Speaker
Eulogio Oset
(IFIC , University of Valencia)
Description
The K^- induced production of Lambda(1405) is investigated in K^- d to pi Sigma n reaction based on coupled-channels chiral dynamics, in order to discuss the mass of the Lambda(1405) and the prediction of two Lambda(1405) states made by the chiral unitary theory. We find that the K^-d to Lambda(1405)n process favors the production of Lambda(1405) initiated by the KbarN channel, which favors the Lambda(1405) at higher energy. The present approach indicates that the Lambda(1405) resonance position is 1420 MeV rather than 1405 MeV in the pi Sigma invariant mass spectra of K- d to pi Sigma n reactions. This is consistent with an observed spectrum of the K^- d to pi^+ Sigma^- n with 686-844 MeV/c incident K^- by bubble chamber experiments done in the 70's. Our model also reproduces the measured Lambda(1405) production cross section [1].
After that, we have evaluated the cross sections for the K^- induced production of Lambda(1405) in the K^- d to pi Sigma n reaction, having in mind the conditions of the DAFNE facility at Frascati where kaons are obtained from the decay of slow moving phi mesons. We also find that the K^- d to Lambda(1405) n process favors the production of Lambda(1405) initiated by the K^- p channel, which gives largest weight to the higher mass Lambda(1405) appearing at 1420 MeV in chiral theories. We find that the fastest kaons from the decay of the phi are well suited to see this resonance, particularly if one selects forward going neutrons in the center of mass, which reduce the contribution of single scattering and make the double scattering dominate where the signal of the resonance appears clearer [2].
[1] D. Jido, E. Oset and T. Sekihara, Eur.Phys.J. A42 (2009) 257-268
[2] D. Jido, E. Oset and T. Sekihara, Eur.Phys.J. A47 (2011) 42
Primary author
Eulogio Oset
(IFIC , University of Valencia)
Co-authors
Dr
Daisuke Jido
(Yuyawa Institute, Kyoto)
Dr
Takayasu Sekihara
(Yuyawa Institute, Kyoto)
