworth, IJ, Bloomer, JE, Bobinski, M, Bock, P, Bonacorsi, D, Boutemeur, M, Bouwens, BT, Braibant, S, Brigliadori, L, Brown, RM, Burckhart, HJ, Burgard, C, Bürgin, R, Capiluppi, P, Carnegie, RK, Carter, AA, Carter, JR, Chang, CY, Charlton, DG, Chrisman, D & Komamiya, S 1997, 'Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks', Zeitschrift fur Physik C-Particles and Fields, vol. 76, no. 3, pp. 387-400.
Ackerstaff K, Alexander G, Allison J, Altekamp N, Anderson KJ, Anderson S et al. Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks. Zeitschrift fur Physik C-Particles and Fields. 1997 Jan 1;76(3):387-400.
Ackerstaff, K. ; Alexander, G. ; Allison, J. ; Altekamp, N. ; Anderson, K. J. ; Anderson, S. ; Arcelli, S. ; Asai, S. ; Axen, D. ; Azuelos, G. ; Ball, A. H. ; Barberio, E. ; Barlow, R. J. ; Bartoldus, R. ; Batley, J. R. ; Baumann, S. ; Bechtluft, J. ; Beeston, C. ; Behnke, T. ; Bell, A. N. ; Bell, K. W. ; Bella, G. ; Bentvelsen, S. ; Berlich, P. ; Bethke, S. ; Biebel, O. ; Biguzzi, A. ; Bird, S. D. ; Blobel, V. ; Bloodworth, I. J. ; Bloomer, J. E. ; Bobinski, M. ; Bock, P. ; Bonacorsi, D. ; Boutemeur, M. ; Bouwens, B. T. ; Braibant, S. ; Brigliadori, L. ; Brown, R. M. ; Burckhart, H. J. ; Burgard, C. ; Bürgin, R. ; Capiluppi, P. ; Carnegie, R. K. ; Carter, A. A. ; Carter, J. R. ; Chang, C. Y. ; Charlton, D. G. ; Chrisman, D. ; Komamiya, S. / Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks. In: Zeitschrift fur Physik C-Particles and Fields. 1997 ; Vol. 76, No. 3. pp. 387-400.
@article{25c32605c3034b58b23498c886e7db03,
title = "Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks",
abstract = "Using approximately 4.3 million hadronic Z0 decays collected with the OPAL detector at LEP between 1990 and 1995, we measure the branching fractions of the Z0 into up-type and down-type light quarks, Rq, and the forward-backward asymmetries, AFB(q), using high-momentum stable particles as a tag. Adopting a method that employs double tagged events to determine the flavour tagging efficiencies, and assuming the flavour independence of strong interactions and SU(2) isospin symmetry, we measure: Rd,s/(Rd + Ru + Rs) = 0.371 ±0.016 (stat.) ±0.016 (syst.) and AFB(d, s) = 0.068 ±0.035 (stat.) ±0.011 (syst.) , assuming the branching fractions and forward-backward asymmetries of down and strange quarks to be equal. The results are essentially free of assumptions based on hadronisation models. These results are in agreement with the Standard Model expectations and are used to infer the left and right handed couplings of strange/down quarks to the Z0, yielding gL d,s = -0.44-0.09 +0.13 and gR d,s = +0.13-0.17 +0.15. The results for the up quark, Ru/(Rd + Ru + Rs) = 0.258 ± 0.031 (stat.) ± 0.032 (syst.) and AFB(u) = 0.040 ±0.067 (stat.) ±0.028 (syst.), are fully negatively correlated and almost completely positively correlated, respectively, with the corresponding down-type results.",
author = "K. Ackerstaff and G. Alexander and J. Allison and N. Altekamp and Anderson, {K. J.} and S. Anderson and S. Arcelli and S. Asai and D. Axen and G. Azuelos and Ball, {A. H.} and E. Barberio and Barlow, {R. J.} and R. Bartoldus and Batley, {J. R.} and S. Baumann and J. Bechtluft and C. Beeston and T. Behnke and Bell, {A. N.} and Bell, {K. W.} and G. Bella and S. Bentvelsen and P. Berlich and S. Bethke and O. Biebel and A. Biguzzi and Bird, {S. D.} and V. Blobel and Bloodworth, {I. J.} and Bloomer, {J. E.} and M. Bobinski and P. Bock and D. Bonacorsi and M. Boutemeur and Bouwens, {B. T.} and S. Braibant and L. Brigliadori and Brown, {R. M.} and Burckhart, {H. J.} and C. Burgard and R. B{\"u}rgin and P. Capiluppi and Carnegie, {R. K.} and Carter, {A. A.} and Carter, {J. R.} and Chang, {C. Y.} and Charlton, {D. G.} and D. Chrisman and S. Komamiya",
year = "1997",
month = "1",
day = "1",
language = "English",
volume = "76",
pages = "387--400",
journal = "European Physical Journal C",
issn = "1434-6044",
publisher = "Springer New York",
number = "3",

}

TY - JOUR

T1 - Measurement of the branching fractions and forward-backward asymmetries of the Z0 into light quarks

AU - Ackerstaff, K.

