ππ phase shifts from Chew-Low extrapolations of π−p→ππN at 2.77 GeV/c

Dual crossing-symmetric representations with finite-width resonances

“…The dip in the phase shift is due to interference between the E and El. Notice that the behavior is'similar to that found by Baton (1970) near the KK threshold.…”

“…The agreement with unitarity below the inelastic threshold, in fact, is to within 8% (see figure VI.lO). The resulting phase shift 68 is not too far from the "down-down" solution of Baton (1970).…”

“…Be1.ow 700 MeV there is a unique solution (Baton 1970). Above 700 MeV, however, there are two solutions, the "down-down" and "down-up"…”

“…The "down-up" solution of Baton (1970) imp1ies an S-wave TITI resonance (E) near the mass of the p: ME = 736 MeV, f E = 181 MeV (5) The "down-down" solution is mi1d1y prefened, however. As is seen in figure VI.3, this solution is in qualitative agreement with the higher energy solutions ( Beaupre 1971, Oh 1970).…”

“…A slightly more complicated K-matrix method has been used by Lovelace (1969) The phase shifts are compared with the elastic phase shifts of Baton (1970).…”