Event generator for the single- and double-photon emission associated with neutrino pair-production

TL;DR

This paper introduces a new event generator for neutrino-associated photon emission processes in electron-positron collisions, combining exact matrix elements with QED parton showers to improve simulation accuracy.

Contribution

It presents a novel event generator that accurately models single- and double-photon emissions with careful treatment of radiative photon double counting, including anomalous gauge couplings.

Findings

Good agreement with O(alpha) calculations and existing Monte Carlo generators.

Effective simulation of total cross sections and photon distribution patterns.

Potential to observe effects of anomalous triple-gauge-boson couplings.

Abstract

A new event generator is proposed for two processes e+e- -> nu nu-bar gamma and e+e- -> nu nu-bar gamma gamma where nu includes all the neutrino species. The exact matrix elements of single- and double-photon emission, generated by the GRACE system, are convoluted with the QED parton shower(QEDPS) to deal with the initial state radiations(ISR). It is pointed out that a careful treatment is required to avoid the double counting of the radiative photons between the matrix elements and the ISR part. A detailed comparison of grc-nu-nu-gamma with the O(alpha) calculations and other similar Monte Carlo generators is discussed on the total cross section and on various distributions. It is also examined how the possible effects of the anomalous triple-gauge-boson couplings can be observed.