Partial Wave Amplitudes of the Reaction π^-+p→ η +n

Abstract

Energy dependent partial wave anlyses for the reaction rc-+p ':"'J+n are carried out with respect to S, P, D and F waves in the energy range 561-1300 MeV. Two different types of the solutions are obtained. In the first solution, the "'J-production peak is dominated by the S 11 resonance with mass M = 1570 MeV, total width TT = 140 MeV, branching ratios (S 11 res. --->rcN) I (S 11 res.->all) =40% and (S 11 res.-----'7"1JN)/(S 11 res.--'lall) =50%. In the second solution, it is dominated by the P 11 resonance with M=1580 MeV, TT=130 MeV, (P 11 res.-'TrcN)/(P 11 res.-----'7all) =35% and (P 11 res.-?"'JN)j(P 11 res.-'Tall) =305-~-This P 11 resonance is a new one which is different from Roper's resonance. In this analysis the second solution_ is better fitting experimental data than the first solution.P 11 and D 13 • When the peak is dominated by a resonance (called the Resonant Case) , we can consider the following three cases ;

A Calculation of the Viscosity to Entropy Ratio of a Hadronic Gas

“…One of the present authors (N. S.) improved and tuned the parameters of URASiMA so as to realize an equilibrium state of hadrons for temperatures in the rande 100 -180 MeV for nuclear densities near twice the normal nuclear density. 7) In Ref. 7), equilibration of the system is discussed in detail and thermodynamical quantities are analyzed.…”

“…7). Figure 1 displays the obtained equation of state (the pressure P as a function of the energy density ε).…”

Charge-screened nontopological solitons in a spontaneously broken U(1) gauge theory

“…Generalization of the model is an interesting issue. Furthermore, stability of the solutions should be clarified from various points of view [20][21][22][23][24].…”

Homogeneous balls in a spontaneously broken U(1) gauge theory

“…By comparison of the energies, it was shown that if the charge of the matter field is greater than a critical value, a Q-ball is stable against dispersion into free particles and against decay into two smaller Q-balls. In addition to the analysis in this paper, it is important to investigate the stability in various view points [22][23][24][25][26][27].…”