HEPData Search

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Low Mass Electron Pair Anomaly in 17-{GeV}/c $\pi^- P$ Collisions

Stekas, J. ; Abshire, G. ; Adams, M.R. ; et al.

Phys.Rev.Lett. 47 (1981) 1686-1689, 1981.

Inspire Record 172147 DOI 10.17182/hepdata.20624

Inclusive e+e− production in 17-GeV/c π−p collisions has been measured. An excess of e+e− pairs over those from known sources for 0.1<~mee<~0.6 GeV and x<0.5 was found. No evidence is found for enhancements in specific final states involving electrons and photons or charged particles. The photon multiplicity associated with these pairs is measured.

1 data table

Table 1

No description provided.

Total Cross-sections for $\nu_\mu$ and $\bar{\nu}_\mu$ Charged Current Interactions Between 20-{GeV} and 200-{GeV}

The Aachen-Bonn-CERN-Democritos-London-Oxford-Saclay collaboration Bosetti, P. ; Deden, H. ; Fritze, P. ; et al.

Phys.Lett.B 110 (1982) 167-172, 1982.

Inspire Record 169123 DOI 10.17182/hepdata.30976

Exposures of the Ne/H 2 filled Big European Bubble Chamber (BEBC) to a dichromatic neutrino (antineutrino) beam produced by 400 GeV protons of the CERN SPS yielded ∼ 3100 events with a negative, and ∼ 1100 with a positive, muon. The neutrino flux is determined from the muon flux in the shielding. Assuming a linear energy dependence of the cross section, the values σ E between 20 and 200 GeV are found to be 0.657 ± 0.012 (stat.) ± 0.027 (syst.) and 0.309 ± 0.009 (stat.) ± 0.013 (syst.) cm 2 (GeV nucleon) −1 , for neutrinos and antineutrinos, respectively. The scaling variable q 2 E decreases significantly with increasing energy both for neutrinos and antineutrinos.

3 data tables

Table 1

Measured charged current total cross section.

Table 2

Measured charged current total cross section.

Table 3

No description provided.

$J/\psi$ Photoproduction from 60-GeV/c to 300-GeV/c

Binkley, Morris E. ; Bohler, C. ; Butler, J. ; et al.

Phys.Rev.Lett. 48 (1982) 73, 1982.

Inspire Record 168767 DOI 10.17182/hepdata.20597

Measurements of the energy and t dependence of diffractive Jψ photoproduction are presented. A significant rise in the cross section over the energy range 60-300 GeV is observed. It is found that (30±4)% of the events are inelastic.

1 data table

Table 1

No description provided.

Measurements of $\pi^- p$ Forward Elastic Scattering at High-energies

Burq, J.P. ; Chemarin, M. ; Chevallier, M. ; et al.

Phys.Lett.B 109 (1982) 111, 1982.

Inspire Record 166767 DOI 10.17182/hepdata.31011

The differential cross section of π − p scattering has been measured in the energy region 100–345 GeV and in the t -range 0.002<| t |< 0.04 (GeV/ c ) 2 . The real part of the π − p scattering amplitude has been extracted from the data. The results show that the real part continues to increase with energy. The energy dependence of the slope parameter has also been determined. The shrinkage found expressed in terms of the slope of the pomeron trajectory is2 α ′ p =0.23±0.04 (GeV/ c ) −2 . This agrees with the energy dependence found at larger| t |-values.

1 data table

Table 1

RE(AMP)/IM(AMP) (REAL/IMAG) AND SLOPE PARAMETERS DEDUCED FROM A FIT TO D(SIG)/DT IN T HE COULOMB INTERFERENCE REGION (-T = 0.002 TO 0.04 GEV**2).

Experimental Results on $p p$ Forward Elastic Scattering and the Possibility of Universal Shrinkage of the Hadronic Diffraction Cone

Burq, J.P. ; Chemarin, M. ; Chevallier, M. ; et al.

Phys.Lett.B 109 (1982) 124-128, 1982.

Inspire Record 168617 DOI 10.17182/hepdata.31001

The differential cross section of pp scattering has been measured in the energy region 100–300 GeV and in the t -range 0.002 < | t | < 0.04 (GeV/| c ) 2 . The results on the real part of the scattering amplitude agrees with dispersion relation calculations. We also report on our determination of the slope parameter b together with an analysis of the world data of b for different hadrons and different t -values. It is shown that the data are consistent with the hypothesis of a universal shrinkage of the hadronic diffraction cone at high energies.

