Simple asymptotic expressions for the four-point N-loop dual amplitude in a specific high energy limit are given. A reasonable approximation of the obtained formula, which can be used in the Chan–Paton–Tsou unitarisation program, is proposed.
We derive an explicit form of the relativistic radial equations for two spin-1/2 particles with a static interaction energy. We solve these equations for Coulomb bound states with \(j = 0\) in an implicit way after applying the weak-potential approximation. This solution reduces to the Sommerfeld fine-structure formula in the one-body approximation.
J.H. Klems, W. Ko, R.L. Lander, D.E. Pellett, P.M. Yager, K. Dziunikowska, D. Kisielewska, H. Rudnicka, P. Stopa, S. Csorna, A. Kocsis, H.J. Lubatti, K. Moriyasu, M. Bardadin-Otwinowska, H. Białkowska, T. Hofmokl, J. Królikowski, A. Para, M. Szczekowski
A search for hadronic production of charmed particle pairs decaying into a \(V^0\) and a \(\mu \) was performed using the FNAL 30-inch deuterium bubble chamber and a downstream \(\mu \) detector. In the mass region 2–2.5 GeV, upper limits of 90 \(\mu \)b, 340 \(\mu \)b, and 350 \(\mu \)b are set on \({\mit \Gamma }\sigma \) for the \(K^0\) mode assuming three different production and decay models. Upper limits for higher charm masses and \({\mit \Lambda }\) modes are also given.
On the basis of the analysis of the gamma-spectrum of \(A=158\) isobars the \(^{158}\)Yb isotope has been identified. Its half-life T\(_{1/2} = 1.1 \pm 0.2\) mm. has been measured. The \(^{158}\)Yb decay is followed by emission of 74.2 \(\pm \) 0.2 keV gamma-ray.
The \(\gamma \)-ray, internal conversion electron, \(\gamma \)–\(\gamma \) and \(\beta ^+\)–\(\gamma \)-coincidence spectra are measured. The excited levels of \(^{156}\)Dy and the ground state and parity \(^{156}\)Ho are suggested.
Alpha particle scattering from \(^{28}\)Si has been studied at five bombarding energies from 23.5 to 28.5 MeV. \(l\)-dependent resonance absorption has been introduced to the optical model analysis of \(^{28}\)Si(\(\alpha ,\alpha \)) \(^{28}\)Si reaction.
Elastic and inelastic alpha particle scattering from \(^{28}\)Si has been studied at the bombarding energies of 24, 25, 2b, 26.5, 27 and 28 MeV. The analysis was carried out with the optical model and distorted wave method. The possibility of resolving some of the optical model ambiguities, and excitation mechanisms of the 1.78 MeV (2\(^+\)) and 4.61 MeV (4\(^+\)) states in \(^{28}\)Si are discussed.
