Virtual Particle discussion

[Silvestru]

I am very interested in the subject of virtual particles and I have opened many threads in which you guys helped me understand related subjects. 

After some initial reading I came to the understanding that there is no "actual" difference between a virtual particle and a "real" one as all particles will eventually decay or be destroyed through one process or another. So lifespan of said particles was the only distinction that I came across.

But "real" particles are independent and self sustaining. Different quantum fields exist and spread all through space. In any of these quantum fields there are/can be transient ripples (virtual particles).

If this ripple absorbs energy or momentum it can form a self-sustaining wave pattern that become "real" particles.

Can we determine that a virtual particle becomes a "real" one when it absorbs the right amount of energy as long as conservation of energy and momentum laws are obeyed?

This is not my speculation, I just want to see if this is a proper understanding of how virtual particles work.

Edited September 19, 2017 by Silvestru

[Silvestru]

[Strange]

I am not informed enough to say much, but was touched by your second post...

Have you seen this page: https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

[Silvestru]

Thank you Strange.

That's exactly what I needed. An interesting article to wrap my mind around for an hour or so.

[Mordred]

Your understanding above is reasonably accurate, you have the essential gist of them in so far as being too short-lived due to insufficient energy to exceed a quanta in value

[MigL]

I am comfortable  with the fact that, what we call virtual particles, are field disturbances that don't need to abide by the classical Lagrangian equations of motion, Mordred,but where does the term 'shell' ( as in on shell or off shell ), which both you and AJB have used, come from.

[StringJunky]

2 minutes ago, MigL said:

I am comfortable  with the fact that, what we call virtual particles, are field disturbances that don't need to abide by the classical Lagrangian equations of motion, Mordred,but where does the term 'shell' ( as in on shell or off shell ), which both you and AJB have used, come from.

Quote

In physics, particularly in quantum field theory, configurations of a physical system that satisfy classical equations of motion are called on shell, and those that do not are called off shell.

In quantum field theory, virtual particles are termed off shell because they don't satisfy the Einstein energy-momentum relationship; real exchange particles do satisfy this relation and are termed on shell (mass-shell).[1] In classical mechanics for instance, in the action formulation, extremal solutions to the variational principle are on shell and the Euler–Lagrange equations give the on shell equations. Noether's theorem is another on shell theorem. https://en.wikipedia.org/wiki/On_shell_and_off_shell

 

[MigL]

Sure Stringy, but what does the term 'shell'/mass-shell refer to ?

Edit:

Oh, OK
Should have read the link before replying.
Thanks Stringy.

Edited September 25, 2017 by MigL

[Mordred]

lol evidentally I need not answer, good question and answer.