A gauge-invariant chiral unitary framework for kaon photo- and electroproduction on the proton

Abstract

Abstract. We present a gauge invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. Within the leading order approximation to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and CBELSA/TAPS are analyzed in the threshold region. The importance of gauge invariance and the precision of various approximations in the interaction kernel utilized in earlier works are discussed.

Chiral dynamics of the S11(1535) and S11(1650) resonances revisited

“…The purely baryonic integrals are set to zero from the beginning, which is in effect, similar to the EOMS regularization scheme advocated in [8]. As it was argued in [6] it is not possible to express the terms necessary to absorb the divergencies in the BSE as counterterms derived from a local Lagrangian. However it is possible to alter the loop integrals in the solution of the BSE in a way that is in principle equivalent to a proper modification of the chiral potential itself, see [9].…”

“…In view of these developments and our attempts to construct a unitary and gauge-invariant model for Goldstoneboson photoproduction off nucleons based on coupled-channel unitarized chiral perturbation theory [6], we consider in this letter the two s-waves S 11 and S 31 in pion-nucleon scattering. We work in the framework of a coupledchannel Bethe-Salpeter equation (BSE) including in the driving potential all local terms of second order in the chiral counting, thus going beyond the often used approximation of simply including the leading order Weinberg-Tomozawa interaction.…”

Role of theN*(1535)in theJ/ψ→pGeng1, Oset2, Zou3 et al. 2009Phys. Rev. C299201View full textAdd to dashboardCite

“…3. As argued in the previous section, we have used the same D and F coefficients as the couplings of the pseudoscalars to the baryon octet: D = 0.795 and F = 0.465 [46,49,50]. In the figure, the curves labeled with an "F" are obtained with the full UχPT amplitudes as described above, while the curves labeled with an "S" are obtained with the amplitudes without the πN → ππN and vertex corrections as explained below.…”

J/ψNinteractions revisited andΛb0→Xiao1 2017Phys. Rev. D15090View full textAdd to dashboardCite

“…One should keep in mind that in our present work we use the chiral unitary approach for the s-wave projections of the interaction potentials, but for the higher partial waves interactions the off-shell contributions should be considered as discussed in Ref. [65] where an approach is constructed for the meson photoproduction based on the chiral effective Lagrangian. We show our results of the modulus squared of the amplitudes in Fig.…”