An enhancement at the Σ threshold (1680) MeV observed in K− p reactions at 4.2 GeV/c

Spin, Parity, and Nature of theΞ(1620)Resonance

“…This is opposite to the observed properties of the 1690 resonance, for which Ref. [28] gives a ratio of branching ratios for K K to K K around 3 and for to K K of less than 0.09. In our opinion, this argument rules out identifying the resonance found here with the 1690 state.…”

“…The 1690 state is better known and is rated as a 3-star resonance. Reference [28] even gives quite accurate ratios of partial decay widths. We therefore investigate whether the parameters of the theory provide enough flexibility to produce a pole with a real part closer to 1690 MeV, since the results of Table II show that by decreasing the size of a or a K K one increases the mass of the resonance.…”

Measurements ofψ(3686)→K−ΛΞAblikim1, Ачасов2, Ai3 et al. 2015Phys. Rev. D16140View full textAdd to dashboardCite

“…− was first observed in the ΣK final state in the reaction K − p → (ΣK)Kπ [3]. Afterwards its existence has been confirmed by other experiments [4][5][6], but its spin-parity was not well determined.…”

Dynamically Generated Ξ(1690)

“…The Ξ(1690) resonance was experimentally discovered in the K − p → (KΣ)Kπ reaction at 4.2 GeV/c [2], which was followed by experimental studies in, e.g., Refs. [3][4][5][6][7][8][9].…”

“…[3][4][5][6][7][8][9]. The spin/parity of Ξ(1690) has not been fixed yet, but experimental data prefer J P = 1/2 − [2,8]. Then, one of the most interesting properties of Ξ(1690) is its decay pattern.…”