Triangle singularity in the $$J/\psi \rightarrow K^+ K^- f_0(980)(a_0(980))$$ decays

Abstract

We study the J/ψ → K + K − f 0 (980)(a 0 (980)) reaction and find that the mechanism to produce this decay develops a triangle singularity around M inv (K − f 0 /K − a 0) ≈ 1515 MeV. The differential width dΓ /d M inv (K − f 0 /K − a 0) shows a rapid growth around the invariant mass being 1515 MeV as a consequence of the triangle singularity of this mechanism, which is directly tied to the nature of the f 0 (980) and a 0 (980) as dynamically generated resonances from the interaction of pseudoscalar mesons. The branching ratios obtained for the J/ψ → K + K − f 0 (980)(a 0 (980)) decays are of the order of 10 −5 , accessible in present facilities, and we argue that their observation should provide relevant information concerning the nature of the low-lying scalar mesons.

Enhancement near the p¯Λ threshold in the χc0→pWang1, Duan2, Wang3 et al. 2020Phys. Rev. DSelf Cite10160View full textAdd to dashboardCite

“…It is easy to test that there is no triangle singularity following Refs. [26][27][28]. In summary, the correction of implementing the three-body unitarity is extremely small and can be neglected in this work.…”

Role of scalar $$a_0(980)$$ in the single Cabibbo suppressed process $$D^+ \rightarrow \pi ^{+} \pi ^{0} \eta $$

“…For the chiral unitary approach with the coupled channels, the potentials of the Bethe-Salpeter (BS) equation are taken from the chiral Lagrangians [18,19], and the scattering amplitudes are obtained by solving the Bethe-Salpeter equation in all possible coupled channels that couple within SU (3) to certain given quantum numbers. Within the chiral unitary approach, the productions of the scalar f 0 (500), f 0 (980), and a 0 (980) have been studied in the decays of the D 0 [10], D + s [12],B andB s [20][21][22][23], χ c1 [24], τ − [25], J/ψ [26], η c [27], and c [28].…”

Triangle singularities in J/ψ→ηπ0ϕ and π0π0Jing1, Sakai2, Guo3 et al. 2019Phys. Rev. D18210View full textAdd to dashboardCite

“…1), and the K Ã decays into πK subsequently; then the K moves in the same direction with theK and catches up with it, and the KK pair finally forms the ϕ. Triangle singularity effects of the K Ã KK loops have been studied for processes with the KK pair forming an f 0 ð980Þ or a 0 ð980Þ instead of a ϕ in Refs. [19][20][21][22][23][29][30][31][32][33][34].…”