Vendredi 14 juin 2013 à 14h15
Auditoire Stueckelberg, Ecole de Physique

Chiral molecules revisited

Giovanni Jona-Lasinio, Roma La Sapienza

According to Hund (1927) quantum mechanics forbids the existence of stable optically active (chiral) molecules as they violate the invariance under parity of the Hamltonian. This paradox has attracted much attention ever since and there is not yet a universally accepted explanation. I will contend that spontaneous symmetry breaking provides a qualitative and quantitative explanation. A second paradox concerning chiral molecules is the predominance of left handed molecules in living matter. This may remind of the predominance of matter over antimatter in the universe. I shall briefly discuss how spontaneous symmetry breaking in non equlibrium may offer a clue.