Collins Fragmentation Function within NJL-jet Model

Abstract

The NJL-jet model is extended to accommodate hadronization of a transversely polarized quark in order to explore the Collins effect within a multihadron emission framework. This is accomplished by calculating the polarized quark spin flip probabilities after a pseudoscalar hadron emission and the elementary Collins functions. The model is used to calculate the number densities of the hadrons produced in the polarized quark's decay chain. The full Collins fragmentation function is extracted from the sine modulation of the polarized number densities with respect to the polar angle between the initial quark's spin and hadron's transverse momentum. Two cases are studied here. First, a toy model for elementary Collins function is used to study the features of the transversely polarized quark-jet model. Second, a full model calculation of transverse momentum dependent pion and kaon Collins functions is presented. The remarkable feature of our model is that the 1/2 moments of the favored Collins fragmentation functions are positive and peak at large values of z but decrease and oscillate at small values of z. The 1/2 moments of the unfavored Collins functions have comparable magnitude and opposite sign to the favored functions, vanish at large z and peak at small values of z. This feature is observed for both the toy and full models and can be attributed to the quark-jet picture of hadronization. Moreover, the transverse momentum dependencies of the model Collins functions differ significantly from the Gaussian form widely used in the empirical parametrizations. Finally, a naive interpretation of the Schafer-Teryaev sum rule is proven not to hold in our model, where the transverse momentum conservation is explicitly enforced. This is attributed to the sizable average transverse momentum of the remnant quark that needs to be accounted for to satisfy the transverse momentum sum-rule.

15 pages, 22 figures. v2 - minor changes/additions to conform to the journal published version

References in corpus (24)

• Quantum Chromodynamics and Other Field Theories on the Light Cone
• The complete tree-level result up to order $1/Q$ for polarized deep-inelastic leptoproduction
• Semi-inclusive deep inelastic scattering at small transverse momentum
• Single-spin asymmetries in semi-inclusive deep-inelastic scattering on a transversely polarized hydrogen target
• Single-spin asymmetries: the Trento conventions
• TMD Parton Distribution and Fragmentation Functions with QCD Evolution
• Measurement of Azimuthal Asymmetries in Inclusive Production of Hadron Pairs in e+e- Annihilation at Belle
• The QCD Evolution of the Sivers Function
• Measurement of Azimuthal Asymmetries in Inclusive Production of Hadron Pairs in e+e- Annihilation at \sqrt{s} = 10.58 GeV
• Measurement of Beam-Spin Asymmetries for Deep Inelastic ${\pi }^{+}$ Electroproduction
• Collins fragmentation function for pions and kaons in a spectator model
• Transverse Momentum Dependent Fragmentation and Quark Distribution Functions from the NJL-jet Model
• Reviewing model calculations of the Collins fragmentation function
• Estimate of the Collins fragmentation function in a chiral invariant approach
• A mechanism for the T-odd pion fragmentation function
• The Collins function: a simple model calculation
• The NJL-jet model for quark fragmentation functions
• Sum rules for the T-odd fragmentation functions
• Calculating Kaon Fragmentation Functions from NJL-Jet Model
• Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive ${\pi }^0$ production
• Momentum sum rules for fragmentation functions
• Monte Carlo Simulations of Hadronic Fragmentation Functions using NJL-Jet Model
• Calculating Dihadron Fragmentation Functions in the NJL-jet model
• Studies of spin-orbit correlations at JLAB

Cited by in corpus (13)

• Parton Fragmentation Functions
• Role of diquark correlations and the pion cloud in nucleon elastic form factors
• Dihadron Fragmentation Functions within the NJL-jet Model
• Studies of Azimuthal Modulations in Two Hadron Fragmentation of a Transversely Polarised Quark
• Several Topics on Transverse Momentum-Dependent Fragmentation Functions
• Combining nonperturbative transverse momentum dependence with TMD evolution
• Quark-Jet model for transverse momentum dependent fragmentation functions
• Monte Carlo Implementation of Polarized Hadronization
• The resolution to the problem of consistent large transverse momentum in TMDs
• Dihadron Fragmentation Functions from the NJL-jet model and their QCD Evolution
• Spin Orbit Correlations and the Structure of the Nucleon
• Azimuthal asymmetries from $\theta$ Vacuum
• Effects of Quark Spin Flip on the Collins Fragmentation Function in a Toy Model