Leading neutron production in e+ p collisions at HERA

The ZEUS collaboration Chekanov, S. ; Krakauer, D. ; Magill, S. ; et al.
Nucl.Phys. B637 (2002) 3-56, 2002.
Inspire Record 587158 DOI 10.17182/hepdata.46613

The production of neutrons carrying at least 20% of the proton beam energy ($\xl > 0.2$) in $e^+p$ collisions has been studied with the ZEUS detector at HERA for a wide range of $Q^2$, the photon virtuality, from photoproduction to deep inelastic scattering. The neutron-tagged cross section, $e p\to e' X n$, is measured relative to the inclusive cross section, $e p\to e' X$, thereby reducing the systematic uncertainties. For $\xl >$ 0.3, the rate of neutrons in photoproduction is about half of that measured in hadroproduction, which constitutes a clear breaking of factorisation. There is about a 20% rise in the neutron rate between photoproduction and deep inelastic scattering, which may be attributed to absorptive rescattering in the $\gamma p$ system. For $0.64 < \xl < 0.82$, the rate of neutrons is almost independent of the Bjorken scaling variable $x$ and $Q^2$. However, at lower and higher $\xl$ values, there is a clear but weak dependence on these variables, thus demonstrating the breaking of limiting fragmentation. The neutron-tagged structure function, ${{F}^{\rm\tiny LN(3)}_2}(x,Q^2,\xl)$, rises at low values of $x$ in a way similar to that of the inclusive \ff of the proton. The total $\gamma \pi$ cross section and the structure function of the pion, $F^{\pi}_2(x_\pi,Q^2)$ where $x_\pi = x/(1-\xl)$, have been determined using a one-pion-exchange model, up to uncertainties in the normalisation due to the poorly understood pion flux. At fixed $Q^2$, $F^{\pi}_2$ has approximately the same $x$ dependence as $F_2$ of the proton.

0 data tables match query

Production of J / psi and psi (2S) mesons in pi- Be collisions at 515-GeV/c

The E672 E706 collaborations Gribushin, A. ; Abramov, V. ; Antipov, Yu. ; et al.
Phys.Rev. D53 (1996) 4723-4733, 1996.
Inspire Record 401108 DOI 10.17182/hepdata.42344
0 data tables match query

Properties of J / psi production in pi- Be and p Be collisions at 530-GeV/c

The E672/706 collaboration Abramov, V. ; Antipov, Yu. ; Baldin, B. ; et al.
No Journal Information, 1991.
Inspire Record 315071 DOI 10.17182/hepdata.42566
0 data tables match query

Measurement of $J/\psi$ and $\psi^\prime$ production in 800-GeV/c proton - gold collisions

The E789 collaboration Schub, M.H. ; Jansen, D.M. ; Mishra, C.S. ; et al.
Phys.Rev. D52 (1995) 1307, 1995.
Inspire Record 394476 DOI 10.17182/hepdata.42428
0 data tables match query

Inclusive V0 production cross-sections from 920-GeV fixed target proton nucleus collisions

The HERA-B collaboration Abt, I. ; Abyzov, A. ; Adams, M. ; et al.
Eur.Phys.J. C29 (2003) 181-190, 2003.
Inspire Record 604661 DOI 10.17182/hepdata.46479

Inclusive differential cross sections $d\sigma_{pA}/dx_F$ and $d\sigma_{pA}/dp_t^2$ for the production of \kzeros, \lambdazero, and \antilambda particles are measured at HERA in proton-induced reactions on C, Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to $\sqrt {s} = 41.6$ GeV in the proton-nucleon system. The ratios of differential cross sections \rklpa and \rllpa are measured to be $6.2\pm 0.5$ and $0.66\pm 0.07$, respectively, for \xf $\approx-0.06$. No significant dependence upon the target material is observed. Within errors, the slopes of the transverse momentum distributions $d\sigma_{pA}/dp_t^2$ also show no significant dependence upon the target material. The dependence of the extrapolated total cross sections $\sigma_{pA}$ on the atomic mass $A$ of the target material is discussed, and the deduced cross sections per nucleon $\sigma_{pN}$ are compared with results obtained at other energies.

0 data tables match query

Production of $J/\psi$ in 16-{GeV} and 22-{GeV} $\pi^-$ Cu Collisions

Phys.Lett. B81 (1979) 401-404, 1979.
Inspire Record 7053 DOI 10.17182/hepdata.50278
0 data tables match query

A Search for weakly interacting neutral particles in missing energy events in 450-GeV/c p N collisions

The HELIOS collaboration Akesson, T. ; Almehed, S. ; Angelis, A.L.S. ; et al.
Z.Phys. C52 (1991) 219-226, 1991.
Inspire Record 302922 DOI 10.17182/hepdata.15014
0 data tables match query