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Questions tagged [antimatter]

Analogous to matter, but with charge of the particles opposite to their ordinary matter counterparts.

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Does ALL mass really have a gravitational pull? If so, wouldn't mean that an “anti-mass” exists? [on hold]

In my 8th grade science class, I learned that all mass creates a gravitational pull. However, I realized that made no sense. If all mass creates a gravitational pull, then the universe would collapse ...
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Could a large amount of antimatter accelerate the universe instead of dark energy? [on hold]

It is not known whether antimatter is repulsed by or attracted to matter. For the purpose of this question, I assume that antimatter is repulsive to regular matter (otherwise this question makes no ...
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When is emitting a particle (e.g. neutrino) the same as absorbing an antiparticle?

I've read that Pauli first proposed the neutrino to explain energy and momentum conservation in this equation: $$n \to p^+ + e^- + \overline\nu_e$$ But it is also written differently here: $$\nu_e ...
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Are neutrinos or antineutrinos more prevalent?

As I understand it, neutrinos were first proposed to explain energy and momentum conservation in beta decay, as a hypothetical particle emitted together with the electron and proton. Thus Pauli gave ...
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Do positrons have electric dipole moments?

Is there experimental evidence checking to see if the positron has an electric dipole moment at rest? Or has an experiment measured it’s magnetic dipole moment at rest?
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How can one of the particles on a pair of virtual particles created by vacuum fluctuations have negative energy? How does it lower black hole mass?

Assuming Stephen Hawking’s 1975 “Particle Creation by Black Holes” : “One might picture this negative energy flux in the following way. Just outside the event horizon there will be virtual pairs of ...
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Matter antimatter annihilation problems

It can be sai!d that antimatter and matter are opposite excitations in an all permeable quantum field. excitations can be said as waves. so, matter and antimatter can be interpreted as waves or ...
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Did Supernova 2007bi really explode due to antimatter creation?

I was watching a video (https://www.youtube.com/watch?v=IZ59_akUUBs) about massive explosions and came across 2007bi. The video stated that this SN happened due to gamma-ray driven antimatter ...
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Would a penning trap be disrupted if passed through the Earth's magnetic field?

Working on my essay for school and currently talking about using antimatter as a propulsion technique for rockets. At the moment I am talking about potential hazards and was wondering if passing ...
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Why particles annihilate only with their antiparticles? [duplicate]

Why particles annihilate only with their antiparticles? Why can't a particle annihilate with any other antiparticle? Is it because both the particle and the antiparticle have to be excitations of the ...
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How can matter and anti-matter coexist in a meson?

Whilst learning about the nature of subatomic particles, I came along a pion zero meson. What really stumbled me was that the quark configuration of the particles was up and anti-up or down and anti-...
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Quantization of the massless neutrino field

If a massless neutrino or anti-neutrino is considered (in the whole post I consider neutrinos res. anti-neutrinos as mass-less), it is described by the Weyl-equation: $$\overline{\sigma}^{\mu}\...
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What is the minimum distance between an electron and a positron so that they do not annihilate? [duplicate]

What is the minimum distance between an electron and a positron so that they do not annihilate? I want to assume that the location of an electron can be determined with an accuracy of 0.004 Angstroms,...
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Antiproton production threshold

Why is the antiproton threshold on cern 6* m_p and on uspas it is 7 * m_p?
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Is it possible to induce left-handed electromagnetic wave from positrons? [duplicate]

All observations of electromagnetic induction we have, are from the flow of electrons. The accelerated electrons in the antenna rod induce an EM wave with a right handed system of the electric field ...
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1answer
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When did we first observe annihilation of antimatter?

Firstly, when did we actually observe this process? (I assume we have but I may be wrong about that as well.) Secondly, did we expect it to happen, or not?
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QFT Matter Fields and Anti-Matter Fields

In QFT is it the case that the electron matter field and anti-electron matter field (using the electron as a specific example) are truly distinct physical fields versus different excitation modes of ...
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Antimatter particle in bananas [duplicate]

I recently came to know that banana produces antimatter. How does this happen and why doesn't the antimatter annihilate as our Earth has matter. I looked for a relevant answer but could not find it.
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Why is there equal protons and electrons in the universe?

Matter and anti-matter are asymmetric. Why are protons and electrons symmetric? Would we still have galaxies and stars if there were a strong overall charge?
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Can an atomic nucleus contain both particles and antiparticles? [duplicate]

Is it theoretically possible to make a "deuterium" atom containing a proton and an antineutron in its nucleus? Would the strong nuclear force cause attraction between a proton and an antineutron? ...
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Why do we have constraints on the baryon asymmetry of the universe and not the lepton asymmetry?

What is it about baryons that means that CMB observations can determine their asymmetry without also including a charged leptonic component?
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How does the negative energy solution to the Dirac equation predict the antielectron?

Please, can someone explain how the negative energy solution can be used to predict the existence of the antielectron?
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42 views

What direction would this photon go?

Say a matter-antimatter pair of particles annihilates linearly (from a reference frame where the sum of the momenta is zero) to create a photon. Wouldn't momentum conservation prevent the photon from ...
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Don't matter-antimatter annihilate each other completely releasing energy as photon?

Matter and antimatter should annihilate each other completely releasing energy in the form of photon, however it is discovered that smashing electron and positron together can also spew out higgs ...
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Is anti-sterile neutrino possible?

