Abstract
Beginning with results for the leading-twist two-particle distribution amplitudes of pi - and K-mesons, each of which exhibits dilation driven by the mechanism responsible for the emergence of hadronic mass, we develop parameter-free predictions for the pointwise behaviour of all pi and K distribution functions (DFs), including glue and sea. The large-x behaviour of each DF meets expectations based on quantum chromodynamics; the valence-quark distributions match extractions from available data, including the pion case when threshold resummation effects are included; and at zeta _5=5.2,GeV, the scale of existing measurements, the light-front momentum of these hadrons is shared as follows: langle x_{mathrm{valence}} rangle ^pi = 0.41(4), langle x_{mathrm{glue}} rangle ^pi = 0.45(2), langle x_{mathrm{sea}} rangle ^pi = 0.14(2); and langle x_{mathrm{valence}} rangle ^K = 0.42(3), langle x_{mathrm{glue}} rangle ^K = 0.44(2), langle x_{mathrm{sea}} rangle ^K = 0.14(2). The kaon’s glue and sea distributions are similar to those in the pion, although the inclusion of mass-dependent splitting functions introduces some differences on the valence-quark domain. This study should stimulate improved analyses of existing data and motivate new experiments sensitive to all pi and K DFs. With little known empirically about the structure of the Standard Model’s (pseudo-) Nambu-Goldstone modes and analyses of existing, limited data being controversial, it is likely that new generation experiments at upgraded and anticipated facilities will provide the information needed to resolve the puzzles and complete the picture of these complex bound states.
Highlights
The past decade saw discovery of the Higgs boson [1,2], thereby completing the Standard Model (SM)
In terms of the two-particle light front wave function (LFWF) defined via Eq (6a), the meson’s valence u-quark distribution functions (DFs) is u M(x; ζH ) =
Reference [51] (GRS) postulates that hadron DFs at a scale ζ can be computed by beginning with nonzero valence-like distributions for all partons at a scale ζ0 and using pQCD DGLAP equations to evolve these input distributions to the larger scale, ζ, in the process of fitting a selected body of structure function data
Summary
The past decade saw discovery of the Higgs boson [1,2], thereby completing the Standard Model (SM). Such behaviour may be associated with the opening of a conformal window at long wavelengths. 7 describes predictions for all the kaon’s DFs They include results for the hostdependence of valence, glue and sea DFs, i.e. K /π ratios for all common DFs. It should be emphasised that within the SM’s strong interaction sector there can be no differences between π and K mesons without a Higgs mechanism; but EHM modulates the observable effects of this mechanism in a.
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