Location: Cyclotron Building (434), Seminar Room
Dr. Daniel Cabrera, Texas A&M University
Interaction of the Θ+ with the nuclear medium and its effect on the
kaon optical potential
Abstract:
We study the Θ+ selfenergy in nuclei associated with the KN decay and the two-meson coupling of the Θ+ as a member of a baryon antidecuplet. The first source produces a small potential, whereas the second source gives rise to a large attractive potential. The total Θ+ decay width in nuclei remains small, thus creating an ideal scenario for the observation of possible Θ+ bound states in nuclei.
As an application, we calculate the kaon (K+) nuclear optical potential in a selfconsistent approach, starting from the meson exchange Jülich potential. Selfconsistency leads to significant differences as compared to the standard T-ρ approximation for the kaon potential. The influence of the one-nucleon process KN -> Θ+ is found to be negligible, due to the small KN coupling. In contrast, the two-nucleon mechanism KNN -> Θ+ N, estimated from the coupling of the pentaquark to the two-meson cloud, provides the necessary amount of kaon absorption to reconcile with data the systematically low K+ nucleus cross sections found by theoretical models.