Abstract
We summarize the results of a recent study on a new perturbative QCD factorization formalism for the production of heavy quarkonia of large transverse momentum pT at collider energies. Such a new factorization formalism includes both the leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the [Formula: see text] expansion for heavy quark mass mQ. For the NLP contribution, the so-called double parton fragmentation functions are involved, whose evolution equations have been derived. We estimate fragmentation functions in the non-relativistic QCD formalism, and found that their contribution reproduce the bulk of the large enhancement found in explicit NLO calculations in the color singlet model. Heavy quarkonia produced from NLP channels prefer longitudinal polarization, in contrast to the single parton fragmentation function. This might shed some light on the heavy quarkonium polarization puzzle.
Highlights
In these proceedings we present the results of Refs. [1, 2], where a perturbative QCD factorization formalism for the production of heavy quarkonium of large transverse momentum pT at collider energies is proposed and it includes both leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the m2Q/p2T expansion for heavy quark mass mQ
We find that the probability for such a heavy quark pair to evolve into a heavy quarkonium is naturally enhanced compared to that of a single parton, and can promote the NLP channel to phenomenological interest, despite its suppression by two powers of pT
A first result was published in Ref.[1], where we show that the NLP contribution shows the similar enhancement above the LO color singlet model (CSM) as the full next-to-leading order (NLO) result in CSM
Summary
In these proceedings we present the results of Refs. [1, 2], where a perturbative QCD factorization formalism for the production of heavy quarkonium of large transverse momentum pT at collider energies is proposed and it includes both leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the m2Q/p2T expansion for heavy quark mass mQ. [1, 2], where a perturbative QCD factorization formalism for the production of heavy quarkonium of large transverse momentum pT at collider energies is proposed and it includes both leading power (LP) and next-to-leading power (NLP) contributions to the cross section in the m2Q/p2T expansion for heavy quark mass mQ. The perturbative production of a collinear heavy quark pair directly at the short distance scale 1/pT is suppressed by 1/p2T relative to the production rate of a single parton at the same pT , which is referred to as the NLP contribution. We find that the probability for such a heavy quark pair to evolve into a heavy quarkonium is naturally enhanced compared to that of a single parton, and can promote the NLP channel to phenomenological interest, despite its suppression by two powers of pT
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Modern Physics: Conference Series
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