Due to the surplus of electron neutrino led people to suggest the possibility of 4th neutrino flavour, and it is thought to only interact with gravity and nothing else not even weak interaction. So is ...
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What would happen if antiprotons were studied under the conditions of particle deceleration that they are collected under? [closed]

I have not had a very clear understanding of how antiprotons are collected, but I do know that when they collide with matter they explode in a puff of energy. Or so I have been told. If the current ...
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Is it possible to transform energy stored in anti-matter into coherent radiation?

In Travellers, a sci-fi show on netflix, they have 10g of some form of anti-matter floating around. A quick $mc^2$ calculation gives a quantity of $E = 10^{15} J$. For reference, Little Boy released $...
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What happens to the quantum information of a particle and an antiparticle when they annihilate?

I understand that the quantum no-deleting theorem dictates that it's impossible to delete quantum information, so what happens to the quantum information of a particle and an antiparticle when they ...
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Do hydrogen and anti-helium annihilate one another? [duplicate]

So far I know that electron and positron annihilate each other completely and release energy, how about matter hydrogen atom with 1 proton and 1 electron come into contact with antimatter anti-helium ...
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Corresponding particle-antiparticle solutions for Klein-Gordon equation

For free particle solutions in a box, the following 4 solutions are possible(Not all 4 are independent though) as $$\psi_+=A_+ \exp{\frac{i}{\hbar}(px-Et)}\\\psi_+^*=A_+^* \exp{\frac{-i}{\hbar}(px-Et)}...
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Is the spin-statistics theorem true for antifermions?

The spin-statistics theorem says that having a system of identical fermions, the total wavefunction is antisymmetric with respect to exchange of any two fermions. My question is, does this hold for ...
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Is it possible to add energy to an antiparticle?

The title says most of it but the more drawn out version is. If you were to add energy to a single particle or antiparticle in a pair, what would be the effects, if it is possible to do.
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One-loop diagram in scalar field theory

We see that this loop contain particle with momentum $p+k$ and anti-particle with momentum $k$. But I fall into contradiction because the Feynman integral corresponds to this loop (see the book http:...
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Do antiquarks cancel quarks out?

I heard that antiquarks are just like antimatter. Does that mean that they cancel quarks out? If so, does that mean that there are more quarks than antiquarks?
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1answer
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Is it possible for antimatter to be created from a nucleus of regular matter decaying?

I have a limited understanding of nuclear reactions. I know of the decay in which a positron is emitted from a nucleus and a proton is converted back into a neutron. There is also another type of ...
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Do antiparticles behave opposite of the particle?

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 ...
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In which direction does the positron's magnetic moment point?

Suppose I have an electron, with its spin pointing in some direction, so that the magnetic moment caused by the spin is pointing upwards. Then, I hold a positron next to the electron so that their ...
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Where is all the Antimatter?

This is obviously a duplicate of If matter and antimatter... However, it's now four to five years after a swarm of videos were made on this subject. At the time, there was a consensus that the LHC ...
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How is antimatter stored in the large hadron collider?

we studied that antimatter can be stored in the large hadron collider. what i dont get is that the collider is used to collide particles and antiparticles together right? so how is antimatter stored ...
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Is there a gravitational force among antiparticles? [duplicate]

Is there a gravitational force between antiparticles? For example, between two antiprotons. Do the antiprotons repluse each other?
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Testing if antimatter is backwards-travelling matter?

I've read about how antimatter can be modeled as matter traveling backwards in time before but always viewed this as a sort of mathematical curiosity. With this question I'm not so much asking if ...
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Is there such a thing as an anti-boson?

Can there be an anti-boson that when interacting with normal bosons, creates matter, like when anti-matter creates energy when interacting with matter? I know that anti-particles can be considered ...
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Are positrons affected by electromagnetic fields?

I know positrons are anti-electrons. But electromagnetic fields aren't matter, and are pretty good for containing high energy particles, especially in something like a stellerator. So, would it be ...
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Why don't we use positrons from beta plus radiation as a source of anti-electrons for energy?

Why can't we use the positrons (let off by beta plus radiation) as a source of anti-matter, such that we can collide it with an electron for 100% efficient mass to energy conversion?
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Does the positron prove that Dirac's electron sea must exist? [duplicate]

Does the fact that the positron exists in cosmic rays prove the existence of Dirac' s 'sea' of spin-paired electrons in space.
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So is it not $CP$ instead of $C$ that is responsible for changing a particle to its antiparticle?

The charge conjugation operator $C$ reverses the charge of a state. But it may or may not convert a particle to its antiparticle. For example, consider a neutrino which is charge-neutral and left-...
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Energy difference between enantiomers (matter/antimatter)

I am aware of the fact that enantiomers have different energies, for example L-amino acids have different energy than D-amino acids. The difference is not significant and is most usually about $10^{-...
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Question about the spin of the antiparticle of $Δ^-$

Ι came across a statement in a physics book that the spin of the antiparticle of baryon $Δ^-$ is 1/2. I know that the spin for regular $Δ^-$ is 3/2, and - as far as I know - the spin of particles and ...
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How does something start interacting with the Higgs field?

When two high energy photons are smashed together they create a matter-antimatter pair. The photons do not interact with the higgs field, but when they convert into matter-antimatter pair, they start ...
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What is the exact relation between anti-matter and relativity?

I have seen in relativistic QM that, when trying to create the Dirac Equation, it only make sense to be acting on -- at minimum -- a 4-component vector (actually a bi-spinor). I guess this is because ...