Wednesday, February 8, 2012

1109.0851 (Marian Kolesar)

Analysis of discrepancies in Dalitz plot parameters in eta to 3 pion
decay
   [PDF]

Marian Kolesar
We analyze the Dalitz plot parameters of eta to 3 pion decay in the framework
of resummed chiral perturbation theory. This approach allows us to keep the
uncertainties in the NNLO and higher orders under better control and estimate
their influence. We cannot confirm the suspected discrepancy in the case of the
charged decay parameter b, where even small uncertainties in higher orders
could accommodate the difference. On the other hand, we find the experimental
value of the neutral decay parameter alpha incompatible with an assumption of
good convergence properties in the center of the Dalitz plot. We calculate
pion-pion rescattering bubble corrections up to three loops and show that these
might explain the discrepancy, especially for a low value of the pseudoscalar
decay constant in the chiral limit. However, that could indicate a failure of
convergence of the chiral series in this channel already at low energies around
500MeV.
View original: http://arxiv.org/abs/1109.0851

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