Qcd Definition and 169 Threads

Dear friends, i was working on a hadronic decays. It appears that one has to calculate form factors. These form factors involve some very complex numerical integration. I would like to know if there are some packages available for calculating these form factors.

http://arxiv.org/abs/0804.3210 Introduction to String Theory and Gauge/Gravity duality for students in QCD and QGP phenomenology Authors: Robi Peschanski (Saclay) (Submitted on 20 Apr 2008) Abstract: String theory has been initially derived from motivations coming from strong interaction...

Hi, As you knew "Asymp. freedom in QCD" did explain th strong interactions... I want anyone to simplify this theory and show that: why g factor above 1? and Is Feynman rules still work for strong interactions, I mean as it successfully interpret QED interactions? Thanks in advance

I have been working in the properties of the large gauge transformation of QCD in the temporal gauge and I have shown that these satisfy U_{n}U_{m} and commutes with the translations where the large gauge transformations U_n and U_m belongs to the homotopy classes characterized by winding...

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...

Which is the connection between the perimeter law for Wilson loops and quantum fluctuations of matter fields (presenting in the QCD Lagrangian); and why quantum fluctuations of gauge (Yang-Mills, gluonic) fields infolve the area law for appropriate Wilson loops? Senk You. Leonid.

Why a magnetic current obviously must be C- parity odd in the (exact) SU(2) theory? (C^{-1} J_M C=-J_M). Best regard. Leonid

I find it awkward that quarks are in fundamental representation of SU(3) while gluons are in adjoint representation of SU(3). Is there a reason as to why this is the case? Why aren't they in the same representation or in the current specific representation?

Hi, I was wondering, what does the realm of quantum mechanics cover? I mean, I always hear a talk about how it would be a holy grail of physics if we could somehow combine GR and QM. But what about QCD, QED, and other theories. Why aren't they mentioned? Is it because QM encompasses them?

CarlB called attention to this paper by Johan Hanssen: http://arxiv.org/abs/hep-ph/0011060, on the BTSM forum. Hanssen asserts that because the Lagrangian of QCD is nonlinear, since the structure constants for su(3) do not vanish, therefore you can't do Fourier transforms on the fields, and...

What is QCD sum rule(s)?

What is the relationship between pQCD and NRQCD? Is it that pQCD is for high energy/short-distance regime, e.g. quark gluon plasma? And NRQCD is for low energy/long-distance regime, e.g. quarkonium ? And what is relation between heavy quark effective theory and pQCD and that between heavy...

How is it not an exactly accurate understanding that QCD is a part/sector of the standard model of particle physics ? Or, it actually is?

i am encoutering a problem i use helicity method to caculate six photon amplitude in scalar QED but i don't know explicit form of wave fuction QED . And i need a book with title " R. Gastmans, Ubiquitous photon: Helicity method for QED and QCD" where can i find it? thank you

In modify minimal subtract sheme,using dimension regulation, I calculate the the renormalization constant of massive quark and massless quark,get the same result.But in some papers,they are different. Is there a review or any book on MS renormalization,that giving all the self energy and...

Has there ever been/is there a project for lattice QCD which uses idle home PCs to assist in QCD calculations, similar to SETI@home? Just wondering as it seems like the kind of project that is perfectly suited to the @home structure.

wat do u need to learn to learn qcd and qed

Why is QCD non-perturbative at low energies? In QCD isn't the expansion parameter the fine structure constant? \alpha_s \approx \frac{1}{137} Does this somehow depend on energy, which wouldn't make sense to me. I cannot seem to find a good answer anywhere, so I thought I would ask here...

Why can people learn about QED and QCD and not about:QGD(i.e.Quantum gravitodynamics)?What are then the difficulties (both physically and mathematically speaking)that prevented theoretical physicists to develop such a theory??