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MEASUREMENT OF POLARIZATION OF RECOIL PROTONS IN PI0 PHOTOPRODUCTION FOR THETA* (PI0) = 60-degrees IN RESONANCE REGION. (IN RUSSIAN)

Avakian, R.O. ; Avakian, E.O. ; Avetisian, A.E. ; et al.

Sov.J.Nucl.Phys. 37 (1983) 199-201, 1983.

Inspire Record 183972 DOI 10.17182/hepdata.17739

None

1 data table

Table 1

Axis error includes +- 0.0/0.0 contribution (?////NO DISCUSSION OF ERRORS AT ALL).

ELECTROPRODUCTION OF pi0 MESONS ON PROTONS AT W = 1400-MeV TO 2000-MeV, q2 = 0.01-GeV2 TO 0.1-GeV2, AND t = 0.6-GeV2 TO 2.2-GeV**2 CORRESPONDING TO Theta (CM) pi = 145-degrees TO 180-degrees

Blume, H. ; Farber, R. ; Feldmann, N. ; et al.

Z.Phys.C 16 (1983) 283, 1983.

Inspire Record 180101 DOI 10.17182/hepdata.16387

The electroproduction of π0-mesons on protons has been measured with electrons of 1.7 and 2.1 GeV energy in the region of the nucleon resonances at$W = \sqrt {(q + p)^2 }= 1,400 - 2,000MeV$ at rather low values of |q2|=|(e−e′)2|=0.01–0.1 GeV2 but at high values of the nucleon recoil |t|=|(p−p′)2|≈0.6–2.2 GeV2 corresponding to$\Theta _\pi ^{cm}\approx 145^ \circ- 180^ \circ$. Up toW≈1,650 MeV the cross section for π0-production with virtual photons of |q2|≈0.03 GeV2 is only slightly smaller than that with real photons. ForW≳1,700 MeV the cross section at |q2|≈0.03 GeV2 is on average a factor of 2 smaller than that atq2=0 but only slightly higher than that at |q2|≈0.3–1 GeV2.

6 data tables

Table 1

INCLUDING RADIATIVE CORRECTIONS.

Table 2

INCLUDING RADIATIVE CORRECTIONS.

Table 3

INCLUDING RADIATIVE CORRECTIONS.

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Multiplicity Distributions in $p \alpha$ and $\alpha \alpha$ Collisions in the {CERN} {ISR}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.

Phys.Lett.B 119 (1982) 464, 1982.

Inspire Record 179518 DOI 10.17182/hepdata.6665

Measurements of charged particle multiplicity distributions in the central rapidity region in p-p and p-α, and α-α collisions are reported. They are better fitted to the “wounded nucleon” than to the “gluon string” model. The average transverse momenta, for all three reactions, are identical (and almost independent of multiplicity) up to very high multiplicities.

2 data tables

Table 1

THE FIRST PP DATA IS AT 44 GEV, THE SECOND AT 63 GEV.

Table 2

No description provided.

Experimental Study of the a-Dependence of Inclusive Hadron Fragmentation

Barton, D.S. ; Brandenburg, G.W. ; Busza, W. ; et al.

Phys.Rev.D 27 (1983) 2580, 1983.

Inspire Record 12592 DOI 10.17182/hepdata.23823

Data are presented on the inclusive production of π±, K±, p, and p¯ for π+, K+, and protons incident on nuclear targets at 100 GeV. The results cover the kinematic range 30≤P≤88 GeV/c for Pt=0.3 and 0.5 GeV/c. The observed A dependence of the invariant cross sections exhibits remarkable simplicity, which does not naturally follow from current models of particle production. The results show that the hypothesis of limiting fragmentation can be extended to include collisions with nuclei.

1 data table

Table 1

No description provided.

Small Angle Elastic Scattering at the {CERN} Proton Anti-proton Collider

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.

Phys.Lett.B 121 (1983) 77-82, 1983.

Inspire Record 180683 DOI 10.17182/hepdata.66558

3roton-antiproton elastic scattering at cm energy 540 GeV has been studied in the t range 0.14 ⩽ − t ⩽ 0.26 GeV 2 . The data is well fitted by an exponential form exp( bt ) with b = 13.3 ± 1.5 GeV −2 .

2 data tables

Table 1

Elastic Differentiaol Cross Section (545 events). DATA REQUESTED 21 FEB 1983. Data read from plot in paper (29 JAN 2015).

Table 2

No description provided.

