0
$\begingroup$

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?

$\endgroup$
  • $\begingroup$ I've edited you decay equation to more accurately reflect the nature of the neutral lepton. $\endgroup$ – dmckee --- ex-moderator kitten Jul 25 '13 at 20:43
1
$\begingroup$

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.

$\endgroup$
  • $\begingroup$ so you are saying that quark can decay? Isn't it a fundamental one? $\endgroup$ – Raisa Jul 25 '13 at 21:03
  • 1
    $\begingroup$ The weak interaction does not (fully) respect flavor. Weak interaction can convert quarks of one flavor to another. $\endgroup$ – dmckee --- ex-moderator kitten Jul 25 '13 at 22:41
  • $\begingroup$ @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. $\endgroup$ – Trimok Jul 26 '13 at 13:03
  • $\begingroup$ so quark is decaying and u turning into d, therefore the electron formation comes from the energy releases by up quark? $\endgroup$ – Raisa Jul 26 '13 at 13:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.