Developed by Glashow, Weinberg, and Salam, FTP, identify this theory that combines two of the fundamental forces.
This theory was tested by passing a laser through a vapor of thallium atoms.  This theory was based on the earlier Fermi and Cabibbo theorems, and was the result of observing neutral kaon systems and strangeness oscillations.  Finally calculated using the Cabibbo-Kobayashi-Maskawa matrix, its developers postulated the existence of the W-plus, W-minus, and Z-naught particles.  Developed by Glashow, Weinberg, and Salam, FTP, identify this theory that combines two of the fundamental forces.
This theory was tested by passing a laser through a vapor of thallium atoms.  
electroweak theory