arXiv subjects

J. M. de Miranda

Publications and source records attributed to J. M. de Miranda.

3 recordsLinked to original sources

arXiv2003

Asymmetries in the Production of Lambda0 in 250 GeV/c pi+-, K+- and p -- Nucleon Interactions

Using data from Fermilab fixed-target experiment E769, we have measured particle-antiparticle production asymmetries for Lambda0 hyperons in 250 GeV/c pi+-, K+- and p -- nucleon interactions. The asymmetries are measured as functions of Feynman-x (x_F) and p_t^2 over the ranges -0.12<=x_F<=0.12 and 0<=p_t^2<=3 (GeV/c)^2 (for positive beam) and -0.12<=x_F<=0.4 and 0<=p_t^2<=10 (GeV/c)^2 (for negative beam). We find substantial asymmetries, even at x_F around zero. We also observe leading-particle-type asymmetries. These latter effects are qualitatively as expected from valence-quark content of the target and variety of projectiles studied.

hep-ex↗

arXiv2000

A nonextensive thermodynamical equilibrium approach in $e^+ e^- \to hadrons$

We show that the inclusion of long distance effect, expected in strong interactions, through a nonextensive thermodynamical approach is able to explain the experimental distribution of the transverse momentum of the hadrons with respect to the jet axis ($p_{t}$) $e^+ e^- \to hadron$ reaction. The observed deviation from the exponential behavior, predicted by the Boltzmann-Gibbs thermodynamical treatment, is automatically recovered by the nonextensive Tsallis statistics used here. We fitted the observed $p_{t}$ spectrum in the range of 14 GeV to 161 GeV and obtained, besides a good fit, the theoretical important fact that the temperature becomes independent of the primary energy.

hep-ph↗

arXiv1996

Asymmetries between the production of D+ and D- mesons from 500 GeV/c pi- nucleon interactions as a function of xF and pt**2

We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.

hep-ex↗