Do Xi Xi bound states exist?

作者：Haidenbauer J^*; Meissner Ulf G; Petschauer S

来源：European Physical Journal A, 2015, 51(2): 17.

DOI：10.1140/epja/i2015-15017-0

The existence of baryon-baryon bound states in the strangeness sector is examined in the framework of SU(3) chiral effective field theory. Specifically, the role of SU(3) symmetry breaking contact terms that arise at next-to-leading order in the employed Weinberg power counting scheme is explored. We focus on the S-1(0) partial wave and on baryon-baryon channels with maximal isospin since in this case there are only two independent SU(3) symmetry breaking contact terms. At the same time, those are the channels where most of the bound states have been predicted in the past. Utilizing pp phase shifts and Sigma(+) p cross section data allows us to pin down one of the SU(3) symmetry breaking contact terms and a clear indication for the decrease of attraction when going from the NN system to strangeness S = -2 is found, which rules out a bound state for Sigma Sigma with isospin I = 2. Assuming that the trend observed for S = 0 to S = -2 is not reversed when going to Xi Sigma and Xi Xi makes also bound states in those systems rather unlikely.

• 出版日期2015-2-12