What did Ignatov and Todyshev discover about electron-positron collisions?

[Grosvenor2]

I recently heard about the experiments made by Fedor Ignatov and Korbely Todyshev who just received a prize for a series of studies on the properties of elementary particles in colliding electron-positron beams.
Unfortunately I haven't been able to find out what exactely their discovery is about, as I'm new in the physics environment and I couldn't fully understand the specific terminology I found in some scientific articles.
Could somebody clarify it to me in a more accessible way?

 

[Bobbywhy]

http://eng.news.kremlin.ru/ref_notes/94

Edit: For some details of the accelerators and detectors they used, see the "Electron-Positron Collider" section on:
http://en.wikipedia.org/wiki/List_of_accelerators_in_particle_physics