Differential Cross Section
To leading order, the spin-averaged differential cross section for this process is
- where s,t, and u are the Mandelstam variables, is the fine-structure constant, and is the scattering angle.
This cross section is calculated neglecting the electron mass relative to the collision energy and including only the contribution from photon exchange. This is a valid approximation at collision energies small compared to the mass scale of the Z boson, about 91 GeV; for energies not too small compared to this mass, the contribution from Z boson exchange also becomes important.
Read more about this topic: Bhabha Scattering
Famous quotes containing the words differential, cross and/or section:
“But how is one to make a scientist understand that there is something unalterably deranged about differential calculus, quantum theory, or the obscene and so inanely liturgical ordeals of the precession of the equinoxes.”
—Antonin Artaud (1896–1948)
“Things have dropped from me. I have outlived certain desires; I have lost friends, some by death ... others through sheer inability to cross the street.”
—Virginia Woolf (1882–1941)
“Every man has been brought up with the idea that decent women don’t pop in and out of bed; he has always been told by his mother that “nice girls don’t.” He finds, of course, when he gets older that this may be untrue—but only in a certain section of society.”
—Barbara Cartland (b. 1901)