Measurement of $J/\psi$ and $\psi^\prime$ Real Photoproduction on $^{6}$Li at a Mean Energy of 90-{GeV}

The NA14 collaboration Barate, R. ; Bareyre, P. ; Bloch, D. ; et al.
Z.Phys.C 33 (1987) 505, 1987.
Inspire Record 235579 DOI 10.17182/hepdata.15814

Inelastic and elasticJ/ψ (3097) photoproduction on Li6 are measured at a mean γ energy of 90 GeV in an open spectrometer. TheJ/ψ are identified by their decays intoμ+μ− ore+e−. A signal of ψ′(3685) intoμ+μ− andJ/ψπ+π− is also seen. The inelastic cross-section withZ=Eψ/Eγ<0.9 is compared in shape and magnitude with the colour singlet model of photon-gluon fusion.

2 data tables

DIMUON TRIGGER, INELASTIC MEANS Z < 0.9.

ELECTRON TRIGGER, INELASTIC MEANS Z < 0.9.


Photoproduction of the LAMBDA(c) charmed baryon

The NA14/2 collaboration Alvarez, M.P. ; Barate, R. ; Bloch, D. ; et al.
Phys.Lett.B 246 (1990) 256-260, 1990.
Inspire Record 296476 DOI 10.17182/hepdata.29677

In a photoproduction experiment using a mean photon energy of 100 GeV we have observed 29±8 Λ c ( Λ c ) charmed-baryon and antibaryon decays in the pK − π + ( p K + π − ) final state. Quasi two-body final states do not contribite significantly to this channel. The mass of the Λ c was measured to be 2281.7±2.7±2.6 MeV/ c 2 and its lifetime 0.18±0.03±0.03 ps. The ratio of Λ c D production, measured in this experiment, is significantly greater than that predicted by photon-gluon fusion and using a Lund model to describe the hadronization. This excess cannot be completely accounted for in this model, even using a Λ c branching fraction in pK π as high as 5%.

1 data table

Result extrapolated to all lambda/c energies has large model dependent uncertainties.


Measurement of Hadronic Production of the $\chi$ 1++ (3507) and the $\chi$ 2++ (3553) Through Their Radiative Decay to $J/\psi$

Lemoigne, Y. ; Barate, R. ; Bareyre, P. ; et al.
Phys.Lett.B 113 (1982) 509, 1982.
Inspire Record 176731 DOI 10.17182/hepdata.30918

The χ 1 ++ (3507) and the χ 2 ++ (3553) states have been observed in the Goliath spectrometer at the CERN SPS in 185 GeV/ c π − -Be collisions. Their radiative decays contribute 27.7% (for the χ 1 ++ ) and 12.8% (for the χ 2 ++ ) to J ϕ production. At this energy, their cross sections are 65±19 nb and 96±29 nb, respectively

1 data table

No description provided.


High-energy Photoproduction of Large Transverse Momentum $\pi^0$ Mesons: A Quantitative Test of {QCD}

The NA14 collaboration Auge, E. ; Barate, R. ; Bloch, D. ; et al.
Phys.Lett.B 168 (1986) 163-169, 1986.
Inspire Record 227057 DOI 10.17182/hepdata.30278

The first results on inclusive photoproduction of π 0 at transverse momenta up to 4 GeV/ c , using incident γ energies between 50 and 150 GeV are presented. A comparison is made with inclusive π 0 production obtained, in the same experiment, with incident π − . Using the π − data to parametrize the hadronic behaviour of the photon, significant differences are observed in quantitative agreement with QCD Compton scattering and corrections thereof.

2 data tables

FC,IC,BC REFER TO FORWARD,INTERMEDIATE AND BACKWARD CALORIMETERS.

FC,IC,BC REFER TO FORWARD,INTERMEDIATE AND BACKWARD CALORIMETERS.


Study of charm photoproduction mechanisms

The NA14/2 collaboration Alvarez, M.P. ; Barate, R. ; Bloch, D. ; et al.
Z.Phys.C 60 (1993) 53-62, 1993.
Inspire Record 333271 DOI 10.17182/hepdata.14331

This paper presents results on charm photoproduction in the energy interval 40 to 160 GeV, obtained from the high-statistics charm samples of the NA 14/2 experiment at CERN. We measure the charm cross-section, the distributions inxF andp2T and various production ratios and charge asymmetries. The total non-diffractive open-charm cross-section per nucleon is measured to be\(\sigma _{(\gamma N \to c\bar cX)} \) at 〈Eγ〉 =100 GeV. We discuss the photoproduction of charm in terms of theoretical and phenomenological models. We compare the measuredp2T andxF distributions with first-order QCD calculations of photon-gluon fusion and obtain a value for the charm-quark mass ofmc=1.5+0.2−0.1GeV/c2.

10 data tables

D0 cross section assuming branching ratio of D0 --> K- PI+ of 3.65 +- 0.21 PCT.

