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Yashani
2008-Nov-20, 02:24 PM
Hi there!

Today in school we (me and my teacher) were discussing about the reaction between protons and electrons. He said that protons and electrons cannot form a neutron, because of the fact that protons consist of quarks and electrons don't. But as I read in this forum and on Universe Today, electrons and protons can be forced together by gravity and become neutrons.
Now my question is:
Are the electrons just forced into the protons and both will be just LIKE a neutron?
And if the electrons and protons react with each other, where do the quarks go or what happens to them?


Yashani

alainprice
2008-Nov-20, 03:15 PM
The strong nuclear force makes the neutron stable(inside a nucleus) so that it doesn't 'fall apart'.

Take a neutron and let it float and you have about 15 minutes before it breaks down into:
-a proton
-an electron
-an anti-electron neutrino(not 100% sure about the neutrino type and too lazy to look it up)

It's not as simple as taking the 3 pieces and jamming them back together, but almost.

What normally happens in an accelerator is that you take a proton, and smash it head on with an anti-proton. A bunch of the quantum numbers involved add up to 0. Immediately after the collision, all that energy can make whatever it wants. You could end up with nothing but positrons, anti-protons and neutrinos. Likewise, you might get a bunch of electrons, protons and anti-neutrinos. It's pure odds at that point.

The important thing to remember is that an electron does not exist inside of a neutron. Get rid of that idea. Instead, if the neutron is removed from a nucleus, it becomes unstable and may 'convert' into these products.

trinitree88
2008-Nov-20, 03:38 PM
The strong nuclear force makes the neutron stable(inside a nucleus) so that it doesn't 'fall apart'.

Take a neutron and let it float and you have about 15 minutes before it breaks down into:
-a proton
-an electron
-an anti-electron neutrino(not 100% sure about the neutrino type and too lazy to look it up)

It's not as simple as taking the 3 pieces and jamming them back together, but almost.

What normally happens in an accelerator is that you take a proton, and smash it head on with an anti-proton. A bunch of the quantum numbers involved add up to 0. Immediately after the collision, all that energy can make whatever it wants. You could end up with nothing but positrons, anti-protons and neutrinos. Likewise, you might get a bunch of electrons, protons and anti-neutrinos. It's pure odds at that point.

The important thing to remember is that an electron does not exist inside of a neutron. Get rid of that idea. Instead, if the neutron is removed from a nucleus, it becomes unstable and may 'convert' into these products.



alain. Those are the three. The chance of all three coming together in reverse , with enough energy to recreate the neutron are slim. The forum saying protons are squeezed with electrons to form neutrons is wrong. The teacher is right about the quarks. At a sufficiently high temperature, collisions of protons will cause W+ particles to be formed as up quarks convert to downs, changing the proton (up,up,down) into a neutron (up,down,down) as it does. The W+ particle decays almost instantly into a positron and a neutrino. The neutrino escapes, and the positron annihilates a nearby electron in either two or three gamma rays.
Emission of a particle...positron and neutrino...is exactly the same in conservation laws as absorbtion of an anti-particle...in this case the electron and electron type antineutrino. pete

Eroica
2008-Nov-20, 03:44 PM
An electron and a proton react together in a weak interaction.

A proton consists of three quarks: up, up, down.
A neutron consists of three quarks: up, down, down.

In the weak interaction between a proton and an electron, an up quark in the proton is converted into a down quark, turning the proton into a neutron. In becoming a down quark, the up quark emits a W+ boson. This boson is absorbed by the electron, which thereby becomes an electron neutrino.

Alternatively, the electron may be the one that emits a W boson, in which case it is a W- boson. This emission converts the electron into an elctron neutrino. The absorption of the W- boson by an up quark in the proton converts that quark into a down quark, turning the proton into a neutron.

In neither case is the electron absorbed into the resultant neutron

Yashani
2008-Nov-20, 03:57 PM
thank you for your quick answers. I think I understand that process now. :)

PraedSt
2008-Nov-20, 06:27 PM
thank you for your quick answers. I think I under stand that process now. :)
I'm impressed; because I'm having a hard time following it. Welcome to BAUT Yashani. :)

mugaliens
2008-Nov-20, 06:30 PM
The strong nuclear force makes the neutron stable(inside a nucleus) so that it doesn't 'fall apart'.

Take a neutron and let it float and you have about 15 minutes before it breaks down into:
-a proton
-an electron
-an anti-electron neutrino(not 100% sure about the neutrino type and too lazy to look it up).

It's an electron antineutrino. The break-down is simple Beta- decay.

Because both neutrinos and antineutrinos are neutral, they may in fact be the same particle, similar to photons emitted by matter/antimatter interactions.

alainprice
2008-Nov-20, 08:49 PM
It's an electron antineutrino. The break-down is simple Beta- decay.

Because both neutrinos and antineutrinos are neutral, they may in fact be the same particle, similar to photons emitted by matter/antimatter interactions.

I knew my text didn't look right. Thanks for the correction.

trinitree88
2008-Nov-20, 09:15 PM
I knew my text didn't look right. Thanks for the correction.

As neutrinos have handedness, and are chiral, they can only be the same as antineutrinos if they are subluminal. It's one of the arguments for massless neutrinos and antineutrinos. If they're massive, then by SR they are subluminal and are indistinguishable as their identity depends upon what reference frame you measure them in. So far all flavor swaps involve superposition of Eigenstates with matter paths....truly massive ones ought to flavor swap in vacuo. That has not been seen...yet.

edgarhughes
2009-Sep-11, 01:11 PM
Lets make this simple

A proton is 3 quarks: up, up, down + light
A neutron is 3 quarks: up, down, down + light.

quarks are anti electrons.

With out taking into account EMF (light) or space/time (gravity) effects.

1 electron + 1 proton or 1 neutron (3 anit electrons) = 2 anti electrons + light.

Nick Theodorakis
2009-Sep-11, 01:32 PM
Lets make this simple

A proton is 3 quarks: up, up, down + light
A neutron is 3 quarks: up, down, down + light.

quarks are anti electrons.

With out taking into account EMF (light) or space/time (gravity) effects.

1 electron + 1 proton or 1 neutron (3 anit electrons) = 2 anti electrons + light.

Simple, perhaps, but wrong. A quark is not an anti-electron.

Nick

trinitree88
2009-Sep-11, 02:01 PM
Beta decay looks like this:http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/qrkdec.html


pete