A new global fit of the L(i)(r) at next-to-next-to-leading order in Chiral Perturbation Theory

• Abstract in Undeterminednew fit is done to obtain numerical values for the order p(4) low-energy-constants L(i)(r) in Chiral Perturbation Theory. This includes both new data and new calculated observables. We take into account masses, decay constants, K(l4), pi pi and pi K scattering lengths and slopes and the slope of the pion scalar formfactor. We compare in detail where the changes w.r.t. the 10 years old "fit 10" come from. We discuss several scenarios for estimating the order p(6) constants C(i)(r) and search for possible values of them that provide a good convergence for the ChPT series. We present two such sets. One big change is that the fits do not have the expected behaviour in the limit of large N(c) as well as before. (C) 2011 Elsevier B.V. All rights reserved.

Subject headings

NATURVETENSKAP  -- Fysik -- Subatomär fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Subatomic Physics (hsv//eng)

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art (subject category)

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