Heavy quarkonium production at collider energies: Partonic cross section and polarization

Kang, Zhong‐Bo; Ma, Yan-Qing; Qiu, Jian‐Wei; Sterman, George

doi:10.1103/physrevd.91.014030

Cited by 62 publications

(103 citation statements)

References 73 publications

Supporting

Mentioning

103

Contrasting

Order By: Relevance

“…In principle, input fragmentation functions are non-perturbative and should be extracted from fitting experimental data, just as one derives parton fragmentation functions to light hadrons through QCD global analysis. However, as pointed out in our companion paper [41], it may also be a very reasonable conjecture to use the NRQCD factorization formalism to calculate all input fragmentation functions. With the calculated/estimated input fragmentation functions, and perturbatively calculated hard parts and evolution kernels, our new factorization formalism could provide predictions with absolute normalization, which can be tested by data from the LHC and other colliders [63].…”

Section: Discussionmentioning

confidence: 99%

“…The short-distance hard parts reflect partonic dynamics at a distance scale of 1/p T , and are the same for the production of all heavy quarkonium states. The leading order short distance functions for the production of a heavy quark pair in all perturbative color-spin states are presented in a companion paper [41].…”

Section: Discussionmentioning

confidence: 99%

“…As explained in our companion paper [41], however, we should be able to provide a good estimate of the input fragmentation functions by using NRQCD factorization, since input fragmentation functions to heavy quarkonia can have a large perturbative scale, µ 0 > ∼ 2m Q , which is well separated from the soft scales responsible for the binding. Although there is as yet no formal proof for the NRQCD factorization, the clear separation of momentum scales for the input fragmentation functions provides a good justification for using the formalism as a reasonable conjecture.…”

Section: Introductionmentioning

confidence: 99%

“…III, the factorization formalism provides a unique prescription to calculate all short-distance functions and evolution kernels order-by-order in powers of α s up to a freedom to choose the factorization scheme. In a companion paper [41], we present calculations of short-distance functions for all partonic production channels at LO in powers of α s . With the evolution kernels calculated in this paper, we still need the fragmentation functions at the input scale µ 0 in order to make numerical predictions and comparison with data.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Heavy quarkonium production at collider energies: Factorization and evolution

et al. 2014

Self Cite

View full text Add to dashboard Cite

We present a perturbative QCD factorization formalism for inclusive production of heavy quarkonia of large transverse momentum, pT at collider energies, including both leading power (LP) and next-to-leading power (NLP) behavior in pT . We demonstrate that both LP and NLP contributions can be factorized in terms of perturbatively calculable short-distance partonic coefficient functions and universal non-perturbative fragmentation functions, and derive the evolution equations that are implied by the factorization. We identify projection operators for all channels of the factorized LP and NLP infrared safe short-distance partonic hard parts, and corresponding operator definitions of fragmentation functions. For the NLP, we focus on the contributions involving the production of a heavy quark pair, a necessary condition for producing a heavy quarkonium. We evaluate the first non-trivial order of evolution kernels for all relevant fragmentation functions, and discuss the role of NLP contributions.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Heavy quarkonium production at collider energies: Factorization and evolution

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…Besides the exclusive processes, our results can also be applied to study the B c semiinclusive productions in hadron colliders at relatively low p T region. Some researchers have pointed out that the double parton fragmentation mechanism may become as important as the single-parton fragmentation mechanism for quarkonia productions at colliders at relatively low p T region [40][41][42][43][44]. In the corresponding factorization formula, the doubleparton fragmentation functions serve as very important non-perturbative quantities.…”

Section: Jhep07(2016)098mentioning

confidence: 99%

The leading twist light-cone distribution amplitudes for the S-wave and P-wave Bc mesons

Xu¹,

Yang²

2016

J. High Energ. Phys.

View full text Add to dashboard Cite

The light-cone distribution amplitudes (LCDAs) serve as important nonperturbative inputs for the study of hard exclusive processes. In this paper, we calculate ten LCDAs at twist-2 for the S-wave and P-wave B c mesons up to the next-to-leading order (NLO) of the strong coupling α s and leading order of the velocity expansion. Each one of these ten LCDAs is expressed as a product of a perturbatively calculable distribution and a universal NRQCD matrix-element. By use of the spin symmetry, only two NRQCD matrix-elements will be involved. The reduction of the number of non-perturbative inputs will improve the predictive power of collinear factorization.

show abstract

Gluon fragmentation into quarkonium at next-to-leading order using FKS subtraction

Artoisenet

Braaten

2019

J. High Energ. Phys.

View full text Add to dashboard Cite

We present the calculation at next-to-leading order (NLO) in α s of the fragmentation function of a gluon into heavy quarkonium in the color-octet spin-singlet S-wave channel. To calculate the real NLO corrections, we adapt a subtraction scheme introduced by Frixione, Kunszt, and Signer.Ultraviolet and infrared divergences in the real NLO corrections are calculated analytically by evaluating the phase-space integrals of the subtraction terms using dimensional regularization. The subtracted phase-space integrals are then evaluated in 4 space-time dimensions. The divergences in the virtual NLO corrections are also calculated analytically. After renormalization, all the divergences cancel. The NLO corrections significantly increase the fragmentation probability for a gluon into the spin-singlet quarkonium states η c and η b . The sum extends over the types of partons i (gluons, quarks, and antiquarks). The symbol "⊗" in Eq. (1) represents a convolution integral over the longitudinal momentum fraction z of the hadron H relative to the parton. The pQCD cross section dσ for producing the parton i can be expanded in powers of α s (p T ), and it includes convolutions with parton distributions if the colliding particles are hadrons. The nonperturbative factor D i→H (z) is a fragmentation function that gives the probability distribution for z. We refer to Eq. (1) as the leading-power (LP) factorization formula. It was derived by Collins and Soper in 1981 for the case of a light hadron H at a transverse momentum satisfying p T Λ QCD [1].The LP factorization formula in Eq. (1) applies equally well to heavy quarkonium at a transverse momentum satisfying p T m, where m is the mass of the heavy quark.A proof of this factorization theorem that deals with issues specific to heavy quarkonium production was first sketched by Nayak, Qiu, and Sterman in 2005 [2]. The LP factorization formula gives the leading power in the expansion in powers of m/p T . In the case of cross sections summed over quarkonium spins, the corrections are suppressed by m 2 /p 2 T . The LP factorization formula has limited predictive power, because the nonperturbative factors D i→H (z) are functions of z that must be determined from experiment.In 1994, Bodwin, Braaten, and Lepage proposed the NRQCD factorization formula for cross sections for heavy quarkonium production [3]. It uses an effective field theory called nonrelativistic QCD to separate momentum scales of order m and larger from momentum scales of order mv and smaller, where v is the typical relative velocity of the Q orQ in the quarkonium. The theoretical status of the NRQCD factorization conjecture is discussed in Ref. [4]. The predictive power of the LP factorization formula for heavy quarkonium in Eq. (1) can be increased by applying the NRQCD factorization formula to the fragmentation

show abstract

Heavy quarkonium production at collider energies: Partonic cross section and polarization

Cited by 62 publications

References 73 publications

Heavy quarkonium production at collider energies: Factorization and evolution

Heavy quarkonium production at collider energies: Factorization and evolution

The leading twist light-cone distribution amplitudes for the S-wave and P-wave Bc mesons

Gluon fragmentation into quarkonium at next-to-leading order using FKS subtraction

Contact Info

Product

Resources

About