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41 views

Is there violation of energy conservation when a particle transforms to its anti-particle, for example $B^0\to\bar{B}^0$, or $K^0\to\bar{K}^0$

additive information : $B^0$ and $\bar{B}^0$ don't have the same mass, $K^0$ and $\bar{K}^0$ don't have the same mass. is there energy violation? if yes, is the key explanation of this coming from the ...
1
vote
0answers
35 views

CP violation measurement

I have a question regarding the measurement of CP Violation in experiment. How is parity measured in an experiment? I know that in the direct measurement of CP violation we look at a particle process ...
0
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0answers
88 views

Detail on C vs. CP violation

In the answer given by knzhou to the post What distinguishes the behaviour of particle from its antiparticle: C violation or CP violation? it is said that "but the reaction $i \rightarrow f$ will ...
1
vote
0answers
64 views

Antiparticles, CPT and leptogenesis

When people are being careful they'll tell you that antiparticles are the CPT conjugates of particles. You can't say that they are C conjugates or CP because these, while they do reverse the charge, ...
0
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2answers
142 views

How can spontaneous $P$ or $CP$ violation arise? Examples needed

In quantum field theory, there can be a spontaneous breakdown of discrete and continuous symmetries. Can there be a spontaneous breakdown of P and CP violation where P represents parity and C ...
3
votes
1answer
107 views

What distinguishes the behaviour of particle from its antiparticle: C violation or CP violation?

It is said that a CP violation would mean that the behaviour of the particle is different from the behaviour of antiparticle. Why is C violation not good/enough?
0
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1answer
63 views

What is unsolved in CP Violation?

I learnt about CP Violation in my Quantum Information Theory and Particle Physics courses. However I have not understood what exactly has not been solved yet about CP Violation. I thought that the ...
2
votes
0answers
96 views

Parity violation

I've been reading on wikipedia about parity violation in the weak force and the conclusion is: This implies that parity is not a symmetry of our universe, unless a hidden mirror sector exists in ...
0
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0answers
23 views

Dependence of decay width on the CKM parameters

So what i want to know mainly is when do i use the conjugate? Like when should it be $V_{cd}$ or $V^*_{cd}$? Please look at a pic for example - So should I used conjugate? $V^*$ instead of $V$? ...
2
votes
1answer
142 views

Can experiments measure the Majorana phases?

Unlike the Dirac CP-phase $\delta$, the Majorana CP-phases $\alpha,\beta$ do not appear in the formula of neutrino flavour oscillation probability. Hence, they cannot be measured from oscillation ...
0
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1answer
66 views

C, P and CP in particle physics

We know that the charge conjugation (C) and parity (P), both are violated maximally in particle physics. Then what is the need for looking for CP symmetry in order to distinguish matter from ...
3
votes
1answer
191 views

Why is $|\bar{K}^0\rangle=\mathscr{CP}|K^0\rangle$ and not $|\bar{K}^0\rangle=\mathscr{C}|K^0\rangle$?

If the charge conjugation operator $\mathscr{C}$ changes a particle state into the corresponding anti-particle state then we must write $|\bar{K}^0\rangle=\mathscr{C}|K^0\rangle$. But instead, we ...
2
votes
1answer
317 views

What is the correct definition of the Jarlskog invariant?

In this lecture on neutrino physics, Prof. Feruglio defines the Jarlskog invariant as $$J=\text{Im}(U_{\alpha i}^{*} U_{\beta i} U_{\alpha j} U_{\beta j}^{*})\tag{1}$$ where $U$ is the neutrino mixing ...
5
votes
2answers
85 views

What are the anti-neutrino flavour oscillation formulae?

All the textbooks and references that I have come across give the neutrino 3-flavor oscillation formulae. However, the formulae for antineutrino oscillations are never given. Is it possible to derive ...
2
votes
2answers
177 views

What is the most natural way in which the Jarlskog invariant makes its appearance?

What is the most natural way in which the Jarlskog invariant can be introduced? I have seen ad hoc definitions given as $$J_{CP}=\text{Im}(V_{us}V_{cb}V^*_{ub}V^*_{cs})\tag{1}$$ which, to me, appears ...
2
votes
1answer
64 views

How does one measure anti-neutrino flavor oscillation probabilities?

The Dirac $CP$ phase $\delta_{CP}$ in the $U_{PMNS}$ mixing matrix lead to the $CP$-violation in the Lepton sector. I think this can be tested by comparing neutrino flavour oscillation probabilities ...
2
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0answers
125 views

Consequence of C and CP-violation: What does it ensure and what it does not?

