[Q] electron
Lee Sunghae
An electron can not be broken?
Is an electron a fundamental particle?
An the energy increases, the nucleus is broken from u and d to t and b
quarks.
But, I've never heard that an electron is broken.
Please let me know whether it is right or not.
grossep
Nobody to date has seen any indication that an electron, neutrino, or
quark is made of smaller particles. Indeed, present field theories seem
to forbid it.
-Josh G :)
Douglas A. Singleton
In article <33B693...@cadvision.com>,
There is certainly no experimetnal evidence (at least confirmed)
that the electron, muon, tau etc. have any kind of substructure.
But I'm not aware of any fundamental restriction that forbids
them from having such a substructure. In fact people used to
work on this kind of stuff -- making electrons and other
point particles out of smaller sub-particles which were given
various names (rishon comes to mind, but I think there were
other names given to these sub-leptons and sub-quarks). I say
used to because I haven't seen (m)any recent papers that
discuss this.
Doug
.
grossep
Douglas A. Singleton wrote:
>
> There is certainly no experimetnal evidence (at least confirmed)
> that the electron, muon, tau etc. have any kind of substructure.
> But I'm not aware of any fundamental restriction that forbids
> them from having such a substructure. In fact people used to
> work on this kind of stuff -- making electrons and other
> point particles out of smaller sub-particles which were given
> various names (rishon comes to mind, but I think there were
> other names given to these sub-leptons and sub-quarks). I say
> used to because I haven't seen (m)any recent papers that
> discuss this.
>
Rishons were the best theory I heard of. In it, each lepton/quark is
made of 3 smaller particles. Every fermion can be accounted for with
them.
However, it doesn't work to well with electroweak theory. How come an
electron (3 particles) only has to emit a single W boson to become a
neutrino (3 different particles)?
The only way to account for this is to say that a W is composed of 3
smaller bosons. A little investigation shows that these are leptoquarks
(like X bosons). But this would mean a leptoquark interaction would be
easier than a W one! And that is clearly not the case.
To the best of my knowledge, noone has ever sorted out this
inconsistensy between electroweak theory and rishon theory...
-Josh G :)
Douglas A. Singleton
In article <33B6D8...@cadvision.com>,
grossep <gro...@cadvision.com> wrote:
>Douglas A. Singleton wrote:
>>
[sub-lepton/quark stuff snipped]
>
>Rishons were the best theory I heard of. In it, each lepton/quark is
>made of 3 smaller particles. Every fermion can be accounted for with
>them.
>
>However, it doesn't work to well with electroweak theory. How come an
>electron (3 particles) only has to emit a single W boson to become a
>neutrino (3 different particles)?
Why is this a problem ? If it is a problem then it would also be
a criticism against the current Standard Model. For example in
neutron beta decay you have the same thing except with quarks
instead rishons or whatever. You start with a neutron (3 quarks
u d d) which emits a single W and becomes a proton (also three
quarks u u d).
>The only way to account for this is to say that a W is composed of 3
>smaller bosons. A little investigation shows that these are leptoquarks
>(like X bosons). But this would mean a leptoquark interaction would be
>easier than a W one! And that is clearly not the case.
>To the best of my knowledge, noone has ever sorted out this
>inconsistensy between electroweak theory and rishon theory...
>
> -Josh G :)
One problem with lepton substructure that I can think of (and
this is just from the top of my head so any corrections are
welcome) is that the sub constitutents would have to be squeezed
into a very small radius (smaller than the current experimentnal
limit on the size of the electron) and this tends to give a large
binding energy (from NRQM, which may be a mistake to use here even
as an approximation, the energy of a particle confined to a box
goes as 1 / (box dimension)^2, and for (box dimension) on the
order of the current experimetnal limit of the electron's radius
I think you get a large number. Large compared to the known mass
of the electron). There's probably some way to fix this up (say
by giving the rishons a large enough constituent mass to cancel
the large binding energy), but I think it ends up being more or
less artifical. Again this is from the top of my head so
corrections are welcome.
Doug
.
grossep
Douglas A. Singleton wrote:
>
> >However, it doesn't work to well with electroweak theory. How come an
> >electron (3 particles) only has to emit a single W boson to become a
> >neutrino (3 different particles)?
>
> Why is this a problem ? If it is a problem then it would also be
> a criticism against the current Standard Model. For example in
> neutron beta decay you have the same thing except with quarks
> instead rishons or whatever. You start with a neutron (3 quarks
> u d d) which emits a single W and becomes a proton (also three
> quarks u u d).
