Recent content by helpcometk

Homework Statement Compute ∫^{∞}_{-∞}dx (x2+a2)-1δ(sin(2x)), without calculating the resulting sum. Homework Equations This is a very specific integral which ,has a delta function δ operating on sin function The Attempt at a Solution Does anyone know this integral ? I...

Homework Statement Dear friends I am trying to type Latex using a proffesional package. I have installed MikTex 2.9 ,but i also need a comfortable editor,which will not cause too much trouble to me when trying associate it with MikTex after installing it. So, which editor should i...

is coupling G (graviational coupling) actually a constant of nature or it can vary?

The image i uploaded as i said , was taken from a homework assighnement.I don't know where he found it ,maybe a book came from an alternative universe through a wormhole,where the charge conservation law doesn't hold ,and so my teacher thought it was from our own universe.

well, i have just entered the field of particle physics ,and i don't know many things. Thanks for the replies

From my minimal knowledge on Feynaman rules i know that a feynman diagram has to conserve charge along a vertex. If it is the e-e+ --- > e-e+ process shouldn't the question also clarify if it is spinless or not andrien ?

No charge conservation Do you think this might be a typo? I will completely honest with you , this is a question from a homework :(look the attachement) if there is a typo then should the process e-e+ --- > e-e+ be considered an exotic scattering?

ee --->e+e+ scattering Homework Statement I have come across the following scattering : e-e- ---->e+e+ Does anyone know the name of this scattering ? Do you know of any book describing simililar lepton scatterings? Thank you Homework Equations The Attempt at a Solution

Yes its sort of obvious that I am stupid. Thanks

Homework Statement I have read the following text in a textbook(look the attaxhement) ,and i have a simple question .WHY every 2x2 hermitian matrix would have to satisfy this Equation.It is not obvious to me why.Does anyone know the answer? The textbook stops there without giving any...

thanks

qq- --->qq- differential cross section and mandelstam variables Homework Statement for the problem statement please look the attachement Homework Equations The problem is asking to express the mandelstam variables in temrs of the scattering angle θ.I would like to ask the quastion...

Homework Statement Hi guys ,please look at the integral on the attachement.Does anyone have seen this integral before ? Homework Equations We have the following two properties : ∫δ'(x-x0)f(x) dx =-f'(x0) δ(x^2-a^2)= {δ(x-a) +δ(x+a)}/2a The Attempt at a Solution Please help...

Homework Statement Given that the derivative θμ transforms as a covariant vector ,show that θμ transforms as a contravariant vector. Homework Equations Please look the attachement The Attempt at a Solution Does anyone know how i should go to prove it ?Is it just a trivial...

you can play as long as you ant with this formula ,but you will never be able to get what is asked except if you differentiate somehow ,becsuse you need have one n ,that is not exponent of A or B