HEPData Search

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Measurement of the total photon-proton cross-section and its decomposition at 200-GeV center-of-mass energy

The H1 collaboration Aid, S. ; Andreev, V. ; Andrieu, B. ; et al.

Z.Phys.C 69 (1995) 27-38, 1995.

Inspire Record 399015 DOI 10.17182/hepdata.44969

We present a new measurement of the total photoproduction cross section performed with the H1 detector at HERA. For an average centre of mass energy of 200GeV a value of $\sigma_{tot}~{\gamma{p}}= 165\pm2\pm11\mu$b has been obtained. A detailed analysis of the data in adequate kinematic regions enabled a decomposition of the total cross section in its elastic, single diffractive dissociation and remaining non-diffractive parts, based on safe assumptions on the double diffractive dissociation contribution.

2 data tables

Table 1

No description provided.

Table 2

Total GAMMA P cross section.

Inclusive parton cross-sections in photoproduction and photon structure

The H1 collaboration Ahmed, T. ; Aid, S. ; Andreev, V. ; et al.

Nucl.Phys.B 445 (1995) 195-218, 1995.

Inspire Record 394176 DOI 10.17182/hepdata.44975

Photoproduction of 2-jet events is studied with the H1 detector at HERA. Parton cross sections are extracted from the data by an unfolding method using leading order parton-jet correlations of a QCD generator. The gluon distribution in the photon is derived in the fractional momentum range $0.04\le x_\gamma \le 1$ at the average factorization scale $75$ GeV$~2$.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

Gluon density of the photon (alpha is the fine structure constant).

Photoproduction of J / psi mesons at HERA

The H1 collaboration Ahmed, T. ; Aid, S. ; Andreev, V. ; et al.

Phys.Lett.B 338 (1994) 507-518, 1994.

Inspire Record 376566 DOI 10.17182/hepdata.45103

We present a study of J ψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The J ψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → J ψ X) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ W γp ≤ 180 GeV and Q 2 ≲ 4 GeV 2 . Using the flux of quasi-real photons with Q 2 ≲ 4 GeV 2 , a total production cross section of σ ( γp → J / ψX ) = (56±13±14) nb is derived at an average W γp =90 GeV. The distribution of the squared momentum transfer t from the proton to the J ψ can be fitted using an exponential exp(− b ∥ t ∥) below a ∥ t ∥ of 0.75 GeV 2 yielding a slope parameter of b = (4.7±1.9) GeV −2 .

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

QED background subtracted.

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Measurement of inclusive jet cross-sections in photoproduction at HERA

The H1 collaboration Abt, I. ; Ahmed, T. ; Andreev, V. ; et al.

Phys.Lett.B 314 (1993) 436-444, 1993.

Inspire Record 356741 DOI 10.17182/hepdata.28821

The inclusive jet cross section in photoproduction has been measured as a function of transverse energy and pseudorapidity using the H 1 detector at the HERA electron-proton collider. The results are compared with leading order QCD calculations.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Total photoproduction cross-section measurement at HERA energies

The H1 collaboration Ahmed, T. ; Andreev, V. ; Andrieu, B. ; et al.

Phys.Lett.B 299 (1993) 374-384, 1993.

Inspire Record 340891 DOI 10.17182/hepdata.45139

We present first results on the total photoproduction cross section measurement with the H1 detector at HERA. The data were extracted from low Q 2 collisions of 26.7 GeV electrons with 820 GeV protons. The γp total cross section has been measured by two independent methods in the γp center of mass energy range from 90 to 290 GeV. For an average center of mass energy of 195 GeV a value of σ tot ( γp ) = 159 ± 7 (stat.) ± 20 (syst.) μb was obtained.

2 data tables

Table 1

Data from tagged sample.

Table 2

Data from untagged sample.