Ambiguities in π4He phase-shift analysis

Regularization of singular terms in the N¯ potential model

“…It was indeed discovered in the Low Energy Antiproton Ring (LEAR) experiments [12, 13,14] that certain partial cross-sections sharply increase with decreasing of energy down to the N N threshold (so called P -wave enhancement), which could be a manifestation of the narrow weakly-bound state or resonance. This conclusion was verified by the experiments with antiprotonic atoms [15,16] and detailed experimental studies of antiproton annihilation at rest by OBELIX collaboration [17,18,19,20]. The recent experimental data [21] on J/ψ decay into γpp channel also indicate a strong enhancement near the pp threshold.…”

Amplitude analysis and branching-fraction measurement of $D^{+}_{s}\rightarrow K^{0}_{S}K^{-}π^{+}π^{+}$

“…The ratios between different orbital angular momenta of the two vector mesons for the dominant quasi-two-body decay D + s → K * (892) + K * (892) 0 provide valuable information on CP violation with Tviolating triple-products [9]. In addition, several mesons with J P = 0 − , 1 + are reported in the mass region between 1.2 and 1.6 GeV/c 2 and decay to the (KKπ) 0 final state [10][11][12][13]. These are the η(1295), η(1405), η(1475), f 1 (1285), f 1 (1420) and f 1 (1510), although many of these states are not well established.…”

The GLUEBALL CANDIDATE Η(1440) AS Η RADIAL EXCITATION

“…At that time it was proposed (and often still is) to be a glueball. Further studies, in particular by the Obelix collaboration at LEAR [7], showed that the ι(1440) is split into two components, a η L → a 0 (980)π with M = 1405 ± 5, Γ = 56 ± 6 MeV and a η H → K * K + K * K with M = 1475 ± 5, Γ = 81 ± 11 MeV: there seem to be 3 η states in the mass range from 1280 to 1480 MeV.…”