HEPData Search

Showing 10 of 2574 results

Search for New Heavy Quarks at the CERN Proton - anti-Proton Collider

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

Z.Phys.C 37 (1988) 505-525, 1988.

Inspire Record 250763 DOI 10.17182/hepdata.15651

A search has also been made for a fourth generation, charge 1/3 quark (b'). Assuming that theb' mass is smaller than that of the top quark and that it can-not be produced inW decays, the mass limits, using the above procedures, are respectivelymb'>32 GeV/c2 andmb'>44 GeV/c2, both at 95% confidence level.

0 data tables

High Transverse Momentum $J/\psi$ Production at the {CERN} Proton - Anti-proton Collider

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

Phys.Lett.B 200 (1988) 380-390, 1988.

Inspire Record 250764 DOI 10.17182/hepdata.28173

We have studied high transverse momentum J/ψ production in p p interactions at s =630 GeV . The measured cross section times branching fraction for J/ψ→μ + μ − production with p T ⩾5 GeV / c and | y |<2.0 is 7.5±0.7±1.2 nb . The event topology is used to establish that there is J/ψ production from both the direct production of c c bound states and the decay of B hadrons. The inferred yield of J/ψ from beauty decays is compatible with our estimates of beauty production in other channels.

3 data tables

Table 1

Table 2

Data extracted from figure with g3data.

Table 3

Data extracted from figure with g3data.

NEUTRAL MESONS WHICH DECAY INTO 4 pi0

The Serpukhov-Brussels-Los Alamos-Annecy(LAPP) collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 198 (1987) 286-291, 1987.

Inspire Record 250768 DOI 10.17182/hepdata.30106

Data on the 4π 0 decay mode of mesons have been obtained in a search for glueballs performed at the CERN SPS with the GAMS-4000 multiphoton spectrometer. A new tensor glueball candidate X(1810) appears as a clear peak in the 4π 0 mass spectrum. The 4π 0 decay of G(1590) is also observed. The measured value of BR(G→4 π 0 )/BR(G→ ηη )=0.8±0.3 further supports the glueball assignment of this scalar particle. The rate decay of f(1270) into 4π 0 has been measured: BR(f→4 π 0 ) = (3±1)×10 −3 .

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

The Transverse Energy Distribution in $^{16}$O - Nucleus Collisions at 60-{GeV} and 200-{GeV} Per Nucleon

The HELIOS collaboration Akesson, T. ; Almehed, S. ; Angelis, A.L.S. ; et al.

Z.Phys.C 38 (1988) 383, 1988.

Inspire Record 250767 DOI 10.17182/hepdata.15648

None

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

A Study of Bhabha Scattering at {PETRA} Energies

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

Z.Phys.C 37 (1988) 171, 1988.

Inspire Record 249557 DOI 10.17182/hepdata.45173

We report on high statistics Bhabha scattering data taken with the TASSO experiment at PETRA at center of mass energies from 12 GeV to 46.8 GeV. We present an analysis in terms of electroweak parameters of the standard model, give limits on QED cut-off parameters and look for possible signs of compositeness.

7 data tables

Table 1

Axis error includes +- 1/1 contribution (The overall uncertainty in the bin-to-bin polar acceptance due to shower corrections, trigger and reconstruction efficiencies was estimated to be less than 1% and was added in quadrature to the statistical errorsData have been corrected for qed radiative effects up to order alpha**3 (F.A.Berends, R.Kleiss, Nucl.Phys.B206(1983)61)//Weak radiative corrections have not yet been provided in a form of a Monte Carlo generator program, but are estimated to be negligible at PETRA energies (M.Bohm, A.Denner, W.Hollik, DESY-86-165)).

Table 2

Table 3

More…

rivet Analysis
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

Table 1

No description provided.

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.

More…

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.

More…

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

Table 1

No description provided.

Table 2

No description provided.

Table 3

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

More…

A Measurement of the Inclusive $\pi^0$ and $\eta$ Production Cross-sections at High $p_T$ in $p \bar{p}$ and $p p$ Collisions at $\sqrt{s}=24$.3-{GeV}

The UA6 & CERN-Lausanne-Michigan-Rockefeller collaborations Antille, J. ; Baumann, S. ; Bernasconi, A. ; et al.

Phys.Lett.B 194 (1987) 568, 1987.

Inspire Record 247579 DOI 10.17182/hepdata.30119

Inclusive π 0 and η production at large transverse momentum were studied in both p̄p and pp interactions at √ s = 24.3 GeV. The experiment was performed using an internal molecular hydrogen gas jet target in the CERN SPS collider. No significant differences between production in p̄p and pp were observed in the transverse momentum range 2.5 < P T < 5.1 GeV/ c .

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Date

Collaboration

Subject_areas

Phrases

Reactions

Observables

CM Energies (GeV)

Authors Reset

Search for New Heavy Quarks at the CERN Proton - anti-Proton Collider

High Transverse Momentum $J/\psi$ Production at the {CERN} Proton - Anti-proton Collider

NEUTRAL MESONS WHICH DECAY INTO 4 pi0

The Transverse Energy Distribution in $^{16}$O - Nucleus Collisions at 60-{GeV} and 200-{GeV} Per Nucleon

A Study of Bhabha Scattering at {PETRA} Energies

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

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

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

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

A Measurement of the Inclusive $\pi^0$ and $\eta$ Production Cross-sections at High $p_T$ in $p \bar{p}$ and $p p$ Collisions at $\sqrt{s}=24$.3-{GeV}