0000000000351847
AUTHOR
David London
Looking for Delta I=5/2 amplitude components in B ->pi pi and B ->rho rho experiments
We discuss how experiments measuring B -> pi pi and B -> rho rho may be used to search for a Delta I = 5/2 amplitude component. This component could be the explanation for a recent (albeit very tentative) hint from B(Bbar) -> rho rho decays that the isospin triangles do not close.
Measurements of new physics in B -> pi pi decays
If new physics (NP) is present in B -> pi pi decays, it can affect the isospin I=2 or I=0 channels. In this paper, we discuss various methods for detecting and measuring this NP. The techniques have increasing amounts of theoretical hadronic input. If NP is eventually detected in B -> pi pi -- there is no evidence for it at present -- one will be able to distinguish I=2 and I=0, and measure its parameters, using these methods.
Measurements of new physics inB→ππdecays
If new physics (NP) is present in B{yields}{pi}{pi} decays, it can affect the isospin I=2 or I=0 channels. In this paper, we discuss various methods for detecting and measuring this NP. The techniques have increasing amounts of theoretical hadronic input. If NP is eventually detected in B{yields}{pi}{pi}--there is no evidence for it at present--one will be able to distinguish I=2 and I=0, and measure its parameters, using these methods.
Can one detect new physics in I=0 and/or I=2 contributions to the decays B ->pi pi
We study the effects of new-physics contributions to B --> pi pi decays, which can be parametrized as four new complex quantities. A simple analysis is provided by utilizing the reparametrization invariance of the decay amplitudes. We find that six quantities can be reabsorbed into the definitions of Standard Model-like parameters. As a result, the usual isospin analysis provides only two constraints on new physics which are independent of estimates for the Standard Model contributions. In particular, we show that one is not sensitive to new physics affecting the I=0 amplitudes. On the other hand, I=2 new physics can be detected, and its parameters can be measured by using independent deter…