Dynamical generation of hadronic resonances

Abstract

One type of dynamical generation consists in the formation of multiple hadronic resonances from single seed states by incorporating hadronic loop contributions on the level of $s$-wave propagators. Along this line, we study the propagator poles within two models of scalar resonances and report on the status of our work: (i) Using a simple quantum field theory describing the decay of $f_0(500)$ into two pions, we may obtain a second, additional pole on the first Riemann sheet below the pion-pion threshold (i.e., a stable state can emerge). (ii) We perform a numerical study of the pole(s) of $a_0(1450)$ by using as an input the results obtained in the extended Linear Sigma Model (eLSM). Here, we do not find any additional pole besides the original one, thus we cannot obtain $a_0(980)$ as an emerging state. (iii) We finally demonstrate that, although the coupling constants in typical effective models might be large, the next-to-leading-order contribution to the decay amplitude is usually small and can be neglected.

6 pages, 1 figure, 1 table, prepared for proceedings of the workshop "EEF70 - Workshop on Unquenched Hadron Spectroscopy: Non-Perturbative Models and Methods of QCD vs. Experiment", Coimbra, Portugal, September 1-5, 2014

References in corpus (20)

• Observation of the resonant character of the $Z(4430{)}^{-}$ state
• A low-lying scalar meson nonet in a unitarized meson model
• A Theory of Scalar Mesons
• Hadron Loops: General Theorems and Application to Charmonium
• Observation of Y(2175) in $J/\psi \to \eta \varphi f_0(980)$
• Evidence that the Y(4660) is a f_0(980)psi' bound state
• The nature of $\sigma$, $\kappa$, $a_0(980)$ and $f_0(980)$
• Mixing of scalar tetraquark and quarkonia states in a chiral approach
• Comprehensive Amplitude Analysis of $\gamma \gamma \to {\pi }^{+}{\pi }^{-},{\pi }^0{\pi }^0$ and $\overline{K}K$ below 1.5 GeV
• Confirming the molecular nature of the $Z_b(10610)$ and the $Z_b(10650)$
• High statistics study of f_0(980) resonance in gamma gamma --> pi^+ pi^- production
• On the spectral functions of scalar mesons
• Two-photon decays of hadronic molecules
• Dalitz plot analysis of Ds+ --> K+ K- pi+
• Two photon couplings of the lightest isoscalars from BELLE data
• Once more about the K\bar K molecule approach to the light scalars
• $X(1835)$ and the New Resonances $X(2120)$ and $X(2370)$ Observed by the BES Collaboration
• The role of the next-to-leading order triangle-shaped diagram in two-body hadronic decays
• Two-photon decay of a light scalar quark-antiquark state
• The scalar-isovector sector in the extended Linear Sigma Model

Cited by in corpus (3)

• $a_0(980)$ revisited
• Dynamical generation of hadronic resonances in effective models with derivative interactions
• $a_0(980)$ as a companion pole of $a_0(1450)$