This question is a continuation of one of my earlier posts here and the accepted answer. Consider a two-body hypothetical decay $p^+\to e^+\gamma$ in a quantum field theory (say, a GUT). If the ...
5
votes
1answer
223 views

Difference between “C-violation without CP-violation” and “C-violation with CP -violation”

Consider two possible decay channels of a massive particle as $X\to A+B$ and $X\to C+D$ with decay rates $r$ and $1-r$ respectively. Let the decay rates of its antiparticle into channels $\bar X\to \...
4
votes
1answer
248 views

Do we know whether the “electron” neutrino is lighter than the “muon” neutrino?

The labeling of the neutrino mass eigenstates is arbitrary [PDG Neutrino Review]. Regularly it is assumed for convenience that $$\Delta m^2_{21} = m_2^2 - m_1^2 > 0.$$ Then, values for the mixing ...
2
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0answers
140 views

How to find the CP violating effective operator?

I've been meeting with one not-very-small problem in arriving at (3.3) in Shaposhnikov's "Structure of the high temperature gauge ground state and electroweak production of the barygon asymmetry" (...
6
votes
2answers
410 views

Kaon oscillations

Neutral Kaons CP eigenstates can be built as following: $$|K_1\rangle=\frac{|K^0\rangle-\bar{|K^0\rangle}}{\sqrt{2}}$$ $$|K_2\rangle=\frac{|K^0\rangle+\bar{|K^0\rangle}}{\sqrt{2}}$$ So that we ...
5
votes
2answers
506 views

How to understand CP-violation in kaon systems with Feynman diagrams and matrix elements?

I am trying to understand CP-Violation in the Kaon system using feynman diagrams and matrix element. Here is a slide from Mark Thomson corresponding exactly to what I am looking for (http://www.hep....
4
votes
1answer
411 views

Understanding CP-violation from a toy model of two fermions and a scalar boson

Consider a field theory given by the following Lagrangian $$\mathcal{L}_{int}=y\overline{\psi_1}\psi_2\phi+y^*\overline{\psi}_2\psi_1\phi^\dagger$$ where $\phi$ is a complex scalar field, and $\psi_1,\...
2
votes
1answer
516 views

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 ...
3
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0answers
41 views

CP violation in B meson system through mixing

Mathematically, $\left|\Gamma_{12}\right|<<\left|M_{12}\right|$ implies $\left|q/p\right|=1$,i.e there is no CP violation due to mixing. Please explain why it happens beyond this mathematical ...
3
votes
1answer
995 views

How to determine if interaction is allowed?

I'm trying to determine if the reaction $$n\rightarrow p + \pi^-$$ is allowed. First of, this doesn't list this as one of the decay modes of the neutron, so I suspect that it should not be allowed. ...
7
votes
1answer
185 views

Importance of CP violation

To explain the matter-antimatter assymmetry, CP should be violated according to Sakharov conditions. Charge conjugation is required as matter and antimatter have opposite charges but why Parity ...
1
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0answers
19 views

T invariance in flavored meson system

Consider Kaon CP conjugate states $\left|K^{0}\right>$ and $\left|\bar{K^{0}}\right>$. The physical states i.e, eigenstates of effective hamitonian can be written as \begin{equation} \left|M_{a}...
3
votes
0answers
80 views

Would CP Violation happen in a universe with four spatial dimensions?

The weak force is the force that violates CP symmetry as the way it effects a particle depends on that particles handedness. Particles have a property known as spin although it is different from ...
1
vote
1answer
71 views

How was there an extra particle in the early universe?

According to theories.. In the early universe.. There were particles and anti-particles in equal number.. But there seems to be one extra particle against the number of anti-particles.. As the ...
3
votes
1answer
844 views

Understanding Kaon Mixing

While studying Neutral-Kaon mixing, I learnt that the way we observe them is through their decays to Pions. But the states that decay are not the particles/antiparticles themselves but their mixture. $...
4
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0answers
97 views

Condition for CP violation

I am studying how weak and strong phases lead to CP violation. I am following CP Violation by Branco. There is some algebra that I can not follow. Consider the process : $ a + \bar{a} \rightarrow b ...
2
votes
1answer
372 views

Direct and indirect CP violation

Experimentally, what is the difference between direct and indirect CP violation? An example of indirect CP violation is: $$ \Gamma(\overline{B}^0 \rightarrow B^0) \neq \Gamma(B^0 \rightarrow \...
3
votes
1answer
254 views

Why does the pion not undergo netural particle oscillation?

