Day one -- afternoon

I haven't been able to live-blog yesterday's afternoon session, so here there are only the parts of the heavy quark sessions that stuck with me for some reason or another:

CDF has observed two new decays of the B_s meson that are both Cabbibo and colour suppressed, namely B_s --> J/ψ K^* and B_s --> J/ψ K_S, with a significance of over 7σ.

BELLE has observed charmless B_s decays B_s --> K⁺K-, but no B_s --> Kπ or B_s --> ππ decays. They have also observed B_s --> D_s^*π, B_s --> D_s^*ρ, and B_s --> D_sρ decays.

Nicolas Garron spoke about the determination of the bottom quark mass and the B_s decay constant in nonperturbative Heavy Quark Effective Theory (HQET) on the lattice. This approach is based on a fully nonperturbative lattice formulation of HQET, the effective theory obtained by expanding QCD in powers of the inverse heavy quark mass. Using this formulation, one can nonperturbatively match HQET to QCD on a very fine (and hence necessarily very small) lattice and thus determine the HQET couplings, which then can be extended to larger lattices and be used to make predictions. The results presented were still for quenched (i.e. N_f=0) QCD, but the calculation of N_f=2 results is far advanced.

The poster session took place in the evening. Since I had a poster to present myself, I didn't really get to discuss any posters with their presenters. At the reception afterwards, the food was very nice, but was hard to obtain because the density of physicists approached a singularity near the plates.

Day one, session two -- Heavy Quarks

The first talk of this session was given by Matthias Steinhauser, who spoke about the three-loop heavy quark potential. The heavy quark potential, which describes the forces acting between two quarks in the limit in which those quarks are taken to be infinitely heavy, is an important quantity in QCD -- its non-perturbative linear rise at large distances encodes confinement, and its perturbative short-distance behaviour gives a way to define the strong coupling α_s. It also plays a role in theoretical descriptions of quarkonium physics. The three-loop calculation presented is the result of long and very hard work by theorists.

This was followed by experimental results for radiative transitions between charmonium states, presented by Gang Li, and radiative decays of charmonia, presented by Rong-Gang Ping, both from BESIII, and on the properties of ψ resonances by Korneliy Todyshev from the KEDR expriment at the Russian VEPP-4M collider.

Moving from Charmonium to Bottomonium, but staying with experimental, Bryan Fulsom presented BaBar results for Υ(1D_J) states, finding the Υ(1D₂) at 10164.5(8)(6) MeV, for the η_b, where the Υ(1S)-η_b(1S) hyperfine splitting is about 70 MeV, a fair bit larger than theoretical predictions. It should be noted, however, that those theoretical predictions rely on effective field theories for heavy quarks, and that the next order in 1/M may account for the difference. Some indications for the h_b were presented, but the significance was below 3σ.