Neutrino Cross Section

The larger the neutron cross section the more likely a neutron will react with the nucleus.

Neutrino cross section. An isotope or nuclide can be classified according to its neutron cross section and how it reacts to an incident neutron. Note that the neutrino cross section grows linearly with en ergy. The higher energy a neutrino has the more likely it is to interact.

For electron neutrinos the elastic scattering with electrons can be mediated by charged and neutral weak bosons w and z whereas the scattering of muon and tau neutrinos from electrons is mediated only by the neutral boson. The data displayed at right is taken at energies far above the range of neutrinos from radioactive decay. The neutrinos decouple when we have the rates comparable which is.

Neutrinos interact only by the weak force. Neutrino cross sections are an essential ingredient in all neutrino experiments. Knowledge of neutrino interaction cross sections is an important and necessary ingredient in any neutrino measurement.

Interest in neutrinoscatteringhasrecentlyincreasedduetotheneedforsuchinformationintheinterpretation of neutrino oscillation data. In the case where e ethresh integration of the above expression yields a simple expression for the total neutrino cross section as a function of neutrino energy. It is usually measured in barns b.

2meg2 fe ˇ g2 fs ˇ 14 where sis the center of mass energy of the collision. The standard unit for measuring the cross section is the barn which is equal to 10 28m2or 10 24cm2. The absorption neutron cross section of an isotope of a chemical element is the effective cross sectional area that an atom of that isotope presents to absorption and is a measure of the probability of neutron capture.

Absorption cross section is often highly dependent on neutron. Hence the reaction cross sections are much smaller than those of other particle species. Neutrino cross section the nominal neutrinocross section for interaction with a nucleon increases with energy as indicated by the data at right cited by rohlf.