$K$, $B$ and now $D$ mesons exhibit neutral particle oscillation, where we see the spontaneous interchange between a particle and its antiparticle, i.e. $K^0 \Leftrightarrow \overline{K}^0$, $B^0 \...
6
votes
1answer
193 views

What CP violating processes do we know of?

So, after going over my particle physics notes and some introducing literature, it seems the currently known processes we experimentally confirmed to be CP violating are Kaon mixing (an indirect ...
6
votes
1answer
124 views

How could one measure the necessary CP violation needed to account in the SM?

The Standard Model contains at least three sources of CP violation. The first of these, involving the Cabibbo–Kobayashi–Maskawa matrix in the quark sector, has been observed experimentally and can ...
8
votes
1answer
919 views

CP violation from the Electroweak SU(2)$_{weak,flavor}$ by $\int \theta F \wedge F $

Question: Why there is NO Charge-Parity (CP) violation from a potential Theta term in the electroweak SU(2)$_{weak,flavor}$ sector by $\theta_{electroweak} \int F \wedge F$? (ps. an explicit ...
7
votes
1answer
543 views

Has non-conservation of baryon number been observed?

CP violation (as I understand it) allows for non-conservation of baryon number, and thus can contribute (at least a little) to the baryon asymmetry in the universe today (far more matter than ...
13
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1answer
571 views

Baryogenesis only at the Planck scale, or none at all?

I can think of three general ways of explaining why the universe contains more matter than antimatter: (1) Near the Planck time, the universe had zero baryon asymmetry, but at some later time, ...
3
votes
1answer
148 views

How to determine predicted CP violation for a given SUSY point?

I'm currently studying at the spectra of some supersymmetric models, and would like to know whether the parameter points I'm looking at are ruled out due to excessive CP violation. I am using SPheno, ...
6
votes
1answer
4k views

Jarlskog Invariant and its mathematical origin

CP violation is present in the weak interactions if There are no degeneracies in the up-quark/down-quark matrices The Jarlskog invariant $J=Im(V_{us} V_{cb} V_{ub}^* V_{cs}^*)$ is nonvanishing ...
2
votes
1answer
166 views

Coefficients in V-A interaction

To account for parity violation the weak interaction matrix element is written in the form $$ M \propto \sum_{i} C_i (\bar u_p O_i u_n) (\bar u_e O_i (1 + {{C'_i}\over{C_i}}\gamma^5)u_\nu) $$ Why ...
1
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0answers
355 views

What are the prerequisites to study CP violation?

If one would like to study CP violation, what would be the prerequisites for it? For example, until now I have not studied quantum field theory and have done very little classical field theory, but ...
8
votes
1answer
2k views

CP Violation of the CKM Matrix

Considering the relation between the $SU(2)_{WEAK}$ partners of the $|u \rangle$, $|c \rangle$, and $|t \rangle$ mass eigenstates and the corrseponding downtype eigenstates $ \left( \begin{array}{...
6
votes
1answer
74 views

Which arguments for $m_u \approx 0$ are still in the market?

The RPP note on quarks masses has traditionally carried, and it is still there, the comment that It is particularly important to determine the quark mass ratio mu/md, since there is no strong CP ...
1
vote
1answer
679 views

Understanding P-, CP-, CPT-violation etc. in field theory and in relation to the principle of relativity

I can never get my head around the violations of $P-$, $CP-$, $CPT-$ violations and their friends. Since the single term "symmetry" is so overused in physics and one has for example to watch out and ...
2
votes
2answers
1k views

What is the correct term for the “polarity” of matter (matter vs. antimatter)? Are fractional polarities allowed?

What is the correct term for the "polarity" of matter (matter vs. antimatter)? Are neutral polarities allowed? (1,0,-1) Are fractional polarities allowed?
4
votes
1answer
416 views

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 ...
15
votes
5answers
950 views

Matter-Antimatter Asymmetry in Experiments?

As I hope is obvious to everyone reading this, the universe contains more matter than antimatter, presumably because of some slight asymmetry in the amounts of the two generated during the Big Bang. ...
2
votes
1answer
344 views

How much CP violation does the weak force cause?

I'm looking for the most readable quantitative explanation, with the least amount of difficult mathematics. Rather than an answer with just a number, I'd like to see the derivation from the CKM matrix....