The K-meson form factor and charge radius: linking low-energy data to future Jefferson Laboratory measurements

Abstract

Starting from a successful model of the π -meson electromagnetic form factor, we calculate a similar form factor, F K (Q 2 ), of the charged K meson for a wide range of the momentum transfer squared, Q 2 . The only remaining free parameter is to be determined from the measurements of the K -meson charge radius, r K . We fit this single parameter to the published data of the NA-7 experiment which measured F K (Q 2 ) at Q 2 → 0 and determine our preferred range of r K , which happens to be close to recent lattice results. Still, the accuracy in the determination of r K is poor. However, future measurements of the K -meson electromagnetic form factor at Q 2 5.5 GeV 2 , scheduled in Jefferson Laboratory for 2017, will test our approach and will reduce the uncertainty in r K significantly.

Magnetic moment of the ρ meson in instant-form relativistic quantum mechanics

“…Our quadrupole form factor differs strongly from that of other given results. In this context it is necessary to note that we (as opposed to, e.g., [46]) take into account the quark structure in terms of quark form factors (21), (22), that accelerating the decay of form factors. Note that the calculation using the formulae analogous to (14) described well the electron-deuteron polarization scattering [19] and so the experimental deuteron quadrupole form factor.…”

“…[16][17][18] for details. Let us note that mIF was successfully used also for other composite systems, namely, the deuteron [19][20][21] and the K-meson [22].…”

Linking infrared and ultraviolet parameters of pion-like states in strongly coupled gauge theories

“…The model we discuss here [22][23][24][25][26] has been developed for the description of electroweak properties of light strongly interacting two-particle bound states and has been succesfully applied to the deuteron [27], π [5,9], ρ [28,29] and K [30] mesons. The model is based on the instant form of the relativistic Hamiltonian dynamics (see e.g.…”

“…Reaching the QCD asymptotics is an infrequent, though welcome, feature of infrared models of mesons; to our best knowledge, no other model achieves it without introduction of new tunable parameters. For the QCD case, unusual predictivity of the model allowed for construction of a "parameter-free model of electromagnetic properties of light mesons", successfuly connecting corresponding observables of π, ρ and K mesons[28][29][30].Meanwhile, methods to relate infrared and ultraviolet physics of strongly coupled gauge Re-cently, the interest in models with new strong dynamics increased considerably because of their possible relation to flavour anomalies observed at the Large Hadron Collider (LHC)…”

Quadrupole moments of the ρ meson and the S -wave deuteron and some general constraints on quadrupole moments of spin-1 systems

“…Here we use our version of RQM, -the modified instant form (mIF) of RQM , that was successfully used for various composite two-particle systems, namely, the deuteron [35], the pion [36][37][38][39], the ρ meson [40,41] and the kaon [42]. This model has predicted with surprising accuracy the values of the form factor F π (Q 2 ), which were measured later in JLab experiments [43][44][45][46][47] (see discussion in Ref.…”