Fernandez, C.
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rivet Analysis
Total Cross-Section for Hadron Production by e+ e- Annihilation at PETRA Energies

The JADE collaboration Bartel, W. ; Canzler, T. ; Cords, D. ; et al.
Phys.Lett.B 88 (1979) 171-176, 1979.
Inspire Record 142874 DOI 10.17182/hepdata.27277

The cross section for the process e + e − → multihadrons has been measured at the highest PETRA energies. We measure R (the total cross section in units of the point-like e + e - → μ + μ - cross section) to be 2.9 ± 0.7, 4.0 ± 0.5, 4.6 ± 0.4 and 4.2 ± 0.6 at s of 22, 27.7, 30 and 31.6 GeV, respectively. The observed average multiplicity, together with existing low energy data, indicate a rapid increase in multiplicity with increasing energy.

2 data tables
Table 1

STATISTICAL ERRORS ONLY. RADIATIVE CORRECTIONS APPLIED AND TAU HEAVY LEPTON CONTRIBUTION SUBTRACTED. AVERAGE VALUE OF R FOR ALL THESE DATA IS 4.14 +- 0.26.

Table 2

AVERAGE CHARGE MULTIPLICITY. ADDITIONAL, SYSTEMATIC ERROR IS ABOUT 1.5.


Study of the Reaction $\bar{\nu} p \to \mu^+ p \pi^-$

Barish, S.J. ; Brock, R. ; Engler, A. ; et al.
Phys.Lett.B 91 (1980) 161, 1980.
Inspire Record 8430 DOI 10.17182/hepdata.51335

We present data on the reaction ν p → μ + pπ − from an exposure of the Fermilab 15 ft hydrogen bubble chamber. The channel cross section for 5 GeV < E ν < 70 GeV and M( p π − ) < 1.9 GeV is σ = (27 ± 5) × 10 −40 cm 2 . This cross section is dominated by the I = 1 2 production amplitude.

1 data table
Table 1

No description provided.


Experimental Proof of the Existence of the A1 Meson

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 281-284, 1980.
Inspire Record 143044 DOI 10.17182/hepdata.27272

In partial wave analyses of the ( π − π − π + ) system, substantial shape changes of the 1 + S ( ϱπ ) intensity as a function of t , and relative phase changes of ≈ 90°, provide compelling evidence for a resonant A 1 of mass ≈ 1280 MeV and width ≈ 300 MeV.

1 data table
Table 1

No description provided.


3 $\pi$ Resonances in 2- Partial Waves

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 285-289, 1980.
Inspire Record 143045 DOI 10.17182/hepdata.27275

The J PC = 2 −+ partial wave intensities and their large phase changes prove the resonant nature of the A 3 meson (mass ≈ 1670 MeV, width ≈ 210 MeV). The decay modes are f 0 π , ϱ 0 π , and ϵ 0 π . Evidence is found for a further 2 − enhancement.

1 data table
Table 1

No description provided.


A2 Meson Production at 63-{GeV} and 94-{GeV} in the Reaction $\pi^- p \to \pi^- \pi^- \pi^+ p$

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 276-280, 1980.
Inspire Record 143255 DOI 10.17182/hepdata.27274

The A 2 meson is studied in the decay mode ϱ 0 π − using partial wave analyses of 600 000 events from the reaction π − p→ π − π − π + p at 63 and 94 GeV incident momentum. Common production mechanisms are indicated for this resonance and diffractive 1 + and 2 − components.

1 data table
Table 1

No description provided.


rivet Analysis
Search for a 'Top' Threshold in Hadronic $e^+ e^-$ Annihilation at Energies Between 22-{GeV} and 31.6-{GeV}

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 86 (1979) 413-417, 1979.
Inspire Record 142517 DOI 10.17182/hepdata.27295

Results on e + e − annihilation into hadrons at c.m. energies between 22 and 31.6 GeV are presented. The data were accumulated with the PLUTO detector at PETRA. The events are dominantly of the two-jet type. The value of the relative hadronic cross section R =3.88 ± 0.22 along with the details of the sphericity and thrust distribution rule out an open (tt̄) channel (Q t = 2 3 ) below 30 GeV. The inclusive muon results support the above conclusion.

