Date

Differential Cross-sections for $\gamma \gamma \to p \bar{p}$ in the Center-of-mass Energy Range From 2.0-{GeV} to 3.1-{GeV}

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 130 (1983) 449-453, 1983.
Inspire Record 191417 DOI 10.17182/hepdata.6654

Exclusive production of proton-antiproton pairs by two photon scattering at CM energies between 2.0 GeV and 3.1 GeV has been measured with the TASSO detector at the e + e − storage ring PETRA. The angular distribution is flat within the accepted CM angular range | cos Θ ∗ |⩽0.7 . The integrated cross section (| cos Θ ∗ |⩽0.6) drops from about 4 nb at 2 GeV to less than 0.5 nb above 3 GeV. For the two-photon production of the η c (2984) and its subsequent decay into proton-antiproton the upper limit Γ(η c →γγ)· B (η c → p p )<0.32 keV (95% CL) is found.

5 data tables

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UPPER LIMIT FOR THE PRODUCT OF THE ETA/C --> GAMMA GAMMA WIDTH AND THE BRANCHING RATIO OF ETA/C --> P AP IS DETERMINED TO BE 0.32 KEV WITH 90 PCT CL.

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Observation of a Spin 6 Neutral Meson R (2510)

The Serpukhov-Brussels-Annecy(LAPP) collaboration Binon, F.G. ; Donskov, S.V. ; Duteil, P. ; et al.
Lett.Nuovo Cim. 39 (1984) 41, 1984.
Inspire Record 191410 DOI 10.17182/hepdata.37330

In a high-statistics experiment (200 events/nanobarn) performed at the 70 GeV IHEP accelerator, a new dipion resonance has been observed in π−p collisions at 38 GeV/c momentum. The gamma-rays in reaction π−p → M0n, M0 → π0π0 → 4γ have been detected in the hodoscope spectrometer GAMS-2000. The new meson, r(2510), has a mass (2510±30) MeV/c2, a width (240±60) MeV/c2 and spin-parityJPC=6++. The production cross-section of the f, h and r mesons decreases exponentially with spin like exp [−0.9J].

1 data table

No description provided.


WEAK NEUTRAL CURRENT EFFECTS IN e+ e- ---> mu+ mu- AT 29-GeV

Fernandez, E. ; Ford, William T. ; Read, Alexander L. ; et al.
SLAC-PUB-3133, 1983.
Inspire Record 190846 DOI 10.17182/hepdata.18659

None

2 data tables

No description provided.

Data extrapolated to full solid angle.


A Comparison of Charged Current Cross-sections and Structure Functions for Neutrino and Anti-neutrinos Beams on Hydrogen and Neon

The BEBC TST Neutrino collaboration Parker, M.A. ; Francois, T. ; Guy, J.G. ; et al.
Nucl.Phys.B 232 (1984) 1-20, 1984.
Inspire Record 192873 DOI 10.17182/hepdata.33899

Using BEBC equipped with a hydrogen-filled neon-surrounded track-sensitive target, the charged current cross sections and structure functions of hydrogen and neon targets traversed by the same neutrinos and antineutrinos are compared directly. The measured total cross-section ratios between hydrogen and neon allow precise total cross-section values for hydrogen to be inferred. Using this normalization, the ν and ν hydrogen data are combined and the quark distributions in free nucleons, parametrised as functions of ξ, are extracted. This free-nucleon parametrisation is then compared directly with the neon data in order to measure nuclear effects such as those recently reported by the EMC collaboration. Only small effects are seen, in excellent agreement with recent SLAC data in a more similar A and q 2 range.

3 data tables

Measured charged current total cross section.

Measured charged current total cross section.

AVERAGE Q**2 IS 6.9GEV**2 FOR NU AND 4.3GEV**2 FOR ANU.


Production of Charmed Mesons in $e^+ e^-$ Annihilation at 10.5-{GeV}

The CLEO collaboration Avery, P. ; Bebek, C. ; Berkelman, Karl ; et al.
Phys.Rev.Lett. 51 (1983) 1139, 1983.
Inspire Record 191835 DOI 10.17182/hepdata.20524

A measurement is presented of the inclusive production of charged D* and neutral D mesons from nonresonant e+e− annihilation in the energy region near the ϒ(4S) resonance. The momentum distribution shows a large contribution at high momenta as expected for heavy quark production. Comparison of the spectrum with several phenomenological models is made. The relative yields of the D* and D mesons indicate that the charm cross section is dominated by the D* contribution.

