A QED shower including the next-to-leading order logarithmic correction ine(+)e(-) annihilation

We develop an event generator, NLL-QEDPS, based on the QED shower including the next-to-leading order logarithmic correction in e(+)e(-) annihilation. The shower model is a Monte Carlo technique to solve the renormalization g roup equation so that contributions of alpha(m)log(n)(S/m(e)(2)) can be cal culated for any m and n systematically. Here alpha is the QED coupling, m(e ) is the mass of the electron, and S is the square of the total energy in t he e(+)e(-) system. While the previous QEDPS is limited to the leading orde r logarithmic approximation, which includes only contributions of the form (alpha log(S/m(e)(2)))(n), the model developed here contains terms of the f orm alpha(alpha log(S/m(e)(2)))(n), the the next-to-leading order logarithm ic correction. The shower model is formulated for the initial radiation in e+e- annihilation. The generator based on this model gives us events with q (2), which is a virtual mass squared of the virtual photon and/or Z-boson, to an accuracy of 0.04%, except for small q(2)/S.