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

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14
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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% ...
1
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0answers
75 views

Is it possible that Einsteins famous equasions $E=mc^2$ is slightly incomplete?

I don't know much about physics, but I plan to be a physicist some day. I noticed Feynman diagrams show antiparticles moving backwards in time. Wouldn't that mean that they are moving faster than ...
2
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2answers
58 views

Decay of matter

I was watching Stephen Hawking's documentary and in there he explained how he realized why black holes eventually disintegrate: ...
1
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2answers
58 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
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2answers
33 views
3
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2answers
71 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 ...
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1answer
38 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?
2
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1answer
43 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 ...
3
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1answer
285 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
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2answers
44 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 ...
8
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3answers
2k views

Does a particle annihilate only with its antiparticle? If yes, why?

Or to put the question another way - what is the result of a proton-positron collision, or an up quark-charm antiquark collision, etc.? As far as I know, annihilation happens only between particles of ...
2
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1answer
61 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?
21
votes
3answers
5k views

Do anti-photons exist?

I know what anti-matter is and how when it collides with matter both are annihilated. However, what about anti-photons? Are there such things as anti-photons? I initially thought the idea ...
1
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1answer
161 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
32 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
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1answer
32 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
1answer
74 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)= ...
2
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0answers
63 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 ...
7
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2answers
653 views

the causality and the anti-particles

How can I quantitatively and qualitatively understand the fact that there is a relevence between the existence of anti-particles and the causality?
7
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1answer
2k views

Electric charge in string theory

The mass of an elementary particle in string theory is related with the way the string vibrates. The more frantically a string vibrates the more energy it posses and hence the more massive it is. My ...
3
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2answers
154 views

On non-local physics in cosmology by prof. B.V. Alekseev

Recently I've encountered work by prof. B.V. Alekseev, in which he claims that some physical problems can be easily solved if we consider non-local interactions in kinetic theory (interactions of ...
1
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3answers
108 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
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0answers
24 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 ...
37
votes
7answers
24k views

Is anti-matter matter going backwards in time?

Or: can it be proved that anti-matter definitely is nót matter going backwards in time? From wikipedia: There is considerable speculation as to why the observable universe is apparently almost ...
4
votes
2answers
430 views

Can different species of particles annihilate with other species

Obviously electrons annihilate with positrons, but can a muon annihilate with an positron, or can an anti-taon cancel with a muon? similarly for quarks of different species, e.g. u and anti-strange. ...
2
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4answers
232 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
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1answer
91 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
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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 ...
0
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2answers
47 views

How are positrons produced? [closed]

What are the methods of positron production? Please don't use mathematical formulas in the explanation.
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2answers
199 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 ...
2
votes
1answer
86 views

Electron/positron annihilation lines in astrophysics

I have a reasonable understanding of electron/positron annihilation, in that it is a collision between a pair of particles, one matter and one antimatter, that generally produces gamma radiation. ...
1
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0answers
31 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
103 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
83 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 ...
1
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2answers
67 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 ...
11
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3answers
369 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 ...
4
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1answer
79 views

materials that repel positrons?

In this article is discussed at some length positron formation in metallic surfaces. Positrons have work functions that describe how much energy they have to receive in order to be extracted from the ...
24
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4answers
1k views

Why do or don't neutrinos have antiparticles?

This was inspired by this question. According to Wikipedia, a Majorana neutrino must be its own antiparticle, while a Dirac neutrino cannot be its own antiparticle. Why is this true?
5
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3answers
78 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
votes
1answer
38 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
191 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
52 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 ...
1
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2answers
118 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
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1answer
45 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
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1answer
110 views

How the neutron magnetic moment was measured?

How was the neutron magnetic moment measured? Was the antineutron magnetic moment measured too?
1
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1answer
83 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?
2
votes
2answers
163 views

What's the symbol for the antiparticle of the delta plus baryon?

It can't be $\Delta^-$ since that is another particle also made up of quarks (not antiquarks). I can think of four possibilities: $\overline\Delta^+$ $\overline{\Delta^+}$ $\overline\Delta^-$ ...
7
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1answer
818 views

Anti-Matter for Neutrons

The anti-particle corresponding to a proton or an electron is a particle with an equal mass, but an opposite charge. So what is the anti-particle corresponding to a neutron (which does not possess a ...