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Neutrinos: Key to New Physics

 
This forum is locked: you cannot post, reply to, or edit topics.   This topic is locked: you cannot edit posts or make replies.    jcYoon's Physics Forum Index -> Professor Pierre Ramond
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jcyoon



Joined: 08 Aug 2006
Posts: 213

PostPosted: Sun Oct 22, 2006 12:57 pm    Post subject: Neutrinos: Key to New Physics Reply with quote

ramond@phys.ufl.edu
Wed 2004-11-24 9:08 AM

Dear Professor Ramond,

Recently, I have read your preprint "Neutrinos: Key to New Physics".
In my opinion, one of the question in the Standard Model we should address is
its approximation of massless limit of massive fermions.

The helicity is not well defined in massive fermions so that they are not definite.
We cannot use this bad quantum number to classify particles as we did in
Standard Model and the approximation of massless limit is proved to be Lorentz
violating.

Maybe, there is something I could not see here.
I would like to appreciate if you can help me understand this issue.

Thanks,
J.C. Yoon
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Pierre Ramond



Joined: 28 Sep 2006
Posts: 2

PostPosted: Sun Oct 22, 2006 12:58 pm    Post subject: Re: Neutrinos: Key to New Physics Reply with quote

Wed 2004-11-24 10:21 AM

in the standard model, the fermions are massless, and acquire mass through Higgs vev's. So it is OK.


The right-handed neutrinos are massive and have spin, not helicity.

P.
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jcyoon



Joined: 08 Aug 2006
Posts: 213

PostPosted: Sun Oct 22, 2006 1:00 pm    Post subject: RE: Neutrinos: Key to New Physics Reply with quote

Wed 2004-11-24 10:48 AM

Dear Professor Ramond,
I would like to appreciate your kind response.

Within the standard model, it may be consistent.
But, this leads us to question the fundamentality of Dirac equations,
since it implies that Dirac equations of massive fermion is not the
fundamental ones but massless ones are and mass is also not fundametal
one but some derived properties of particle, which makes doubtful
all the properties we have acquired from massive Dirac equations.

I would also be great if you let me know the definition of right-handed neutrio.

Thanks,
J.C. Yoon
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Pierre Ramond



Joined: 28 Sep 2006
Posts: 2

PostPosted: Sun Oct 22, 2006 1:01 pm    Post subject: Re: Neutrinos: Key to New Physics Reply with quote

Wed 2004-11-24 10:55 AM

right handed fermions. Look at my field theory book.

P.
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jcyoon



Joined: 08 Aug 2006
Posts: 213

PostPosted: Sun Oct 22, 2006 1:02 pm    Post subject: RE: Neutrinos: Key to New Physics Reply with quote

Wed 2004-11-24 11:44 AM

Dear Professor Ramond,

In your book, it is defined rather nomialy designating a part of
Dirac spinor. This also comes back to the issue of fundamentality
of Dirac particle, since I hold a point of view understanding a massive
neutrino from massive Dirac equations.

I just don't see why we have to give up on massive Dirac equations.

Thanks,
J.C. Yoon
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