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Questions tagged [interactions]

Particle interactions are changes in the nature, number, or state of several particles, usually at a specific space-time point, underlying dynamics. They are represented by special "field interaction terms" in quantum field theory and normally entail interchanges of energy, momentum, and sundry quantum numbers. They include scattering, and particle creation and annihilation.

Particle interactions are changes in the nature, number, or state of several particles, usually at a specific space-time point, underlying dynamics. They are represented by special "field interaction terms" in quantum field theory and normally entail interchanges of energy, momentum, and sundry quantum numbers. They include scattering, and particle creation and annihilation.

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Is there an equation for the strong nuclear force?

The equation describing the force due to gravity is $$F = G \frac{m_1 m_2}{r^2}.$$ Similarly the force due to the electrostatic force is $$F = k \frac{q_1 q_2}{r^2}.$$ Is there a similar equation that describes the force due to the strong nuclear…
ergodicsum
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How exactly is a normal force exerted, at the molecular level?

I've been surfing the web for quite a while, finding the answers I would need, but couldn't find a convincing one. First of all I need to remind you that this a very long/continuous question, so please kindly take your time. I'll provide some…
user226894
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Why isn't Higgs coupling considered a fifth fundamental force?

When I first learned about the four fundamental forces of nature, I assumed that they were just the only four kind of interactions there were. But after learning a little field theory, there are many other kinds of couplings, even in the standard…
user542
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How exactly does gravity work?

The electromagnetic force and strong and weak forces require particles like photons and gluons. But in case of gravity there is no such particle found. Every mass bearing object creates a gravitational field around it, and whenever another mass…
Normie
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Why are there only four fundamental interactions of nature?

Is there an answer to the question why there are only four fundamental interactions of nature?
Solidification
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Why is the gravitational force always attractive?

Why is the gravitational force always attractive? Is there another way to explain this without the curvature of space time? PS: If the simple answer to this question is that mass makes space-time curve in a concave fashion, I can rephrase the…
New Horizon
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What is the issue with interactions in QFT?

I've started studying QFT this year and in trying to find a more rigorous approach to the subject I ended up find out lots of people saying that "there is no way known yet to make QFT rigorous when there are interactions". As for the textbook…
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Do gravitons interact with each other?

I always thought the non-linearity of Einsteins field equations implies that there should be direct graviton-graviton interactions. But I stumbled upon Wikipedia which argues: If gravitons exist, then, like photons and unlike gluons, gravitons do …
asmaier
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For collision, physical contact is not a necessary condition. Why?

In my textbook, it is written that "For collision, physical contact is not a necessary condition". How can collision occur without physical contact? If there is no physical contact, then there would be no contact force between particles to act…
Arishta
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Was X17 predicted before it was observed?

Articles, with very little detail, have made their rounds about an X17 boson (16.7 MeV) being observed in tests of decaying beryllium-8 and perhaps once in a test with helium. Most of the undiscovered particles that are searched for in CERN or other…
userLTK
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What does it mean to say "Gravity is the weakest of the forces"?

I can understand that on small scales (within an atom/molecule), the other forces are much stronger, but on larger scales, it seems that gravity is a far stronger force; e.g. planets are held to the sun by gravity. So what does it mean to say that…
Smashery
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Can all fundamental forces be fictitious forces?

After reading many questions, like this and this, I wonder: Is it possible to consider the other fundamental forces too, the electroweak interaction and the strong interaction or ultimately the unification of these, to be fictitious forces like…
Costantino
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Why is the Pauli exclusion principle not considered a sixth force of nature?

Why is the Pauli exclusion principle not considered a sixth force of nature, given it produces such things as repelling of atoms and molecules in solids?
Anixx
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Simple example showing why measurement & interaction are different

Does someone know of a clear (pedagogical) example where one can really see(with the math) where interaction and measurement are not synonymous in quantum mechanics? I know that every measurement involves a certain interaction with the outside…
user929304
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If I push someone, what fundamental force do I create?

According to Wikipedia, all forces can be decomposed to four fundamental forces: gravity, electromagnetism, strong interaction and weak interaction. When I push someone, this generates a force. Which of the 4 forces is this composed of?
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