6533b871fe1ef96bd12d2368

RESEARCH PRODUCT

Clues for the existence of twoK1(1270)resonances

subject

description

The axial-vector meson ${K}_{1}(1270)$ was studied within the chiral unitary approach, where it was shown that it has a two-pole structure. We reanalyze the high-statistics WA3 experiment ${K}^{\ensuremath{-}}p\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}p$ at 63 GeV, which established the existence of both ${K}_{1}(1270)$ and ${K}_{1}(1400)$, and we show that it clearly favors our two-pole interpretation. We also reanalyze the traditional $K$-matrix interpretation of the WA3 data and find that the good fit of the data obtained there comes from large cancellations of terms of unclear physical interpretation.