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> Neutrons in beams seem to live longer on average Isn’t this due to relativistic effects? What percentage of the speed of light are these beams?
> [isolated neutrons] decay into protons. During the process, each decaying neutron emits an electron and an antineutrino. > ...detected sparks of light each time a neutron decayed. Detecting a spark of light would also require photon(s) to be emitted, right? Is this not called out because it is a byproduct of the decay and not part of the decay reaction itself?
The decay products of neutrons is a proton, and electron and electron antineutrino. Light emissions would most likely be in the from acceleration or impingement of charge particles in the “bottle” magnetic field.
Clearly the article claims they are detecting “sparks”.
The reason the photons are not part of the primary emission is related to the momentum / energy balance in the decay. There are other conserved quantities such as lepton number.
As you say the light is a byproduct of the acceleration/ detections scheme of the charged particles emitted.
Stupid question, do they account for speed dilation on the beam experiment? The difference in lifetime will translate to 50k km/s speed of neutrons or roughly 1/6c
From skimming the review paper from OP (the "source:" in the caption on that error-bar chart), the neutrons in the beam experiments are thermalized, to a mean velocity of ~2,200 m/s. So, slower than 1e-5 c. https://doi.org/10.3390/atoms6040070 (Thermal meaning the neutrons scatter lots of times against atoms in a solid material, until they reach thermal equilibrium. ~km/s is a typical Boltzmann velocity for atom-size…
Stupid question, do they account for speed dilation on the beam experiment? The difference in lifetime will translate to 50k km/s speed of neutrons or roughly 1/6c
From skimming the review paper from OP (the "source:" in the caption on that error-bar chart), the neutrons in the beam experiments are thermalized, to a mean velocity of ~2,200 m/s. So, slower than 1e-5 c. https://doi.org/10.3390/atoms6040070 (Thermal meaning the neutrons scatter lots of times against atoms in a solid material, until they reach thermal equilibrium. ~km/s is a typical Boltzmann velocity for atom-size…
If the speed of the neutrons is less than 1e-5 c, the correction is less than 1e-10.
The lifetime of neutrons is approximately 15 minutes lifetime, so the correction is less than 1e-7 seconds. But they are measuring with a precision of only only a few tenths of a second, so the corrections is negligible.
Why does a neutron star not decay, as it is composed of neutrons, and free neutrons should decay in 15 minutes?
Is it because the neutrons are in an energetic "well" and to decay out would actually require energy? In collapsing under gravity to neutron degeneracy, did the neutrons say, radiate away their ability to decay any more?
Here's a question I was always curious to hear a good intuitive explanation for -- Why does a neutron star not decay, as it is composed of neutrons, and free neutrons should decay in 15 minutes? Is it because the neutrons are in an energetic "well" and to decay out would actually require energy? In collapsing under gravity to neutron degeneracy, did the neutrons say, radiate away their ability to decay any more?
When the W- boson decays into an electron and antineutrino it happens millions of times faster than the life of the neutron itself. What makes that trigger point happen when it does?
Stupid question, do they account for speed dilation on the beam experiment? The difference in lifetime will translate to 50k km/s speed of neutrons or roughly 1/6c