An Investigation of Quark and Diquark Fragmentation in Neutrino $p$ and Anti-neutrino $p$ Charged Current Interactions in {BEBC}

The Aachen-Bonn-CERN-Munich-Oxford collaboration Allen, P. ; Grassler, H. ; Lanske, D. ; et al.

Nucl.Phys.B 214 (1983) 369, 1983.

Inspire Record 180772 DOI 10.17182/hepdata.34013

Distributions of the Feynman x variable have been determined for positive and negative pions in charged current neutrino-proton and antineutrino-proton reactions with hadronic energy W > 3 GeV and Bjorken x B > 0.1. The distributions have been corrected for experimental effects such as measurement errors, uncertainties in estimating the neutrino energy and particle misidentification. In the framework of the quark-parton model, the distributions yield information about the fragmentation of forward going u and d quarks and backward going uu and ud diquarks. Approximate Feynman scaling is observed for the invariant Feynman x F distributions. They can be fitted by a power law of the form (1 − | x F |) n as suggested by the dimensional counting rules. Simple isospin relations predicted by the quark-parton model are fulfilled. The fragmentation of diquarks is compared with that of protons into π ± .

2 data tables

Table 1

No description provided.

Table 2

No description provided.

An Experimental Study of Large Angle Elastic Scattering of Charged Mesons and Anti-protons on Protons at 20-{GeV}/$c$ and 30-{GeV}/$c$

The Annecy(LAPP)-CERN-Bohr Inst-Genoa-Oslo-London collaboration Baglin, C. ; Bock, R. ; Brobakken, K. ; et al.

Nucl.Phys.B 216 (1983) 1-39, 1983.

Inspire Record 180922 DOI 10.17182/hepdata.34020

A description is given of an experiment to study elastic scattering of π ± , K ± and p on protons at c.m. scattering angles from 45° to 100° at incident laboratory momenta 20 GeV/ c and 30 GeV/ c . The corresponding t range is from −6.2 (GeV/ c ) 2 to −28 (GeV/ c ) 2 . There are no previous observations for these reactions in this t range. High intensity and large geometrical acceptance were required in order to measure the low cross sections. The experiment used a double-arm spectrometer. MWPCs were used for reconstruction, and threshold and differential Čerenkov counters for identification. Scintillation counters, Čerenkov counters and a hadron calorimeter were used in the trigger. The trigger logic utilized specially designed matrices and a hard wired microprocessor. The π − p elastic scattering cross sections follow approximately the dimensional counting rule from 3.5 GeV/ c .and up to 30 GeV/ c . The cross sections decrease by seven orders of magnitude in this energy range. The data is compared to quark models. None of these models give a comprehensive description of the results. However, some modifications to these models improve their consistency with the data.

8 data tables

Table 1

EARLIER RESULTS GIVEN IN 'A'.

Table 2

No description provided.

Table 3

No description provided.

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Production of Charmonium in 250-GeV mu+ - Iron Interactions

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Nucl.Phys.B 213 (1983) 1-30, 1983.

Inspire Record 180791 DOI 10.17182/hepdata.34060

The production of J/ ϑ and ϑ′ has been measured in 250 GeV muon iron interactions. The measured total cross sections are σ ( μ N → μ J/ ϑ X)=0.74±0.14 nb and σ ( μ N → μϑ ′X)=0.16 ± 0.07 nb. An upper limit on the cross section times branching ratio for ϒ production of BR · σ ( μ N → μϒ X) < 5.2 × 10 −38 cm 2 (at 90% confidence level) is obtained. About half the J/ ϑ cross section is found to have Z ⩾ 0.95 (where Z = E (J/ ϑ / ν ). The first-order photon-gluon fusion model agrees well with the measured Q 2 and ν dependence of the J/ ϑ data and is used to extract the gluon momentum distribution. However, higher order QCD effects are needed to explain the Z distribution of the J/ ϑ and the observed broadening of the P t 2 distribution with decreasing Z . The decay angular distributions of the J/ ϑ are found to be flat in the s -channel frame, but there is evidence for polarisation in the t -channel frame.

5 data tables

Table 1

NUMBERS ARE CROSS-SECTIONS FOR PSI AND PSI(PRIME) BUT CROSS-SECTION*BR.RATIO FOR THE UPSILON.

Table 2

THE COHERENT PRODUCTION IS NOT SUBTRACTED.

Table 3

THE COHERENT PRODUCTION IS SUBTRACTED.