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ahaanomegas
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The charged pion particles ([itex]\pi^+[/itex] and [itex]\pi^-[/itex]) have different masses from the neutral pion particle ([itex]\pi^0[/itex]). Why? It's not like the pions are nuclei that they have binding energy.
Agreed!Bill_K said:In the limit of massless quarks the pion is a Goldstone boson and must also be massless. This has been confirmed in lattice QCD.
Bill_K said:In the limit of massless quarks the pion is a Goldstone boson and must also be massless. This has been confirmed in lattice QCD. If the pion had a mass less than the muon, it would be perfectly happy decaying into an electron instead.
Bill_K said:In the limit of massless quarks the pion is a Goldstone boson and must also be massless. This has been confirmed in lattice QCD.
No. The mass generated by QCD is dominated by non-perturbative effects, not by the mass of the individual particles. If quark mass would be relevant you would have something likekurros said:If the pion mass would be zero, does not this imply that the binding energy of the strong interaction is also zero?
Yes.kurros said:So would pions even be bound particles in such circumstances?
Binding energy is no reasonable concept in QCD b/c it applies only if the bound state is approximately 'the sum of its pieces', e.g. 'deuteron = proton + neutron + small el.-mag. field corrections', but in QCD the individual pieces do not exist in isolation (color confinement) and the bound state is by no means approximately the sum of three quarks (even if this was the original idea in the naive quark model).kurros said:I suppose strictly the binding energy of these particles is infinite (since it takes infinite energy to rip the quarks apart) and that doesn't mean they should have infinite mass.
Pions are subatomic particles that belong to the family of mesons. They are composed of a quark and an anti-quark, specifically an up quark and a down anti-quark. They have a relatively short lifespan and decay into other particles.
There are three types of pions: the pi-plus (π+), the pi-minus (π-), and the pi-zero (π0). The pi-plus and pi-minus have the same mass of approximately 139.6 MeV/c², while the pi-zero has a slightly lower mass of approximately 135.0 MeV/c².
The masses of pions are determined through experiments, specifically particle accelerators and colliders. By studying the interactions and decays of pions, scientists can calculate their masses. The current accepted values for the masses of pions come from the Particle Data Group.
The different masses of pions have implications in particle physics and the study of the fundamental forces of nature. The masses of pions, along with other particles, contribute to the understanding of the Standard Model and the behavior of subatomic particles.
The masses of pions, like other subatomic particles, can change through interactions and decays. However, their masses are considered constants within the current understanding of particle physics. Any changes to their masses would require a revision of the current theories and models.