At least if it interacts as strongly with ordinary matter as would be necessary to make that anomaly.If there was a new particle with a mass as low as 17MeV, the LHC would be churning them out by the millions. It seems very unlikely indeed that such a thing exists but hasn't been noticed before.
That argument appears to assume the suspected fifth force works the same way as the strong, weak and electromagnetic forces. Proposed theories-of-everything have gravitons, and gravitons are presumed massless, so by your argument the LHC should be churning out even more of those. But LHC experiments haven't been observed to generate artificial gravitational fields, or even lose energy to gravity wave radiation, and that hasn't been treated as a show-stopper for the existence of gravitons.If there was a new particle with a mass as low as 17MeV, the LHC would be churning them out by the millions. It seems very unlikely indeed that such a thing exists but hasn't been noticed before.
Well, no effects at human scales. It might be important in ultra-dense ultra-hot environments such as the very early universe, and perhaps black holes or supernovae; Or on hyper-large scales, such as that of galaxies or galaxy clusters.The "fifth force" was discussed with respect to PSI a decade or more on the board.
The bottom line is that we would have seen any possible fifth force. If it exists it seems to have no effects.
I presume that this is because Catholicism is a local phenomenon, found only in our solar system.Not certain why a fifth force gets too much talk, isn't the problem we have deal with mass. IE we can pretty much explain what is going on in the universe with the current model, we just seem to be incapable of observing a large amount of mass.
Not following your reasoning. Why is the Planck mass in the formula?That is because gravity is extremely weak, though it is cumulative. Let's estimate the relative emission rate of gravitons from elementary-particle collisions. That's roughly
(E / mPl)2
Not certain why a fifth force gets too much talk, isn't the problem we have deal with mass. IE we can pretty much explain what is going on in the universe with the current model, we just seem to be incapable of observing a large amount of mass.
The Planck mass is the quantum-mechanical mass scale associated with gravity. Here is a rather hand-waving derivation.Not following your reasoning. Why is the Planck mass in the formula?That is because gravity is extremely weak, though it is cumulative. Let's estimate the relative emission rate of gravitons from elementary-particle collisions. That's roughly
(E / mPl)2
If I'm following that correctly (that's a Big if) it sounds like you're saying the reason the LHC isn't churning gravitons out by the millions is because gravity's analog of the fine structure constant is so much smaller than the fine structure constant. Doesn't that mean the conclusion that a fifth force is unlikely is unwarranted? The fact that the LHC isn't churning out X17 particles by the millions just places an upper bound on the hypothetical fifth force's fine structure constant analog.The Planck mass is the quantum-mechanical mass scale associated with gravity. Here is a rather hand-waving derivation.Not following your reasoning. Why is the Planck mass in the formula?That is because gravity is extremely weak, though it is cumulative. Let's estimate the relative emission rate of gravitons from elementary-particle collisions. That's roughly
(E / mPl)2
The World of Everyday Experience, In One Equation – Sean Carroll
Linearizing gravity - adding perturbation h to the space-time metric - I find this Lagrangian:
...
One can estimate the strength of emitting a particle as roughly (amplitude for doing so)2, and that is rougly
(interaction Lagrangian term / number density)2
For emitting a photon, that is e2 or (fine structure constant).
For emitting a graviton, that is (E/mPl)2
That's essentially it, though it's an interaction strength that varies with interaction energy. At Planck scales (quantum-gravity scales), gravity would be as strong as everything else.If I'm following that correctly (that's a Big if) it sounds like you're saying the reason the LHC isn't churning gravitons out by the millions is because gravity's analog of the fine structure constant is so much smaller than the fine structure constant.
Not just the LHC itself, but it and several of its predecessors. Consider the Gargamelle experiment of the 1970's at CERN. It was for looking for reactions of neutrinos with the Gargamelle bubble chamber's detector material. The neutrinos were made rather indirectly, by crashing accelerated protons onto targets. Among the particles to come out were strongly-interacting particles like pions. Some of them then decayed into muons, and in turn to electrons, the latter two decays also making neutrinos. The neutrinos continued into the bubble chamber, where they would sometimes make reactions. It is there that weak neutral currents were discovered, like a neutrino kicking an electron out of an atom.Doesn't that mean the conclusion that a fifth force is unlikely is unwarranted? The fact that the LHC isn't churning out X17 particles by the millions just places an upper bound on the hypothetical fifth force's fine structure constant analog.
The most that that proves is that wavefunction collapse is not very well-understood. Other than that, Sean Carroll is essentially correct.(On another note, your link seems to imply Sean Carroll is a blowhard. "... the laws underlying the physics of everyday life are completely understood", he says, and tries to prove it with an equation for an amplitude. "No experiment ever done here on Earth has contradicted this model.", the man says. Wrong. Every experiment ever done here on Earth has contradicted this model. His model says how the wave function evolves when it is not being observed. But the wave function appears not to follow that equation when it is being observed, and every experiment ever done here on Earth contains an observation. Sorry man, but no Born Rule explanation, no "the physics of everyday life are completely understood.")