Transverse $\Lambda$ polarization in $e^{+}{e}^{-}$ processes within a TMD factorization approach and the polarizing fragmentation function

Abstract

We perform a re-analysis of Belle data for the transverse $\Lambda$ and $\bar{\Lambda }$ polarization in $e^{+}{e}^{-}$ annihilation processes within a transverse momentum dependent (TMD) factorization approach. We consider two data sets, one referring to the associated production of $\Lambda$'s with a light unpolarized hadron in an almost back-to-back configuration, and one for the inclusive $\Lambda$ production, with the reconstruction of the thrust axis. We adopt the Collins-Soper-Sterman framework and employ the recent formulation on the factorization of single-inclusive hadron production. This extends a previous phenomenological study carried out in a more simplified TMD approach, leading to a new extraction of the polarizing fragmentation function (FF). While confirming several features of the previous analysis, here we include the proper QCD scale dependence of this TMD FF and carefully exploit the role of its nonperturbative component. The compatibility, within a unique TMD factorization scheme, of double and single-inclusive hadron production is discussed in detail. Moreover, we consider another data set for inclusive $\Lambda$ production, at much larger energies, from the OPAL Collaboration, in order to test the consistency of the entire approach. Finally, we elaborate on some fundamental issues like the role of $SU(2)$ isospin symmetry and the heavy quark contributions.

45 pages, 14 figures

References in corpus (16)

• Global analysis of fragmentation functions for pions and kaons and their uncertainties
• Sivers Effect for Pion and Kaon Production in Semi-Inclusive Deep Inelastic Scattering
• Understanding the large-distance behavior of transverse-momentum-dependent parton densities and the Collins-Soper evolution kernel
• Unpolarized Transverse Momentum Distributions from a global fit of Drell-Yan and Semi-Inclusive Deep-Inelastic Scattering data
• Extracting the Transverse Momentum Dependent Polarizing Fragmentation Functions
• Factorization for the light-jet mass and hemisphere soft function
• Isospin Symmetry of Fragmentation Functions
• Transverse $\Lambda$ Polarization in $e^{+}{e}^{-}$ collisions
• QCD resummation on single hadron transverse momentum distribution with the thrust axis
• Joint thrust and TMD resummation in electron-positron and electron-proton collisions
• General helicity formalism for two-hadron production in $e^{+}{e}^{-}$ annihilation within a TMD approach
• Transverse Momentum Dependent Fragmentation Functions from recent BELLE data
• Factorization of $e^{+}{e}^{-}\to HX$ cross section, differential in $z_h$, $P_T$ and thrust, in the $2$-jet limit
• Universality-breaking effects in $e^{+}{e}^{-}$ hadronic production processes
• Longitudinal and transverse polarizations of $\Lambda$ hyperon in unpolarized SIDIS and $e^{+}{e}^{-}$ annihilation
• Non-global and rapidity logarithms in narrow jet broadening

Cited by in corpus (3)

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• Measurement of transverse polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons inside jets in $pp$ collisions at $\sqrt{s}=200$ GeV