Calculation of theHΣ4eBound State in theH

Abstract

We examine phenomenologically the 4 He͑in-flight K 2 , p 2 ͒ spectrum at p K 2 600 MeV͞c and u Kp 4 ± within distorted-wave impulse approximation calculations by using a coupled ͑3N-L͒ 1 ͑3N-S͒ model. The result shows that there exists a pole of the 4 S He unstable bound state on the second Riemann sheet of the complex energy plane, and its complex eigenvalue is E ͑pole͒ S 1

Deeply boundK−ppstate in theHe3(in-flightKoike1, Harada2 2009Phys. Rev. CSelf Cite171130View full textAdd to dashboardCite

“…In a previous work [23], we examined these spectra of the 3 He(in-flight K − , n) reactions within a distorted-wave impulse approximation (DWIA) employing the Green's function method [24] which well describes unstable hadron systems [25]. It has been shown that the 3 He(in-flight K − , n) reaction provides a promising spectrum which contains a s-wave dominance in the K − bound region, where a strong nuclear distortion for K − is reduced [23].…”

Pole of the S Matrix of the \(_{\Sigma }^{4}\text{He}\) Hypernucleus on Riemann Sheets

“…In Fig. 3(a), we show these spectra obtained with (N R , N I ) = (0.6, 0.9), which values were suggested by the theoretical analyzes of the HeBC data [10]. We find that the 1 − resonant state is favored rather than the 0 + ground state in the conversion spectrum due to the momentum transfer q Σ ≃ 286 MeV/c, so that a peak of the spectrum is seen at ω ≃ 275 MeV above the Σ threshold.…”

“…Now let us evaluate pole positions of the three-channel coupled system in a ( 3 He-Λ)+( 3 H-Σ + )+ ( 3 He-Σ 0 ) model [11], solving the multichannel Lippmann-Schwinger equation with a phenomenological 3N-Y potential determined by theoretical analyzes [10]. We obtain the trajectories of the poles with s and p waves by changing the strengths of the 3N-Σ potential,…”

“…This state may be identified as an s-wave Σ quasibound (or unstable bound) state with J π = 0 + , T ≃ 1/2 [10]. Recently, we have investigated the inclusive and Σ-Λ conversion spectra in the 4 He(K − , π − ) reaction at 1.5 GeV/c [11].…”

“…It has been recognized that a 4 Σ He hypernucleus is experimentally confirmed in 4 He(K − , π − ) reactions at KEK [6,7] and BNL [8], ending a decade-long discussion of whether 4 Σ He is a Σ bound state or not [9,10]. This state may be identified as an s-wave Σ quasibound (or unstable bound) state with J π = 0 + , T ≃ 1/2 [10].…”