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We all know that, according to general relativity, all particles feel the gravitational force. The other forces are not so ubiquitous.
The proton interacts with the electromagnetic and strong forces, but apparently not with the weak. The electron interacts only with the electromagnetic; the neutrino only with the weak. Let's make a table:
I am not sure about the gluon -- I know it is chargeless, but does it interact weakly? I don't think it does.
I also spent some time thinking about a particle which interacts only strongly and weakly, but not via E&M, and couldn't think of one. My first instinct was the pi-zero, but it decays into photons...
My real question, however, is this:
Does the standard model have anything to say about a hypothetical particle which interacts ONLY gravitationally?
Has such a thing been proposed? I understand that we simply would not be able to detect such a particle at all with current instruments, but can we say anything else about their existence? I'm thinking along the lines of dark matter, of course...
Thanks for any input.
- Warren
The proton interacts with the electromagnetic and strong forces, but apparently not with the weak. The electron interacts only with the electromagnetic; the neutrino only with the weak. Let's make a table:
Code:
E&M S W
hadrons x x x
e.g. protons x x
e.g. muon x x
e.g. electron x
? x x
gluons? x
neutrinos x
I am not sure about the gluon -- I know it is chargeless, but does it interact weakly? I don't think it does.
I also spent some time thinking about a particle which interacts only strongly and weakly, but not via E&M, and couldn't think of one. My first instinct was the pi-zero, but it decays into photons...
My real question, however, is this:
Does the standard model have anything to say about a hypothetical particle which interacts ONLY gravitationally?
Has such a thing been proposed? I understand that we simply would not be able to detect such a particle at all with current instruments, but can we say anything else about their existence? I'm thinking along the lines of dark matter, of course...
Thanks for any input.
- Warren