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Differences in Leading Baryon Production From $p \bar{p}$ and $p p$ Collisions With $\sqrt{s}=31$-{GeV} at the {CERN} {ISR}

Chauvat, P. ; Cousins, R.D. ; Erhan, S. ; et al.

Phys.Lett.B 127 (1983) 384-388, 1983.

Inspire Record 190333 DOI 10.17182/hepdata.30717

Significant differences are observed between forward-produced Δ ++ (1232) and Λ 0 's in pp interactions and their corresponding anti-particles in p p interactions, as expected from quark counting and single q q annihilation. A possible relationship between these results and the p p -pp total cross section difference is discussed.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Measurement of the Processes $e^+ e^- \to e^+ e^-$ and $e^+ e^- \to \gamma \gamma$ at {PETRA}

The JADE collaboration Bartel, W. ; Becker, L. ; Bowdery, C. ; et al.

Z.Phys.C 19 (1983) 197, 1983.

Inspire Record 191231 DOI 10.17182/hepdata.45206

Cross sections for the reactionse+e−→e+e− (Bhabha scattering) ande+e−→γγ are measured for center-of-mass (c.m.) energies$\sqrt s $ between 12.0 and 34.6 GeV. The results agree with the predictions of Quantum Electrodynamics (QED) and the cut-off parameters are determined. From Bhabha scattering at the highest energy,$\left\langle {\sqrt s } \right\rangle= 34.6 GeV$, the 1 δ limits 0.12<sin2 ϑw<0.38 are obtained for the weak mixing angle. The higher order (α3) QED processese+e−→e+e−γ ande+e−→γγγ are also studied and are found to agree with the α3 QED predictions. A search for excited electrons is carried out by investigating the (e±γ) invariant mass distribution in the reactione+e−→e+e−γ.

3 data tables

Table 1

Total cross sections.

Table 2

Angular distribution.

Table 3

Angular distribution.

Radiative Width of the $K^*$+ (890)

Chandlee, C. ; Berg, D. ; Cihangir, S. ; et al.

Phys.Rev.Lett. 51 (1983) 168, 1983.

Inspire Record 13393 DOI 10.17182/hepdata.20522

Coherent production of Kπ systems observed in the excitation of 200-GeV/c positive kaons on nuclear targets has been analyzed, including both electromagnetic and strong contributions, to yield a new value for the radiative width for the process K*+(890)→K+γ of 51 ± 5 keV.

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.

Study of the $\bar{p} p \to \bar{n} n$ Reaction in the Momentum Range 480-{MeV}/$c$ to 728-{MeV}/$c$

Tsuboyama, T. ; Kubota, Y. ; Sai, F. ; et al.

Phys.Rev.D 28 (1983) 2135, 1983.

Inspire Record 189641 DOI 10.17182/hepdata.23789

The total and differential p¯p charge-exchange cross sections were obtained at seven momenta in the range 480 to 728 MeV/c. The total cross sections are roughly consistent with other data. The momentum dependences of the Legendre coefficients a1a0, a2a0, and a3a0 of the differential cross sections do not agree well with the predictions of the Bryan-Phillips model, unlike the case of elastic scattering.

5 data tables

Table 1

TWO SETS OF DATA ARE GIVEN. THIS FIRST IS THAT PREFERRED USING THE CROSS SECTIONS OF BIZZARI ET AL.

Table 2

SECOND SET USING BURROWS ET AL., CROSS SECTIONS.

Table 3

DATA NORMALIZED TO THE CROSS SECTIONS OF HAMILTON ET AL., PRL 44, 1179 (1980).

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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 $\pi^0$ mesons in muon - hydrogen interactions at 200-GeV

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

Z.Phys.C 18 (1983) 189, 1983.

Inspire Record 189283 DOI 10.17182/hepdata.16369

Thez andpT2 distributions of π0 mesons produced by the interaction of 200 GeV muons on hydrogen are presented. Comparisons are made with other π0 and charged hadron data and with the predictions of perturbative QCD. The data show a rise of 〈pT2〉 withW2 which is consistent with QCD, and withz2 which requires a contribution from a primordialkT. The fraction of total energy which appears as π0 mesons is 0.27±0.05.

1 data table

Table 1

No description provided.