...system

This cut has been used in [5] for 161#161, because this kinematical region is free from 162#162 background. We apply it here for illustration also to the electron mode 163#163.

...is

In all four experiments [7,4,5,8] discussed here and below , the form factors A and V have been treated as constants.

...[#pdg82##1#]

Please note that the most recent measurements of 504#504 go back to 1981 [3]!

...(#s319#1278>)

We do not quote an error for the result (3.35), because one should estimate higher-order chiral corrections for this purpose.

...symmetry

We use the Condon-Shortley phase conventions.

...real

Note that, according to what is said in the previous subsection, the terms denoted by ''D-wave'' in Eq. (5.34) all contain (complex) contributions which are proportional to 960#960.

...becomes

If not stated otherwise, we use 1009#1009 MeV, 1010#1010 and 1011#1011 MeV, 1012#1012 MeV and 1013#1013 MeV for the decays (5.1), (5.2) and (5.3), respectively.

...above

We always use for 1171#1171 the values quoted in table 1 of Ref. [2].

...well

We thank B. Moussallam for pointing this out to us.

...discuss

The material in this section is taken from Ref. [85].

Carlos E.Piedrafita