Deschizeaux, B.
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A Model Independent Second Order Determination of the Strong Coupling Constant $\alpha^- s$

Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rev.Lett. 50 (1983) 2051, 1983.
Inspire Record 189724 DOI 10.17182/hepdata.3086

With use of the MARK-J detector at s=34.7 GeV 21 000 e+e−→hadron events have been collected. By measurement of the asymmetry in angular energy correlations the strong coupling constant αs=0.13±0.01 (statistical)±0.02 (systematic) is determined, in complete second order, and independent of the fragmentation models and QCD cutoff values used.

2 data tables
Table 1

DATA REQUESTED FROM THE AUTHORS.

Table 2

No description provided.


Positive Pion Photoproduction From Hydrogen at Photon Energies Between 500-{MeV} and 1400-{MeV} in Forward Direction

Althoff, K.H. ; Anton, G. ; Bock, B. ; et al.
Z.Phys.C 18 (1983) 199, 1983.
Inspire Record 189703 DOI 10.17182/hepdata.16352

The differential cross section of the reactionγ+p→π+ was measured at pion CM-angles of 20° and 30° for photon energies between 500 MeV and 1,400 MeV. The pions were detected in a magnetic spectrometer. By measuring each pion trajectory and by offline calculation of the initial pion parameters an energy resolution of about 2.5% FWHM was achieved. The results complete a set of data which were measured in recent years at the Bonn 2.5 GeV synchrotron. In comparison to photoproduction analyses two effects were revealed: The η cusp appears in the energy dependence of the cross section as a sharp drop atKγ=710 MeV. In the region of the third resonance the data show a greater enhancement than predicted by most of the analyses.

1 data table
Table 1

No description provided.


CHARM PHOTOPRODUCTION CROSS-SECTION AT 20-GeV

Abe, K. ; Bacon, T.C. ; Ballam, Joseph ; et al.
Phys.Rev.Lett. 51 (1983) 156, 1983.
Inspire Record 189662 DOI 10.17182/hepdata.20508

Forty-seven charm events have been observed in an exposure of the SLAC Hybrid Facility bubble chamber to a 20-GeV backward-scattered laser beam. Thirty-seven events survive all the necessary cuts imposed. Based on this number the total charm cross section is calculated to be 63−28+33 nb.

1 data table
Table 1

No description provided.


Fragmentation of Heavy Quarks Produced in $e^+ e^-$ Annihilation

Fernandez, E. ; Ford, William T. ; Read, Alexander L. ; et al.
Phys.Rev.Lett. 50 (1983) 2054, 1983.
Inspire Record 189417 DOI 10.17182/hepdata.20548

Identification of muons in hadronic events from e+e− annihilation observed in the MAC detector at the storage ring PEP provides flavor tagging of heavy primary quarks. A sample enriched in events from bb¯ production is obtained and the b-quark fragmentation function is inferred from the momentum spectrum of the muons. The b quark is found to fragment predominantly with high values of z, with 〈zb〉=0.8±0.1, and to have an over-all semimuonic branching fraction of (15.5−2.9+5.4)%.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Experimental Study of the Hadronic Photon Structure Function

The CELLO collaboration Behrend, H.J. ; Fenner, H. ; Gumpel, U. ; et al.
Phys.Lett.B 126 (1983) 391-397, 1983.
Inspire Record 198110 DOI 10.17182/hepdata.30720

We have measured at PETRA the process e γ → e + hadrons at an average Q 2 value of 9 GeV 2 / c 2 . The total number of observed events attributed to this process is 215. Our data are compared to calculations based on the estimation of the photon structure function F 2 in the quark parton model and in QCD.

1 data table
Table 1

No description provided.


Production of $\pi^0$ and Eta0 at 11-degrees in $p p$ Collisions at $\sqrt{s}=63$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Z.Phys.C 18 (1983) 5, 1983.
Inspire Record 188928 DOI 10.17182/hepdata.16326

The inclusive π0 production cross-section and the η/π0 ratio have been measured inpp collisions at\(\sqrt s= 63 GeV\) at the CERN Intersecting Storage Rings in the rapidity range 2.00

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Inclusive electron Production in e+ e- Annihilation at 29-GeV

Nelson, M.E. ; Blondel, A. ; Trilling, G. ; et al.
Phys.Rev.Lett. 50 (1983) 1542, 1983.
Inspire Record 188964 DOI 10.17182/hepdata.38161

The total momentum and transverse momentum spectra of electrons in e+e− annihilation at 29 GeV have been measured. The inclusive cross section is determined to be 14.4±1.6±5.2 pb for momenta greater than 2 GeV/c. The average semielectronic branching ratios of charm and bottom quarks are measured to be (6.3±1.2±2.1)% and (11.6±2.1±1.7)%, respectively. The fragmentation function for bottom quarks is determined to be peaked at high z, with 〈z〉b=0.75±0.05±0.04.

2 data tables
Table 1

PT is the transverse momentum of the muon relative to the event thrust axis.

Table 2

PT is the transverse momentum of the muon relative to the event thrust axis.


Photoproduction of an Isoscalar 3$\pi$ Resonance at 1.67 GeV

The Bonn-CERN-Glasgow-Lancaster-Manchester-Paris-Rutherford-Sheffield collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Phys.Lett.B 127 (1983) 132-136, 1983.
Inspire Record 189046 DOI 10.17182/hepdata.30699

A ϱπ enhancement with mass 1.67 ± 0.02GeV and width 0.16 ± 0.02GeV is observed in the channel γp→pπ + π − π 0 . Assuming an incoherent background, the cross section × branching ratio is 100 ± 20 nb. A spin-parity analysis favours J P = 1 − . The enhancement is most simply interpreted as a radial recurrence of the ω meson.

1 data table
Table 1

No description provided.


High $p_T$ Direct Photon Production at 11-degrees in $p p$ Collisions at $\sqrt{s}=63$-{GeV}

The Axial Field Spectrometer collaboration Akesson, T. ; Albrow, M.G. ; Almehed, S. ; et al.
Phys.Lett.B 123 (1983) 367-372, 1983.
Inspire Record 188929 DOI 10.17182/hepdata.30744

The production of direct photons has been measured relative to π 0 's in the rapidity range 2.00 < y < 2.75 in pp collisions at s = 63 GeV at the CERN Intersecting Storage Rings. The γ/π 0 ratio increases from ⪅2% at p T = 1.5 GeV/ c to ∼8% at p T = 4.25 GeV/ c , similar to the value observed near 90°. The results indicate no strong enhancement of single-photon production due to quark bremsstrahlung in this kinematic region.

1 data table
Table 1

No description provided.


The Reaction $\gamma p \to p \omega \pi^+ \pi^-$ for Photon Energies of 25-{GeV} - 50-{GeV}

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Nucl.Phys.B 229 (1983) 269-283, 1983.
Inspire Record 189045 DOI 10.17182/hepdata.33921

Measurements of the reaction γ p → p ωπ + π − are reported for photon energies 25–50 GeV. Particular attention is paid to ωπ + π − masses < 2 GeV. A search is made for ω′ or φ′ partners of the ϱ′(1600). Evidence is presented against the existence of narrow states and against the production of a broad state by an s -channel helicity conserving mechanism.

1 data table
Table 1

No description provided.