Recent content by Naeem Anwar

Does Charm-Anticharm (in relative S-wave with spin-1) annihilates to a single photon? How does this vertex look like in QCD?

How to understand QCD vacuum? What is the model independent expectation value for it? Looking for some basic literature on it. Thanks in advance!

Although my background is not LQCD but still this material is at least giving me the spirit of my query. Thanks & looking forward some exact explanations in detail.

Just started the study Exotic Hadrons (like mixing of Charmonium states with tetraquarks etc.) and got confused with quenched & unquenched quark model. What are the major differences between these two models? What key factors I should keep in mind doing calculations with these models...

Thanks dear P. Labelle, I acknowledge your help. Sorry for my poor understanding & language used in question. I found all of your papers on HEP-INSPIRE, I also found many of my answers there. The paper you mentioned (with Buckley), I just downloaded & reading now. I am not able to get your...

Dear nrqed, I know the diagram, I am curious about how to add the details of the "box" in the amplitude?

Studying the production of the bound state of ##μ^+μ^- ## in the scattering experiments of ##e^+e^-## at electron positron colliders ##e^+e^-\toμ^+μ^- ## via ##e^+e^-\to 2γ\toμ^+μ^- ##. This bound state further can decay into ##e^+e^-## or ##2γ##. I am confused about the vertex ## 2γ\toμ^+μ^-...

Dear Envelope, Thanks! its interesting, indeed. Hope so if they are enough lucky they will probe new physics signal by using this single channel. "Compositeness" is really attractive idea, could you guys explain lepto-quarks a little more? Its expected nature? Quantum numbers etc.

Ok got it. Thanks! But in theoretical calculation I am not clear what is the major difference I should have to keep in mind in calculating these partial decay widths. I know in the final result there must be projection on some Y^m_{l} but I am not able to get the difference from start. Do you...

How the relative angular momentum of two particles can be detect by detector in two particle decay (center of mass frame)? I am curious about the signatures/differentiation between different relative momenta, means how one can decide that it is L=0, L=1,2,3,...? Of course the distribution would...

Just read a report on Muon to Electron conversion experiment ground breaking at Fermilab today. What kind of new physics one can probe from this flavor changing among leptons? http://www.symmetrymagazine.org/article/april-2015/mu2e-breaks-ground-on-experiment

Dear Sir Einj..! Thanks for the valuable comments. Could you kindly recommend some basic literature on the fundamentals of hadron decays. I am quite new in this field, just started the graduation course work with little research related the strong decays of hadrons (mesons). Thanks! Looking...

Got it! Yes I was exactly looking this. Thanks for this brief & exact answer, I am on the track now. Let me please correct here once more, for the channel ##a_2\to\rho\pi## with quantum numbers ##2^+\to1^-0^-##, by using relation ##P_{\rho\pi}=P_\rho P_\pi (-1)^L##, now possible value of...

I am a little confused about; how to identify that Hadron/Meson may have S, P or D wave contribution to its decay to other hadrons. e.g in case of light meson decay a1→ ρπ this decay channel have two partial...