Neutrino

Statement-1 : In a nuclear reaction it is concluded that a beta emission is accompanied by a neutrino or an antineutrino. Statement-2 : It is observed that different beta particles emitted from same sample posses different K.E .

Following reactions are known as inverse beta decay p+vecvrarrn+e^(+) n+vrarrp+e^(-) These reactions have extremely low probabilities. Because of this, neutrinos and antineutrinos are able to pass through vast amount of matter without any interaction. In an experiment to detect neutrinos, large number of neutrinos coming out from beta decays of a radioactive material were made to pass through a tank of water, containing a cadmium compound in solution, which provided the protons to interact with antineutrinos, which provided the protons to interact with antineutrinos. Immediately after a proton absorbed a neutrino to yield a positron and a neutron, the positron encountered an electron and both got annihilated. the gamma ray detectors surrounding the tanks responded to the resulting photons. This confirmed that the above reaction has taken place. (a) How many gamma ray photons are produced when a electron annihilates with a positron? What is energy of each photon? Take the mass of an electron to be 0.00055 u. (b) The neutron produced in the above reaction was captured by .^(112)Cd to form .^(113)Cd . The atomic masses of these two isotopes of cadmium are are 111.9028u and 112.9044u respectively. mass of a neutron is 1.0087u. find the Q value of this reaction. Assume half of this energy is excitation energ of .^(113)Cd . if the nucleus de-excites by emitting a gamma ray photon find its wavelenght.

Before the neutrino hypothesis the beta decay process was throught to be the transition. n to p+bar(e) If this was true show that if the neutron was at rest the proton and electron would emerge with fixed energies and calculate them. Experimentally the electron energy was found to have a large range.

In the bets decay of Na^(24) , the combined electron neutrino momentum has a magnitude equal to 4MeV//c. What is the recoil energy of daughter nucleus , given that its mass 23.99u ? Take c=3xx10^(8)m//s and 1u=1.66xx10^(-27)kg .

In the decay ^64(Cu) rarr ^64(Ni)+e^+v, the maximum kinetic energy carried by the netrino which was emitted together with a positron of kinetic energy 0.150 meV? (b)What is the momentum of this neutrino in kg m s^(-1) ?Use the formula applicable to photon.