Parity Definition and 200 Threads

Consider a system of two identical spin zero particles on a sphere. Let ##\vec{L} = \vec{L}_1 + \vec{L}_2## be the total orbital angular momentum of the two particles, and ##l_1, l_2## be the orbital angular momentum quantum numbers corresponding to particle 1 and particle 2. Consider the...

My answer: Then, if I am not mistaken, the solution made in that video is mostly guessing about which columns combination can be equals to zero and I found 1st, 2nd, and 3rd rows as well as 2nd, 3rd, 4th rows are equals to zero so the minimum hamming distance is 3 since my answer is mostly...

What I know: Parity check is used to detect if there are errors when transmitting data by adding redundancy bits to the dataword (data that we want to send) which creates a codeword. Then the receiver checks if the 1's are even or odd and based on that, we know that there was corruption during...

Hi, First of all, I'm not sure to understand what he Kramers-kronig do exactly. It is used to get the Real part of a function using the imaginary part? Then, when asked to add a peak to the parity at ##\omega = -\omega_0##, is ##Im[\epsilon_r(\omega)] = \delta(\omega^2 - \omega_0 ^2)## correct...

This is for a Quantum Mechanics class but part b of this question seemed like it relied more on math than physics so I think it appropriate to post here. If not, Mods please move to appropriate place. For the ##\Pi xf(\vec r)+x\Pi f(\vec r)=0## I have my answer circled in red on the first...

help me in my problem set qs

I'm confused by the discussion in section §30 (Parity of a state), page 98 of Landau's QM. The functions ##\psi_u## and ##\psi_g## are odd an even states respectively. If ##f## is a true scalar, then it should remain unchanged by inversion of the co-ordinates. Writing ##q' = -q##, then its...

Hello! What is the 2D (acting in spin space) representation of the parity operator. In principle we can make it a diagonal matrix with the right transformation and given that ##P^2=1## the matrix would be diag(1,1) or diag(1,-1). However spin shouldn't change under parity and using that it seems...

Recently I saw this YouTube video from Veritassium about CPT -Symmetry: In this video an experiment of Prof. Chien-Shiung Wu is presented, which has proven that parity is not symmetric, by observing the emmition of electrons from Co60 atoms with synchronised spin. After thinking about this...

When we are talking about Bloch's theorem and also the tight-binding approximation, we can use them to help finding eigenstates of a system. However, I am so confused how to apply it in this case (below is my homework) and don't even know how to start it... All I understand about the Bloch's...

If Hamiltonian commutes with a parity operator ##Px=-x## are then all eigenstates even or odd? Is it true always or only in one-dimensional case?

On page 298 of Shankar's 'Principles of Quantum Mechanics' the author makes the statement : ""In an arbitrary ##\Omega## basis, ##\psi(\omega)## need not be even or odd, even if ##| \psi \rangle ## is a parity eigenstate. "" Can anyone show me how this is the case when in the X basis...

I looked in the instructor solutions, which are given by: But I don't quite understand the solution, so I hope you can help me understand it. First. Why do we even know we are working with wavefunctions with the quantum numbers n,l,m? Don't we only get these quantum numbers if the particles...

Hello! I don't know much about this, so maybe the answer to my questions follows directly from the math of it, but I was wondering if there is an answer providing more physics intuition to this, not just math: Why can a nucleus have an octupole deformation, as a ground state stationary state...

Can we predict the positive parity, and zero spin of the Higgs boson from the decay mode: 𝐻 → 𝛾𝛾?

Hi, I'm trying to check that the QED Lagrangian $$\mathscr{L}=\bar{\psi}\left(i\!\!\not{\!\partial}-m\right)\psi - \frac{1}{4}F^{\mu\nu}F_{\mu\nu} - J^\mu A_\mu$$ is parity invariant, I'm using the general transformations under parity given by $$\psi(x) \rightarrow...

I read in Greiner Field Quantization that parity only has meaning in interactions. Did I misread or not understand something correctly?

Hello everybody! Let's begin with the spin. Spin of the ##\Lambda## is ##1/2## and of the pion is ##0##: $$ \frac{1}{2} \otimes 0 = \frac{1}{2}$$ Since I know from the homework statement that ##L=1##: $$ \textbf{J} = \textbf{spin} \otimes \textbf{L} = \frac{1}{2} \otimes 1 = \frac{1}{2} \oplus...

