Titans Cross Swords On CPT Violation
I (T.D.) arrived late today in the conference hall, since I spent the morning in Padova attending the graduation of two PhD students from my group. As Angela and Luca already lamented, the weather is horrible to shitty today, and I drove my car for 40 kilometers breaking at least a dozen rules of the road. I expect my lifetime on the wheel in days such as this one to be quite small, maybe of the order of 1000 driving hours. We will see about that.
As I got in the hall, I listened to the conclusions of the talk by Maltoni on non-standard interactions from atmospheric neutrino interactions. There followed an interesting exchange with two old HEP titans: Rubbia and Altarelli. Here is a transcript.
C. Rubbia (to the speaker): I know very little to nothing about this, but I think that one cannot describe CPT with a local interaction, and thus it is not meaningful to discuss a 2.4 sigma discrepancy (Minos, in neutrino vs antineutrino oscillation parameters) in this context.
G. Altarelli (sitting two seats away from Carlo, and replying for the speaker): but maybe the neutrino mass is determined by physics at the Planck scale, and there the physics might not be local. There could be a CPT violation there.
C. Rubbia: Well, I do not need to understand these models until you discover it, so good luck…