H - N

The D-term form factor from dispersion relations in deeply virtual Compton scattering

“…[13]. This information is then combined with the ππ → NN partial wave amplitudes, which are determined by analytical continuation of the πN scattering amplitudes [16]. As final result, we obtain…”

N* resonances from K $\Lambda$ Λ amplitudes in sliced bins in energy

“…where q and k are the initial and final meson momenta respectively in the centre of mass frame [10]. Both amplitudes depend on the invariant mass W and z = cos θ, with θ being the scattering angle.…”

“…In πN elastic and charge exchange scattering, the excited states may have isospin I = 1/2 (N * ) and I = 3/2 (∆ * ). A large amount of data was analyzed by the groups at Karlsruhe-Helsinki (KH84) [10], Carnegie-Mellon (CM) [11] and at GWU [12]. The 1850 -2100 MeV mass region -where the missing resonances of the second excitation shell are predicted in most constituent quark models (see, e.g., [2,3,4,5,6,13,14]) -is dominated by the production of ∆ * resonances with spin-parity J P = 1/2 ± , 3/2 ± , 5/2 ± , 7/2 + ; nucleon resonances are difficult to establish in this mass range due to the overwhelming background from ∆ * resonances.…”

“…Indeed, a number of new resonances has been reported (or have been upgraded in the star rating) from a combined analysis of a large number of pion and photoproduced reactions [15]. Some of the "new" resonances had been observed before [10,11,16,17,18] or were confirmed in later analyses [19,20,21]. The evidence for the existence of the new states stemmed from energy-dependent fits to the data using the BnGa approach [22,23,24,25].…”

“…Mittag-Leffler expansion[50] is the generalization of a Laurent expansion to a more-than-one pole situation. From now on, for simplicity, we will simply refer to this as a Laurent expansion.2 A conformal mapping expansion of this particular type was introduced by Ciulli and Fisher[51,52], was described in detail and used in pion-nucleon scattering by Esco Pietarinen[53,54], and named as a Pietarinen expansion by G. Höhler in[10].…”