Estimates for parameters and characteristics of the confining SU(3)-gluonic field in charged pions and kaons from leptonic decays and chiral symmetry breaking

The confinement mechanism proposed earlier by the author is employed for to compute the decay constants $f_P$ corresponding to leptonic decays $P\to l^\pm+\nu_l$, $l=\mu, e$, where $P$ stands for any meson from $\pi^\pm$, $K^\pm$. For this aim the weak axial form factor of $P$-meson is nonperturbatively calculated. The study entails estimates for parameters of the confining SU(3)-gluonic field in charged pions and kaons. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the mesons under consideration. Further the obtained results are applied to the problem of chiral symmetry breaking in quantum chromodynamics (QCD). It is shown that in chirally symmetric world masses of pions and kaons are fully determined by the confining SU(3)-gluonic field among (massless) $u$, $d$ and $s$ quarks and not equal to zero. Accordingly chiral symmetry is sufficiently rough approximate one holding true only when neglecting the mentioned SU(3)-gluonic field between quarks and no additional mechanism of the spontaneous chiral symmetry breaking connected to the so-called Goldstone bosons is required. Finally, a possible relation of the results obtained with a phenomenological string-like picture of confinement is discussed too.Comment: 31 pages, LaTeX, 2 figures. Nucl. Phys. A812 (2008) to appea

Estimates for parameters and characteristics of the confining SU(3)-gluonic field in neutral kaons and chiral limit for pseudoscalar nonet

First part of the paper is devoted to applying the confinement mechanism proposed earlier by the author to estimate the possible parameters of the confining SU(3)-gluonic field in neutral kaons. The estimates obtained are consistent with the widths of the electromagnetic decays $K^0,\bar{K}^0\to2\gamma$ too. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of the mesons under consideration. The second part of the paper takes into account the results obtained previously by the author to estimate the purely gluonic contribution to the masses of all the mesons of pseudoscalar nonet and also to consider a possible relation with a phenomenological string-like picture of confinement. Finally, the problem of masses in particle physics is shortly discussed within the framework of approach to the chiral symmetry breaking in quantum chromodynamics (QCD) proposed recently by the author.Comment: LaTeX, 16 pages, 2 figure

Estimates for parameters and characteristics of the confining SU(3)-gluonic field in the ground state of toponium: Relativistic and nonrelativistic approaches

The confinement mechanism earlier proposed by author is applied to describe the (possible) ground state of toponium $\eta_t$. For this aim the nonperturbative consistent approach is elaborated in both relativistic and nonrelativistic cases. The study entails estimates for parameters of the confining SU(3)-gluonic field in the above quarkonium, those estimates being also consistent with possible width of decay $\eta_t\to2\gamma$. The corresponding estimates of the gluon concentrations, electric and magnetic colour field strengths are also adduced for the mentioned field at the scales of toponium.Comment: 28 pages, LaTe

Estimates of the gluon concentrations in the confining SU(3)-Yang-Mills field for the first three states of charmonium

The estimates of the gluon concentrations in the classical SU(3)-Yang-Mills field modelling confinement are given for the first three states of charmonium whose spectrum is tuned by calculating electromagnetic transitions among the mentioned levels in dipole approximation. For comparison the corresponding estimates for the photon concentration in the ground state of positronium (parapositronium and orthopositronium) are also adduced.Comment: 15 pages, LaTe

Structure of the confining solutions for SU(3)-Yang-Mills equations and confinement mechanism

Structure of exact solutions modelling confinement is discussed for SU(3)-Yang-Mills equations and uniqueness of such confining solutions is proved in a certain sense. Relationship of the obtained results to QCD and the confinement mechanism is considered. Incidentally the Wilson confinement criterion for the found solutions is verified and also numerical estimates for strength of magnetic colour field responsible for linear confinement are adduced in the ground state of charmonium.Comment: 16 pages, LaTe

Classical Polylogarithms for Amplitudes and Wilson Loops

We present a compact analytic formula for the two-loop six-particle MHV remainder function (equivalently, the two-loop light-like hexagon Wilson loop) in N = 4 supersymmetric Yang-Mills theory in terms of the classical polylogarithm functions Li_k with cross-ratios of momentum twistor invariants as their arguments. In deriving our result we rely on results from the theory of motives.Comment: 11 pages, v2: journal version, minor corrections and simplifications, additional details available at http://goo.gl/Cl0