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2011 QCD and High Energy Interactions - Rencontres de Moriond ...

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4 Low energy precision<br />

Spectroscopy of the whole spectrum of heavy flavors is still a very active field. K factories like<br />

NA48 are measuring K <strong>de</strong>cays with very low branching ratios, constraining chiral perturbative<br />

<strong>QCD</strong> computations of mesons form factors. The BES III charm factory is now fully operational <strong>and</strong><br />

provi<strong>de</strong>s a harvest of high precision results including several unexpected effects which could be<br />

related to glueball production. At B factories BABAR <strong>and</strong> BELLE are completing their<br />

measurements of rare D <strong>de</strong>cays <strong>and</strong> D meson masses, providing results in reasonable agreement<br />

with <strong>QCD</strong> expectations (figure 17).<br />

Figure 17: Latest measurements of the masses of D mesons states (top) by BABAR <strong>and</strong> BELLE,<br />

compared to <strong>QCD</strong> computations.<br />

The highlight of the <strong>2011</strong> <strong>Moriond</strong> <strong>QCD</strong> edition however comes from the B physics results from<br />

the Tevatron experiments <strong>and</strong> the LHCb Collaboration. Compared to B factories, hadron colli<strong>de</strong>rs<br />

benefit from much higher production cross sections of B mesons, with an extra large enhancement<br />

at LHCb compared to Tevatron due to the forward configuration of the experiment. There is<br />

currently a strong focus on the Bs o meson, which cannot be precisely studied at B factories due to its<br />

production threshold, <strong>and</strong> whose oscillation pattern gives access to the Vts term of the CKM matrix,<br />

as well as to possible non-SM extra terms. The oscillation of the Bs o system is characterized by 3<br />

parameters: Δms, the mass difference of the 2 mass eigenstates, which controls the frequency of the<br />

oscillation, ΔΓs, the life time difference of the 2 mass eigenstates, <strong>and</strong> Φs = -2βs, the phase

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