A neutron changes to proton and electron during beta decay. Is this true? how does it happen?

Question

I read this in my text book. "Beta decay occurs when a neutron is changed to a proton within the nucleus. As a result a nucleus with N neutrons and Z protons becomes a nucleus of N-1 neutrons and Z+1 protons after emitting beta particles." I dun really understand how it works.. can someone plz explain?

Answer 1

The weak nuclear force mediates beta decay. When a nucleus has too many neutrons it may decay via beta decay. As follows: -

'In β− decay, the weak interaction converts a neutron (n0) into a proton (p+) while emitting an electron (e−) and an antineutrino (νe):

n0  Ã¢Â†Â’  p+  +  e−  +  ÃŽÂ½e

At the fundamental level, this is due to the conversion of a down quark to an up quark by emission of a W− boson; the W− boson subsequently decays into an electron and an antineutrino. (Wikipedia)'

Wikipedia further adds, '... The W and Z bosons are carrier particles that mediate the weak nuclear force, much like the photon is the carrier particle for the electromagnetic force. The W boson is best known for its role in nuclear decay. Consider, for example, the beta decay of cobalt-60, an important process in supernova explosions.

60 ........ 60

27Co → 28Ni + e− + νe

This reaction does not involve the whole cobalt-60 nucleus, but affects only one of its 33 neutrons. ..... the neutron is not an elementary particle but a composite of an up quark and two down quarks (udd). It is in fact one of the down quarks that interacts in beta decay, turning into an up quark to form a proton (uud). At the most fundamental level, then, the weak force changes the flavor of a single quark:

d → u + W−

which is immediately followed by decay of the W− itself:

W− → e− + νe

... '

The overall change to the nucleus  (atomic number A, proton charge Z, neutron number N) may be notated as: -

Z A N ----> Z+1 A N-1 + e- +  ÃŽÂ½e

I hope this is of some help.

Answer 2

This is a reasonably easy explaination

http://en.wikipedia.org/wiki/Beta_decay