2 data tables

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A STUDY OF e+ e- ANNIHILATION IN THE 1400-MeV TO 2250-MeV ENERGY RANGE WITH THE MAGNETIC DETECTOR DM2 AT DCI

Augustin, J.E. ; Ayach, L. ; Calcaterra, A. ; et al.
LAL-83-21, 1983.
Inspire Record 192321 DOI 10.17182/hepdata.13242

None

5 data tables

ASSUMING ABS(GE)=ABS(GM).

No description provided.

No description provided.

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Inclusive $\gamma$ and $\pi^0$ Production in $e^+ e^-$ Annihilation at 14-{GeV}, 22-{GeV}, and 34-{GeV} Center-of-mass Energy

The CELLO collaboration Behrend, H.J. ; Fenner, H. ; Schachter, M.J. ; et al.
Z.Phys.C 20 (1983) 207, 1983.
Inspire Record 191415 DOI 10.17182/hepdata.16318

We have measured the scale invariant inclusive photon and π0 cross sections atW=14, 22 and 34 GeV. A comparison with π± data shows no significant difference between neutral and charged pion production. Comparing the integrated cross sections in thex range 0.15<x<1.0 we observe a considerable decrease from 14 GeV to 34 GeV with a statistical significance of 1.5 standard deviations. This is compatible with the expectations for scaling violations from QCD.

8 data tables

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

NUMERICAL VALUES OF DATA SUPPLIED BY H. OBERLACK.

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Observation of Inclusive $\eta$ Production in $e^+ e^-$ Annihilation at {CM} Energies of 34-{GeV}

The JADE collaboration Bartel, W. ; Becker, L. ; Bowdery, C. ; et al.
Phys.Lett.B 130 (1983) 454-458, 1983.
Inspire Record 191416 DOI 10.17182/hepdata.30634

The inclusive production of η mesons at CM energies around 34 GeV has been studied for e + e − annihilation into hadrons. The average number of η-mesons per event is found to be 0.72 ± 0.10 (stat.) ± 0.18 (syst.). The abundance of η's is studied as a function of event shape parameters and it is compared to the corresponding π 0 rates.

2 data tables

No description provided.

DATA REQUESTED FROM AUTHORS.


Measurement of the Neutral Current Coupling Constants in Neutrino and Anti-neutrinos Interactions With Deuterium

The Amsterdam-Bergen-Bologna-Padua-Pisa-Saclay-Turin collaboration Allasia, D. ; Angelini, C. ; Baldini, A. ; et al.
Phys.Lett.B 133 (1983) 129, 1983.
Inspire Record 191539 DOI 10.17182/hepdata.30635

We have measured neutral and charged current interactions of ν μ and ν μ on proton and neutron. From a combination of ratios we determine the neutral current chiral coupling constants. The results are u 2 L = 0.13 ± 0.03, d 2 L = 0.19 ± 0.03, u 2 R = 0.02 ± 0.02 and d 2 R = 0.00 ± 0.02. These results agree with the predictions of the standard SU(2) × U(1) model. The corresponding value of sin 2 θ W is 0.20 ± 0.04.

6 data tables

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Experimental J/psi Hadronic Production from 150-GeV/c to 280-GeV/c

The NA3 collaboration Badier, J. ; Boucrot, J. ; Bourotte, J. ; et al.
Z.Phys.C 20 (1983) 101, 1983.
Inspire Record 191240 DOI 10.17182/hepdata.2212

A detailed study ofJ/ψ hadronic production has been performed in a high statistics experiment (more than 1.5 106J/ψ observed in their dimuon decay mode). Data have been taken with incident π±,K±,p±, on hydrogen and platinum targets, at 150, 200 and 280 GeV/c. We find from the observed nuclear dependance of the cross sections, that about 18% of theJ/ψ are produced diffractively. Using known structure functions of the quarks in the nucleon and in the pion, we derive estimations for the gluon structure functions.

11 data tables

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