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

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2
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2answers
122 views

What is the mechanism of particle anti-particle annihilation

My question is loaded with assumptions so to minimize them, I would like to ask it with respect to an electron and anti-electron annihilating. When I think of annihilation, I think of electron and ...
0
votes
1answer
55 views

Difference between anti-matter and matter black holes [duplicate]

Laymen question: Is there any way to determine by observation whether or not a black hole has resulted from the core collapse supernova of a star originally composed of anti-matter versus a star ...
3
votes
1answer
88 views

Could the universe's antimatter be hiding in black holes?

As far as we know almost all the mass in the universe is matter, not antimatter. There are three scenarios: The universe started off with more matter than antimatter and the small amount of ...
0
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1answer
37 views

What is antimatter and its role in the universe?

As we know everything has its opposite. Like matter its opposite is antimatter. So why the universe is not made by antimatter instead of matter. And what is the main role of antimatter in the ...
0
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0answers
29 views

Can antimatter becomes black hole? [duplicate]

I know it seems unlikely to accumulate sufficient amount of antimatter to let it collapse under its own weight to become a black hole(maybe the gravity works differently I don't know) since they will ...
0
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1answer
50 views

Is a matter anti-matter collision comparable to Gamma Ray Burst (GRB) energy output?

Is a matter anti-matter collision (please assume two cosmological objects, neutron star sized say), the largest energy release method known? Would it be comparable in order of magnitude to gamma ray ...
-1
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1answer
29 views

can we see or accumulate antiparticles

I would like to know if we can see antiparticles with our bare eyes instead of a technological detector. I realize we cant see individual atoms or particles but enough photons grouped together, for ...
1
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2answers
31 views

Neutron antineutron reaction documentation

Has neutron-antinutron reaction been observed? If so, can you please provide a documentation (experimental observation) for neutron antineutron reaction?
3
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2answers
82 views

Sign of momentum in fermion propagator

Thinking of a process like Compton scattering, where we have an electron as a propagator, I would typically write down the propagator as $$i \frac{\not q+m}{q^2-m^2}.$$ If I were to replace the ...
-1
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1answer
30 views

Similarity between particles and antiparticles

I was doing a past exam paper and there was this question: State the similarities between a particle and its antiparticle. The answer given was: Same mass and rest energy. I am not too bothered ...
2
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1answer
350 views

Is the virtual photon a particle?

I just saw an exam question: Write down the antiparticle for the virtual photon. The answer was "virtual photon". Is the question even a meaningful one? If so please explain why?
2
votes
3answers
65 views

Does (mass $\rightarrow$ pure energy) conversion need both matter $and$ antimatter?

A question in my revision guide: "Explain why the mass of a tree cannot be converted directly into energy." The answer explains that the tree contains particles but not their corresponding ...
24
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5answers
3k views

Will 1 gram of matter moving at relativistic speeds completely annihilate a larger quantity of stationary antimatter?

This is a question about the relativistic mass concept which I am having trouble understanding, mainly because of the scenario below. Simple scenario: Suppose 1 gram of matter is accelerated to 99% ...
2
votes
3answers
88 views

Decay of matter

I was watching Stephen Hawking's documentary and in there he explained how he realized why black holes eventually disintegrate: There are ripples in space, an antiparticle and a particle get ...
1
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2answers
73 views

Could the missing antimatter lie outside the observable universe?

While I was reading a similar question asking if other galaxy could be made of antimatter, to which the answer was: if they were, we should detect the radiation from matter interacting with antimatter ...
0
votes
2answers
56 views

Is every aspect (fundamental forces, periodic table) of an antimatter universe exactly the same, except the fact that it's all antimatter?

Are all the constants (Boltzmann's, gravitational, $c$) the same? Would elements react differently? Would it look the same?
3
votes
2answers
79 views

Questions about the strange character of antimatter

Its been a few days and i have just been introduced to the concept of antimatter. Every Speck of matter in the world has its anti form basically that we have antimatter whenever we have matter. But I ...
2
votes
1answer
63 views

Charge conservation in the complex Klein-Gordon Field

This is an extremely naive question (based on a knowledge of chapter 2 of peskin and schroeder) so apologies for any things that seem obvious. The complex scalar field, when quantized, has a conserved ...
1
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1answer
41 views

Has the human race ever done Antimatter experiments in outer space (e.g. on the ISS)? [closed]

If not, what is the roadmap for the first Antimatter experiment in outer space?
3
votes
1answer
297 views

Antineutron repelled by gravity?

I was reading an old post, Can gravity be shielded, like electromagnetism?. One of the responses had this comment. There are some experiments trying to measure whether antiprotons ( antimatter) ...
0
votes
2answers
47 views

On Elementary Particles

The mass of positron and electron are same. Also their charges are equal in magnitude but opposite in nature. Then why positron is not called one of the elementary particles? Is this only because it ...
2
votes
1answer
77 views

Pair-annihilation why does it occour? [duplicate]

Why does pair annihilation occur with particles and only their matching anti-particle? E.g., electrons and positrons, but not protons and positrons? What is the difference?
1
vote
1answer
193 views

How can anti-matter annihilate matter?

I heard that anti-particles annihilate when in contact with normal-particles but the odd thing is that in fusion reaction normal-particles often "fuse" into each other but the weak force often ...
1
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0answers
37 views

Do quasiparticles have antiparticles?

