Chiral Definition and 92 Threads

I'm doing this same problem found on the following link for a biochemistry homework. http://www.chegg.com/homework-help/questions-and-answers/nucleoside-phosphorothioates-synthetic-nucleotide-analogs-used-enzymology-molecular-biolog-q1481931 My question is regarding both finding the...

I am following Pierre Ramond's book "Field Theory - A Modern Primer", chapter 8, section 8.9, "Anomalies". My question starts in what follows from p.304. Homework Statement He draws the triangular diagram with one axial vector at one of the vertices and, using the standard Feynman rules...

I have been studying stereochemistry and it says that optically active molecules(chiral molecules) rotate plane of polarisation. I suppose that's because of the electrons in the molecule. I know that all molecules can rotate the plane of polarisation but when achiral moelcules are present in...

I am currently trying to check the formula for the chiral current of the Dirac equation for a plane wave solution (found here ), that is, j_{R}^\mu = \psi_R^\dagger \sigma^\mu \psi_R j_{L}^\mu = \psi_L^\dagger \sigma^\mu \psi_L With \psi_R = I( \cosh(\frac{\theta}{2}) + \sigma^i...

How are our hands chiral?? How are human hands chiral at all. Put them in the praying position and they are superimposable! "The left hand is a non-superposable mirror image of the right hand; no matter how the two hands are oriented, it is impossible for all the major features of both hands...

Hi, So to break the axial part of SU(2)_L \times SU(2)_R we use the composite field \chi_{\alpha i} \xi^{\alpha \bar{j}} (since this is Lorentz scalar, colour singlet, and has the right transformation under the flavour symmetries, only breaking the axial part etc). We assume that \langle...

Hi, If I have three light quark flavours with massses m_u, m_d,m_s , I want to try and calcuate the masses of the eight pseudogoldstone bosons. I have found from my mass term in the Chiral L that: L_{mass}=-2v^3...

Hi, If I have the Lagrangian L=i\chi^{\dagger\alpha i}\bar{\sigma}^{\mu}(D_{\mu})_{\alpha}^{\beta}\chi_{\beta i}+i\xi^{\dagger}_{\bar{i}\alpha}\bar{\sigma}^{\mu}(\bar{D}_{\mu})^{\alpha}_{\beta}\xi^{\beta i}-1/4 F^{a\mu\nu}F_{\mu\nu}^{a} where \alpha,\beta are colour indices, and i=1,2 is a...

I just read that the reason molecules rotate plane polarized light is because the light interacts with the electron cloud of the molecule. That makes sense but why aren't achiral molecules optically active? Achiral molecules have electron clouds too so why don't their electron clouds cause...

Homework Statement Why may the specific rotation of a sample of (R)-(+)-limonene be less than the literature value of (R)-(+)-limonene. Assume that there are so (S) enantiomers present. Homework Equations The Attempt at a Solution There are no (S) enantiomers, but there are some...

So my book has an equation describing the wavelengths of light that are diffracted by a chiral nematic liquid crystal in terms of the refractive index (n), the pitch of the helix (p), and the angle (θ) with respect to the surface. The equation is this - λ = np√((1-cos2θ)/n2) If this isn't...

I was learning about chirality in my organic chemistry class when we were talking about meso compounds. The professor stated that for a compound to be meso, you needed there to be two or more chiral centers. After thinking about it for a while, I can come up with abstract structures for meso...

Hi all, I'm trying to calculate the Feynman Rules for the effective electroweak chiral Lagrangian. For example, this is the first term in the Lagrangian: \begin{eqnarray} \mathcal{L}=\frac{v^2}{4}\text{Tr}(D_{\mu}U D^{\mu}U^{\dagger}) \end{eqnarray} where \begin{eqnarray}...

Homework Statement I have two questions. I have attached two pictures, 1 for each. 1. For the question about stability, the answer is C, but I thought it should be B. I would imagine the strain of two OH groups would be greater than an OH group with a CH3 group. Can someone explain what...

Homework Statement From Mandl and Shaw (exercise 4.5): Deduce the equations of motion for the fields: \psi_L(x)\equiv{1 \over 2} (1-\gamma_5)\psi(x) \psi_R(x)\equiv{1 \over 2} (1+\gamma_5)\psi(x) for non-vanishing mass, and show that they decouple in the limit m=0. Hence show that the...

Hi, Is it possible to construct chiral superfield from Vectorsuperfields and/or combinations of vector superfield and some another chiral superfield... Thanks

Question 1: I am aware the Higgs lies in a chiral supermultiplet, but I realized I don't have an intuitive idea of i) how many Higgsinos there are (since the MSSM has 2 complex isodoublets) ii) how many Higgsinos there are after EWSB and you gauge away three of the scalar fields iii) their...

Hello everyone, I was learning about the topic "chiral symmetry breaking" recently and got couple questions. I try to describe my understandings below, then list the questions: From the QCD Lagrangian level (quark level), I can understand the exact chiral symmetry exists when we take...

recently i am reading chiral symmetry in QFT. Almost all textbooks define γ5 as a chiral operator without saying some reasons. i am very confused why γ5 has something to do with chiral symmetry, can somebody explain it more intuitively and physically? who first introduce γ5 as a chiral...

