- #1
Rahmuss
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Homework Statement
A particle of mass m is placed in a finite spherical well:
[tex]V(r) = \{^{-V_{0}, if r \leq a;}_{0, if r > a.}[/tex]
Find the ground state, by solving the radial equation with [tex]l = 0[/tex]. Show that there is no bound state if [tex]V_{0}a^{2} < \pi^{2}\hbar^{2}/8m[/tex].
Homework Equations
[tex]\frac{d}{dr}(r^{2}\frac{dR}{dr}) - \frac{2mr^{2}}{\hbar^{2}}[V(r) - E]R = l(l + 1)R[/tex].
The Attempt at a Solution
For [tex]r \leq a[/tex]
[tex]\frac{d}{dr}(r^{2}\frac{dR}{dr}) - \frac{2mr^{2}}{\hbar^{2}}[V(r) - E]R = 0[/tex] [tex]\Rightarrow[/tex][tex]
[tex]2r\frac{dR}{dr} + \frac{2mr^{2}}{\hbar^{2}}(V_{0} + E)[/tex] [tex]\Rightarrow[/tex]
[tex]\frac{dR}{dr} = \frac{-mr}{\hbar^{2}}(V_{0} + E)[/tex] [tex]\Rightarrow[/tex]
[tex]R = \frac{-m}{\hbar^{2}}\int r(V_{0} + E) dr[/tex]
But I'm not sure about the second part to show that there is no bound state with the given conditions.