Narrow Jπ=1/2+, 3/2+, and 3/2- states of Θ+ in a quark model with antisymmetrized molecular dynamics -: art. no. 045202

The exotic baryon Theta(+)(uudd(s) over bar) is studied with microscopic calculations in a quark model by using a method of antisymmetrized molecular dynamics. We predict that three narrow states, J(pi)=1/2(+)(I=0),J(pi)=3/2(+)(I=0), and J(pi)=3/2(-)(I=1) nearly degenerate with the lowest 1/2(-) state in the uudd(s) over bar system. We discuss KN decay widths and estimate them to be Gamma < 7 for the J(pi)={1/2(+),3/2(+)}, and Gamma < 1 MeV for the J(pi)=3/2(-) state. In contrast to these narrow states, the 1/2(-) states should be much broader. We assign the observed Theta(+) as the J(pi)={1/2(+),3/2(+)}.