In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

The E-158 experiment at Stanford investigated this interaction's role in Moller scattering. A simple way to visualize the elements of one mathematical structure used in this interaction is the unitarity triangle. That structure is the subject of a parametrization of Wolfenstein. The Lagrangian of this interaction is a vector minus axial vector. The decay of neutral kaons was used by Cronin and Fitch to show that this interaction violates CP symmetry. That previous structure is the CKM matrix, which describes the probability of quark flavor transitions. Salam, Sheldon, and Weinberg won a Nobel for unifying the electromagnetic force with this force, which mediates beta decay. This force is mediated by the W and Z bosons. For 10 points, name this fundamental force that is, curiously, stronger than gravity.
Science