7–11 Nov 2022
Seville
Europe/Madrid timezone

Nature of Tcc with effective field theory

Not scheduled
20m
Seville

Seville

Universidad Pablo de Olavide, de Sevilla, Ctra. de Utrera, km. 1 41013, Sevilla
Parallel contribution Theory for strong QCD

Speaker

Tomona Kinugawa (Tokyo Metropolitan University)

Description

The exotic hadrons have a different internal structure from the ordinary hadrons with $qqq$ or $q\bar{q}$. $T_{cc}$, observed by the LHCb Collaboration last year, is considered as the exotic state with $cc\bar{u}\bar{d}$ [1]. One of the possible internal structures of the exotic hadron is the hadronic molecule state which is a weakly bound state of hadrons. The weight of the hadronic molecule component in a hadron wavefunction is quantitatively expressed as the compositeness [2]. We discuss the internal structure of $T_{cc}$ by calculating the compositeness with the effective field theory.

We construct a model to reproduce the mass of $T_{cc}$ with the scattering of $D^{0}D^{*+}$ coupled with the compact four-quark state. The model parameters are the cutoff $\Lambda$, coupling constant $g_0$ and energy of the compact four-quark state $\nu_0$ measured from the threshold of the $D^{0}D^{*+}$ scattering. We employ $\Lambda=0.14$ [GeV] based on the pion exchange interaction. The relation between $g_0$ and $\nu_0$ is obtained from the bound-state condition with the binding energy $B=0.36$ [MeV] of $T_{cc}$. We vary $\nu_0$ in the region $−B\leq \nu_0 \leq \Lambda^2/(2\mu)$ which is the allowed region in this model. We show that $T_{cc}$ is hadronic molecule dominant for almost all region of $\nu_0$ even without $D^{0}D^{*+}$ direct interactions.

[1] R. Aaij et al. [LHCb], Nature Phys 18 (2022) no.7, 751-754; Nature Commun. 13, no.1, 3351 (2022).
[2] T. Kinugawa and T. Hyodo, Phys. Rev. C 106, 015205 (2022).

Primary author

Tomona Kinugawa (Tokyo Metropolitan University)

Co-author

Tetsuo Hyodo (Tokyo Metropolitan University)

Presentation materials