Clear indication of a strong I=0 Kbar-N attraction in the Lambda (1405) region from the CLAS photo-production data

TL;DR

This paper analyzes CLAS photo-production data to confirm a strong I=0 Kbar-N attraction in the Lambda(1405) region, supporting the hypothesis of a deeply bound kaonic nuclear state.

Contribution

It demonstrates that the Lambda(1405) mass is consistent with 1405 MeV/c2, providing evidence for the strong Kbar-N attraction from experimental data.

Findings

Lambda(1405) mass deduced as 1405 MeV/c2

Supports existence of deeply bound kaonic systems

Confirms strong I=0 Kbar-N attraction

Abstract

Possible existence of deeply bound kaonic nuclear systems was proposed Akaishi and Yamazaki (2002} more than a decade ago, based on an ansatz that the Lambda* = Lambda(1405) mass is 1405 MeV/c2, where the Lambda* is a Kbar-N quasi-bound state decaying to Sigma-pi. Recently, a large number of data on photo-production of Lambda(1405) in the gamma p to K+ pi{0+-} Sigma{0-+} reaction were provided by the CLAS collaboration Moriya et al.(2013}, and double-pole structure of the Lambda* has been intensively discussed by chiral dynamics analyses {Roca (2013),Mai 2015}, whereas we show that a Lambda* mass of 1405 MeV/c2 is deduced from the same CLAS data.