We measured, with the KLOE detector, the spectrum of π+π− invariant mass in a sample of 6.7×105e+e−→π+π−γ events with the photon at large polar angle (θγ>45°) at a centre of mass energy s around the ...ϕ mass. We observe in this spectrum a clear contribution from the intermediate process ϕ→ f0(980)γ. A sizeable effect is also observed in the distribution of the pion forward–backward asymmetry. We use different theoretical models to fit the spectrum and we determine the f0 mass and coupling constants to the ϕ, to π+π− and to KK¯.
The WASA Detector Facility is an internal experiment at the cooler synchrotron (COSY) in Jülich, Germany. The COSY accelerator provides proton and deuteron beams with momenta up to 3.7 GeV/c giving ...access to hadron physics including the strange quark sector. The physics program with the WASA detector involves hadron dynamics and hadron structure. Key experiments address fundamental symmetries and symmetry violations via the study of rare and not-so-rare meson decays. From the very first production run, results on the Dalitz plot slope parameter in the isospin violating
η
→ 3
π
0
decay have been obtained. The 3
π
0
final state is also used to study meson production mechanisms. Investigations of other decay modes of the
η
-meson address
C, P
, and
T
symmetries and combinations. Higher orders in chiral perturbation theory are probed with the
η
→
π
0
decay. The status and plans for studying hadron structure with Dalitz decays of mesons are presented.
Various recent experimental results from BaBar are presented concerning both semileptonic and leptonic decays. The most important is the excess of events observed in the decay B→D(⁎)τν¯τ, where we ...measure R(D)=0.440±0.058±0.042 and R(D⁎)=0.332±0.024±0.018, exceeding the SM expectations by 2.0σ and 2.7σ respectively; together our results disagree with SM expectations at the 3.4σ level. This excess cannot be explained by the contribution of a charged Higgs boson in the type II two-Higgs-doublet model.
We also present results for other recent analyses in other leptonic and semileptonic decays.
No definite proof for New Physics has yet been found, altough in the conclusions we outline present ‘tensions’ of various experimental measurements vs the SM expectations.
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