J/ψ Production and Polarization within a Jet

Area of Science:

• High Energy Physics
• Particle Physics
• Quantum Chromodynamics

Background:

• J/ψ meson production is a key process in high-energy physics.
• Understanding heavy quarkonium production mechanisms is crucial for testing Quantum Chromodynamics (QCD).
• Previous studies often relied on inclusive J/ψ measurements.

Purpose of the Study:

• To investigate the production and polarization of J/ψ mesons within jets at the Large Hadron Collider (LHC).
• To introduce and validate the J/ψ-jet fragmentation function as a novel observable.
• To provide a tool for distinguishing between different nonrelativistic QCD (nrQCD) models.

Main Methods:

• Definition of the J/ψ-jet fragmentation function as a ratio of differential jet cross sections.
• Analysis of proton-proton collision data from the LHC.
• Comparison of experimental results with theoretical predictions from nrQCD global fits.

Main Results:

• The J/ψ-jet fragmentation function is demonstrated to be a powerful observable.
• This function aids in exploring the J/ψ production mechanism.
• It effectively differentiates between various nrQCD global fits.

Conclusions:

• The J/ψ-jet fragmentation function provides valuable insights into J/ψ production.
• Measuring J/ψ meson polarization within jets can further constrain heavy quarkonium production models.
• This approach enhances our understanding of fundamental particle interactions at the LHC.