July 28, 2020 to August 6, 2020
virtual conference
Europe/Prague timezone

On dispersive representation of kaon and eta decays to 3 pions

Jul 29, 2020, 7:45 PM
virtual conference

virtual conference

Talk 06. Strong Interactions and Hadron Physics Strong Interactions and Hadron Physics


Dr Martin Zdrahal (Charles University)


We present and develop a general dispersive framework allowing to construct representations of the amplitudes for the processes Pπ→ππ, P=K,η, valid at the two-loop level in the low-energy expansion. The construction proceeds through a two-step iteration, starting from the tree-level amplitudes and their S and P partial-wave projections. The one-loop amplitudes are obtained for all possible configurations of pion masses. The second iteration is presented in detail in the cases where either all masses of charged and neutral pions are equal, or for the decay into three neutral pions. Issues related to analyticity properties of the amplitudes and of their lowest partial-wave projections are given particular attention. This study is introduced by a brief survey of the situation, for both experimental and theoretical aspects, of the decay modes into three pions of charged and neutral kaons and of the eta meson.

Primary author

Dr Martin Zdrahal (Charles University)


Marc KNECHT (CNRS) Dr Novotny Jiri (Charles University) Karol Kampf (Charles University (CZ))

Presentation materials