Index

Quarkonium Resources


Quarkonium Production Experiments

Charmonium Experiments

Differential cross sections of J/ψ and ψ' in 800 GeV/c p-Si interactions. T. Alexopoulos et al. (E771 Collaboration), Phys. Rev. D 55 (1997) 3927.
Reaction: 800 GeV (fixed target) p + Si → J/ψ, ψ'
Acceptance: -0.05<xF<0.25, pT<3.5 GeV, -0.8<Cos(θ)<0.8
Sample size: 11660±139 J/ψ, 218±24 ψ'
Nuclear effects: Correction using α=0.920±0.008
Results:
σ= 375±4±30 nb (J/ψ),
σ= 46±3±10 nb (ψ')
Detailed xF and pT distributions are given. A fit to the Cos(θ) distribution is also presented.

Measurement of J/ψ and ψ' production in 800 GeV/c p-Au collisions. M. H. Schub et al. (E789 Collaboration), Phys. Rev. D 52 (1995) 1307.
Reaction: 800 GeV (fixed target) p + Au → J/ψ, ψ'
Acceptance: -
Sample size: 112649±486 J/ψ, 1824±114 ψ'
Nuclear effects: Correction using α=0.90±0.02
Results:
σ= 442±2±88 nb (J/ψ),
σ= 75±5±22 nb (ψ')
The systematic error for ψ' is stated to be a lower bound. Detailed xF and pT distributions are given.

Measurement of J/ψ, ψ' and Υ total cross sections in 800 GeV/c p-Si interactions. T. Alexopoulos et al. (E771 Collaboration), Phys. Lett. B 374 (1996) 271.
Reaction: 800 GeV (fixed target) p + Si → J/ψ, ψ', Υ
Acceptance: -0.1<xF<0.3, pT<3.5 GeV
Sample size: 11660±139 J/ψ, 218±24 ψ'
Results:
BR . σ = 21.8±0.3±1.4 nb (J/ψ),
σ= 0.360±0.040±0.024 nb (ψ')

Production of Charmonium states in π- Be collisions at 515 GeV/c. V. Koreshev et al. (E672-E706 Collaborations), Phys. Rev. Lett. 77 (1996) 4294.
Reaction: 515 GeV (fixed target) π + Be → J/ψ, ψ'

Production of J/ψ and ψ(2S) mesons in π- Be collisions at 515 GeV/c. A. Gribushin et al. (E672-E706 Collaborations), Phys. Rev. D 53 (1996) 4723.
Reaction: 515 GeV (fixed target) π- + Be → J/ψ, ψ'
Acceptance: 0.1<xF<0.8, pT<3.5 GeV, -0.8<Cos(θ)<0.8
Sample size: 11660±139 J/ψ, 218±24 ψ'
Nuclear effects: Correction using α=0.920±0.008
Results:
BR . σ = 9.3±0.1±1.1 nb (J/ψ, xF>0.1),
BR . σ = 12.9±0.2±1.6 nb (J/ψ, xF>0.0),
BR . σ = 7.4±1.5±1.2 nb (ψ', xF>0.1)
Fraction of J/ψ due to ψ' = 0.083±0.017±0.013
Detailed xF and pT distributions are given. A fit to the Cos(θ) distribution is also presented.

Production of χ Charmonium via 300 GeV/c pion and proton interactions on a Lithium target. L. Antoniazzi et al. (E705 Collaboration), Phys. Rev. D 49 (1994) 543.
Reaction: 300 GeV (fixed target) p + Li → χc
Reaction: 300 GeV (fixed target) π + Li → χc

A measurement of J/ψ and ψ' production in 300 GeV/c proton, anti-proton and π± nucleon interactions. L. Antoniazzi et al. (E705 Collaboration), Phys. Rev. D 46 (1992) 4828.
Reaction: 300 GeV (fixed target) p + Li → J/ψ, ψ'
Reaction: 300 GeV (fixed target) pbar + Li → J/ψ, ψ'
Reaction: 300 GeV (fixed target) π + Li → J/ψ, ψ'

