🚀 go-pugleaf

In article <1992Nov8.233712.14557@mnemosyne.cs.du.edu> ddixon@nyx.cs.du.edu (David Dixon) writes:

> If electron mass comes from the coupling to a scalar Higgs field, then
> what would the mechanism be for converting this mass to the energy in
> a gamma-ray if the electron is annihilated (one n or two?) by a positron?
> Does this also account for the relativistic mass?  How about the
> electromagnetic binding energy of a hydrogen (or other) atom?

Essentially, none of these questions depend at all on the Higgs
mechanism.  (Pretty much all of them can be answered perfectly well
using ordinary QED.)

There's a reason for this which is actually quite general: all of
these questions involve physics at a scale of an MeV or less, but the
mass-generating mechanism (whether a Higgs boson or something else)
involves scales of a couple hundred GeV or so.  It is a general
property of quantum field theories that physics at very high energy
scales decouples from physics at low energy scales.  That's why we
still don't know just what the mass-generating mechanism is:
low-energy experiments don't really probe that sector.

I haven't stated this "decoupling theorem" very precisely; a more
precise statement of it would explain exactly in what sense the
different scales decouple, and it would also explain just what the
conditions are under which it applies.  Still, it is at least a good
rule of thumb that physics at some particular energy scale doesn't
depend very much on what's going on at an energy scale 100,000 times
larger.


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