Parity Definition and 200 Threads

We're working on the parity operator in my second semester quantum mechanics class and there is one point I am confused about, either in the definition of degeneracy or in the parity operator itself. We talked about a theorem whereby the parity operator and the Hamiltonian cannot share...

I have a question, in Time Reversal operator, does an external magnetic field would get a minus sign, I guess that yes cause it changes direction, i.e if it's directed orthogonal to the surface then after time reversal I think it will direct anti-orthogonal to the surface, in Parity I don't...

Homework Statement Which of the following states have odd parity? a. 2p m=0 b. 2p m=1 c. 26f m=0 d. 2s The Attempt at a Solution Knowing the wavefunctions for a,b, and d, i think that all of them have odd parity. What about the 26f m=0 state?

Hi! Recently I am studying on parity and CRC(cyclic redundancy checks) this two error checking methods. The problem is can this both methods combine to use together during transmission data? Let say I need to transfer ASCII code and I do CRC first,then before sending data I do parity on...

The Lagrangian \mathcal L =\psi^{\dagger}\gamma^0 \gamma^\mu (1-\gamma^5)\partial_\mu \psi should violate parity, but I'm getting that it doesn't. \psi(x) changes to \gamma^0 \psi( Px) where Px=(t,-x) and x=(t,x). \gamma^j goes to - \gamma^j , while \gamma^0 stays the same...

Ryder in chapter two of his book says that if we consider parity then it is no longer enough to talk about two spinors and so he introduces 4 spinors. Is there some postulate of Quantum physics that has to do with state trasformation under parity??

Hi all. This isn't a homework question, but something I thought about. When looking at a system of 2 fermions, we have that: \Psi(r_1,r_2)=-\Psi(r_2,r_1). Now if we look at a 3 fermion system, then what is the demand for the waveequation? Does it have to be anti-symmetric when switching two...

Hi all, Homework Statement In this question consider the nucleus 15N (The 15 is the atomic mass, so superscript top left of N), and refer to the shell model diagram. (a) Predict the ground state spin and parity, Jpi. (b) Write out the relevant odd particle configuration in the form: p (or n)...

Can anyone explain this to me? It piqued my interest, especially since I nominally work with radioactive materials (though admittedly, not fissile material) and didn't know where this came from. "It is not a coincidence, for example, that the three nuclei which are fissionable with slow...

Hello all ! I was trying to solve the following problem : you have a particle with spin J=1 and unknown parity that decays into 2 indentical particles of spin = 1/2 We want to know how much the angular momentum of the final state is and also the final total spin. Now, my reasonment was...

I'm reading a book: B.R. Martin's Nuclear and Particle Physics - An Introduction. In section 1.3.1 on Parity, it states the following: When dealing with p·x in the exponent, which should p and x be treated as - vectors or operators? Suppose I work it out. If exp[i(p·x-Et)] is an...

shell model determining spin and parity - urgent Homework Statement Find the spin and parity of _{20}^{41}Ca and _{20}^{40}Ca Homework Equations http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/shell.html The Attempt at a Solution For _{20}^{41}Ca we've an odd number...

Hi, i separated parity question from my question posted just below Parity operator reveal parity of function such that Pf = \pm f But In fact, in order to get parity of function f, we should already know parity of function In that way, Why should we know Parity operator ? we already...

Hi, I encountered three conserative theorem in textbook One of conserative theorem is involving my question. Liboff defined displacement operator as \hat{D}(\varsigma) = e^(\frac{i\varsigma\hat{p}_{x}}{\hbar}f(x) = f(x + \varsigma ) but is it right? If system is displaced from x...

How do we know that half of permutations are odd and half are even? Why not 1/4, 3/4 or other proportions?

Parity Conservation Means? Hello all, What is Mean By Parity Conservation?.Dont tell That When Parity Of L.H.S and R.H.S Become Equal.I want to Know the Concept Behind It.Please help Thanks

Parity vs. group theory? Parity is a special property in Quantum mechanics. I don't know whether it relates to group thery? Is it O(2), U(1), or others? Thank you!

