0

Quark doesn't constitutes more fundamental particle and proton and neutron consist of quarks. Now come to beta decay.

$n \rightarrow p + e^{-} + \bar{\nu}_e $

How can an electron emit from an neutron whereas electron is a fundamental particle? Is the electron created from gluon?

dmckee --- ex-moderator kitten
  • 86,062
Raisa
  • 651

1 Answers1

1

This is a weak decay and it is mediated by a weak boson. In this case a $W^-$.

betadec

The Feynman diagram for β− decay of a neutron into a proton, electron, and electron antineutrino via an intermediate W− boson.

At vertex level a down-quark is converted into a up-quark by the emission of virtual W-boson which decays to the electron electron-antineutrino pair. Charge is carried by the mediating boson.

anna v
  • 233,453
dmckee --- ex-moderator kitten
  • 86,062
  • so you are saying that quark can decay? Isn't it a fundamental one? – Raisa Jul 25 '13 at 21:03
  • 2
    The weak interaction does not (fully) respect flavor. Weak interaction can convert quarks of one flavor to another. – dmckee --- ex-moderator kitten Jul 25 '13 at 22:41
  • @Raisa : Weak interactions involve left-handed particles. Left Quarks $d$ and $u$ are a SU(2) doublet, that is you have to consider the doublet left $(u,d)$ as a whole, exactly as a vector with $2$ dimensions, and SU(2) operations on this vector are allowed, for instance, a "rotation" could transform $u$ in $d$. Same thing for the doublet electron/ neutrino. – Trimok Jul 26 '13 at 13:03
  • so quark is decaying and u turning into d, therefore the electron formation comes from the energy releases by up quark? – Raisa Jul 26 '13 at 13:14