1 data table
Table 1

CROSS SECTIONS CORRECTED FOR BEAM-GAS SCATTERING BACKGROUND, INITIAL STATE RADIATION, TAU HEAVY LEPTON CONTRIBUTION AND TWO-PHOTON EVENTS.


TASSO RESULTS ON e+ e- ANNIHILATION BETWEEN 13-GeV AND 31.6-GeV AND EVIDENCE FOR THREE JET EVENTS

The TASSO collaboration Wolf, G. ; Brandelik, R. ; Braunschweig, W. ; et al.
eConf C790823 (1979) 34, 1979.
Inspire Record 142614 DOI 10.17182/hepdata.45227

None

2 data tables
Table 1

CORRECTIONS HAVE BEEN APPLIED FOR CONTRIBUTIONS FROM BEAM-GAS SCATTERING, TWO PHOTON SCATTERING, TAU HEAVY LEPTON PAIR PRODUCTION, AND FOR RADIATIVE EFFECTS. THE 13 AND 17 GEV MEASUREMENTS WERE PREVIOUSLY REPORTED IN R. BRANDELIK ET AL., PL 83B, 261 (1979).

Table 2

PRELIMINARY INCLUSIVE CHARGED PARTICLE DISTRIBUTIONS.


Evidence for Planar Events in e+ e- Annihilation at High-Energies

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 86 (1979) 243-249, 1979.
Inspire Record 142123 DOI 10.17182/hepdata.27312

Hadron jets produced in e + e − annihilation between 13 GeV and 31.6 GeV in c.m. at PETRA are analyzed. The transverse momentum of the jets is found to increase strongly with c.m. energy. The broadening of the jets is not uniform in azimuthal angle around the quark direction but tends to yield planar events with large and growing transverse momenta in the plane and smaller transverse momenta normal to the plane. The simple q q collinear jet picture is ruled out. The observation of planar events shows that there are three basic particles in the final state. Indeed, several events with three well-separated jets of hadrons are observed at the highest energies. This occurs naturally when the outgoing quark radiates a hard noncollinear gluon, i.e., e + e − → q q g with the quarks and the gluons fragmenting into hadrons with limited transverse momenta.

1 data table
Table 1

NORMALIZED TRANSVERSE MOMENTUM DISTRIBUTION WITH RESPECT TO THE SPHERICITY AXIS AT 13, 17, AND 27.4 TO 31.6 GEV.


X Dependence of the Proton Structure Functions From Inelastic Anti-neutrino - Proton Scattering

Fernandez, E. ; Barnes, V.E. ; Carman, T.S. ; et al.
Phys.Rev.Lett. 43 (1979) 1975, 1979.
Inspire Record 8235 DOI 10.17182/hepdata.20741

From an analysis of 2275 ν¯p→μ++X0 events at an average Q2 of 4.5 GeV2, there are presented the first measurements, up to one undetermined overall normalization constant, of the x dependence of the proton structure functions using antineutrinos, and of the u and d¯+s¯ quark distributions. The result for u(x) is in good agreement with models based on fits to electron and muon scattering data. With u(x) normalized to those models the absolute antiquark momentum distribution x[d¯x+s¯(x)] in the proton is determined.

1 data table
Table 1

No description provided.


The hadronic final state in $e^{+}e^{-}$ annihilation at c.m. energies of 13, 17 and 27.4 GeV

The TASSO collaboration Cashmore, R.J. ; Brandelik, R. ; Braunschweig, W. ; et al.
1 (1979) 330-337, 1979.
Inspire Record 142275 DOI 10.17182/hepdata.45234

Results on the hadronic final state in e/sup +/e/sup -/ annihilation at 13, 17 and 27.4 GeV are presented. There is no compelling evidence for the existence of the t quark in these data, which are in general agreement with a simple quark parton model. Some tentative indications of QCD effects are observed in the p/sub T//sup 2/ distributions.

2 data tables
Table 1

TAU HEAVY LEPTON CONTRIBUTION SUBTRACTED.

Table 2

INCLUSIVE HADRON SPECTRUM. THESE DATA AT 13, 17 AND 27.4 GEV ON S*D(SIG)/DX ARE INCLUDED IN THE RECORD OF R. BRANDELIK ET AL., PL 89B, 418 (1980).