Breakdown of Nonrelativistic QCD Factorization in Processes Involving Two Quarkonia and its Cure.

Area of Science:

• High Energy Physics
• Quantum Chromodynamics
• Particle Physics

Background:

• Inclusive processes with heavy quarkonia are crucial for understanding quantum chromodynamics.
• Nonrelativistic QCD (NRQCD) is a framework used to study these processes.
• Previous studies have not fully addressed factorization issues with multiple P-wave states.

Purpose of the Study:

• To investigate the breakdown of NRQCD factorization in processes involving two heavy quarkonia.
• To identify and resolve infrared singularities arising from P-wave Fock states.
• To propose a solution for accurate theoretical predictions in heavy quarkonium physics.

Main Methods:

• Analysis of inclusive processes with two heavy quarkonia within the NRQCD framework.
• Examination of decays like ϒ→χ_{cJ}+X and production processes like e^{+}e^{-}→J/ψ+χ_{cJ}+X.
• Introduction of novel operators into the NRQCD effective field theory.

Main Results:

• Demonstrated the breakdown of NRQCD factorization due to two P-wave Fock states, leading to uncanceled infrared singularities.
• Identified these singularities in specific decay and production processes.
• Showed that new operators in NRQCD effectively absorb these singularities.

Conclusions:

• The standard NRQCD factorization fails for certain multi-heavy quarkonium processes.
• The newly introduced operators provide a mechanism to handle infrared singularities.
• This work offers a path towards more precise theoretical calculations in heavy quarkonium physics.