- #1
*LouLou*
- 9
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Hi physics people,
This is a past (3rd year university level) exam question, so I hope it's ok that I didn't post this in the homework section even if it's set out like a homework question.
The Question:
Suppose we are observing the collision
Anti-electron-neutrino + electron ---> W-minus boson
What energy has the Anti-Electron-Neutrino, to produce the W particle?
Relavant equations and data:
mass of electron = 0.511 MeV/c^2
mass of W-minus boson = 80.403 GeV/c^2
Four-momentum equation
[tex]S = -(\overrightarrow{{p_{e}}}+\overrightarrow{{p_{\nu }}})^{2} = -(cp_{e}+cp_{\nu })^{2}+(E_{e}+E_{\nu})^{2}[/tex]
Thoughts so far:
My understanding is that the four-momentum is always conserved so I have to equate the initial four-momentum to the final four-momentum using the assumption that the electron and the W boson have no kinetic energy.
[tex]S_{initial} = -c^{2}p_{\nu }^{2} + E_{\nu }^{2}[/tex]
[tex]S_{final} = ((m_{W^{-}}) c^{2})^{2}[/tex]
to the initial four-momentum becomes zero since
cp = E
So I'm not sure how to carry on, the energy of the neutrino can't be zero!?
Thanks to anyone who helps
xoLouLouox
This is a past (3rd year university level) exam question, so I hope it's ok that I didn't post this in the homework section even if it's set out like a homework question.
The Question:
Suppose we are observing the collision
Anti-electron-neutrino + electron ---> W-minus boson
What energy has the Anti-Electron-Neutrino, to produce the W particle?
Relavant equations and data:
mass of electron = 0.511 MeV/c^2
mass of W-minus boson = 80.403 GeV/c^2
Four-momentum equation
[tex]S = -(\overrightarrow{{p_{e}}}+\overrightarrow{{p_{\nu }}})^{2} = -(cp_{e}+cp_{\nu })^{2}+(E_{e}+E_{\nu})^{2}[/tex]
Thoughts so far:
My understanding is that the four-momentum is always conserved so I have to equate the initial four-momentum to the final four-momentum using the assumption that the electron and the W boson have no kinetic energy.
[tex]S_{initial} = -c^{2}p_{\nu }^{2} + E_{\nu }^{2}[/tex]
[tex]S_{final} = ((m_{W^{-}}) c^{2})^{2}[/tex]
to the initial four-momentum becomes zero since
cp = E
So I'm not sure how to carry on, the energy of the neutrino can't be zero!?
Thanks to anyone who helps
xoLouLouox
Last edited: