(from 36grit's thread "What is energy?", #39)

When I calculate neutron decay,

into proton & electron

using momentum

& starting (both e & p) with light speed c

instead of (the neutron's) 0 m/s,

then I get a mass deficit

of 2 electron masses

instead 3/2=1.5 electrons,

e.g. what you call an anti_neutrino.

 

Please show me a neutrino "particle"

that you claim to have discovered,

I've never seen 1.

Edited May 11, 20178 yr by Capiert

We can ignore the first part as being obviously nonsense.

 

The neutrino was proposed in 1930 and first detected in1956: https://en.wikipedia.org/wiki/Neutrino#Direct_detection

 

There are now many neutrino detectors around the world: https://en.wikipedia.org/wiki/Neutrino_detector

 

They can be used for astronomy and also to test the predictions of the standard model and (hopefully) discover new physics.

We can ignore the first part as being obviously nonsense.

 

Please explain.

 

(Perhaps you are saying

a particle cannot go at light speed,

so the (newly released) Beta particle cannot (begin at c,

(from the Coulomb charge repulsion)

to) slow down from light speed

via collisions

to (e.g.) ~0.98*c;

 

& the proton's speed

would be much slower

(in the opposite direction)

from the recoil.)

 

Thanks for the links.

 

But each (small) particle decayed (or thrown off, e.g. mom1=m1*v1,

using small syntax number 1 for simplicity, smallest)

will have its own appropriate "deficit" (-2*mom1*mom2)

depending on its own mass (m1),

the (larger) partner daughter product mom2=m2*v2

& (largest=) original parent mom3=mom1+mom2. (Largest number, of the 3.)

 

Thus your variety of (so_called) neutrinos.

 

The important thing is,

something is suppose to be missing

if we add terms

(of the equation's squared sides).

Edited May 11, 20178 yr by Capiert

Please explain.

 

(Perhaps you are saying

a particle cannot go at light speed,

so the (newly released) Beta particle cannot (begin at c,

(from the Coulomb charge repulsion)

to) slow down from light speed

via collisions

to (e.g.) ~0.98*c;

 

 

Yes, precisely. It is nonsense to claim that anything with mass travels at c.

 

The speed of the ejected particles is related to the energy released in the reaction. Take a neutron's mass, subtract a proton's mass, and multiply by c^2. That's how much energy is released in the beta decay of a neutron. I have no idea why you think the mass deficit should be 1.5 electron masses. That's more nonsense.

Yes, precisely. It is nonsense to claim that anything with mass travels at c.

 

The speed of the ejected particles is related to the energy released in the reaction. Take a neutron's mass, subtract a proton's mass, and multiply by c^2. That's how much energy is released in the beta decay of a neutron. I have no idea why you think the mass deficit should be 1.5 electron masses. That's more nonsense.

Is it really?

 

I've seen the formula

n0 = p+ + e- + 0.766 MeV (anti_neutrino).

 

An electron is 0.511 MeV.

 

(Energy, mass equivalence.)

 

 

Now, take a neutron's mass, subtract a proton's mass, and multiply by c.

That's how much momentum is released in the beta decay of a neutron. (?)

(No!, doesn't fit because you ignored the proton's recoil.)

 

(But that's no problem:

opposite & equal reaction (Newton's 3rd law)

says it (=the total (released momentum))

must be double (the electron's (released) momentum).

 

What's the difference between Einstein's

rest mass energy E=m*(c^2) formula

& KE~m*(v^2)/2, using v=c?

Answer: the half.

E.g. (My) speed energy SE=2*KE (definition=substitution).)

Edited May 11, 20178 yr by Capiert

Is it really?

 

I've seen the formula

n0 = p+ + e- + 0.766 MeV (anti_neutrino).

 

An electron is 0.511 MeV.

 

(Energy, mass equivalence.)

 

 

Yes, that's a description. A neutron becomes a proton, electron and antineutrino, with the release of .766 MeV. (even though that number is off)

 

The calculation of the energy released is (m_n-m_H)c^2 (the Hydrogen includes the mass of the electron created)

 

(1.008664u-1.007825u) 931.5 Mev/u = 0.782 MeV

 

https://en.wikipedia.org/wiki/Neutron#Free_neutron_decay

The speed of the ejected particles is related to the energy released in the reaction. Take a neutron's mass, subtract a proton's mass, and multiply by c^2. That's how much energy is released in the beta decay of a neutron. I have no idea why you think the mass deficit should be 1.5 electron masses. That's more nonsense.

Well, you forgot to subtract mass of electron as well (later fixed in #6 post).

m_n = 939.565 MeV/c^2

m_p = 938.272 MeV/c^2

m_e = 0.511 MeV/c^2

(Mass of Hydrogen m_h = m_p+m_e-13.6 eV = ~ 938.783 MeV/c^2 )

m_n*c^2 = m_p*c^2 + m_e*c^2 + D.E. (Decay Energy) (meaningless/unknown mass of antineutrino)

Reverse equation:

D.E. = ( m_n - ( m_p + m_e ) ) * c^2 = ( m_n - m_h ) * c^2

D.E = ( 939.565 MeV/c^2 - ( 938.272 MeV/c^2 + 0.511 MeV/c^2 ) ) * c^2 = ( 939.565 MeV/c^2 - 938.783 MeV/c^2 ) * c^2 = 0.782 MeV

 

I have no idea why you think the mass deficit should be 1.5 electron masses. That's more nonsense.

If somebody will take 0.511 MeV/c^2 + 0.782 MeV/c^2 = 1.293 MeV/c^2 (difference between mass-energy of neutron and proton)

and divide it by 0.511 MeV/c^2 he will get 2.53, subtract 1 (mass of single electron) = 1.53.. This is how he get these 1.5..

That mass is converted to kinetic energy of newly created particles after decay.

 

 

Capiert, you need to remember that Decay Energy is calculated in rest-frame of particle or nucleus that's decaying.

So you have momentum p=0 in this FoR (it's called CoM = Center of Mass FoR)

After decay they are accelerated, either proton, electron and antineutrino (especially).

To try to calculate it in Lab frame you need astonishing knowledge in Special Relativity.

See example here (creation of pion meson and antiprotons):

http://galileo.phys.virginia.edu/classes/252/particle_creation.html

 

 

I've seen the formula

n0 = p+ + e- + 0.766 MeV (anti_neutrino).

[math]n^0 \rightarrow p^+ + e^- + \bar{v}_e + 0.782 MeV[/math]

 

Electron and antineutrino split decay energy as their kinetic energy. If electron takes more, antineutrino takes less. If antineutrino takes more, electron takes less.

Proton is barely recoiled, because it's 1836.15 times more massive than electron.

Edited May 12, 20178 yr by Sensei