# Glashow resonance (UHE neutrinos)

1. Apr 12, 2015

### ChrisVer

I'm obviously studying about neutrinos lately.....

So, I wanted to ask about the Glashow resonance. I don't understand what they mean when saying:
http://arxiv.org/pdf/1108.3163v2.pdf (sec.2)

Unfortunately I don't have access in the refs.

If I understand this correctly, it says that the intermediate W-boson is a real particle, right? But if that's true, I don't understand why this appears at PeV energies and not energies ~$M_W$. Thanks...

2. Apr 12, 2015

### Staff: Mentor

You have to consider energy and momentum conservation at the same time. An 80 GeV neutrino with an electron at rest has a CMS energy way lower than 80 GeV.

3. Apr 12, 2015

### ChrisVer

So I should say that the initial 4-momentum is:
$P_{in} = \begin{pmatrix} E_\nu + m_e \\ \vec{p}_\nu \end{pmatrix}$ and that its square =$M_W^2$?

4. Apr 12, 2015

### Staff: Mentor

Right.

5. Apr 12, 2015

### ChrisVer

Yes, that works fine :) I think I need to regain my form...

6. Apr 12, 2015

### Orodruin

Staff Emeritus
Or even simpler:
$$M_W^2= (p_e + p_\nu)^2 = m_e^2 + m_\nu^2 + 2p_e\cdot p_\nu \simeq 2m_e E_\nu$$
Actually summing it first is just extra work.