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Differential cross sections, charge production asymmetry, and spin-density matrix elements for D*(2010)+- produced in 500-GeV/c pi- nucleon interactions.

The Fermilab E791 collaboration Aitala, E.M ; Amato, S ; Anjos, J.C ; et al.

Phys.Lett.B 539 (2002) 218-226, 2002.

Inspire Record 587686 DOI 10.17182/hepdata.42892

We report differential cross sections for the production of D*(2010) produced in 500 GeV/c pi^- nucleon interactions from experiment E791 at Fermilab, as functions of Feynman-x (x_F) and transverse momentum squared (p_T^2). We also report the D* +/- charge asymmetry and spin-density matrix elements as functions of these variables. Investigation of the spin-density matrix elements shows no evidence of polarization. The average values of the spin alignment are \eta= 0.01 +- 0.02 and -0.01 +- 0.02 for leading and non-leading particles, respectively.

8 data tables

Table 1

Acceptance corrected differential cross sections for D*+- production as a function of XL, Feynman X.

Table 2

Acceptance corected differential cross sections for D*+- production as a function of PT**2.

Table 3

Charge production asymmetry as a function of Feynman X.

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Large Inclusive Charged Particle Distributions in Deep Inelastic Scattering Events at HERA

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.

Z.Phys.C 70 (1996) 1-16, 1996.

Inspire Record 402646 DOI 10.17182/hepdata.44930

A measurement of inclusive charged particle distributions in deep inelastic $ep$ scattering for $\gamma~* p$ centre-of-mass energies $75< W < 175$GeV and momentum transfer squared $10< Q~2 < 160$GeV$~2$ from the ZEUS detector at HERA is presented. The differential charged particle rates in the $\gamma~* p$ centre-of-mass system as a function of the scaled longitudinal momentum, $x_F$, and of the transverse momentum, $p_t~*$ and $<\!\!p_t~{*\,2}\!\!>\,\,$ , as a function of $x_F$, $W$ and $Q~2$ are given. Separate distributions are shown for events with (LRG) and without (NRG) a rapidity gap with respect to the proton direction. The data are compared with results from experiments at lower beam energies, with the naive quark parton model and with parton models including perturbative QCD corrections. The comparison shows the importance of the higher order QCD processes. Significant differences of the inclusive charged particle rates between NRG and LRG events at the same $W$ are observed. The value of $<\!\!p_t~{*\,2}\!\!>\,\,$ for LRG events with a hadronic mass $M_X$, which excludes the forward produced baryonic system, is similar to the $<\!\!p_t~{*\,2}\!\!>\,\,$ value observed in fixed target experiments at $W \approx M_X$.

11 data tables

Table 1

Differential multiplicites for NRG events.. XL is parallel to the virtual photon axis.

Table 2

Differential multiplicites for NRG events.. PT is relative to the virtual photon axis.

Table 3

Mean PT**2 for NRG events.. PT is relative to the virtual photon axis.