HEPData Search

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Measurement of inelastic J / psi photoproduction at HERA

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.

Z.Phys.C 76 (1997) 599-612, 1997.

Inspire Record 446830 DOI 10.17182/hepdata.44512

We present a measurement of the inelastic, non diffractive J/$\psi$ photoproduction cross section in the reaction $e^{+} p \to e^{+} {J}/\psi X$ with the ZEUS detector at HERA. The J/$\psi$ was identified using both the $\mu^{+}\mu^{-}$ and $e^{+}e^{-}$ decay channels and events were selected within the range $0.4 1$ GeV$^2$, NLO calculations of the photon-gluon fusion process based on the colour-singlet model are in good agreement with the data. The predictions of a specific leading order colour-octet model, as formulated to describe the CDF data on J/$\psi$ hadroproduction, are not consistent with the data.

13 data tables

Table 1

Cross section for the MU+ MU- decay channel.

Table 2

Cross section for the MU+ MU- decay channel.

Table 3

Cross section for the MU+ MU- decay channel.

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D* production in deep inelastic scattering at HERA.

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.

Phys.Lett.B 407 (1997) 402-418, 1997.

Inspire Record 443964 DOI 10.17182/hepdata.44585

This paper presents measurements of D^{*\pm} production in deep inelastic scattering from collisions between 27.5 GeV positrons and 820 GeV protons. The data have been taken with the ZEUS detector at HERA. The decay channel $D^{*+}\to (D^0 \to K^- \pi^+) \pi^+ $ (+ c.c.) has been used in the study. The $e^+p$ cross section for inclusive D^{*\pm} production with $5

11 data tables

Table 1

No description provided.

Table 2

Integrated charm cross sections in two Q**2 regions.

Table 3

Distribution of the fractional momentum of the D* in the gamma*-p system.

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Measurement of elastic J / psi photoproduction at HERA

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.

Z.Phys.C 75 (1997) 215-228, 1997.

Inspire Record 442537 DOI 10.17182/hepdata.44626

The reaction gamma p -> J/Psi p has been studied in ep interactions using the ZEUS detector at HERA. The cross section for elastic J/Psi photoproduction has been measured as a function of the photon-proton centre of mass energy W in the range 40 < W < 140 GeV at a median photon virtuality Q^2 of 5*10^{-5} GeV^2. The photoproduction cross section, sigma_{gamma p -> J/Psi p}, is observed to rise steeply with W. A fit to the data presented in this paper to determine the parameter $\delta$ in the form sigma_{gamma p -> J/Psi p} \propto W^{\delta} yields the value \delta = 0.92 \pm 0.14 \pm 0.10. The differential cross section dsigma/d|t| is presented over the range |t| < 1.0 GeV^2 where t is the square of the four-momentum exchanged at the proton vertex. d\sigma/d|t| falls exponentially with a slope parameter of 4.6 \pm 0.4 (+0.4-0.6) GeV^{-2}. The measured decay angular distributions are consistent with s-channel helicity conservation.

9 data tables

Table 1

Data from the electron channel. Second systematic error is that attributed to the uncertainty in the modelof proton dissociation used for background subtraction.

Table 2

Data from the muon channel. Second systematic error is that attributed to the uncertainty in the modelof proton dissociation used for background subtraction.

Table 3

Data from the electron channel. Second systematic error is that attributed to the uncertainty in the modelof proton dissociation used for background subtraction.

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Inclusive pi0 production in p C and p Cu interactions at 4.5-GeV/c

Abraamian, Kh.U. ; Izyurov, V.M. ; Kozhin, M.A. ; et al.

Phys.Atom.Nucl. 59 (1996) 252-256, 1996.

Inspire Record 382328 DOI 10.17182/hepdata.17174

None

1 data table

Table 1

THE CROSS SECTION HAS BEEN FITTED BY THE FORMULA: D(SIG)/D(PT**2)= CONST*EXP(-SLOPE*PT**2).

Inclusive production of pi0 mesons in the reaction C-12 + C-12 --> pi0 + X at 4.5-GeV/c/nucleon.

Abraamian, Kh.U. ; Arkhipov, V.V. ; Izyurov, V.M. ; et al.

Sov.J.Nucl.Phys. 53 (1991) 297-299, 1991.

Inspire Record 305970 DOI 10.17182/hepdata.38296

None

1 data table

Table 1

No description provided.

Inclusive production of pi0 mesons in p C-collisions at 4.5-GeV/c. (In Russian)

Abraamian, Kh.U. ; Arkhipov, V.V. ; Astvatsaturov, R.G. ; et al.

308-316, 1988.

Inspire Record 263949 DOI 10.17182/hepdata.38836

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

A STUDY OF ANTI-N P ANNIHILATIONS BETWEEN 0.5-GEV/C AND 0.8-GEV/C

The BOMBAY-CHANDIGARH-JAMMU-TOKYO collaboration Banerjee, S. ; Ganguli, S.N. ; Gurtu, A. ; et al.

Z.Phys.C 32 (1986) 163-170, 1986.

Inspire Record 238230 DOI 10.17182/hepdata.15843

None

10 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Studies of $\bar{p} p \to \bar{n} n$ and $\bar{n} p$ Annihilation at Incident Momenta of 700-{MeV}/$c$ and 760-{MeV}/$c$

The Bombay-Chandigarh-Jammu-Tokyo collaboration Banerjee, S. ; Ganguli, S.N. ; Gurtu, A. ; et al.

Z.Phys.C 28 (1985) 163, 1985.

Inspire Record 217418 DOI 10.17182/hepdata.1974

Results are presented on the charge exchange reaction$\bar pp \to \bar nn$ and$\bar np$ annihilations from bubble chamber exposures to antiproton beam of momenta 700 and 760 MeV/c. The differential cross section of$\bar pp \to \bar nn$ shows a forward spike followed by a clear dip bump structure. Total annihilation cross section of$\bar np$ for average$\bar n$ momentum of 700 MeV/c has been evaluated to be 55.4±2.2 mb. The multiplicity, Feynmanx andpT2 distributions for inclusive charged pions in$\bar pp$ and$\bar np$ annihilations are found to be similar. The emission of charged pions from$\bar np$ annihilations are found to be consistent with thermodynamic models with temperature ∼110 MeV.

11 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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PRODUCTION OF THE anti-K*0 (890) RESONANCE IN pi+ p INTERACTIONS AT 16-GeV/c

Jawahery, A. ; Mann, W.A. ; Maruyama, T. ; et al.

Phys.Rev.D 31 (1985) 961, 1985.

Inspire Record 15966 DOI 10.17182/hepdata.23562

The inclusive process π++P→K¯ *0(890)+X is studied at 16 GeV/c using a 2-m streamer chamber containing a central liquid hydrogen target. From photographs triggered by detection of a forward K− meson, the signal K¯ K−*0π+ is extracted. The inclusive rate for K¯ * production into the forward hemisphere σ(xF>0.3) is 115±27 μb; the pT2 distribution is found to have a slope constant of 3.3±0.6 (GeV/c)2. The Feynman-x distribution for K¯ *0 is consistent with a Kuti-Weisskopf model in which the valence and sea quarks of the incident pion interact with only the sea quarks of the target proton.

2 data tables

Table 1

No description provided.

Table 2

No description provided.