D+(-) cross section assuming branching ratio of D+ --> K- PI+ PI+ of 8.0 +0.8,-0.7 PCT.

Total non diffractive open charm production cross section allowing for contributions for other charmed particles (D/S and LAMBDA/C). Comparison of data with first order QCD leads to a predicted charm quark mass of 1.5 +0.2,-0.1 GeV.

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Production of High Mass Muon Pairs in $\pi^-$ Be Collisions at 150-{GeV}/$c$ and 175-{GeV}/$c$

Barate, R. ; Bareyre, P. ; Bonamy, P. ; et al.
Phys.Rev.Lett. 43 (1979) 1541, 1979.
Inspire Record 142156 DOI 10.17182/hepdata.20768

This paper presents production and decay characteristics of 500 high-mass, high-resolution μ+μ− pairs produced in π− Be collisions at 150 and 175 GeV/c. The data do not agree with a simple Drell-Yan production mechanism, but indicate that higher-order quantum-chromodynamic corrections must be included.

2 data tables

No description provided.

No description provided.


Production of $\psi$ and $\psi^\prime$ Mesons in $\pi^- N$ Scattering at 150-{GeV}/$c$

Abolins, M.A. ; Barate, R. ; Bareyre, P. ; et al.
Phys.Lett.B 82 (1979) 145, 1979.
Inspire Record 133175 DOI 10.17182/hepdata.27333

In a large-acceptance spectrometer, muon pairs and associated hadrons were observed with μμ masses up to 10 GeV/ c 2 and ΔM M = 0.015 resolution. We report here on the production of 4000 J/ ψ and 80 ψ ′ mesons.

4 data tables

No description provided.

No description provided.

No description provided.

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Measurements of BR(b --> tau- anti-nu/tau X) and BR(b --> tau- anti-nu/tau D*+- X) and upper limits on BR(B- --> tau- anti-nu/tau) and BR(b --> s nu anti-nu).

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Eur.Phys.J.C 19 (2001) 213-227, 2001.
Inspire Record 534887 DOI 10.17182/hepdata.49822

Inclusive branching ratios involving b to tau transitions are measured in approximately four million hadronic Z decays collected by the ALEPH detector at LEP. The fully-inclusive branching ratio b -> tau nu X and the semi-inclusive branching ratio b -> tau nu D*+/- X are measured to be (2.43 +/- 0.20 +/- 0.25)% and (0.88 +/- 0.31 +/- 0.28)%, in agreement with the standard model predictions. Upper limits on the branching fractions b -> tau nu and b -> s nu nubar are set to 8.3 10**-4 and 6.4 10**-4 at the 90% C.L. These results allow a 90% C.L. lower limit of 0.40 (GeV/c**2)**-1 to be set on the tan(beta)/mH+/- ratio, in the framework of type-II two-Higgs-doublet mode

1 data table

TAN(BETA) is the two-Higgs-doublet model parameter, while M_H is the mass of charged Higgs.


Study of the CP asymmetry of B0 ---> J / psi K0(S) decays in ALEPH

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Phys.Lett.B 492 (2000) 259-274, 2000.
Inspire Record 533961 DOI 10.17182/hepdata.49841

The decay B0 -> J/psi K0_S is reconstructed with J/psi -> e+ e- or mu+ mu- and K0_S -> pi+ pi-. From the full ALEPH dataset at LEP1 of about 4 million hadronic Z decays, 23 candidates are selected with an estimated purity of 71%. They are used to measure the CP asymmetry of this decay, given by sin 2beta in the Standard Model, with the result sin 2beta = 0.84 +0.82-1.04 +-0.16. This is combined with existing measurements from other experiments, and increases the confidence level that CP violation has been observed in this channel to 98%.

1 data table

Standard Model predicts the time-dependent rate asymmetry as follows: A(t) = (B0(t)-BBAR0(t))/(B0(t)+BBAR0(t)) = SIN(2*BETA)*SIN(Delta(M)*t), where Delta(M) is the mass difference between the two B0 mass eigenstates.


A measurement of the b-quark mass from hadronic Z decays.

The ALEPH collaboration Barate, R. ; Decamp, D. ; Ghez, Philippe ; et al.
Eur.Phys.J.C 18 (2000) 1-13, 2000.
Inspire Record 531468 DOI 10.17182/hepdata.49909

Hadronic Z decay data taken with the ALEPH detector at LEP1 are used to measure the three-jet rate as well as moments of various event-shape variables. The ratios of the observables obtained from b-tagged events and from an inclusive sample are determined. The mass of the b quark is extracted from a fit to the measured ratios using a next-to-leading order prediction including mass effects. Taking the first moment of the y3 distribution, which is the observable with the smallest hadronization corrections and systematic uncertainties, the result is: mb(MZ) = [3.27+-0.22(stat) +-0.22(exp)+-0.38(had)+-0.16(theo)] GeV/c2. The measured ratio is alternatively employed to test the flavour independence of the strong coupling constant for b and light quarks.

1 data table

No description provided.