y***@fas.harvard.edu
2008-06-07 19:49:05 UTC
[Moderator's note: Quoted-printable stuff NOT corrected. Sometimes I
correct small errors, but a) there are several here and b) it is not
obvious what the meaning should be. Please submit only 100% 7-bit ASCII
plain-text posts. Even if YOU can read something fancier, many readers
can't. -P.H.]
I read the abstract of Prof. Vafa's recent paper on string
phenomenology. (arXiv:0806.0102)
But, I don't really understand the following part:
"This effect can simultaneously generate a viably small =A5=EC term as well
as an acceptable Dirac neutrino mass on the order of 0.5=A1=BF 10^(-2=A1=BE0=
.5)
eV. In another scenario, we find a modified seesaw mechanism which
predicts
that the light neutrinos have masses in the expected range while the
Majorana mass term for the heavy neutrinos is =A1=AD 3=A1=BF10^(12=A1=BE1.5)=
GeV."
So, it seems that the Majorana mass of neutrino is much much bigger
than the Dirac mass of neutrino.
Why is it so? As far as I know, the mass of neutrino is very small.
But, how can this light neutrinos have so big Majorana mass? Or,
rather, as stated in the excerpt, is there something called "the heavy
neutrinos" different from the light neutrinos which I am familiar
with?
Or, rather, even though it's unlikely, is Prof. Vafa suggesting that
"another scenario" of his is incorrect, since it predicts a big
Majorana mass?
I am confused,
Youngsub.
correct small errors, but a) there are several here and b) it is not
obvious what the meaning should be. Please submit only 100% 7-bit ASCII
plain-text posts. Even if YOU can read something fancier, many readers
can't. -P.H.]
I read the abstract of Prof. Vafa's recent paper on string
phenomenology. (arXiv:0806.0102)
But, I don't really understand the following part:
"This effect can simultaneously generate a viably small =A5=EC term as well
as an acceptable Dirac neutrino mass on the order of 0.5=A1=BF 10^(-2=A1=BE0=
.5)
eV. In another scenario, we find a modified seesaw mechanism which
predicts
that the light neutrinos have masses in the expected range while the
Majorana mass term for the heavy neutrinos is =A1=AD 3=A1=BF10^(12=A1=BE1.5)=
GeV."
So, it seems that the Majorana mass of neutrino is much much bigger
than the Dirac mass of neutrino.
Why is it so? As far as I know, the mass of neutrino is very small.
But, how can this light neutrinos have so big Majorana mass? Or,
rather, as stated in the excerpt, is there something called "the heavy
neutrinos" different from the light neutrinos which I am familiar
with?
Or, rather, even though it's unlikely, is Prof. Vafa suggesting that
"another scenario" of his is incorrect, since it predicts a big
Majorana mass?
I am confused,
Youngsub.