16-8-14

Post date: Aug 16, 2014 2:49:36 PM

Funny enough the last two weeks were the most busy and fruitful in some time. Maybe it was

good to postpone the vacation a bit after all. Managed to convince Alessandro Strumia to work on composite

dark matter even though the project was somehow diverted into modified naturalness.

The great lesson of the SM is that no symmetries are exact except for gauge symmetries (if they are symmetries at all!).

Symmetries can however arise accidentally in renormalizable theories. For example according to our understanding

the proton is stable as a consequence of the accidental baryon symmetry of the SM. To keep the standard set by the SM also

dark matter should be accidentally stable (unlike time-honored WIMPs). Simplest example is baryon of a QCD like hidden

sector with SM gauge interactions.

Well now off to the seaside for a week. September is going to be busy!