1. The problem statement, all variables and given/known data write the radial equation for a particle with mass m and angular momentum l=0 which is under the influence of the following potential: V(r)=-a*delta(r-R) a,R>0 write all the conditions for the solution of the problem. 2. Relevant equations Schroedinger's equation: Hu=Eu Hamiltonian: H=p/2m +V = pr/2m+L^2/2mr^2+V(r) 3. The attempt at a solution since the angular momentum is zero, the radial equation appears as: (-hbar/2m)(d^2u/dr^2)-a*delta(r-R)u=Eu the conditions I can think of are: 1) continuity of u 2) u(infinity)= 0 (for u to be square integrable) 3) from integration of Schroedinger's equation on the interval [R-epsilon, R+epsilon] the jump in the first derivative of u at r=R should be -2mau(R)/hbar^2 but there is another condition according to the answers, that is, u(0)=0. where does this condition come from?