Production of J/ψ via ψ' and χ decay in 300 GeV/c proton and π± nucleon interactions. L. Antoniazzi et al. (E705 Collaboration), Phys. Rev. Lett. 70 (1993) 383.
Reaction: 300 GeV (fixed target) p + Li → χc, ψ' → J/ψ
Reaction: 300 GeV (fixed target) π + Li → χc, ψ' → J/ψ

Bottomonium Experiments

Measurement of J/ψ, ψ' and Υ total cross sections in 800 GeV/c p-Si interactions. T. Alexopoulos et al. (E771 Collaboration), Phys. Lett. B 374 (1996) 271.
Reaction: 800 GeV (fixed target) p + Si → J/ψ, ψ', Υ
Acceptance: -0.1<xF<0.3, pT<3.5 GeV
Sample size: 10±4 Upsilon
Results: BR . σ = 8.0±3.3±0.6 nb (Υ+Υ')


NRQCD Production Matrix Elements


Notation: Hc(SLJ) for long distance matrix elements [eg: J/ψ8(3S1) for the J/ψ colour octet, spin triplet, S wave, J=1 matrix element]. The production matrix elements are distinct from the decay matrix elements (see BBL).

J/psi Matrix Elements

J/ψ1(3S1)

J/ψ8(3S1)

J/ψ8(1S0) +7 J/ψ8(3P0)/(2 m2)

J/ψ8(1S0) +3.1 J/ψ8(3P0)/m2

J/ψ8(1S0) +3 J/ψ8(3P0)/m2 +4 J/ψ8(3P2)/(5 m2)

χc Matrix Elements

χ11(3P1)

χ18(3S1)

ψ' Matrix Elements

ψ'1(3S1)

ψ'8(3S1)

ψ'8(1S0) +7 ψ'8(3P0)/(2 m2)

ψ'8(1S0) +3.1 ψ'8(3P0)/m2

Υ Matrix Elements

Υ1(3S1)

Υ8(3S1)

Υ'1(3S1)

Υ'8(3S1)

Υ''1(3S1)


References

  1. S. Baek, P. Ko, J. Lee and H. S. Song, Phys Rev D 55 (1997) 6839.
    Quote values for two J/ψ production matrix elements without attribution.
  2. M. Beneke and M. Kramer, Phys Rev D 55 (1997) 5269.
    Performs a fit to the Tevatron data to extract two combinations of J/ψ and ψ' octet matrix elements. The results are reported for mc=1.5 GeV and a choice of factorisations scale of (PT2+4mc2)1/2. Uncertainties from choice of scale, structure function set etc are systematically explored.
  3. Peter Cho and Adam K. Leibovich, Phys Rev D 53 (1996) 150.
    Uses a quark potential model to compute several colour singlet matrix elements. Some colour octet matrix elements are obtained by a fit to Tevatron data on total J/ψ and ψ' cross sections as well as the χc contribution to the total J/ψ rate.
  4. Peter Cho and Adam K. Leibovich, Phys Rev D 53 (1996) 6203.
  5. Sean Fleming and Igor Maksymyk, hep-ph/9603266.
    Fits a particular combination of J/ψ octet matrix elements to data on almost elastic photo-production. The diffractive component of the data is not removed before fitting.
  6. M. L. Mangano and Andrea Petrelli, Phys Lett B 352 (1995) 445.
    Uses data on decays of the χc states into two photons and light hadrons to fix the decay matrix elements. Comparison with Braaten, Brodsky and Lepage is necessary to convert their parameters into the standard form. Subsequently, the singlet decay matrix elements may be converted to production matrix elements using the vacuum saturation approximation.
  7. M. Beneke, F. Maltoni and I. Z. Rothstein, hep-ph/9808360.
    Obtains the long-distance matrix elements from the decays $B→H(cc)+X$.

Compiled by: Sourendu Gupta, June 12, 1997.