Hi all, I have a question on G-parity. I know it's defined as ## G = exp(-i\pi I_{y})C ##, with ##I_y## being the second component of the isospin and ##C## is the C-parity. In other words, the G-parity should be the C-parity followed by a 180° rotation around the second axis of the isospin...

Summary: Why parity have vectors and pseudovectors? why not only vectors? I am reading Griffiths "Introduction to elementary particle physics" Ed.1. The book obviously is an undergraduate introduction.Thus, not much detail is presented, but I cannot get my head around pseudovectors...

My idea was straight forward calculation: $$\begin{align*}\bar { \psi }' ( x' ) \gamma ^ { \mu } \partial _ { \mu }' \psi ( x' ) &= \psi^\dagger\gamma^{0\dagger}\gamma^0\gamma^\mu \partial_\mu'\gamma^0\psi = \bar\psi\underbrace{\gamma^0\gamma^\mu\gamma^0}_{=\gamma^{\mu\dagger}=-\gamma^\mu}...

I'm working on some stuff for particle physics and I had a few questions I wanted to ask . Heres the outline of the problem : Establish which initial states of the ppbar system amongst 1^S_0, 3^S_1, 1^P_1, 3^P_0, 3^P_1, 3^P_2, 1^D_2, 3^D_1, 3^D_2, 3^D_3 the reaction ppbar->npi^0 can...

Hi. I have just looked at a question concerning a free particle on a circle with ψ(0) = ψ(L). The question asks to find a self-adjoint operator that commutes with H but not p. Because H commutes with p , i assumed there was no such operator. The answer given , was the parity operator. It acts...

Hi physics forms! I'm practicing to for an Quantum mechanics exam, and i have a problem. 1. Homework Statement I have two problems, but it's all related to the same main task. I have a state for the Hydrogen: ## \Psi = \frac{1}{\sqrt{2}}(\psi_{100} + i \psi_{211})## where ## \psi_{nlm}##...

http://oeis.org/A000088 This is a list that gives the number of simple graphs on n unlabeled vertices. Could someone conversant in graph theory explain why the number of simple graphs on 4 unlabeled vertices, which is 11, is the only one that seems to be odd (nontrivially), while the rest seem...

Hello! I want to know how does a parity transformation affect Bloch states! I always knew that parity takes the position vector to minus itself (in odd number of dimensions), but I have read that it also takes the Bloch wave vector to minus itself but I have not found a satisfactory proof of...

A pair of non-interacting particles can be described by the state vector: \begin{equation} \Psi_{p_1,\sigma_1,p_2,\sigma_1, t_1, T_1, t_2, T_2} \end{equation} Where T is the isospin and t is the 3rd-component. The parity of this state is the product of the intrinsic parities of the two...

I am wondering what would be an experiment demonstrating that photon parity is -1. It also occurs to me that one might deduce the parity from Maxwell's equations, though that might be a bit of a stretch since they are classical of course. Also, it occurs to me that parity might be assigned a...

Does anyone have a reference to a good explanation of this experiment. I am looking at https://quantummechanics.ucsd.edu/ph130a/130_notes/node323.html I am unable to comprehend the reasoning by which it determines the parity of the two neutrons in the final state. Particularly when it says the...

It is known that vectors change them sing under the influence of parity when ##(x,z,y)## change into ##(-x,-z,-y)## $$P: y_{i} \rightarrow -y_{i}$$ where ##i=1,2,3## But what about vectors in Minkowski space? Is it true that $$P: y_{\mu} \rightarrow -y_{\mu}$$ where ##\mu=0,1,2,3##. If yes how...

I have a very simple question. Let's consider the theta term of Lagrangian: $$L = \theta \frac{g^2}{32 \pi^2} G_{\mu \nu}^a \tilde{G}^{a, \mu \nu}$$ Investigate parity of this term: $$P(G_{\mu \nu}^a)=+G_{\mu \nu}^a$$ $$P( \tilde{G}^{a, \mu \nu} ) =-G_{\mu \nu}^a$$ It is obvious. But what about...

Wikipedia only tells neutrino spin 1/2, but no tell parity sign: positive or negative?

I bought one of those small tritium veils with phosphorus. Read about beta decay, wow what an interesting read! So there was mention when a neutron decays into a proton it emits an electron and an electron anti-neutrino. Also that there is no spatial parity with the physics. What does no...

Why is a vector's parity +1 and pseudo vector's parity -1 ? While it is the opposite case for scalars.

