6533b7d2fe1ef96bd125ec8d
RESEARCH PRODUCT
The radiative decay of the Lambda(1405) and its two-pole structure
E. OsetM. DoringLi-sheng Gengsubject
Nuclear and High Energy PhysicsParticle physicsRadiative decayStructure (category theory)radiative decay [Lambda(1405)]chiral [perturbation theory]Lambda(Sigma0 photon) [mass spectrum]Measure (mathematics)Lambda(1405) --> Lambda photonK- p --> Lambda pi0 photonK- p --> Sigma0 pi0 photonAtompi- p --> Lambda K0 photonpi- p --> Sigma0 K0 photonRadiative transferddc:530Invariant massnumerical calculationsPhysicsLambda(1405) --> Sigma0 photonSigma0inelastic scattering [K- p]Físicapole [approximation]hadroproduction [Lambda(1405)]High Energy Physics - Phenomenology(Lambda photon) [mass spectrum]Isobarinelastic scattering [pi- p]hadroproduction [hyperon]width [Lambda(1405)]description
We evaluate theoretically the radiative decay widths into $\gamma\Lambda$ and $\gamma\Sigma^0$ of the two poles of the $\Lambda(1405)$ found in chiral unitary theories and we find quite different results for each of the two poles. We show that, depending on which reaction is used to measure the $\Lambda(1405)$ radiative decays, one gives more weight to one or the other pole, resulting in quite different shapes in the $\gamma\Lambda(\Sigma^0)$ invariant mass distributions. Our results for the high-energy pole agree with those of the empirical determination of the $\gamma\Lambda$ and $\gamma\Sigma^0$ radiative widths (based on an isobar model fitting of the $K^-p$ atom data), which are sometimes referred to as ``experimental data''. We have made a detailed study of the $K^-p\to\pi^0\gamma\Lambda(\Sigma^0)$ and $\pi^-p\to K^0\gamma\Lambda(\Sigma^0)$ reactions and have shown that they, indeed, lead to different shapes for the $\gamma\Lambda(\Sigma^0)$ invariant mass distributions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2007-01-01 |