HEPData Search

Using the ARGUS detector at the DORIS II e + e − storage ring we have measured direct photons from the decay ???(1 S )→ γgg . The ratio R γ = Γ (???(1S)→ γgg )/ Γ (???(1S)→ ggg )=(3.00±0.13±0.18)% has been determined, from which we deduce values of the strong coupling constant α s =0.225±0.011±0.019 and the QCD scale parameter Λ MS =115±17±28 MeV defined in the modified minimal-subtraction scheme. The shape of the measured spectrum clearly rules out the predictions of the lowest order QCD calculations.

1 data table

Table 1

No description provided.

Intermediate Vector Boson Cross-Sections at the CERN Super Proton Synchrotron Collider and the Number of Neutrino Types

The UA1 collaboration Albajar, C. ; Albrow, M.G. ; Allkofer, O.C. ; et al.

Phys.Lett.B 198 (1987) 271-280, 1987.

Inspire Record 249745 DOI 10.17182/hepdata.30076

We present updated results from the UA1 experiment on cross sections times leptonic branching ratios for intermediate vector bosons produced in proton-antiproton collisions at a centre-of-mass energy of 0.630 TeV. We find that σ·B( W → l βn)=0.63±0.04±0.10 nb and σ·B( Z 0 → l + l − =0.071±0.011 nb where l denotes an average of electron and muon channels. An average over all data (electron and muon channels at 0.546 and 0.630 TeV) gives a ratio of R≡σ·( W → l ν)/σ·B( Z 0 → l + l − ) = 9.1 +1.7 −1.2 . Using current theoretical predictions for this quantity, limits are extracted on the number of light neutrino types. Combining UA1 and UA2 data and imposing the bound N ν ⩾3 we find that N ν ⩽5.9 at 90% CL. Constraints on the mass of the top quark are also discussed.

9 data tables

Table 1

THE CORRESPONDING VALUE FROM UA2 IS BR*SIG = 0.61+-0.10+-0.07.

Table 2

No description provided.

Table 3

THE CORRESPONDING VALUE FROM UA2 IS BR*SIG = 0.57+-0.04+-0.07.

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rivet Analysis
First Observation of $\gamma \gamma \to K^0 \bar{K}^$0

The ARGUS collaboration Albrecht, H. ; Andam, A.A. ; Binder, U. ; et al.

Phys.Lett.B 198 (1987) 255-260, 1987.

Inspire Record 248680 DOI 10.17182/hepdata.30080

The final state K + K − π + π − has been studied in γγ interactions using the ARGUS detector at the e + e − storage ring DORIS II at DESY. Production of the vector meson pair K ∗0 (892) K ∗0 (892) is observed for the first time. The cross section for K + K − π + π − , K ∗0 K − π + +c.c. and K ∗0 K ∗0 are all found to be of the order of a few nb. In the W γγ range accessible, a mean upper limit of 0.5 nb at 95% CL is derived for φϱ 0 production.

6 data tables

Table 1

TOPOLOGICAL CROSS SECTION.

Table 2

(K*0 K*BAR0) cross section.

Table 3

(K*0 K- PI+ + CC) CROSS SECTION WITH (K*0 K*BAR0) REMOVED.

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A Precise Determination of the Electroweak Mixing Angle from Semileptonic Neutrino Scattering

The CHARM collaboration Allaby, J.V. ; Amaldi, U. ; Barbiellini, G. ; et al.

Z.Phys.C 36 (1987) 611, 1987.

Inspire Record 249672 DOI 10.17182/hepdata.15697

The cross-section ratio of neutral-current and charged-current semileptonic interactions of muon-neutrinos on isoscalar nuclei has been measured with the result:Rv=0.3093±0.0031 for hadronic energy larger than 4 GeV. From this ratio we determined the electroweak mixing angle sin2θW, wheremc is the charm-quark mass in GeV/c2. Comparison with direct measurements ofmw andmz determines the radiative shift of the intermediate boson mass Δr=0.077±0.025(exp.)±0.038(syst.), in agreement with the prediction. Assuming the validity of the electroweak standard theory we determined ϱ=0.990−0.013(mc−1.5)±0.009(exp.)±0.003(theor.).

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

STATISTICAL ERROR IN THE VALUE CITED IS REDUCING, WHEN CUT IS MORE STRINGENT?.

DETERMINATION OF THE TOPOLOGICAL CROSS-SECTIONS OF INELASTIC anti-d d INTERACTIONS AT 12-GeV/c

The Dubna-Bucharest-Yerevan-Kosice-Moscow-Prague-Sofiya collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.

