Questions tagged [cpt-violation]
17 questions
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CPT violation and how could quark masses differ from anti-quark masses?
A recent experimental paper measures a difference between the top quark and anti-top quark masses:
Fermilab-Pub-11-062-E, CDF Collaboration, Measurement of the mass difference between $t$ and $\bar{t}$ quarks
We present a direct measurement of the
…
Carl Brannen
- 13,059
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1 answer
Does kaon decay etc prove "CP violation" or just "CP or CPT violation"
Shlomo Sternberg (math professor at Harvard) wrote a book called "Group theory and physics". On p156 (link) there's a strange offhand comment:
"Experiments done in 1964 by Fitch and Cronin seem to indicate that CP is not conserved. I do not fully…
Steve Byrnes
- 17,082
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CPT and event horizon
Is the example of neutrino entering the event horizon of BH quoted from this article a valid possible example of CPT violation due to the presence of event horizon in BH ?
Please, note that there is a very similar previous Question here .
I don't…
user31807
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1 answer
$CPT$ symmetry in curved spacetimes
$CPT$ symmetry is a well-known symmetry that holds for all observed systems, and experimental efforts have been unable to find a breakdown of $CPT$. The proof relies on Lorentz symmetry, so in principle it applies to flat spacetimes. Okay, so far so…
TopoLynch
- 721
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Is antimatter a result of $C$ inversion, or $CPT$ inversion?
This is something I'm struggling to get a clear answer on.... So on the one hand we say $C$ is the charge inversion operator and describes a particle turning into its antiparticle.
However if this is the case, then antimatter study is not testing…
lukygee
- 23
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3 answers
How is this not a violation of CPT symmetry?
Imagine an electron and a positron, initially held stationary some distance apart at time $t=0$. There is an attractive force between them, so they will approach one another.
I am told that all the fundamental laws of physics are CPT-symmetric, so…
spraff
- 5,256
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Why is it important that the combination of charge, parity & time reversal symmetry not violated?
If looking for more particles or decays that violate CP symmetry can explain why there is so few antimatter in the known universe, I guess finding things that violate CPT symmetry might helps clear up some mystery about the universe. However all…
user6760
- 13,214
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Could an antimatter-dominated end of universe fix CPT?
My question is about the apparent CPT violation of the observed universe, due to the imbalance of matter and antimatter, but first I have a motivating observation:
General relativity respects time reversal (T) symmetry. However, formation of black…
Yly
- 3,729
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Can the time direction of wave function collapse be reversed?
The laws of physics are invariant under CPT transformations reversing time, inverting space and flipping charges. Almost so. The collapse of the wave function is the odd man out. Can the time direction of the collapse of the wave function be…
fpn
- 31
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Electric dipole moment(EDM) underlying physics
I read in a physics today paper,
The electron can have nonvanishing EDM only if nature violates symmetry under time reversal (T) and under the combined operations of charge conjugation (C), which replaces particle by antiparticle (as we all know),…
L.K.
- 190
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Self-antiparticles and broken symmetries
certain particles (i.e: certain bosons like the photon) do not have an anti-particle, or rather, they are they own anti-particles.
Let's assume that such symmetry is only approximate and these particles are actually different than their…
lurscher
- 14,933
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Are Hamiltonians CPT invariant?
I'm confused by the CPT theorem. It states (more or less) that a Lorentz invariant quantum field theory needs to be CPT invariant. But what does it actually mean for a QFT to be CPT invariant? It surely means that it's Lagrangian is. What about the…
user
- 13
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Does symmetry violation make a approximate conservation law?
I know that Noether's theorem relates conservation laws with symmetries, and I read that to find CPT violation, Lorentz invariance symmetry needs to be broken.
This implies that if a symmetry is broken, it's associated conservation law becomes an…
Loren Meehan
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Why does spin break time reversal symmetry but electric dipole moment does not break time reversal symmetry?
I wasn't able to get a proper reason behind this and the only thing I could find were classical analogies for spin which (when I asked my prof) were not to be relied upon.
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What is relation between CPT invariance & Lorentz invariance, and why mass of particle/antiparticle is different in CPT violation?
(1) I read that CPT theorem can be proved with Lorentz invariance. Also, CPT violation implies Lorentz violation.
Is CPT invariance equivalent with Lorentz invariance, or just one-side direction holds?
CPT transformation is discrete, in contrast,…
YCK39
- 323