AU - Alexander, G.

AU - Allison, J.

AU - Altekamp, N.

AU - Anderson, K. J.

AU - Anderson, S.

AU - Arcelli, S.

AU - Asai, S.

AU - Axen, D.

AU - Azuelos, G.

AU - Ball, A. H.

AU - Barberio, E.

AU - Barlow, R. J.

AU - Bartoldus, R.

AU - Batley, J. R.

AU - Baumann, S.

AU - Bechtluft, J.

AU - Beeston, C.

AU - Behnke, T.

AU - Bell, A. N.

AU - Bell, K. W.

AU - Bella, G.

AU - Bentvelsen, S.

AU - Berlich, P.

AU - Bethke, S.

AU - Biebel, O.

AU - Biguzzi, A.

AU - Bird, S. D.

AU - Blobel, V.

AU - Bloodworth, I. J.

AU - Bloomer, J. E.

AU - Bobinski, M.

AU - Bock, P.

AU - Bonacorsi, D.

AU - Boutemeur, M.

AU - Bouwens, B. T.

AU - Braibant, S.

AU - Brigliadori, L.

AU - Brown, R. M.

AU - Burckhart, H. J.

AU - Burgard, C.

AU - Bürgin, R.

AU - Capiluppi, P.

AU - Carnegie, R. K.

AU - Carter, A. A.

AU - Carter, J. R.

AU - Chang, C. Y.

AU - Charlton, D. G.

AU - Chrisman, D.

AU - Komamiya, S.

PY - 1997/1/1

Y1 - 1997/1/1

N2 - Using approximately 4.3 million hadronic Z0 decays collected with the OPAL detector at LEP between 1990 and 1995, we measure the branching fractions of the Z0 into up-type and down-type light quarks, Rq, and the forward-backward asymmetries, AFB(q), using high-momentum stable particles as a tag. Adopting a method that employs double tagged events to determine the flavour tagging efficiencies, and assuming the flavour independence of strong interactions and SU(2) isospin symmetry, we measure: Rd,s/(Rd + Ru + Rs) = 0.371 ±0.016 (stat.) ±0.016 (syst.) and AFB(d, s) = 0.068 ±0.035 (stat.) ±0.011 (syst.) , assuming the branching fractions and forward-backward asymmetries of down and strange quarks to be equal. The results are essentially free of assumptions based on hadronisation models. These results are in agreement with the Standard Model expectations and are used to infer the left and right handed couplings of strange/down quarks to the Z0, yielding gL d,s = -0.44-0.09 +0.13 and gR d,s = +0.13-0.17 +0.15. The results for the up quark, Ru/(Rd + Ru + Rs) = 0.258 ± 0.031 (stat.) ± 0.032 (syst.) and AFB(u) = 0.040 ±0.067 (stat.) ±0.028 (syst.), are fully negatively correlated and almost completely positively correlated, respectively, with the corresponding down-type results.

AB - Using approximately 4.3 million hadronic Z0 decays collected with the OPAL detector at LEP between 1990 and 1995, we measure the branching fractions of the Z0 into up-type and down-type light quarks, Rq, and the forward-backward asymmetries, AFB(q), using high-momentum stable particles as a tag. Adopting a method that employs double tagged events to determine the flavour tagging efficiencies, and assuming the flavour independence of strong interactions and SU(2) isospin symmetry, we measure: Rd,s/(Rd + Ru + Rs) = 0.371 ±0.016 (stat.) ±0.016 (syst.) and AFB(d, s) = 0.068 ±0.035 (stat.) ±0.011 (syst.) , assuming the branching fractions and forward-backward asymmetries of down and strange quarks to be equal. The results are essentially free of assumptions based on hadronisation models. These results are in agreement with the Standard Model expectations and are used to infer the left and right handed couplings of strange/down quarks to the Z0, yielding gL d,s = -0.44-0.09 +0.13 and gR d,s = +0.13-0.17 +0.15. The results for the up quark, Ru/(Rd + Ru + Rs) = 0.258 ± 0.031 (stat.) ± 0.032 (syst.) and AFB(u) = 0.040 ±0.067 (stat.) ±0.028 (syst.), are fully negatively correlated and almost completely positively correlated, respectively, with the corresponding down-type results.

UR - http://www.scopus.com/inward/record.url?scp=33750109335&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33750109335&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:33750109335

VL - 76

SP - 387

EP - 400

JO - European Physical Journal C

JF - European Physical Journal C

SN - 1434-6044

IS - 3

ER -