A feasible scheme to search for fractional charge particles in low energy accelerator experiments

Abstract

In the Standard Model of particle physics, quarks and anti-quarks have fractional charges equal to ±1/3 or ±2/3 of the electron's charge. There has been a large number of experiments searching for fractional charge particles using a variety of methods, including dE/dx ionization energy loss measurements in e+e− collisions, but no evidence has been found to confirm existence of free fractional charge particles, which leads to the quark confinement theory. In this paper, a proposal to search for fractional charge particles is presented, which is based on the conservation law of four-momentum and the Lorentz force law. To show the power of the new strategy, a fully BESIII detector simulated signal sample mixed with a fully simulated background sample is analyzed and lower signal cross section limits to discover 5σ signal as a function of quark mass are estimated for the background. The analysis result shows that in comparison with ionization energy loss measurements, the advantage of the strategy is that it can identify fractional charge particles without using any theoretical or empirical formulae to calculate any expected observation values.