New feature of low $p_T$ charm quark hadronization in $pp$ collisions at $\sqrt{s}=7$ TeV

Abstract

Treating the light-flavor constituent quarks and antiquarks that can well describe the data of light-flavor hadrons in $pp$ collisions at $\sqrt{s}=7$ TeV as the underlying source of chromatically neutralizing the charm quarks of low transverse momenta ($p_T$), we show that the experimental data of $p_T$ spectra of single-charm hadrons $D^{0,+}$, $D^{\ast +}$ $D_s^{+}$, $\hat{I}{›}_c^{+}$ and $\hat{I}{ž}_c^0$ at mid-rapidity in the low $p_T$ range ($2\lesssim p_T\lesssim 7$ GeV/$c$) in $pp$ collisions at $\sqrt{s}=7$ TeV can be well understood by the equal-velocity combination of perturbatively-created charm quarks and those light-flavor constituent quarks and antiquarks. This suggests a possible new scenario of low $p_T$ charm quark hadronization, in contrast to the traditional fragmentation mechanism, in $pp$ collisions at LHC energies. This is also another support for the exhibition of the effective constituent quark degrees of freedom for the small parton system created in $pp$ collisions at LHC energies.

7 pages, 5 figures. arXiv admin note: text overlap with arXiv:1712.08921