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

TL;DR

This paper proposes a new low transverse momentum charm quark hadronization mechanism in proton-proton collisions at 7 TeV, based on constituent quark combination, challenging the traditional fragmentation picture.

Contribution

It introduces a novel hadronization scenario for low $p_{T}$ charm quarks in $pp$ collisions, supported by data analysis and constituent quark model considerations.

Findings

Data of $p_{T}$ spectra of charm hadrons are well described by the constituent quark combination model.

The results suggest a new hadronization mechanism different from fragmentation at low $p_{T}$.

Supports the effective constituent quark degrees of freedom in small systems at LHC energies.

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 $D^{0,+}$, $D^{*+}$ $D_{s}^{+}$, $\Lambda_{c}^{+}$ and $\Xi_{c}^{0}$ at mid-rapidity in the low $p_{T}$ range ($2\lesssim p_{T}\lesssim7$ 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.