Gluon fragmentation into spin-triplet<i>S</i>-wave quarkonium

Braaten, Eric; Yuan, Tzu-Chiang

doi:10.1103/physrevd.52.6627

Cited by 104 publications

(90 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[8], the initial unpolarized fragmentation function of gluon to J/ψ is given in a form of two-dimensional integrals, which in practice can only be evaluated numerically and thus is not very convenient for the application of the Altarelli-Parisi evolution equation [7]. In use of the obtained initial gluon to unpolarized J/ψ fragmentation function [8], one can integrate out the integrals numerically [15] and fit the z distribution into a combination of functions of z. Then the application of the gluon to J/ψ fragmentation function will be more easier for the phenomenological use.…”

Section: Polarized Fragmentation Functions Wrt Light-cone Definitimentioning

confidence: 99%

“…(5) is better and widely used. About a decade ago, people noticed that the parton to heavy quarkonium fragmentation functions can be obtained analytically [4,8,9,10]. However, in fact the initial scale gluon fragmentation function can also be obtained numerically and works equally well as the analytic one in the application.…”

Section: Introductionmentioning

confidence: 99%

“…The initial gluon fragmentation function D g→H (z, Q 0 ) is a universal function defined by factorization in the infinite momentum frame of the fragmenting gluon. It can also be obtained by calculating a specific physical process in perturbative QCD in the finite momentum frame of fragmenting gluon [4,8], where the z is defined in the Lorentz boost invariant form (e.g. Eq.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Application of gluon to heavy quarkonium fragmentation functions

Qiao

Wang

2007

Phys. Rev. D

View full text Add to dashboard Cite

We analyze the uncertainties induced by different definitions of the momentum fraction z in the application of gluon to heavy quarkonium fragmentation function. We numerically calculate the initial g → J/ψ fragmentation functions by using the non-covariant definitions of z with finite gluon momentum and find that these fragmentation functions have strong dependence on the gluon momentum k. As | k| → ∞, these fragmentation functions approach to the fragmentation function in the light-cone definition. Our numerical results show that large uncertainties remains while the non-covariant definitions of z are employed in the application of the fragmentation functions. We present for the first time the polarized gluon to J/ψ fragmentation functions, which are fitted by the scheme exploited in this work.

show abstract

Section: Polarized Fragmentation Functions Wrt Light-cone Definitimentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Application of gluon to heavy quarkonium fragmentation functions

Qiao

Wang

2007

Phys. Rev. D

View full text Add to dashboard Cite

show abstract

“…The color-singlet gluonfragmentation channel [ Fig. 50(e)] has been investigated in the framework of the fragmentation approximation [679], which is relevant in the limit p T m Q . The processes in which the QQ pair is produced by the exchange of two gluons in the t channel [ Fig.…”

Section: −4mentioning

confidence: 99%

Heavy quarkonium: progress, puzzles, and opportunities

Brambilla¹,

Eidelman²,

Heltsley³

et al. 2011

Advances in the Physics of Particles and Nuclei

103

View full text Add to dashboard Cite

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly-found conventional states expanded to include hc(1P ), χc2(2P ), B + c , and η b (1S). In addition, the unexpected and still-fascinating X(3872) has been joined by * Editors † Section coordinators ‡ Corresponding author: bkh2@cornell.edu more than a dozen other charmonium-and bottomonium-like "XY Z" states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of cc, bb, and bc bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrialstrength effort now dependent more on insight and innovation than pure computational power. New effective field theories for the description of quarkonium in different regimes have been developed and brought to a high degree of sophistication, thus enabling precise and solid theoretical predictions. Many expected decays and transitions have either been measured with precision or for the first time, but the confusing patterns of decays, both above and below open-flavor thresholds, endure and have deepened. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hotand cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.

show abstract

“…For simplicity we treat also this process as g → ψ ′ + g. The error introduced by this simplification, which will be investigated in a future publication, may be assumed to be small since two gluons nearby in phase space are usually well approximated with one within the framework of Lund string fragmentation. The color-singlet gluon fragmentation function is given as a double integral in [22]. Performing one of the integrals we find an analytical expression for the fictitious g → ψ ′ +g splitting kernel.…”

Section: The Implementationmentioning

confidence: 99%

Generating heavy quarkonia in a perturbative QCD cascade

Ernström

Lönnblad

1997

Zeitschrift f�r Physik C Particles and Fields

View full text Add to dashboard Cite

We present an implementation of heavy quarkonium production within a perturbative QCD cascade based on the Color Dipole Cascade model. We consider the processes most relevant in the context of the ψ ′ surplus at the Tevatron; g → ψ ′ and c → ψ ′ in the color-singlet model and g → ψ ′ through the color-octet mechanism. Our implementation is, however, easily extendible to other quarkonia and other production mechanisms.Where comparison is possible we find good agreement with analytical calculations.We present some suggestions for measurements at the Tevatron that would be sensitive to the shape of the fragmentation functions. Our calculations indicate that such measurements could be used to test the color-octet mechanism solution to the ψ ′ surplus at the Tevatron.

show abstract

Gluon fragmentation into spin-tripletS-wave quarkonium

Abstract: The leading color-singlet contribution to the fragmentation function for a gluon to split into spin-triplet S-wave quarkonium is presented. In the case of charmonium, we find that this color-singlet term is always negligible compared to the leading color-octet contribution.

Cited by 104 publications

References 8 publications

Application of gluon to heavy quarkonium fragmentation functions

Application of gluon to heavy quarkonium fragmentation functions

Heavy quarkonium: progress, puzzles, and opportunities

Generating heavy quarkonia in a perturbative QCD cascade

Contact Info

Product

Resources

About