Abstract
The production of Jψ mesons in Z0 decays is studied using 3.6 million hadronic events recorded by the OPAL detector at LEP. The inclusive Z0 to Jψ and b-quark to Jψ branching ratios are measured from the total yield of Jψ mesons, identified from their decays into lepton pairs. The Jψ momentum distribution is used to study the fragmentation of b-quarks. The production rate of ψ′ mesons, identified from their decays into a Jψ and a π+π− pair, is measured as well. The following results are obtained: ${Br(Z^{0}⌝ghtarrow {⤪ J}/ i X)=(3.9pm 0.2pm 0.3)cdot 10^{-3} {⤪ and} ↦op Br(Z^0⌝ghtarrow i ^⌕ime X)=(1.6pm 0.3pm 0.2)cdot 10^{-3}, }$ where the first error is statistical and the second systematic. Finally the Jψ sample is used to reconstruct exclusive b-hadron decays and calculate the corresponding b-hadron branching ratios and masses.
Similar content being viewed by others
References
The various ‘colour-singlet’ models are the following: The ‘charm fragmentation’ process, Z0 →cc̅ followed by c(c̅)→ J/ψc(c̅): E.Braaten, K.Cheung and T.C.Yuan, Phys.Rev. D48 (1993) 4230, V.Barger, K.Cheung and W.Y.Keung, Phys.Rev. D41 (1990) 1541. The ‘gluon fragmentation’ process, Z0→qq̅g followed by g→J/ψ gg: E.Braaten and T.C.Yuan, Phys.Rev.Lett. 71 (1993) 1673, K.Hagiwara, A.D.Martin and W.J.Stirling, Phys.Lett. B267 (1991) 527, erratum B316 (1993) 631. The ‘gluon radiation’ process, Z0→J/ψgg: W.Y.Keung, Phys.Rev. D23 (1981) 2072, J.H.Kühn and H.Schneider, Z.Phys. C11 (1981) 263. The first process is dominant according to theoretical calculations.
M.Cacciari et al., Charmonium Production at the Tevatron, CERNTH/95-129.
P.Cho, Prompt Upsilon and Psi Production at LEP, CALT-68-2020, K.Cheung, W.Y. Keung and T.C.Yuan, Colour-Octet Quarkonium Production at the Z Pole, FERMILAB-PUB-95/300-T.
J.H. Kuhn, S. Nussinov and R. Rückl, Z.Phys. C5 (1980) 117.
OPAL Collab., G. Alexander et al., Phys.Lett. B266 (1991) 485.
ALEPH Collab., D. Buskulic et al., Phys.Lett. B295 (1992) 396.
L3 Collab., O. Adriani et al., Phys.Lett. B317 (1993) 467.
DELPHI Collab., P. Abreu et al., Phys.Lett. B341 (1994) 109.
CLEO Collab., R. Balest et al., Phys.Rev. D52 (1995) 2661.
H. Fritzsch, Phys.Lett. B86 (1979) 164, H.Fritzsch, Phys.Lett. B86 (1979) 343.
CDF Collab., F. Abe et al., Phys.Rev.Lett. 72 (1994) 3456.
CLEO Collab., M.S. Alam et al., Phys.Rev. D50 (1994) 43.
OPAL Collab., P.D. Acton et al., Phys.Lett. B295 (1992) 357, OPAL Collab., R.Akers et al., Phys.Lett. B337 (1994) 196.
ALEPH Collab., D. Buskulic et al., Phys.Lett. B311 (1993) 425.
CDF Collab., F. Abe et al., Phys.Rev.Lett. 71 (1993) 1685.
DELPHI Collab., P. Abreu et al., Phys.Lett. B324 (1994) 500.
UA1 Collab., C. Albajar et al., Phys.Lett. B273 (1991) 540.
CDF Collab., F. Abe et al., Phys.Rev. D47 (1993) 2639.
OPAL Collab., K. Ahmet et al., Nucl. Instrum. and Meth. A305 (1991) 275.
P. Allport et al., Nucl. Instrum. and Meth. A324 (1993) 34, P.Allport et al., Nucl. Instrum. and Meth. A346 (1994) 476.
M. Hauschild et al., Nucl. Instrum. and Meth. A314 (1992) 74.
OPAL Collab., G. Alexander et al., Z.Phys. C52 (1991) 175.
OPAL Collab., P.D. Acton et al., Z.Phys. C58 (1993) 523.
T. Sjöstrand, Computer Physics Commun. 82 (1994) 74, T.Sjöstrand, JETSET 7.4 Manual, CERN-TH.7112/93.
OPAL Collab., G.Alexander et al., A Comparison of b and uds quark jets to gluon jets, CERN-PPE/95-126, submitted to Z.Phys.
J. Allison et al., Nucl.Instrum. and Meth. A317 (1992) 47.
C. Peterson et al., Phys.Rev. D27 (1983) 105.
OPAL Collab., P.D. Acton et al., Z.Phys. C60 (1993) 19.
OPAL Collab., R. Akers et al., Z.Phys. C60 (1993) 199.
F.A. Berends and R. Kleiss, Nucl.Phys. B177 (1981) 237.
O. Nicrosini and L. Trentadue, Phys.Lett. B196 (1987) 551, J.P.Alexander et al., Phys.Rev. D37 (1988) 56.
L. Montanet et al., Review of Particle Properties, Phys.Rev. D50 (1994) 1173.
MARK-III Collab., D. Coffman et al., Phys.Rev.Lett. 68 (1992) 282.
OPAL Collab., G.Alexander et al., A study of b Quark Fragmentation into B0 and B+ Mesons at LEP, CERN-PPE/95-122, submitted to Phys.Lett B.
OPAL Collab., R. Akers et al., Phys.Lett. B327 (1994) 411.
OPAL Collab., P.D. Acton et al., Phys.Lett. B298 (1993) 456.
O.Dahl et al., The SQUAW package, LBL Group A, Programming note P-126(1968).
R. Barlow, Nucl. Instrum. and Meth. A297 (1990) 496.
OPAL Collab., R. Akers et al., Z.Phys. C66 (1995) 555.
OPAL Collab., R. Akers et al., Z.Phys. C63 (1994) 181.
A.Leike and R.Rückl,Production of heavy bound states at LEP and beyond, MPI-PhT/94-41.
Author information
Consortia
Rights and permissions
About this article
Cite this article
OPAL Collaboration. J/Ψ and Ψ′ production in hadronic Z0 decays. Z Phys C - Particles and Fields 70, 197–209 (1996). https://doi.org/10.1007/s002880050096
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s002880050096