[HN Gopher] The first observation of neutrinos at CERN's Large H...
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The first observation of neutrinos at CERN's Large Hadron Collider
Author : wglb
Score : 50 points
Date : 2023-08-29 00:47 UTC (22 hours ago)
(HTM) web link (phys.org)
(TXT) w3m dump (phys.org)
| Aachen wrote:
| Have I read over it, or does the article not answer the main
| question I expect most people have with such a headline: how?
|
| The only descriptions I see are "advanced equipment" and that
| it's 2 meters and has to filter muon background noise. I thought
| neutrino detections were done with a few cubic kilometers of ice,
| but there's no mention of that. Does the higher rate of
| production/concentration simply let them do it with a small
| device, or is there actually a new invention here?
| jptlnk wrote:
| I haven't read the full article yet but the abstract has some
| hints: I think what they're doing is leveraging the fact that
| they know where and when the neutrinos were created to narrow
| down the search in the actual neutrino detector itself.
|
| Because they can see the associated muon, they know when to
| look for a correlated neutrino signal.
|
| Between that and the extremely hot source, they can get away
| with a relatively small active detector volume.
|
| Again that's just based on my reading of the abstract, I need
| to see the full article to validate that guess.
| dotnet00 wrote:
| They seem to point to high flux and high neutrino energy
| offsetting the weakness of neutrino interaction, with the
| neutrinos being the highest energy recorded in a lab
| environment.
| jptlnk wrote:
| relevant pre-print is here:
| https://arxiv.org/pdf/2305.08665.pdf
|
| that'll be my evening reading :)
| smaddox wrote:
| This appears to be the reason:
|
| > Until now no neutrino produced at a particle collider has
| ever been directly detected. Colliders copiously produce both
| neutrinos and anti-neutrinos of all flavors, and they do so
| in a range of very high energies where neutrino interactions
| have not yet been observed. Nevertheless, collider neutrinos
| have escaped detection, because they interact extremely
| weakly, and the highest energy neutrinos, which have the
| largest probability of interacting, are predominantly
| produced in the forward region, parallel to the beam line. In
| 2021, the FASER collaboration identified the first collider
| neutrino candidates 13 using a 29 kg pilot detector,
| highlighting the potential of discovering collider neutrinos
| in LHC collisions.
| aziaziazi wrote:
| > forward region, parallel to the beam line
|
| What collides here exactly? I always thought collider do
| throw a particule A in the direction of particule B while B
| travels in the direction of A, with measure instruments all
| around but _not_ blocking one of the particule path. The
| photographie 0 make me wonder if they also crash particules
| directly into their instruments?
|
| 0 https://scx2.b-cdn.net/gfx/news/hires/2023/the-first-
| observa...
| prewett wrote:
| Well, you sort of have to have the particle collide with
| something in order to detect it. When a photon collides
| with your retina, you see a flash of light (it causes a
| protein to twist, which generates an electrical signal,
| which is sent to your brain). The problem is the
| neutrinos tend to pass right through without getting
| absorbed by anything. No absorption, no change, no
| detection.
|
| So the neutrino has to collide with something to get
| detected. Given that previous neutrino detections require
| a large vat of heavy water underground, while the current
| results are from a little box, the salient question is
| what did they do differently (and is it applicable
| elsewhere). The article completely ignores this.
| aziaziazi wrote:
| > This work has shown that high energy experiments can also study
| neutrinos, and so has brought together the high-energy and high-
| intensity frontiers.
|
| Can someone explain to a layman the difference of HE and HI
| experiments?
| dotnet00 wrote:
| High energy refers to the energy imparted to particles, high
| intensity refers to the number of particles (presumably of the
| particle beams), at least if the terminology is anything
| similar to synchrotrons.
|
| So a high intensity 3GeV beam would be one where the average
| particle energy is 3GeV, with a larger number of particles
| comprising the beam than a low/medium intensity one.
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(page generated 2023-08-29 23:00 UTC)