Can the Higgs be coupled to a nucleus?
alejandro.rivero
not very pausible because of the weak coupling. Now I wonder about
another impausibility:
Can the Higgs couple to the nucleos so that the nuclear mass or the
nuclear levels get measurable corrections? This is again motivated
because the Higgs mass is of nuclear order of magnitude, and in fact
the upper limit at 95% for the Higgs is just in the area of Pb 208, ie
the point where the last magic numbers give place to the sea of
unstability.
Alejandro
Lubos Motl
> Can the Higgs couple to the nucleos so that the nuclear mass or the
> nuclear levels get measurable corrections? This is again motivated
> because the Higgs mass is of nuclear order of magnitude,
Sorry, but the Higgs is about 1000 times heavier than the nuclear physics
energy scale. The QCD scale is about 300 MeV while the Higgs mass is
between 115 and 900 GeV.
> and in fact the upper limit at 95% for the Higgs is just in the area
> of Pb 208, ie the point where the last magic numbers give place to the
> sea of unstability.
It is not reasonable to compare the mass of the Higgs with the mass of
complicated nuclei because they are not point-like. The Planck mass is
equal to the mass of an average grain of dust, but it does not imply that
the dust tells us something about the Planckian physics of quantum
gravity. The complicated nuclei are still "made" of quarks (or protons and
neutrons) and the physical processes can be reduced to these elementary
building blocks. They're much lighter than the Higgs.
In order to study high-energy physics, you must concentrate the energy to
a single particle (or a very small number of them). High energy physics
is only seen if the momentum transfer from one particle to another is
large.
Yes, the Higgs couples to the quarks by the Yukawa coupling and it gives
the quarks their bare masses, but this coupling is on the contrary very
weak, and most of the proton's mass actually arises from the "glue" of
QCD, not from the small masses of bare quarks.
It is not reasonable to consider the coupling of the Higgs directly to the
nuclei because the Higgs does not exist as a degree of freedom at the
energy scale where nuclei can be used as elementary fields.
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Superstring/M-theory is the language in which God wrote the world.
Squark
Lubos Motl <mo...@feynman.harvard.edu> wrote in message news:<Pine.LNX.4.31.031112...@feynman.harvard.edu>...
> Yes, the Higgs couples to the quarks by the Yukawa coupling and it gives
> the quarks their bare masses, but this coupling is on the contrary very
> weak, and most of the proton's mass actually arises from the "glue" of
> QCD, not from the small masses of bare quarks.
Since the proton is a bound state, the potential energy of
interaction between its consituents is negative, and it's the
same as the "glue's" contribution to the proton's mass. The mass
rather comes from the quarks' relative motion, i.e. kinetic
energy w.r.t. center-of-mass. Or am I confusing something?
Best regards,
Squark
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alejandro.rivero
news:<ee8203c6.03111...@posting.google.com>...
> Two weeks ago I was asking about the W coupling to nucleus... which is
> not very pausible because of the weak coupling. Now I wonder about
> another impausibility:
>
> Can the Higgs couple to the nucleus...
An update: The standard model masses W(Z), Higgs (conj) and Top
happen a bit before of the complection of a magic number gap. And a
bit after of the start of the splitted level that generated the gap.
I have drawed the lines above the traditional plot of the Binding
Energy per Nucleon and above the FRDM-1992 discrepancy plot. You can
check the images at this webpage
http://dftuz.unizar.es/~rivero/research/nucleo/
and see if it suggests something to you.
I have played with two ideas until now:
-an resonance effect contributing to the nuclear density.
-a contribution to the spin-orbit coupling.
but both are half-baked, no serius mechanism yet.
Yours,
Alejandro
alejandro.rivero
news:<ee8203c6.03111...@posting.google.com>...
> riv...@sol.unizar.es (alejandro.rivero) wrote in message
> news:<ee8203c6.03111...@posting.google.com>...
>
> > Two weeks ago I was asking about the W coupling to nucleus... which is
> > not very pausible because of the weak coupling. Now I wonder about
> > another impausibility:
> >
> > Can the Higgs couple to the nucleus...
>
> An update: The standard model masses W(Z), Higgs (conj) and Top
> happen a bit before of the complection of a magic number gap. And a
> bit after of the start of the splitted level that generated the gap.
What does "a bit" mean?
update to the update: a (M)agic number starts at some L angular momenta and
spin +1/2 shell. If you define (A)ntimagic number as the number starting
the shell (L, -1/2) then over each doubly magic number you can build
and approximate square (MM, MA, AM, AA). The diagonal of the square contains
exactly the massive boson, for the toppium and Higgs, while the W and Z must
be averaged to fit exactly in the diagonal.
Alejandro.
Lubos Motl
> Since the proton is a bound state, the potential energy of
> interaction between its consituents is negative, and it's the
> same as the "glue's" contribution to the proton's mass. The mass
> rather comes from the quarks' relative motion, i.e. kinetic
> energy w.r.t. center-of-mass. Or am I confusing something?
No, the kinetic energy of the quarks is certainly not enough to be the
majority of the proton's mass. The quarks can move by a significant
fraction of the speed of light - like 20 percent - but their mass only
increases a little bit (according to the rules of special relativity). The
proton is still approximately 200 times heavier than a quark. The proton
is a complicated bound state. You are right that normally the interaction
energy would be negative for a bound state, but it is not quite the case
for QCD. The proton is *not* made of quarks only; imagine that there is a
lot of physical gluons moving inside the proton, and these gluons' energy
is the majority of the proton's mass. Neither gluons nor quarks can leave
the proton - they are confined.
Squark
> The proton
> is a complicated bound state. You are right that normally the interaction
> energy would be negative for a bound state, but it is not quite the case
> for QCD. The proton is *not* made of quarks only; imagine that there is a
> lot of physical gluons moving inside the proton, and these gluons' energy
> is the majority of the proton's mass.
Maybe the way to think about this is that free quarks are infinitely massive
in QCD because of confinement. For instance, if we orbifold the theory
by CP, the resulting theory will be ordinary QCD far from the orientifold
but it will contain super-energetic free quark states. The energy of those
states will scale in linear fashion with distance from the orientifold.
Alternatively, if we want to preserve spatial symmetry we may compactify
on a sphere and orbiold by CD, where D is diametral refelection. This
again leads to ordinary QCD for large compactification radii but adds
superenergitic free quark states (this time the energy is location
independant and the states are symmetric). I don't know whether these
constructions are really useful for anything, though.
I wonder what is, then, the physical meaning of the "perturbative" quark
masses. They are not the masses of any states in the theory, they don't
correspond to poles in the S-matrix... I suppose that if we consider the
theory on small length scales we'll see free quarks with a Coloumb-like
interaction, and those quarks are gonna have the perturbative mass.
I'm not sure how to formalize this notion, though.