JINR-P1-87-523, 1987.

Inspire Record 251575 DOI 10.17182/hepdata.38882

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

rivet Analysis
A Study of Energy-energy Correlations Between 12-{GeV} and 46.8-{GeV} {CM} Energies

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.

Z.Phys.C 36 (1987) 349-361, 1987.

Inspire Record 248660 DOI 10.17182/hepdata.1698

We present data on energy-energy correlations (EEC) and their related asymmetry (AEEC) ine+e− annihilation in the centre of mass energy range 12<W≦46.8 GeV. The energy and angular dependence of the EEC in the central region is well described byOαs2 QCD plus a fragmentation term proportional to${1 \mathord{\left/ {\vphantom {1 {\sqrt s }}} \right. \kern-\nulldelimiterspace} {\sqrt s }}$. BareO(α)s2 QCD reproduces our data for the large angle region of the AEEC. Nonperturbative effects for the latter are estimated with the help of fragmentation models. From various analyses using different approximations, we find that values for$\Lambda _{\overline {MS} } $ in the range 0.1–0.3 GeV give a good description of the data. We also compare analytical calculations in QCD for the EEC in the back-to-back region to our data. The theoretical predictions describe well both the angular and energy dependence of the data in the back-to-back region.

10 data tables

Table 1

Correlation function binned in cos(chi).

Table 2

Correlation function binned in cos(chi).

Table 3

Correlation function binned in cos(chi).

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rivet Analysis
Determination of $\alpha^- s$ From Energy-energy Correlations in $e^+ e^-$ Annihilation at 29-{GeV}

Wood, D.R. ; Petersen, A. ; Abrams, G.S. ; et al.

Phys.Rev.D 37 (1988) 3091, 1988.

Inspire Record 250899 DOI 10.17182/hepdata.23323

We have studied the energy-energy correlation in e+e− annihilation into hadrons at √s =29 GeV using the Mark II detector at the SLAC storage ring PEP. We find to O(αs2) that αs=0.158±0.003±0.008 if hadronization is described by string fragmentation. Independent fragmentation schemes give αs=0.10–0.14, and give poor agreement with the data. A leading-log shower fragmentation model is found to describe the data well.

6 data tables

Table 1

Correlation data from the original PEP-5 detector.

Table 2

Correlation Asymmetry data from the original PEP-5 detector.

Table 3

Correlation data from the upgraded detector.

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CHARACTERISTICS OF FAST SECONDARY NEUTRONS IN p p AND p C-12 INTERACTIONS AT P = 10-GeV/c

Bekmirzaev, R.N. ; Grishin, V.G. ; Dolejsi, J. ; et al.

JINR-P1-87-443, 1987.

Inspire Record 251572 DOI 10.17182/hepdata.9496

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

HADRONS AND GAMMAS ASSOCIATED TO DIMUONS AND J / psi PARTICLES IN pi- C INTERACTIONS AT 38-GeV/c

The RISK collaboration Jani, J. ; Mihalyi, Z. ; Nyitrai, G. ; et al.

JINR-E1-87-397, 1987.

Inspire Record 251044 DOI 10.17182/hepdata.9973

None

7 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Observables

CM Energies (GeV)

Authors Reset

Fast neutron production (p(n) >= 1-GeV/c) in p p and p C-12 interactions at p = 4.2-GeV/c and 10-GeV/c.

rivet Analysis
Determination of $\alpha^- s$ From a Measurement of the Direct Photon Spectrum in $\Upsilon$ (1s) Decays

Intermediate Vector Boson Cross-Sections at the CERN Super Proton Synchrotron Collider and the Number of Neutrino Types

rivet Analysis
First Observation of $\gamma \gamma \to K^0 \bar{K}^$0

A Precise Determination of the Electroweak Mixing Angle from Semileptonic Neutrino Scattering

DETERMINATION OF THE TOPOLOGICAL CROSS-SECTIONS OF INELASTIC anti-d d INTERACTIONS AT 12-GeV/c

rivet Analysis
A Study of Energy-energy Correlations Between 12-{GeV} and 46.8-{GeV} {CM} Energies

rivet Analysis
Determination of $\alpha^- s$ From Energy-energy Correlations in $e^+ e^-$ Annihilation at 29-{GeV}

CHARACTERISTICS OF FAST SECONDARY NEUTRONS IN p p AND p C-12 INTERACTIONS AT P = 10-GeV/c

HADRONS AND GAMMAS ASSOCIATED TO DIMUONS AND J / psi PARTICLES IN pi- C INTERACTIONS AT 38-GeV/c