>
However...notice the neutron decay is uud to udd. That only involves
one quark changing, so it makes sense that one boson would be emitted.
On the other hand, electron to neutrino would be TTT to VVV, at least
according to standard rishon theory. That involves 3 changes.
The rest of your article, about rishon binding energy, makes perfect
sense. That's something I've never thought of! Thanks for the
enlightenment.
-Josh G
Dries van Oosten
On Sun, 29 Jun 1997, Lee Sunghae wrote:
> An electron can not be broken?
> Is an electron a fundamental particle?
> An the energy increases, the nucleus is broken from u and d to t and b
> quarks.
> But, I've never heard that an electron is broken.
> Please let me know whether it is right or not.
>
>
>
>
A particle doesn't have to be non-fundamental to decay, but you are right,
electron tend not to decay. There is nothing to decay to. The only way you
can get rid of an electron is by trying to change it into a particle that
has more energy. Please remember that an electron will not allways stay
an electron. Together with a proton and an anti-neutrino it can be
absorbed to form a neutron. The electron seizes to exist at that moment.
So you can say that in some ways it can be broken.
Dries van Oosten
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Douglas A. Singleton
In article <33B888...@cadvision.com>,
Opps. Right you are. I don't know what I was thinking. There
are some other substructure models (due to Pati and Salam I
think) which pre-date the rishon model and where the gauge
bosons are still fundamental so I might have been confusing
the two. Although now I'm thinking that even in the Pati
Salam model the neutrino and electron where composed of all
different consitutents. If I get the time I'll have a look,
or if anyone knows some details of the Pati-Salam model maybe
they'll post. Finally there was one other obstacle to these
substructure models which went by the name of "'t Hooft anomaly
matching condition". Kerson Huang's book on paticle physics/QFT
has a chapter which talks about this, but I never really
understood the point. It was something like the "substructure
models had to reproduce the anomaly structure of the low
energy theory". Maybe someone who understands this anomaly
matching stuff better can add something.
Doug
.
Frank Schmidt
grossep <gro...@cadvision.com> writes:
[...]
>However...notice the neutron decay is uud to udd. That only involves
>one quark changing, so it makes sense that one boson would be emitted.
>On the other hand, electron to neutrino would be TTT to VVV, at least
>according to standard rishon theory. That involves 3 changes.
I don't see the difference... down to up is -TVV to +TTV, so all three
rishons are exchanged.
IMHO the W bosons could also be explained by forces between the rishons:
at first there is the down-quark, close to which an up-anti-up pair
forms. Then it is possible that the anti-up forms a pair with the down,
and they can 'collide', i.e. come close enough together to enable the
rishons to be exchanged between them: anti-up (-TTV) and down (-TVV)
become electron (-TTT) and antineutrino (-VVV).
The energy attributed to the W boson then is the energy to be overcome
for the rishons to allow an exchange of them between particles.
Frank Schmidt
---
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| Coffeehouse | learn while they teach" Tracey Reilly | Schmidt |
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grossep
Frank Schmidt wrote:
/
/ grossep <gro...@cadvision.com> writes:
/
/ [...]
/
/ >However...notice the neutron decay is uud to udd. That only involves
/ >one quark changing, so it makes sense that one boson would be
emitted.
/ >On the other hand, electron to neutrino would be TTT to VVV, at least
/ >according to standard rishon theory. That involves 3 changes.
/
/ I don't see the difference... down to up is -TVV to +TTV, so all three
/ rishons are exchanged.
Exactly my point...when you have rishons involved, three things change
instead of one. Therefore, 3 bosons should be emitted. But the 3
bosons that make up a W would be leptoquarks...and it is easier to emit
a W then a leptoquark!
/ IMHO the W bosons could also be explained by forces between the
rishons:
/ at first there is the down-quark, close to which an up-anti-up pair
/ forms. Then it is possible that the anti-up forms a pair with the
down,
/ and they can 'collide', i.e. come close enough together to enable the
/ rishons to be exchanged between them: anti-up (-TTV) and down (-TVV)
/ become electron (-TTT) and antineutrino (-VVV).
That I never thought of...I suppose it would work!
/ The energy attributed to the W boson then is the energy to be overcome
/ for the rishons to allow an exchange of them between particles.
/
/ Frank Schmidt
-Josh G :)