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Search for a Threshold Enhancement in the $\gamma (p) \to$ Charmed Baryon + Charmed Meson Cross-section

The SLAC Hybrid Facility Photon collaboration Abe, K. ; Bacon, T.C. ; Bingham, H.H. ; et al.

Phys.Rev.D 30 (1984) 694, 1984.

Inspire Record 200010 DOI 10.17182/hepdata.23592

Results of a search for a predicted enhancement of several microbarns in the charm-photoproduction cross section just above threshold are reported. No charm decays were detected, from which an upper limit to the charm cross section of 94 nb (90% C.L.) at Eγ≃10 GeV was obtained. Upper limits in the range 270 to 450 nb were also obtained for the peak cross sections for threshold enhancements in γp→D−Σc++ and similar channels.

2 data tables

Table 1

UPPER LIMIT TO AVERAGE CHARM CROSS SECTION.

Table 2

UPPER LIMITS TO INDIVIDUAL CHANNELS.

CHARM PHOTOPRODUCTION AT 20-GeV

The SLAC Hybrid Facility Photon collaboration Abe, K. ; Bacon, T.C. ; Ballam, Joseph ; et al.

Phys.Rev.D 30 (1984) 1, 1984.

Inspire Record 194546 DOI 10.17182/hepdata.23639

Sixty-two charm events have been observed in an exposure of the SLAC Hybrid Facility toa backward sacttered laser beam. Based on 22 neutral and 21 charged decays we have measured the charmed-meson lifetimes to be τD0=(6.8−1.8+2.3)×10−13 sec, τD±=(7.4−2.0+2.3)×10−13 sec and their ratio τD±τD0=1.1−0.3+0.6. The inclusive charm cross section at a photon energy of 20 GeV has been measured to be 56−23+24 nb. Evidence is presented for a non-DD¯ component to charm production, consistent with (35±20)% Λc+ production and some D*± production. We have found no unambiguous F decays.

1 data table

Table 1

No description provided.

EXPERIMENTAL STUDIES OF THE SIGMA, T, P POLARIZATION PARAMETERS AND THE GAMMA P ---> P PI0 REACTION MULTIPOLE ANALYSIS IN THE FIRST RESONANCE REGION

Belyaev, A.a. ; Getman, V.a. ; Gorbenko, V.g. ; et al.

Nucl.Phys.B 213 (1983) 201-222, 1983.

Inspire Record 192457 DOI 10.17182/hepdata.34021

A description is given of the experimental techniques and investigation results of the parameters Σ , T , P for the γ p→p π 0 reaction using linear polarized photons and a polarized proton target. The measurements have been made in the photon energy range 280–450 MeV at pion c.m. angles between 60° and 135°. The new experimental data are used in an energy-independent channel multipole analysis without the Watson theorem.

8 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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POLARIZATION PARAMETERS SIGMA, T, P FOR THE REACTION GAMMA P ---> P PI0 NEAR THE FIRST RESONANCE. (IN RUSSIAN)

Belyaev, A.A. ; Getman, V.A. ; Gorbenko, V.G. ; et al.

Yad.Fiz. 35 (1982) 693-699, 1982.

Inspire Record 179827 DOI 10.17182/hepdata.18756

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

INVESTIGATION OF THE REACTION GAMMA P ---> DELTA++ PI- ON POLARIZED PROTONS. (IN RUSSIAN)

Belyaev, A.A. ; Getman, V.A. ; Gorbenko, V.G. ; et al.

Yad.Fiz. 35 (1982) 373-375, 1982.

Inspire Record 179828 DOI 10.17182/hepdata.17756

None

1 data table

Table 1

No description provided.

POLARIZATION OF RECOIL PROTONS FROM THE REACTION GAMMA P ---> PI0 P IN THE PHOTON ENERGY RANGE 450-MEV - 800-MEV

Bratashevsky, A.S. ; Gorbenko, V.G. ; Derebchinsky, A.I. ; et al.

Nucl.Phys.B 166 (1980) 525-533, 1980.

Inspire Record 157933 DOI 10.17182/hepdata.34552

Measurement of secondary-proton polarization from the reaction γ p → π 0 p have been performed in the proton energy range 500–800 MeV at c.m. pion emission angles 100°, 120°, 140°. The experiment was carried out using an optical spark chamber telescope at the output of the magnetic spectrometer. The obtained experimental data are included in a Walker-type analysis in order to verify the parameters of the resonances P 11 (1470), D 13 (1570) and S 11 (1535). Proton polarization in the reaction γ p → π 0 p was measured for a photon energy of 450 MeV at a c.m. pion emission angle of 105° using photons linearly polarized at 45° to the reaction plane. A liquid hydrogen target in the field of a superconducting magnet was used for the separation of the P x ′ and P z ′ components of the secondary-proton polarization vector.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

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