Thursday 12 November 2015

KIAS-CFHEP Workshop Liveblog: Day Four Session One

So yesterday was interesting, the first time I've explored any of Seoul.  Won't be the last time, I'm sure.  Today we have sessions on flavour physics before lunch, and the second parallel session of the conference in the afternoon.  The flavour section is itself split into experiment first, then theory.



9:30 am: Flavour Physics at CERN, Tatsuya Nakada

92 slides!!! I hope most of those are backups... Or most of them are not actually distinct, it's just a counting of every small change from one slide to the next.

"Recent past" includes CPV in Kaons (e.g. NA31, NA48), SppS and LEP.  If an experiment stopped taking data before I started my PhD, it's not really the recent past.  If you are talking about data taken the year I was born, then you're just taking the piss.  I misread that: the earliest data he's mentioned was from 1990.  That's still a long time ago, just not as long.  Though I'm surprised that NA48 didn't finish till 2001; still before my PhD, but later than I thought.

Slide of non-LHC experiments at CERN. Discussion of cosmic ray physics and (lack of) connection to climate change.  Of course.

Actual flavour physics results I haven't heard of before!  Rare kaon decay K to πνν.  Seen, described as larger branching ratio than expected but consistent with SM at 1 sigma.  Ongoing experiment to measure more precisely.  Corresponds to direct measurement of Vtd.

Delays in start of LHC meant Tevatron and B-factories became important.  None of which where at CERN.  But have left us with anomalies that CERN can look at.

LHCb.

Bs to J/ψ φ: Converging on SM.  B to ππ: Convergence of experiments on SM.  CPV in B to Kπ: Cannot be tested at LHCb.  CPV in B/Bbar oscillations: converging on SM.  Bs to μμ: SM result.  Asymmetries in B to Kμμ: nope.

Several elements of unitarity triangle off room for improvement.  This applies both to theory and experiment.

Use of B-baryons to study Vub/Vcb.  Measurement at hadron machines impossible with B-mesons.  Exclusive vs inclusive discrepancy remains.

Discrepancy in B to Dτν vs B to Dμν remains.

CPV in D to 2h decays non-zero at four sigma, tension with SM.  But measurements free of hadronic uncertainties disagree with earlier results.

Question
Can LHC measure R(D)?  Invisible decay makes it difficult.  Not clear if can be done.

Ten minutes over already...

10:10 am: Recent results on flavour physics from the B-factories, Youngjoon Kwon

This is just washing over me.

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