All Questions
Tagged with cpt-symmetry parity
16
questions
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0
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45
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Is really hermiticity necessary to be a physical observable? What about larger class of operators like PT invariant operators or pseudo hermitian one?
It's really necessary for an observable represented by an operator acting in a Hilbert space to be hermitian?
It's known that not only hermitian operators have real eigenvalues and that also normal ...
- 310
1
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1
answer
466
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Regarding the action of Time reversal on Dirac spinors
I'm inquring about the difference between notions of time reversal found in Streater & Wightman's "PCT, Spin and Statistics, and All That", and this accepted answer from Chiral Anomaly. ...
- 1,117
2
votes
1
answer
290
views
Define $C,P,T$ symmetry transformation in even dimensional $d$ spacetime on a relativistic Weyl fermion theory
According to https://physics.stackexchange.com/a/488388/42982 we can define $C,P,T$ discrete symmetry transformation in even dimensional spacetime.
How could we write $C,P,T$ symmetry transformation ...
- 4,336
0
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1
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115
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Why reflection is generator of Minkowski space, if we know that only CPT symmetry is true?
In particular, we know that $P$ symmetry (parity transformation, which is basically a reflection), is not the symmetry of the universe, a whole combination of $C$, $P$, and $T$ is. Because of this, it'...
- 103
3
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174
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C, P and T transformations of $\phi$ that preserves symmetry
I have a series of exercises regarding C, P and T symmetry but I am not really sure how to start with the problems. If anyone could help me with one of the problems, or show me a few example problems ...
- 254
2
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0
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187
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QED $PC$ conservation
I'm trying to prove that the QED Lagrangian
$$\mathscr{L}=\bar{\psi}(i\!\!\not{\!\partial}-m)\psi - \frac{1}{4}F^{\mu\nu}F_{\mu\nu} - J^\mu A_\mu$$
Is invariant under P and C. The two fields transform ...
- 23
2
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1
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1k
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Why is the Higgs $CP$ even?
Why was it always assumed that the Higgs boson is a CP even particle?
I understand that experimentally, it just is so but I am under the impression that before its discovery people took it to be CP ...
- 841
13
votes
2
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1k
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What are the assumptions that $C$, $P$, and $T$ must satisfy?
I am not asking for a proof of the $CPT$ theorem. I am asking how the $CPT$ theorem can even be defined.
As matrices in $O(1,3)$, $T$ and $P$ are just
$$
T = \begin{pmatrix} -1 & 0 & 0 & ...
- 11.6k
0
votes
0
answers
134
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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} \; \; \...
- 131
4
votes
2
answers
323
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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 ...
- 171
1
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117
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Parity conservation in second harmonic generation?
The second harmonic arises from susceptibility of third rank tensor $X^{(2)}$ which have (-1) parity.
page 28
Let say two photons are absorbed and one is emitted, so the total change in parity is $(...
- 1,047
1
vote
1
answer
880
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Conservation of $C$-Parity and $P$-parity
Under what situations are $C$-Parity $C=(-1)^{L+S}$ and/or $P$-parity $P=-(-1)^L$ conserved? ( $L$ here is the relative angular momentum and S is the total intrinsic spin).
It would make sense that ...
- 344
3
votes
1
answer
802
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Intrinsic parity of particle and antiparticle with spin zero
I need to prove that the intrinsic parities of a particle and antiparticle with spin zero are the same. Can I prove that by an argument that operator of $P$-inversion commutes with charge conjugation ...
- 6,564
7
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2
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1k
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C, T, P transformation mistakes in ``Peskin&Schroeder's QFT''?
I suppose the right way to do C (charge), T (time reversal), P(parity) transformation on the state $\hat{O}| v \rangle$ with operators $\hat{O}$ is that:
$$
C(\hat{O}| v \rangle)=(C\hat{O}C^{-1})(C| ...
- 7,848
1
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3
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2k
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Time reversal and parity symmetry
I was previously under the misapprehension that time $T$ and parity $P$ symmetries in conjunction ($PT$) were a reflection in $(3+1)$-dimensional space-time, where
$$P: \vec x \to -\vec x$$
$$T: t \...
- 15.2k