Homework Statement In the weak decay of the lambda baryon to a proton and pion, parity is not conserved, allowing for s and p waves in the orbital wave function of the pion-proton system. Using non-relativistic wavefunctions, find the angular distribution of the protons relative to the...

I have a question concerning the nature of Ms. Wu's experiment confirming parity violation. I'm very familiar with this experiment and its outcomes, but the setup of the experiment itself, alludes me. Wu found that the electron's emitted from the Cobalt-60 atom always went in the direction...

Hi. I have been looking at the proof that the parity operator is hermitian in 3-D in the QM book by Zettili and I am confused by the following step ∫ d3r φ*(r) ψ(-r) = ∫ d3r φ*(-r) ψ(r) I realize that the variable has been changed from r to -r. In 3-D x,y,z this is achieved by taking the...

A matter-antimatter pair have opposite spins and charges. Is this the same for parity?

Hi I have seen an example of commutator of the Parity operator of the x-coordinate , Px and angular momentum in the z-direction Lz calculated as [ Px , Lz ] ψ(x , y) = -2Lz ψ (-x , y) I have tried to calculate the commutator without operating on a wavefunction and just by expanding...

I am trying to learn how parity and time reversal transform the electric field, ##A_\mu## and ##\partial_\mu##. In other words what: what are ##P \partial_\mu P##, ##T \partial_\mu T##, ##T A_\mu T## and ##P A_\mu P##? My first guess was that ##P A_\mu(t,\vec{x}) P = A_\mu(t,-\vec{x})##, ##T...

Homework Statement Using a single 74x138, build a 3-bit, active-low, odd-parity detector. (Y0-Y7 are selected by "b2 b1 b0" in binary. Also the nibble "0 0 0" is considered even parity) You may use one NOR gate and one NAND gate, with arbitrary fan-in(>1). Label input variables "I2 I1 I0" and...

It’s commonly held that left and right photons interact with matter in exactly the same way, because electromagnetism “conserves parity”. But we know that P-symmetry, in our world, is generally broken. Even according to the Standard Model, when light propagates through some media, it interacts...

The spin exchange operator would have the property $$\begin{align*}P\mid \chi_{\uparrow\downarrow} \rangle = \mid\chi_{\downarrow\uparrow} \rangle & &P\mid \chi_{\downarrow\uparrow} \rangle =\mid \chi_{\uparrow\downarrow} \rangle \end{align*}$$ This also implies ##P\mid \chi_{\text{sym.}}...

Hi everyone, I've been working on developing a crypto-currency called eQualityCoin for a while now and hoped someone here might be able to help me "classify" the system in a formal mathematical sense. The system's main feature is a simple rule for how it determines a purchaser's exchange...

Homework Statement Consider the following example from a previous exam. We are to predict the spin and parity for F(A=17,Z=9), Florine, in the ground state and the first two excited states using the shell model. Ground state: Neutrons: (1s 1/2)^2 (1p 3/2)^4 (1p 1/2)^2 Protons: (1s 1/2)^2...

Homework Statement Not exactly a homework problem but I tried to predict the spin and parity of (the ground states of) ##^{89}Sr##,##^{97}Zr## and ##^{137}Ba## using the shell model and my results seem to differ from the tables. Homework Equations Parity ##\pi = (-1)^l## Figure 4 seems to...

Suppose we have an electron in a hydrogen atom that satisfies the time-independent Schrodinger equation: $$-\frac{\hbar ^{2}}{2m}\nabla ^{2}\psi - \frac{e^{2}}{4\pi \epsilon_{0}r}\psi = E\psi$$ How can it be that the Hamiltonian is spherically-symmetric when the energy eigenstate isn't? I was...

Considering a Z boson decay into a fermion-antifermion pair. How can i say if the process respect parity and charge conjugation?Thanks

Hello people! I have ended up to this integral ##\int_{φ=0}^{2π} \int_{θ=0}^π \sin θ \ \cos θ~Y_{00}^*~Y_{00}~dθ \, dφ## while I was solving a problem. I know that in spherical coordinates when ##\vec r → -\vec r## : 1) The magnitude of ##\vec r## does not change : ##r' → r## 2) The angles...

I found two definitions of wigner function on space time. the first uses a Fourier transform of ##\rho (q+ y/2,q-y/2)## the second uses the Weyl transformation and parity operator ## exp (i \pi \theta N)## where N is the occupation number operator. Could you give me a link which shows the...