New physics? Not once again!

Trackers of science news will have noted two new events in the physics world. The Opera experiment has carried out its time of flight experiment again with shorter bunches of neutrinos, spaced further apart, and reconfirms its results about the bunches reaching 60 nanoseconds before photons would have. This eliminates one of the objections to the earlier data, viz. the length of the bursts, although others still remain. The experimenters make a cautious statement, viz. `but it is not yet the final confirmation'. Critics retain their scepticism. Let's see if nonOperatics sing the same tune.

There's one more anomalous result under discussion this week.Decays of D mesons at the LHCb experiment in CERN have found evidence of CP (charge conjugation- parity) violation. The CP symmetry consists of replacing each charged particle by its antiparticle, and reversing all directions in space. Processes which obey the CP symmetry are identical under this symmetry, whereas those that do not, notably those mediated by weak interactions, do not give identical results. The D0 mesons decay into kaons and pions and so do their antiparticles. These rates of decay are expected to be identical under the standard model, but have turned out be not. For those who like the standard deviations, this is a 3.5 sigma result. Will it go away like all those we have encountered so far this year? Only time can tell. However, eventually, one of the "new physics" results will stand up to the test of reproducibility, and keep the next generation of physicists, busy, productive and happy.

This blog post is by Neelima Gupte and Sumathi Rao.