61–70 of 75 posts
Earlier quoted context omitted.
How would you know the two different neutrinos interactions came from the same source/distance without producing them yourself?
I wouldn’t need to. By sampling hundreds of thousands of events, I would know the odds of getting a particular neutrino from a particular source is the same.
I'm surprised Sabine did not bring her usual drama and controversy to this one and talk about the fact that there is, shall we say, "extreme tension" between the results from LSND/MiniBooNE and those of other experiments. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.11... The 4th figure is the money shot.
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To be fair I also heard 10-15 on the first pass and then had to think about it for a second.
That's because she actually said "ten to the fifteen" not "ten to the fifteenth", so you have to decide if you autocorrect by removing the "the" -> "ten to fifteen" or by adding the "th" -> "ten to the fifteenth". Easy to get confused.
I'm surprised Sabine did not bring her usual drama and controversy to this one and talk about the fact that there is, shall we say, "extreme tension" between the results from LSND/MiniBooNE and those of other experiments. https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.11... The 4th figure is the money shot.
She really doesn't explain the basic research problems well, and I'm still mystified as to why she gets so much traction here.
The other side would be someone like Luboš Motl, who used to be quite popular too. His main point is that the mathematical completeness and coherence of string theory means it's the only game in town. Which, that might be a fair point, for all I know, but I'm a maths grad and I can only vaguely appreciate what he's going on about most of the time. It just needs a lot of study to get to grips with these theories well enough to judge them in the absence of confirmatory empirical evidence.
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> But for some reason this process ain't starting. or, 2.5 years, one of which was a global pandemic, is not enough time to design, begin, and publicize a series of experiments that take a few decades to produce data in quantity to continue investigating new physics.
Again: the next step is not more experiments. The experiments are done , and confirmed the discrepancy. The next step is theorizing, which can be done in isolation, relatively unaffected by pandemic. That is what is now neglected. After hypotheses have been shown to be plausible, i.e. account for the result correctly, yet consistent with other results, it will be time to design experiments to choose among them. So, n…
Why do we need a particle accelerator to run experiments on neutrinos, given their apparent abundance? Is there any other way to observe neutrinos without a particle accelerator?
> given their apparent abundance? That's part of the problem. Which Neutrinos are you measuring? The ones from your experiment, the ones from the Sun, the ones from the environment? They're exceptionally light particles, so effective shielding is difficult. It's why a lot of these experiments are deep underground. The one I visited was in northern Minnesota in an old abandoned Mine placed half a mile under the surfac…
So you're detecting all neutrinos, but you're looking in an energy range where the signal you're interested in rises above the background levels.
Earlier quoted context omitted.
Again: the next step is not more experiments. The experiments are done , and confirmed the discrepancy. The next step is theorizing, which can be done in isolation, relatively unaffected by pandemic. That is what is now neglected. After hypotheses have been shown to be plausible, i.e. account for the result correctly, yet consistent with other results, it will be time to design experiments to choose among them. So, n…
There are theories. Such as the discrepancy being due to sterile neutrinos (also explaining dark matter). Confirming or rejecting through data is currently underway, is not at six sigma, and won’t be for years due to rareness and difficulty of detecting events. So it isn’t being talked about since we are in the lurch.
Why do we need a particle accelerator to run experiments on neutrinos, given their apparent abundance? Is there any other way to observe neutrinos without a particle accelerator?
Energy ranges, knowing exactly how far you are from the source of the neutrinos, and background exclusion. If you are too far from the source, the mixing you might be measuring might have happened already happened. You can build a detector right next to the source, and also far away, and correlate the differences. External interference can be excluded on energy range, direction, and “timing” - you know exactly when t…
Earlier quoted context omitted.
> But for some reason this process ain't starting. or, 2.5 years, one of which was a global pandemic, is not enough time to design, begin, and publicize a series of experiments that take a few decades to produce data in quantity to continue investigating new physics.
Again: the next step is not more experiments. The experiments are done , and confirmed the discrepancy. The next step is theorizing, which can be done in isolation, relatively unaffected by pandemic. That is what is now neglected. After hypotheses have been shown to be plausible, i.e. account for the result correctly, yet consistent with other results, it will be time to design experiments to choose among them. So, n…
Given the absurdly low rate of detection, it feels like a focused experiment designed explicitly to maximise detection is warranted. Difficulty of neutrino experiments aside, this is physics! If we want more detection events we just need to make more particles and/or build a bigger detection apparatus. I don’t necessarily think there’s much benefit to a “larger volume” detector in this particular experiment (MiniBooNE) due to beam width and spreading rate, but I don’t see how having one or two more identical detectors lined up along the generated neutrino‘s path wouldn’t help. Building a more “powerful” neutrino production system, even as simply as just having an accelerator with a higher particle flux would likely increase this factor.
If people are arguing over possible issues in the experiment design (which there do appear to be concerns here, but grain of salt as IANAP) then dialling the experiment parameters up will should make any experiment specific effects more obvious as there will now be two sets of data points that can be correlated by the experiment parameters to fill out such effects.
Could someone explain to a layman why "neutrinos can only mix if they have masses"? Perhaps I don't understand what it means to "mix"