# Questions tagged [cpt-symmetry]

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### Where can I get an introduction to the CPT symmetry?

Are there any good books that provide a good background to the CPT symmetry? I'd appreciate some references. Books or Public access papers will also suffice.
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### Why isn't EM radiation from an accelerated charge time reversible?

Let a charge $q$ enter a constant magnetic field $B$ at 90 degrees, hence radiating EM energy-momentum and spiraling inwards to some point as it slows down. Time reversing this, including the current ...
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### Why aren't black holes antimatter fountains?

As I understand it, nothing can escape a black hole because the only worldlines leading 'out' from the event horizon point backwards in time. As I understand it, antimatter is time-reversed ordinary ...
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### Is time reversal of emission and absorption of radiation by a point charge a postulate or consequence of CED?

Suppose a point charge is accelerated by an external field, hence radiating irreversible energy-momentum given by the Lienard-Wiechert fields. We can time reverse this so that the radiation instead ...
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### Does it mean time reverses if all particles were antiparticles and vice versa?

First of all, I'm not major in physics and the question might seems stupid, as I'm layman studying for my self-interest and I really don't know much about it. I only think it might open some ...
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### How is a half-odd integer spin field defined in the Wightman axioms?

Can anyone give me a proper definition of 'half-odd integer spin fields' in terms of the Wightman axioms? I'm trying to prove the anti-unitarity of the PCT operator in 'PCT, Spin and Statistics, and ...
131 views

### What operator gives the mass of a particle?

Talking about why a particle and its antiparticle have the same mass, my professor said the Hamiltonian commutes with TCP, so mass is conserved. I don't understand that.
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### Clarifying PT symmetry

I understand that if a Hamiltonian remains invariant under the following transformations then it is PT invariant, \begin{eqnarray} \mathrm{Parity \; reversal:} \; \; \hat{p} \to -\hat{p} \; \; \...
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### Does reversing time give parity reversed antimatter or just antimatter?

Feynman's idea states that matter going backwards in time seems like antimatter. But, since nature is $CPT$ symmetric, reversing time ($T$) is equivalent to $CP$ operation. So, reversing time gives ...
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### What is the definition of the charge conjugation?

I seem to have troubles finding definitions of the charge conjugation operator that are independant of the theory considered. Weinberg defined it as the operator mapping particle types to ...
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### Clarification on CPT symmetry

CPT symmetry, as I understand it, holds that if all charge, parity, and time were reversed (a mirror-image antimatter time-reversed universe), that universe would behave identically to our current ...
310 views

### CPT symmetry as it applies to matter/antimatter

I've heard/read a couple different definitions for antimatter: it is charge-reversed matter (typical definition, for the lay person at least), or it's time-reversed matter (as described in QED). ...
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### chiral symmetry condensate and 2SC, CFL breaking C, P and T symmetry?

Because we know that chiral symmetry condensate causes the chiral symmetry breaking, and it produces Goldstone modes of pseudo-scalars, so I believe that chiral symmetry breaking also breaks the T ...
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### Is N=6 SUSY gravitino multiplet self-CPT?

I would like to understand why the $N=6$ gravitino (massless) multiplet $$\left(-\frac32,(-1)^{6},(-\frac12)^{15}, 0^{20}, (+\frac12)^{15}, +1^6, +\frac32 \right)$$ is not CPT self-conjuguate?. It ...
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### How to understand $T^2=(-1)^{N_f}$ in terms of operator matrices on Hilbert space

For a time reversal symmetry operator $\hat{T}$, we have $$\hat{T}^2=(-1)^{N_f}$$ for a fermionic (electronic) system. How do we understand $\hat{T}^2=(-1)^{N_f}$ in terms of operator matrices on the ...
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### Is it possible to have renormalisable C-, P-, or T-violating terms in QED?

In a recent paper (1710.01791), Witten claims that there are no renormalisable $\mathrm C,\mathrm P,\mathrm T$-violating terms that can be included in the QED Lagrangian: What does this picture say ...
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### Instanton effects on condensates: (pseudo)scalars, (pseudo)vectors, tensor

I have heard that the instanton effect in quark matter causes the di-quark condensate to be Lorentz scalar. As opposed to the Lorentz scalar, there are possibilities that the condensates are Lorentz ...
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### CPT-symmetric initial state

Consider a hypothetical state of the universe such that it coincides with its CPT “mirror-image”. I.e., let us reflect positions of all objects by some plane (parity inversion), reverse all momenta (...
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### How to classify the symmetry $C$, $P$ and $T$?

What is the difference between internal symmetries and space-time symmetries? Where would the $C$, $P$ and $T$ symmetries be classified?
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### Discovery of anti-deuteron and the implication of CPT violation

From this review by Antonino Zichichi 2009 and this review from T. D. Lee in 2007, it is said that Dirac is very upset when hearing the discovery of anti-deuteron (anti-matter of deuteron, the nucleus ...
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### What feature of QFT requires the C in the CPT theorem?

Classical tensor field theories have a PT theorem, so what changes in a QFT to require charge conjugation to be a part of the theorem? Charge conjugation seems a bit unrelated to space-time, but is an ...
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### Why did they need such short lived isotopes to find pear shaped nuclei?

Recently, pear-shaped nuclei have been discovered. This discovery has interesting implications, as noted in this question: Do pear-shaped nuclei really have anything to do with time travel? At the ...
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### C-parity violation evidence

I know about the CP-violation experiments from the 60's and the P-violation from the 50's. But, is there a similar experiment which displays (perhaps historically in the same way as the experiements ...
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### Consequences of Entropy/Information Reversal in a System?

Can pairs of different physical systems be symmetrical under a process which would turn one of these physical system's entropic and informational contents into another system's respective ...
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### What is the P-parity, T-parity and C-parity of graviton? Are these conserved in general curved space-time?

I'm curious about the P,T,C-parity of graviton? 1)Are these graviton's parities even or odd? 2)Is the C,P,T-parity alternatively conserved in Einstein gravity? And does the CPT theorem still hold ...