I'm confused about how parities 'add up'. (I'm using the shell model of a nucleus) If you have e.g.a neutron in a d state (so l=2) and one in a p state (l=1), what is the parity of the total system? Do you have to multiply (+1*-1=-1?) or add the l values or something completely different?

[SOLVED] Perturbed Ground State Wavefunction with Parity Homework Statement A particle is in a Coulomb potential H_{0}=\frac{|p|^{2}}{2m} - \frac{e^{2}}{|r|} When a perturbation V (which does not involve spin) is added, the ground state of H_{0} + V may be written |\Psi_{0}\rangle =...

Do you think you could give me some helpful insight to a follow up question from the discussion of defining inertial frames: I'm still having trouble figuring out a good way of incorporating parity violation into my intuition. If it wasn't for experiment showing otherwise, I probably would...

I've gained interest in the http://lhc.web.cern.ch/lhc/" , which pertain to CP-violation. QUESTION #1 What sort of classes/branches would teach/contain 'charge conjugation' and 'parity'? QUESTION #2 the wiki article on parity states that parity is an operator- "acting on a state...

Why do they always say parity is maximally violated in weak interaction? This is true for W boson interactions. But not for Z bosons, as the Zs couple to both left and right handed particles. And hence, is not maximally violated in the case of Z.

Can anyone help me understand what is meant by the "parity of a wavefunction"? I know in terms of even/odd parity, that: P \Psi(x,y,z) = \pm \Psi(x,y,z) ie, P = +/- 1 But I don't know what "parity of a wavefunction" physically means...

Question Details: The following blocks have been encoded using the two-dimensional parity error detection scheme. That is, the rows have been encoded using odd parity and the last row holds the parity bits of the columns which have also been encoded using odd parity. There are two possible...

Let's say we have a symmetric potential, in position representation V(x)=V(-x) and let P be the parity operator. Then quite clearly PV=VP but I was told the stronger statement V=PV is not true, but I thought V=\int_{-\infty}^{\infty} V\left|x\right\rangle\left\langle x \right| dx (where I...

I understand that the spin and parity of the nucleus is determined by looking at hte unpaired nucleon (is that the correct way of saying it?). But what if we were looking at nulceus where 2 or more nucleons were excited from the ground state?? What would the spin and parity of the nucleus be...

Hi, I thought pions were assigned parity of -1, but how then can the Pi0 decay into two photons with parity -1?? What am I missing? Thanks, Joe

If I have af wavefunction that is a product of many particle wavefunctions $\Psi = \psi_1(r_1)\psi_2(r_2) ... \psi_n(r_n)$ If I then know that the parity of $ \Psi $ is even. Can I then show that the wavefunction i symmetric under switching any two particles with each other. That is...

just wondering... does the parity operator squared give the identity operator?

Hello all, Im trying to communicate with a RS232 device utilizing stick parity. This is defined as the first byte of a packet having its parity bit set to one, while all proceeding bytes have their parity bit set to 0. This was meant to be used to determine the start of a new packet...

As part of an exam paper I've been using to revise with, I came across a question that simply says "What is parity?" Well I know vaguely what it is. Its to do with whether a wave is odd or even right? For example for cos and sin odd parity occurs because sin(-x) = -sin(x) and cos(-x) =...

Q1 energy no. of times measured a1 n1 a2 n2 a3 n3 a4 n4 expectation value <E> = (a1n1+a2n2+a3n3+a4n4) / (n1+n2+n3+n4) is this correct? Also, how do you caluculate expectation...

Dr. Hadley at Warwick has been trying to describe elementary particles by general relativity. He's had a problem that he ends up with something that conserves parity. So, naturally, he's questioning whether parity is or is not conserved in nature. Now his idea is basically that the true...

what is R Parity and why?

