Is our world CPT symmetric, though it violates CP and T?


A long standing question is of all our interactions in Nature conserve the combined transformation as Charge Conjugation C (a particle-antiparticle exchange), a parity P transformation (mirroring) and a time reversal T, though surprisingly T,C,P and even CP are not generally conserved in Nature.

The J-PET has asked this question for a purely leptonic system, a bounded system of an electron and a positron (=antiparticle of electrons), and it goes without saying a violation would be indeed a shaking result of the very foundations of physics. Fortunately, with novel high precision a symmetry violation was not found.

More to be read in Nature Communication (2021)!