Thursday, February 25, 2010

The Standard Model Particles Are Massless States?

From, the standard textbook on the subject, String Theory by Joseph Polchinski:
Masses that are not zero in string theory are of the order [the Planck mass].  This is so large compared to experimentally accessible scales that these particles appear only in the virtual states.  Thus, we will be especially concerned with the massless string spectrum, since this must include all the particles of the Standard Model.  Of course, most known particles are massive, but these masses are so small compared to [the Planck mass] that they are zero to first approximation and become non-zero due to small symmetry-breaking effects.
So, it appears that the whole standard model is embedded in the massless states of string theory and that their masses on come because of small symmetry breaking.

For those who don't know, particles getting a mass because a symmetry has been broken does happen.  The very real Z abd W bosons get a mass because symmetries are broken.

It's just fun for me to think: assuming string theory is correct: all things we observe in nature are just the massless states of string theory with a some small masses from symmetry breaking.

No comments:

Post a Comment

To add a link to text:
<a href="URL">Text</a>