Bosons (except for W) are their own antiparticles, since they have no electric charge. Charged fermions have antiparticles differing from the particles. Now my question is: has a charged ...
2
votes
1answer
36 views

Proton creation [closed]

My question is simple: if proton antiproton pairs can be created in the laboratory (given certain energies) then they should also be able to be created in the universe at any time, not only during ...
2
votes
0answers
71 views

Antimatter universe and Noether's theorem

I am studying Feynman's "symmetry in physical laws", where he talks about conservation laws for corresponding symmetries. (I know this is Noether's theorem, I am studying this from David Tong's ...
1
vote
3answers
130 views

Quark anti-quark pair creation. Do we need a gluon?

What is the difference between these diagrams? Is the presence of the gluon taken for granted in the second one? and EDIT: I just zoomed into the picture, it is not a single quark state. ...
0
votes
0answers
26 views

Antimatter production using normal matter rest mass

Antimatter could be produced by inverse annihilation from kinetic energy of particles. This is, however, not useful to produce any energy. Is there any pathway (like set of reactions between sub ...
2
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1answer
84 views

Charge operator for Dirac spinor

In QED, the gauge transformation which acts upon a fermionic field $\psi$ is $$\psi'(x)= e^{i \alpha(x) Q}\psi(x)$$ where $Q$ is the charge operator. Most of the time it's just written as $$\psi'(x)= ...
0
votes
1answer
107 views

Theory of black holes producing matter or antimatter [closed]

One of my friends gave a theory about the formation of black holes. He said that: Black holes are formed when an extremely massive star collapses in its own gravity to produce a particle of ...
15
votes
4answers
2k views

Could we make things out of newly discovered particles?

Right now, all of the "stuff" that has been created in the world is made of protons, electrons, and neutrons. I'm aware that particles other than these have much shorter lifetimes. But I've also heard ...
2
votes
4answers
257 views

What is antimatter?

Can you give a visual example of what is antimatter? With the re-opening of Large Haldron Collider scheduled in Mar 2015, I'm reading that they smash two particles together to try to re-create ...
0
votes
2answers
50 views

How are positrons produced? [closed]

What are the methods of positron production? Please don't use mathematical formulas in the explanation.
1
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0answers
32 views

Antimatter traveling back in time and gravity [duplicate]

I've been reading on the construct of considering antimatter as matter traveling backward in time, which seems like an useful tool. There seems to be some discussion around this concept, if ...
3
votes
1answer
105 views

Light in a box with positron walls instead of electrons

I understand that with a hollow cube with the inner walls covered in mirrors given a light source briefly, the light would eventually be absorbed. This is due to electron excitation I believe. So ...
3
votes
4answers
88 views

Can antiprotons make stable bounds with halogens?

Halogens are known for being highly electronegative. That means their electron dipole moment are high enough that they want to share other atoms electrons. I'm wondering If two Halogen atoms could ...
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2answers
247 views

Feynman-Stueckelberg interpretation

My question is related to the interpretation of antiparticles. According to the so called Feynman-Stueckelberg interpretation a negative energy solution of the Dirac equation corresponds to a positron ...
1
vote
2answers
71 views

Can antimatter-matter collisions generate heat?

We have a project at school to develop an idea about how we can generate electricity. My question is: do collisions between matter and antimatter particles generate heat, so that one could harvest it ...
10
votes
3answers
400 views

Are there really left-chiral particles?

A chiral eigenstate is always a linear combination of a particle and an antiparticle state and a particle or antiparticle state is always a linear combination of chiral eigenstates. Now, how can we ...
5
votes
3answers
82 views

What did Skobeltsyn publish about the possible existence of the positron?

I've read across several sources that before C. Anderson discovered the positron in 1933 there were evidence of its existence pointed out previously by C.-Y. Chao and D. Skobeltsyn. After some rearch ...
0
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1answer
44 views

What happens to K.E. in matter antimatter annihilation?

If I have two matter and antimatter particles, say an electron and a positron, each moving towards each other with a certain speed, they annihilate after the collision. Does the energy of the photons ...
6
votes
2answers
202 views

How can we differentiate between matter and antimatter? [duplicate]

For instance if there was a galaxy, assume it to be made up of antimatter (isolated from other "normal" galaxies), how would we, or rather, would we be able to distinguish if it was made up of matter ...
0
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1answer
57 views

Why are we still living if matter and anti-matter annihilate each other? [duplicate]

Everyone knows matter and anti-matter annihilate each other . But still do we are alive . How? Is the statement wrong?? I am a layman and a novice to QM but will appreciate a math-free intuitive ...
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vote
2answers
173 views

Will Positron Cause flow of electricity?

Recently someone told me about antimatter. Antimatter is something that is completely opposite to matter. What I would like to know is let's say this universe was made of Anti-Matter. So since the ...
0
votes
1answer
46 views

If matter and antimatter were produced equally during the big bang, where is the rest of the antimatter? [duplicate]

As far as my understanding goes, during the 'Big Bang' equal amounts of matter and antimatter (matter's oppositely charged twin) were produced, and the physical matter that remains within this ...
1
vote
1answer
87 views

Why is the mass of a particle different from its antiparticle?

Like, for example, the neutrinos and the $B_0$ and the $\overline{B}^0$ mesons?
15
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1answer
1k views

How would one detect antihydrogen in the universe?

Since the spectra of hydrogen and antihydrogen are the same, how do astronomers know which one they're detecting? Is, perhaps, the Lamb shift in antihydrogen different?
0
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1answer
40 views

How is anti-hydrogen captured?

Knowing that the overall charge is zero, what mechanisms/technologies are used to capture anti-hydrogen? Where is it stored until annihilation? I am aware of magnetic traps being used to edge the ...
6
votes
2answers
618 views

How is antimatter made?

How is antimatter made in laboratory? Can anyone explain, at the particle level, specifically how anti-protons and anti-electrons are made?