Chapter #12 Solutions - Quantum Mechanics - Robert Scherrer - 1st Edition

1. Show that in the Born approximation, the differentia] cross section obtained from the negative of a given potential −V(r) is exactly the same as that obtained from the potential V(r). Get solution

2. An incident particle with mass m, velocity υ, and charge ze scatters off of a charge Ze at the origin. Use the Born approximation to calculate the differential scattering cross section for the screened Coulomb potential...Then let d → ∞, so that V(r) approaches the normal Coulomb potential, and show that dσ/dΩapproaches the Rutherford scattering differential cross section... Get solution

3. (a) A particle with charge +e is incident on an electric dipole consisting of a charge of +e and a charge of −e separated by the vector d (which runs from − e to +e). The energy of the incident particle is sufficiently large to treat the dipole as a small perturbation. Calculate the differential scattering cross section dσ/dΩ as a function of the initial wave vector ki, the scattered wave vector kf, and the standard Rutherford scattering cross section (dσ/dΩ)R, given by...where K = kf −ki and Vc(r) is the Coulomb potential.(b) In the limits kid ≪ 1 and kid ≫ 1, determine whether the dipole differential cross section is larger or smaller than the Rutherford differential cross section. Explain the physical reason for these results. Get solution

4. A particle which is travelling in the +z direction scatters off of a potential consisting of four delta functions at the vertices of a square in the x-y plane at the points (−a, 0, 0), (+a, 0, 0), (0, −a, 0), and (0, +a, 0)....The potential is...where A is a constant. Use the Born approximation to calculate the differential scattering cross section. Express the answer in terms of the magnitude of the incident wave vector k and the scattering angles θ and ϕ. (This is an example where the cross section does depend on ϕ.) Get solution

5. (a) A particle of mass m and energy E scatters off of the central potential V(r) = Ar−2, where A is a constant. Use the Born approximation to calculate the differential cross section dσ/dΩas a function of E and the scattering angle θ.(b) Show that the total cross section σ is infinite. Get solution

6. A particle of mass m is incident on the potential ..., where V0 and r0 are constants with units of energy and length, respectively. The potential is independent of θ and ϕ. The energy of the particle is large, so that the potential can be treated as a small perturbation. Calculate the differential scattering cross section dσ/dΩ. Express the final answer as a function of the scattering angle θ and the energy of the particle E. Get solution

7. (a) A particle with mass m scatters off of the potential...where A is a constant. In other words, this potential forms a square in the x-y plane and is infinitesimally thin in the z direction. Use the Born approximation to calculate the differential scattering cross section. (Assume an arbitrary direction for the incident particle, and express the answer in terms of the momentum transfer vector K = kf − ki.)(b) Show that in the limit where a → ∞ (so that the scattering potential occupies the entire x-y plane), the resulting differential cross section corresponds to only two possible results: either the particle will pass through without any scattering or else it will scatter with the angle of incidence equal to the angle of reflection. Get solution

8. Suppose a particle with mass m scatters off of a finite spherical potential of radius R given by...In the limit where the energy of the incident particle is small, show that the total cross section is...where .... Get solution