Fragmentation of charmed quark to double-charmed hadrons

<jats:title>Abstract</jats:title><jats:p>We consider the production of hadrons containing two charmed quarks in <jats:italic>pp</jats:italic> and <jats:italic>ee</jats:italic> collisions. We perform a numerical comparison of the fragmentation approach with the full calculation at <jats:inline-formula><jats:alternatives><jats:tex-math>$${{{\mathcal {O}}}}(\alpha _s^4)$$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
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</mml:math></jats:alternatives></jats:inline-formula>. We conclude that the non-fragmentation contributions remain important up to transverse momenta as large as about 40 GeV, thus making questionable the applicability of the fragmentation approximation at smaller transverse momenta.</jats:p>