I don't know if it is the correct sub-forum, if I choose wrong then feel free to move the thread. I was listening to a talk today using DCSB. I think I could get a glimpse on some other parts of the talk and found some ideas intriguing. I would like to understand them better, but I cannot...

Hello, I was wondering whether anyone knows the Feynman rules for Chiral Perturbation theory? I am trying to calculate K->PiPi and have obtained the relevant diagrams but cannot proceed without the relevant feynman rules.

Hello. I have a query regarding organic chemistry. 1. http://tinyurl.com/y9nvg2p See question number 21. 2. Homework Equations : None 3. The first Carbon atom beneath the top-most CH3 group I can tell is a chiral centre, as it has 4 different groups attached to it (C=O, CH2...

Hello, I'm trying to deduce the suspersymmetry transformation of the chiral multiplet out of the superfield formalism. In doing this I got stuck with this...

Wen local bosonic emergent string net model states he can give rise to electrons and photons, quarks and gluons but not chiral fermions. I know neutrinos are chiral. Any other fermions? If he can provide an explanation for masses and mixing angles for all SM particles except neutrinos...

Hello, I know that Wen might be able to get W Z gauge bosons and chiral neutrinos using his lattice bosonic models he is unable to get chiral interactions using standard bosonic lattice on minkowski space. If instead he used Connes' noncommutative space would he be able to get chiral...

Homework Statement Please bare with me; I don't know all of the terminology for this problem. In many textbooks, the six-dimensional Lie algebra of the Lorentz group is identified with the three components of the rotation generator and the three components of the boost generator. Then, the...

Why in QCD chiral symmetry breaking study only the light quarks are taken into account? And why are their masses usually set to zero, Goldstone bosons are found, and then their masses are corrected by letting the quarks have non-zero mass? What happens if one study this symmetry breaking with...

I have 2 questions: 1. When there are no fermion mass terms, the Dirac part of the Lagrangian posseses an SU(N) left X SU(N) right flavour symmetry for N flavours of fermions. This can be "re-arranged" as an SU(N) vector X SU(N) axial symmetry. The axial part is spontaneously broken by the...

i am trying to understand what a pseudochiral carbon is? please help thanks in advance

Is it true that classical theories tend to treat matter 'in the limit' of large N, or it encodes matter in N_A as N_A(m_e,e) say, and chiral theories need to include \hbar which classicality sees as \{G(h),c\} ? We use 'mass-free' theories that treat charge and spin momentum in circuits =...

Please help me find an asymmetric center There are 5 asymmetric centers in this molecule. I think I've managed to find 4 of them, but where is the last?

I put all of my questions/solutions in the attached file...could someone please check over them before 7:00 am to see if I have them correct? Thanks in advance!

Hello, I understand that the non-zero (or non-small) rate for \pi^0 \rightarrow \gamma\gamma was historically a big motivation for the non-conservation of the axial current. I've been trying to work on problem IV.7.2 (p. 252) in Zee which asks to show that this amplitude vanishes if \partial_\mu...

[SOLVED] Chiral Purity (enantiomer excess) for HPLC Hello! When I use HPLC to test Chiral Purity, obtain chromatogra and peak area. How do I calculate with Peak area? thanks!

For an assignment for organic chem the question asks to convert the structure of a compound into a chair conformation my question is that are equatorial substituents always the ones that are represented as a wedge on a structural diagram? If not could someone please give me tips on how to...

Homework Statement I'm doing a dissertation on heavy ion collisions and one of the things they look for in the collisions is chiral symmetry resolution - what is it? Homework Equations The Attempt at a Solution I understand that it is a type of symmetry that is usually broken...

http://arxiv.org/abs/0710.1548 Propagation and interaction of chiral states in quantum gravity Lee Smolin, Yidun Wan 34 pages, 30 figures (Submitted on 5 Oct 2007) "We study the stability, propagation and interactions of braid states in models of quantum gravity in which the states are...

Could somebody please tell me a workable definition of the term "chiral theory" , and also explain its significance? As far as I know, in a chiral theory not all the fermions obtain a mass but whether this is a definition or a derived result is not clear to me. Thanks in advance

Gents, Is it possible to have the not singular chiral current (singularity is due to the product of fermionic operators) and at the same time the translational invariance. Normaly to get rid of singularity in chiral current one is useing the point splitting regularisation (little shift of...

Dear PF, Could anyone help me to understand the following issue: I don't understand the formation of Goldston bosons in chiral symmmetry breaking. Namely - suppose there is only fermion fields Lagrangian and due to some reasons the fermion field obteins VEV - <0|psi^bar psi|0> is non...

From what I understand a chiral compound is one of which that when mirrored it is not identical. Not identical in what way's? Is it not superposable? Not have same properties? I have a multiple choise question asking which of the following is a chiral compound and the ones I choose are not...

When solving Dirac equation (for free massive particles) we usually impose normalisation conditions upon the eigenfunction in a single stroke. I am wondering, Is it possible/useful to impose separate normalisation conditions upon the left and right spinors? Should we still have a resolution...