0
$\begingroup$

If antiparticles have opposite charge to that of the particle, will their interaction be completely opposite?

For example, an electron and a proton are attracted to each other, will a positron and a proton repel each other? Similarly if a proton is repelled by another proton, will an antiproton be attracted to another proton?

$\endgroup$
  • 2
    $\begingroup$ Sure , that is what antiparticle means, opposite charge too. $\endgroup$ – anna v Dec 5 '18 at 20:35
3
$\begingroup$

What you are saying here is indeed correct. In fact, an electron positron bound state it can be detected in labs too. However, I don't know what you are thinking when you say 'will their interaction be completely opposite?' because all matter interact attractively with gravity, therefore electron as well as positron will fall towards earth the same way and not the opposite way. So you shouldn't get the impression that they behave exactly oppositely.

$\endgroup$
  • $\begingroup$ thanks a lot, just so I completely understand, when they are interacting with gravity all particles and antiparticles will be attracted to it but for electrostatic forces particle and antiparticles will behave completely opposite, an electron will actually be repelled by a antiproton. $\endgroup$ – pre.s Dec 5 '18 at 20:44
  • 1
    $\begingroup$ That's about right. In general, the 'forces' of nature arises by some gauge symmetries, which are some internal symmetries (I am sorry, I am not familiar with your knowledge of quantum field theory, but let me assume that you have at least heard about it). Any particle is either charged or uncharged under this symmetry. Its anti-particle is charged oppositely under the same symmetry (or uncharged). For example, quarks, that make up the protons are charged under strong nuclear force. This charge is called 'color' and takes values 'red', 'blue' and 'green'.... $\endgroup$ – nGlacTOwnS Dec 5 '18 at 20:50
  • 1
    $\begingroup$ .... So the anti-particle of a red quark is anti-red anti-quark, and behaves differently (oppositely) under strong interactions. $\endgroup$ – nGlacTOwnS Dec 5 '18 at 20:52
2
$\begingroup$

For interactions depending on charge-like quantum numbers, this is indeed true. There are even exotic "atoms" like positronium, which consists of an electron and an anti-electron (positron) instead of, say, an electron and a proton (even though positronium has a very short lifetime).

However, there are particles that have no non-zero charge-like quantum numbers, like photons. Those are their own anti-particles. Therefore, particle and anti-particle behave the same way. This is also true for interactions in which particle and anti-particle are different, but charge-like quantum numbers do not matter. Matter and antimatter are, for example, equally affected by gravity.

Edit: I just saw that Pran was a little bit faster.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.