Hadron resonances with coexistence of different natures

¹ Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki 567-0047, Japan
² Department of Physics, Tokyo Institute of Technology, Meguro 152-8551, Japan
³ Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502, Japan
⁴ Department of Physics, Nara Women’s University, Nara 630-8506, Japan
⁵ Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan
⁶ KEK Theory Center, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization, 1-1, Oho, Ibaraki 305-0801, Japan

^a e-mail: hosaka@rcnp.osaka-u.ac.jp

Abstract

We discuss coexistence/mixing of different natures of hadronic composite (molecule) and elementary (quark-intrinsic) ones in hadron resonances. The discussions here are based on our previous publications on the origin of hadron resonances [1], exotic $\overline{D}$ meson-nucleons as hadronic composites containing one anti-heavy quark [2], and the study of a₁ as a typical example to show explicitly the mixing of the two different natures [3]. In all cases, interactions are derived from the chiral dynamics of the light flavor sector. These interactions generate in various cases hadronic composite/molecule states, serving varieties of structure beyond the conventional quark model.