1 data table

Table 1

FROM FITS TO D(SIG)/DT IN THE COULOMB-NUCLEAR INTERFERENCE REGION, USING TOTAL CROSS SECTION VALUES FROM A. S. CARROLL ET AL., PL 80B, 423 (1979). ERRORS INCLUDE STATISTICAL ERRORS AND ERRORS IN NORMALIZATION AND IN SIG.

CHARGED PARTICLE MULTIPLICITY DISTRIBUTION IN anti-p p INTERACTIONS AT 22.4-GeV/c

The Dubna-Alma Ata-Helsinki-Kosice-Moscow-Prague-Tbilisi collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Gramenitsky, I.M. ; et al.

Sov.J.Nucl.Phys. 36 (1982) 234, 1982.

Inspire Record 169806 DOI 10.17182/hepdata.39549

None

1 data table

Table 1

No description provided.

Energy Dependence of Jet Measures in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.

Z.Phys.C 12 (1982) 297, 1982.

Inspire Record 169193 DOI 10.17182/hepdata.16424

The jet character of the hadronic final states produced ine+e− annihilations is studied in terms of jet measures such as thrust, sphericity, jet opening angle and jet masses, in the energy range 7.7 to 31.6 GeV. All distributions and averages have been corrected for detector effects and initial state radiation. The energy dependence of the averages of these jet quantities is used to estimate the contributions due to perturbative QCD and fragmentation effects. Correlations between the jet measures and the multiplicity of charged hadrons are also presented.

12 data tables

Table 1

DIFFERENTIAL THRUST DISTRIBUTIONS WHERE THRUST IS MAX(SUM(ABS(PLONG))/SUM(ABS(P))).

Table 2

MEAN THRUST VALUES AS A FUNCTION OF CM ENERGY.

Table 3

DIFFERENTIAL SPERICITY DISTRIBUTIONS WHERE SPHERICITY IS 3/2*MIN(SUM(PT**2)/SUM(ABS(P))).

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Study of Inclusive Production of Boson Resonances in $\bar{p} p$ Interactions at 32-{GeV}/$c$

The French-Soviet & CERN-Soviet collaborations Starchenko, E.A. ; Chekulaev, S.V. ; Galyaev, N.A. ; et al.

Z.Phys.C 16 (1983) 181, 1983.

Inspire Record 168177 DOI 10.17182/hepdata.22268

The inclusive production ofK*±(890), ρρ(770), ω0(780) andf0(1,270) mesons is studied in$\bar pp$ experiment at 32GeV/c in the MIRABELLE bubble chamber by the analysis of (K0π±) and (π+π−) invariant mass distributions. The inclusive cross sections are σ(K*±)=2.45±0.30 mb, σ(ρ0)=8.8 ±0.9 mb, σ(ω+)≃6.2 mb, and σ(f0)=2.2±0.7 mb. The C.M. longitudinal distribution of theK*±(890) is slightly shifted to the primary particles fragmentation regions; the ρ0 is produced more centrally. The studied mesons alone are responsible for 40% of final state poins. The production features of various resonances are compared with quark models predictions.

13 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Multiplicity Distributions in Anti-muon Neutrino $p$ Interactions

Derrick, M. ; Gregory, P. ; LoPinto, F. ; et al.

Phys.Rev.D 25 (1982) 624, 1982.

Inspire Record 11189 DOI 10.17182/hepdata.23975

We present the multiplicity distributions of the hadrons produced in antineutrinoproton interactions. The data sample, which consists of 2025 charged-current events with antineutrino energy greater than 5 GeV, comes from exposures of the 15-foot hydrogen bubble chamber to the broad-band antineutrino beam at Fermilab. The distribution in hadronic mass W has an average value of 3.7 GeV but extends up to 10 GeV. The mean multiplicity of charged hadrons depends on the hadronic mass W and varies as 〈nch〉=(−0.44±0.13)+(1.48±0.06)lnW2 for W2>4 GeV2. The mean multiplicities for events with three or more charged tracks averaged over the total data sample are 〈n−〉=1.68±0.03 and 〈n0〉=1.11±0.07 for π− and π0 production, respectively. The mean π0 multiplicity is found to increase slowly with n−. The integrated correlation coefficient f2−− and the dispersion D− are given as a function of n−. When compared to the distributions characteristic of other leptonic and hadronic reactions, we find a similarity between the ν¯ data and results from hadronic reactions that have no diffractive component. Multiplicity data for the heavier particles K0, ρ0, and Λ are also summarized. The pion multiplicities in the current fragmentation region exceed those for the target fragmentation at all W values. They also satisfy the isospin relation 2〈n0〉=〈n+〉+〈n−〉 required for the fragmentation of an I=12 quark when a W>4 GeV selection is imposed.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.