Momentum Correlations of Charmed Pairs Produced in $\pi^{-}-Cu$ Interactions at 230 GeV/c

TL;DR

This study measures the production characteristics of charmed hadron pairs in pion-copper interactions at 230 GeV/c, finding agreement with QCD predictions for some variables but a larger-than-expected transverse momentum squared.

Contribution

It introduces a momentum estimator for charmed hadrons with missing decay products and provides detailed measurements of their correlation properties at high energy.

Findings

Mean transverse momentum squared is larger than QCD predictions.

Rapidity difference and effective mass agree with theoretical models.

Provides new data on charmed pair production at 230 GeV/c.

Abstract

We study the production characteristics of 557 pairs of charmed hadrons produced in $\pi^{-}-Cu$\ interactions at 230~GeV/c using a momentum estimator for charmed hadrons with missing decay products. We find, the mean value of the transverse momentum squared of the charmed pairs is $<$\pts$>=(1.98\pm 0.11\pm 0.09)\;$ GeV$^2$/c$^2$, the mean rapidity difference is $<|$\yd$|>=0.54\pm 0.02\pm 0.24$, and the mean effective mass is $<$\mef$>=(4.45\pm 0.03\pm 0.13)\;$ GeV/c$^2$. Comparing these results with the next-to-leading order QCD predictions we find an agreement for the \yd\ and \mef, whilst the measured mean value of \pts\ is significantly larger than the predicted value.