HEPData Search

A test of the QED process e+e- -> gamma gamma (gamma) is reported. The data analysed were collected with the DELPHI detector in 1998 and 1999 at the highest energies achieved at LEP, reaching 202 GeV in the centre-of-mass. The total integrated luminosity amounts to 375.7 pb^{-1}. The differential and total cross-sections for the process e+e- -> gamma gamma were measured, and found to be in agreement with the QED prediction. 95% Confidence Level (C.L.) lower limits on the QED cut-off parameters of Lambda+ > 330 GeV and Lambda- > 320 GeV were derived. A 95% C.L. lower bound on the mass of an excited electron of 311 GeV/c^2 (for lambda_gamma = 1) was obtained. s-channel virtual graviton exchange was searched for, resulting in 95% C.L. lower limits on the string mass scale, M_S: M_S > 713 GeV/c^2 (lambda = 1) and M_S > 691 GeV/c^2 (lambda = -1).

7 data tables

Table 1

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Table 2

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Table 3

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Anti-proton He-4 interactions at 200-MeV/c

Balestra, F. ; Batusov, Yu.A. ; Bendiscioli, G. ; et al.

Phys.Lett.B 305 (1993) 18-22, 1993.

Inspire Record 362745 DOI 10.17182/hepdata.28940

The differential cross sections for antiproton elastic scattering on 4 He at 192.8 MeV/ c are measured. The annihilation cross section σ a = (377.6 ± 8.0) mb, the elastic cross section σ el = (206.3 ± 6.6) mb and the total p 4 He interaction cross section σ tot = (583.9 ± 10.4) mb are determined. The ratio of the real to imaginary part of the forward p 4 He amplitude is found: π =−0.17± 0.33 0.24 . Partial wave analysis reveals that the S, P and D waves are essential in this energy region.

7 data tables

Table 1

Charged prong multiplicity distributions in pbar HE annihilation.

Table 2

Mean charged particle multiplicity in pbar HE4 annihilations.

Table 3

No description provided.

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Elastic scattering of antiprotons by He-4 at 600-MeV/c.

Batusov, Yu.A. ; Bunyatov, S.A. ; Falomkin, I.V. ; et al.

Sov.J.Nucl.Phys. 52 (1990) 776-781, 1990.

Inspire Record 299081 DOI 10.17182/hepdata.47306

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

ANTI-PROTON HE-4 ELASTIC SCATTERING AT 600-MEV/C. (IN RUSSIAN)

Batusov, Yu.A. ; Balestra, F. ; Barbieri, Riccardo ; et al.

DUBNA JINR - N7-88 (88,REC.FEB.89) 15-22, 1988.

Inspire Record 271237 DOI 10.17182/hepdata.9316

None

2 data tables

Table 1

No description provided.

Table 2

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MEASUREMENT OF THE DIFFERENTIAL CROSS-SECTIONS FOR THE PI+ D ---> P P REACTION AT PION ENERGIES OF 280-MEV, 300-MEV, 330-MEV, 357-MEV, 390-MEV, 420-MEV AND 450-MEV

Borkovsky, M.Ya. ; Gaditsky, V.G. ; Gavrilov, G.E. ; et al.

J.Phys.G 11 (1985) 69-83, 1985.

Inspire Record 215606 DOI 10.17182/hepdata.38587

Differential cross sections for the process pi +d to pp at seven energies in the region Tpi =280-450 MeV and in the angular range theta * approximately=4-90 degrees have been measured on the LNPI synchrocyclotron. The results include 94 new data points. The measurements have been carried out using a ten-channel hodoscope set-up. Statistical errors are between 2.5% and 7.8% depending on the scattering angle and Tpi . The data obtained indicate that there is an essential contribution from the partial wave with orbital angular momentum l=3 over the whole energy range considered. The authors also observe a noticeable contribution from the l=4 partial wave to the differential cross sections of the pi +d to pp reaction from Tpi >or=357 MeV. The total cross sections for the process pi +d to pp are also presented.

9 data tables

Table 1

No description provided.

Table 2

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Table 3

No description provided.