(a) |

(b) |

Figure 3: Dependence of , , and on and . The solid, dashed, and dotted curves represent , , and , respectively. (a) Dependence of , , and on . and . In the calculation of , is chosen as . As is positive, for the case is smaller (larger) than this curve. (b) Dependence of , , and on . and . In the calculation of , is chosen as . |