The appearance of a light composite 0+ scalar resonance in nearly conformal gauge-fermion theories motivates further study of the low energy structure of these theories. To this end, we present a nonperturbative lattice calculation of s-wave scattering of Goldstone bosons in the maximal-isospin channel in SU(3) gauge theory with Nf=8 light, degenerate flavors. The scattering phase shift is measured both for different values of the underlying fermion mass and for different values of the scattering momentum. We examine the effect of a light flavor-singlet scalar (reported in earlier studies) on Goldstone boson scattering, employing a dilaton effective field theory (EFT) at the tree level. The EFT gives a good description of the scattering data, insofar as the magnitude of deviations between EFT and lattice data are no larger than the expected size of next-to-leading order corrections in the EFT.
@article{arxiv.2106.13534,
title = {Goldstone Boson Scattering with a Light Composite Scalar},
author = {T. Appelquist and R. C. Brower and K. K. Cushman and G. T. Fleming and A. Gasbarro and A. Hasenfratz and J. Ingoldby and X. Y. Jin and J. Kiskis and E. T. Neil and J. C. Osborn and C. Rebbi and E. Rinaldi and D. Schaich and P. Vranas and E. Weinberg and O. Witzel},
journal= {arXiv preprint arXiv:2106.13534},
year = {2022}
}
Comments
13 pages, 6 figures, 4 tables. References and clarifying comments added. To match published version