Date

Measurements of r and a Search for Heavy Quark Production in e+ e- Annihilation at s**(1/2) = 50-GeV and 52-GeV

The AMY collaboration Sagawa, H. ; Mori, T. ; Abe, K. ; et al.
Phys.Rev.Lett. 60 (1988) 93, 1988.
Inspire Record 251270 DOI 10.17182/hepdata.20143

The ratio R of the cross section for e+e− annihilation into hadronic final states to the QED cross section for muon-pair production is measured to be 4.34±0.45±0.30 and 4.23±0.20±0.21 at c.m. energies of 50 and 52 GeV, respectively. From these values of R and an analysis of the event shapes we deduce a 95%-confidence-level upper limit for the production rate of new heavy charge +23e or −13e quarks to be 0.19 units of R.

1 data table

No description provided.


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

The ARGUS collaboration Albrecht, H. ; Andam, A.A. ; Binder, U. ; et al.
Phys.Lett.B 199 (1987) 291-296, 1987.
Inspire Record 248655 DOI 10.17182/hepdata.30061

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

No description provided.


The Real Part of the Proton - anti-Proton Elastic Scattering Amplitude at the Center-Of-Mass Energy of 546-GeV

The UA4 collaboration Bernard, Denis ; Bozzo, M. ; Braccini, P.L. ; et al.
Phys.Lett.B 198 (1987) 583, 1987.
Inspire Record 249671 DOI 10.17182/hepdata.30077

Proton-antiproton elastic scattering was measured at the CERN SPS Collider at the centr-of-mass energy s =546 GeV in the Coulomb interference region. The data provide information on the phase of the hadronic amplitude in the forward direction. The conventional analysis gives for the ratio ϱ of the real to the imaginary part of the hadronic amplitude the result ϱ =0.24±0.04.

2 data tables

Axis error includes +- 0.025/0.025 contribution (Normalisation was fixed using a previous UA4 measurement of the total cross section: sig(name=tot)*(1 + alpha**2)).

Best estimate of alpha(rho).


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

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

No description provided.

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

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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

TOPOLOGICAL CROSS SECTION.

(K*0 K*BAR0) cross section.

(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

No description provided.

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


Tensor Meson Excitation in the Reaction $\gamma \gamma \to K^0_S K^0_S$

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Lackas, W. ; et al.
Z.Phys.C 37 (1988) 329, 1988.
Inspire Record 250982 DOI 10.17182/hepdata.15690

In the analysis of the reactione+e−→e+e−KS0Ks0 clear evidence for exclusive γγ→f2′ resonance production is observed. The productΓγγ ·B(f2′→K\(\bar K\)) is measured to be 0.10−0.03−0.02+0.04+0.03 keV independent of ana priori assumption on the helicity structure. Our data are consistent with a pure helicity 2 contribution and we derive an upper limit for the ratioΓγγ(0)/Γγγ. The absence of events in the mass region around 1.3 GeV clearly proves destructivef2−a2 interference and allows to measure the relative phases betweenf2,a2 andf2′. Upper limits on the production of the glueball candidate statesf2(1720) andX(2230) as well as theKS0KS0-continuum are given.

1 data table

Data read from graph.


Correlations Among Particles Produced in Proton Interactions With Emulsion Nuclei at 800-{GeV}

Barbier, L.M. ; Jones, W.V. ; Wefel, J.P. ; et al.
Phys.Rev.D 37 (1988) 1113, 1988.
Inspire Record 256580 DOI 10.17182/hepdata.3823

Correlations among the produced particles in interactions of 800-GeV protons with nuclei in photographic emulsion provide evidence for nonindependent production of the secondary particles. Assuming particle production in clusters, the analysis implies an average multiplicity of about 3 charged particles per cluster.

6 data tables

No description provided.

No description provided.

IN THIS TABLE ETARAP(P=3)=ETARAP(P=4).

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Strong Energy Dependence of the Analyzing Power in the $p p \to d \pi^+$ Reaction and the Question of an Isovector Dibaryon Resonance. 2.

Bertini, R. ; Roy, G. ; Durand, J.M. ; et al.
Phys.Lett.B 203 (1988) 18-21, 1988.
Inspire Record 247925 DOI 10.17182/hepdata.29981

Forward angular distributions of the analysing power for the pp→d π + reaction have been measured at six energies T p =1.2, 1.4, 1.6, 1.8, 2.0, 2.3 GeV. A strong energy dependence is observed for A y 0 ( t =0) and A y 0 ( θ CM π =90°). The data are compared with the backward angular distributions previously published and suggest the existence of a resonant state in the pp system at the approximate energy of 2.7 GeV.

6 data tables

No description provided.

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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

No description provided.

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