Ugo Fano and Shape Resonances

Ugo Fano has been a leader in theoretical Physics in the XX century giving key contributions to our understanding of quantum phenomena. He passed away on 13 February 2001 after 67 years of research activity. I will focus on his prediction of the quantum interference effects to understand the high-energy photoabsorption cross section giving the Fano lineshapes. The Fano results led to the theoretical understanding of shape resonances (known also as Feshbach resonances) that should be better called Fano resonances. Finally I will show that today this Fano quantum interference effect is behind several new physical phenomena in different fields.