I think I'm on the right track for this problem, but I'm not entirely sure. Find the solutions to the one-dimensional infinite square well when the potential extends from -a/2 to +a/2 instead of 0 to +a. Is the potential invariant with respect to parity? Are the wave functions? Discuss the...

what is meaning of parity. why is the parity violated in weak interaction. what is meaning of maximal violation of parity

Could you help me to get some sensible definition of parity? In my book they talk about having negative reversing coordinates and stuff. :frown: What does it physically mean to reverse coordinates? :bugeye: Any understandable definition of parity? thank you vr mch.

hey, it's good to be back at pf. :cool: anyway, today i had an exam in my honors modern course, and one of the questions was a proof that the parity operator is hermitian. i don't think i got it right. :/ here's what i did: 1: \int(P_(op) \psi_2(x))^* \psi_1(x) dx = \int \psi_2^*(-x)...

Greetings, I'm curious about parity conservation in the decay\eta \rightarrow \gamma \gamma. The \eta has odd parity, while the product of the two photon parities (each is odd) is even. Now, parity is conserved in the EM interactions, so there must be a factor of (-1) coming in from orbital...

why does J(-n) (x)=[(-1)^n]Jn(x)?

I'm considering the beta decay of a neutron into a proton an electron and an antineutrino. I heard that this was observed in 1957 in Cobalt 60. I don't really understand when the antineutrino comes into action... The experimental results say that they detected more electrons in the direction...

Consider this decay: Pion+ -> muon+ + neutrino It says that one can check the longitudinal polarization of the muon+ and this would confirm that the parity is not conserved. Can you explain what this means in simple terms?

Any comments on this pithy article on parity: A Conserved Parity Operator Mark J. Hadley, Dept of Phys., Univ. of Warwick, Abstract:The symmetry of Nature under a Space Inversion is described by a Parity operator. Contrary to popular belief, the Parity operator is not unique. The choice...

Nuclear physics Pions and Parity? Ignore, nevermind Why can: \pi^- + d \rightarrow n + n + \pi^0 not happen for pions at rest? work so far: \begin{array} {|c|c|c|c|c|c|}\hline&\pi^-&d&\rightarrow &n \ + \ n&\pi^0\\\hline{Spin}&0&1&\ \rightarrow &1/2 \...

Ok,so check this situation out. We have a one-dimensional box with walls at (-a/2,a/2). We know that the particle is in a state with energy probabilities P(E1)=1/3, P(E2)=1/3, and P(E3)=1/3 while P(En)=0 for all n not equal to 1,2,3. The parity is measured ideally and -1 is found. If...

I am reading through this paper and one stage has got me stumbled: http://www.cs.umbc.edu/~lomonaco/lecturenotes/9811056.pdf The part I don't understand is 4.2.3 Phase 3 of Stage 2. Extraction of reconciled key on page 17. I'm pretty sure this is purely mathematical stuff, so you don't...

Now that it is becoming apparent that neutrinos are massive (albeit rather small), I have a question that bears upon the accepted symmetry framework as applied to weak interacton. We know from weak decay (say Beta) that there is parity asymmetry, that the resultant neutrinos are polarized...

Let me see if I can make it clearer. Problem 5.5 In David Griffiths “Introduction to Quantum Mechanics” says: Imagine two non interacting particles, each of mass m, in the infinite square well. If one is in the state psin and the other in state psim orthogonal to psin, calculate < (x1 -...

Problem 5.5 In David Griffiths “Introduction to Quantum Mechanics” says: Imagine two non interacting particles, each of mass m, in the infinite square well. If one is in the state psin and the other in state psim orthogonal to psin, calculate < (x1 - x2) 2 >, assuming that (a) they are...

Chapter 3 #17 (Krane) The spin-parity of 9Be and 9B are both 3/2-. Assuming in both cases that the spin and parity are characteristic only of the odd nucleon, show how it is possible to obtain the observed spin-parity of 10B(3+). What other spin-parity combinations could also appear? (These...