Neutral currents in particle physics are mediated by the neutral Z0 boson, detectable through elastic scattering processes such as $$\bar{\nu}_\mu + e \rightarrow \bar{\nu}_\mu + e$$. Direct observation of the Z0 boson is impractical due to its short lifetime; instead, indirect confirmation is achieved by observing electrons scattered from atoms when bombarded with muon antineutrinos. The discovery of neutral currents occurred in 1973 by the Gargamelle experiment at CERN, while the Z boson was identified through collider experiments.
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That is elastic scattering, not decay.Wledig said:In decay processes ... such as: $$\bar{\nu}_\mu + e \rightarrow \bar{\nu}_\mu + e$$
I had a vague idea of how things could work out, let me see if it's what you're suggesting. If we bombard an atom with muon antineutrinos we ought to observe electrons being scattered out of it, which would give an indirect confirmation for the existence of the ##Z^0## boson. Is that it? No hope for direct observation then, I believe? Or at least not in processes like this?Vanadium 50 said:An electron shooting out from an atom.
Orodruin said:That is elastic scattering, not decay.
Indirect confirmation of the existence of something like the Z and for the existence of neutrinos.Wledig said:I had a vague idea of how things could work out, let me see if it's what you're suggesting. If we bombard an atom with muon antineutrinos we ought to observe electrons being scattered out of it, which would give an indirect confirmation for the existence of the ##Z^0## boson. Is that it? No hope for direct observation then, I believe? Or at least not in processes like this?
Yes, interaction is the right term. A decay needs to start with a single particle.Sure. But the weak neutral boson is the mediator of the interaction, right? Or am I getting something wrong?
Neutral currents were discovered in accelerator experiments, not through neutrino interactions. Being neutral, you will never really see Z interactions with a detector. It also has a very short lifetime. What you see in accelerators when you produce on-shell Zs is a peak in the invariant mass distribution of the decay products.Wledig said:I had a vague idea of how things could work out, let me see if it's what you're suggesting. If we bombard an atom with muon antineutrinos we ought to observe electrons being scattered out of it, which would give an indirect confirmation for the existence of the ##Z^0## boson. Is that it? No hope for direct observation then, I believe? Or at least not in processes like this?
That's a really nice signature, luckily. Here is a graph, dots are measurements.Orodruin said:What you see in accelerators when you produce on-shell Zs is a peak in the invariant mass distribution of the decay products.
Orodruin said:Neutral currents were discovered in accelerator experiments, not through neutrino interactions.
Agreed, I should have formulated that more carefully.Vanadium 50 said:Neutral currents were discovered in accelerator experiments, notthrough neutrino interactions.
They were discovered in 1973 by the Gargamelle experiment at CERN, via a process similar to described in post #2. The Z, on the other hand, was discovered by colliders. While in principle, one could use the sort of measurement as described in #2 to determine the mass of the Z, it requires impractically precise measurements and/or impractically high energy beams to measure the Z mass this way.