Tagged Questions
1
vote
2answers
110 views
matter anti-matter world
let us suppose the gedanken experiment
a man isolated into a room he ask if he is made of matter oder of antimatter
could he set some experiments to see if he is made of matter or if he is made of ...
3
votes
2answers
314 views
Creation of particle anti-particle pairs
I was reading some QFT notes and there is one point that I don't understand, they are justifying why we need QFT saying that the number of particles is not preserved once we consider special ...
6
votes
3answers
175 views
supressing certain decay paths and enhancing others with interference
In a scattering reaction, there are many possible final states for the products, each with different production rates.
Question: Is there a way in which we could in general supress certain rates ...
2
votes
0answers
146 views
What makes *electric* charge special (wrt. CPT theorem)?
I'm wondering why the 'C' in CPT - charge conjugation - refers specifically to electric charge. Of course you could say that C is just defined as $e^+ \leftrightarrow e^-$... but there has to be ...
5
votes
2answers
228 views
How does Annihilation work?
I'm wondering why matter and antimatter actually annihilates if they come into contact. What exactly happens? Is that a known process? Is it just because of their different charges? Then what about ...
14
votes
4answers
610 views
What is anti-matter?
Matter-- I guess I know what it is ;) somehow, at least intuitively. So, I can feel it in terms of the weight when picking something up. It may be explained by gravity which is itself is defined by ...
2
votes
2answers
105 views
Can the charge of particles spontaneously flip from positive to negative or vice versa?
I'm thinking of matter antimatter annihilation, are there reactions where normal matter converts to antimatter?
7
votes
3answers
449 views
What was missing in Dirac's argument to come up with the modern interpretation of the positron?
When Dirac found his equation for the electron $(-i\gamma^\mu\partial_\mu+m)\psi=0$ he famously discovered that it had negative energy solutions. In order to solve the problem of the stability of the ...
4
votes
2answers
335 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?
9
votes
3answers
636 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?
7
votes
5answers
854 views
Why Negative Energy States are Bad
The argument is often given that the early attempts of constructing a relativistic theory of quantum mechanics must not have gotten everything right because they led to the necessity of negative ...
12
votes
3answers
702 views
No hair theorem for black holes and the baryon number
The no hair theorem says that a black hole can be characterized by a small number of parameters that are visible from distance - mass, angular momentum and electric charge.
For me it is puzzling why ...
