Cross section Definition and 287 Threads

Hi.. I've got a problem about moment inertia. I don't understand about looking the distance of centroid (y). I am still confucing about the formula of "y" in Moment Inertia. Can you shows me about the formula of y or if any thread for this before, I am glad to see it too.Thanx's for your help...

Hello, how do the angular distributions of Bhabha Scattering e^+ e^- \Rightarrow e^+ e^- and Muon pair production e+ e- \Rightarrow \mu^+ \mu^- differ? Regards, Phileas Fogg

Hello Ive come across some approximate cross section formulas during a course of particle physics. And in a reaction like A + B --> R --> C + D the cross section should be something like \sigma = K\frac{\Gamma_R^{AB}\Gamma_R^{CD}}{(s-m_R^2)^2+m_R^2\Gamma_R^2} Where K is a constant (depending...

Well I'm supposed to draw Thomson cross section in polar plot by MATLAB software. Have I done it right? I mean does this figure that I got seem to be in polar plot or not? t = 0:.01:2*pi; r = 2.8179e-13 x = t,0.5*power(r,2)*(1+power(cos(t),2)) polar(t,x) Thanks

So here's a crazy question...I was trying to think it through and have come up with nothing. Is it possible to bend a laser beam's cross section? For instance, if you are using a diode bar (which has a beam cross section resembling a line) is there a simple way to bend it into a...

How to determine the darcy friction factor for irregular cross section tunnels hi, I needed to calculate the f value for tunnels with these cross section area but I am not sure what are method available to calculate these shapes. Two of those cross section areas are already provided as...

Does anyone know anywhere where I can find reliable up-to-date cross section infromation? In particular I'm looking for the absorption cross section of Gadolinium-157 for thermal neutrons. Everywhere I look seems to give a different value ranging fro 70000barns up to 450000barns.

why is the cross section of photon - proton less than the electron- photon cross section for the same photon energy??

Is there a difference between (1-\gamma^5) and (1-\gamma_5) ? I see the two used interchangeably when calculating cross section.

Cross section means the effective size of a nucleus for capturing a neutron, am I right? But what makes the cross sections for different nucleus different? I am a bit puzzled, why the cross section for Boron(for example) is so high?

I need to use this libraries with confidence. Any articles that involves benchmarking of these cross sections?

Hi all, I'm trying to teach myself high energy physics and was wondering if anyone knew a good reference site on calculating cross sections. I'm specifically trying to calculate the cross section for \nu _{\mu} + e^- \rightarrow \mu ^- + \nu_e using the 4-fermi interaction. Are there any good...

Problem Determine the differential and total cross sections for scattering from a "hard sphere" of radius R ("hard" means impenetrable). Relevant Formulae \sigma (\Omega) d \Omega = \frac{number \ of \ particles \ scattered \ into \ solid \ angle \ per \ unit \ time}{incident \ intensity}...

What does it mean when they say s wave cross section, p wave cross section .. ?

Homework Statement I've been asked to find the cross section of a hydrogen atom in thermal equalibrum at 6000K for a photon which induces a transition from the ground state to the first excited state. The density of states for n=2 is 4x the density of states for n=1 i.e. g(E2) = 4*g(E1)...

I'm extracting data from a Monte Carlo sim. and i need to extract the differential cross-sections of the resultant protons and neutrons in momentum and rapidity space. ie \frac{d\sigma}{dy} ; \frac{d\sigma}{dp} and \frac{d^2\sigma}{dydp} where I know the values of y and p...

I'm writing a paper on Thorium utilization in nuclear reactors. In this connection I'm looking for figures which describe the neutron capture and neutron fission cross sections over a wide energy range (not only thermal). There are probably some online resources unbeknown to me, any hints?

I'm calculating an ionization cross section in partially ionized plasma, with taking into account of correlation effects. I'm trying to do it with help of variation phase method. Please, help me to find some link to useful articles.

Homework Statement The total cross section of a S wave is given by the following equation Sigma=(pi/k)*(b^2)/((E-En)^2+(b/2)^2)) prove that b is the width of the resonance. Homework Equations Nothing that is the only thing The Attempt at a Solution I already solved the question...

For my diploma thesis I must provide a calculation that reproduces the results given on page 46 of the paper hep-ph/0309342 . For those who do not want to look it up, I briefly explain what it is about: It concerns the two-body scattering processes (1) N + V => L + H, (2) N + L => V + H, (3) N...

In a scattering experiment, an aluminium foil of thickness L = 10E-6 m is placed in a beam of intensity of 6E12 particles per second. The differential scattering crosss section is known to be of the form. \frac{d\sigma}{d\Omega} = A + Bcos^2 (\theta) where \theta is the...

If I show something that a cross section is proportional to: 1 / (16p^2 sin^4( x) + 8mpsin^2 (x) + m^2) does it imply that the cross section is proportional to 1 / sin^4 (x) as well?

What is the cross section of a photon traversing the observable universe? That of a neutrino? Dark matter in general?

Calculating Surface area/volume from 2D cross section?? I'm feeling a little stupid today and I need some help...:-p Assume that I have a radially-symmetric 3D object (for example a candle stick or the base of a table lamp) and that I can calculate the surface area of the largest longitudinal...

What is "momentum transfer cross section" ? Hi all, I'm reading a book on electron-molecule interactions and I'm puzzled by a quantity (well, by the difference in definition of two quantities). The book is, for your information, "fundamental electron interactions with plasma processing gases"...

I got the first part of this question but can't seem to get the 2nd part.. A 105 V potential difference is applied to a space heater that dissipates 1000 W during operation. (a) What is its resistance during operation? 11.025 OHM (b) At what rate do electrons flow through any...

I have read about "Thompson Cross section for free electrons" My problem is there must be the other cross sections photons are scattered by free electrons. photons must be scattered by aka protons and as well by alpha particles. Is there any defined cross sctions for the other particles as...

In the book "Gauge Theories of the strong, weak, and electromagnetic interactions" by Chris Quigg the calculus of the scattering of proton-electron is esbosed (chapter 7, section 3 , pag 168). He get the result (in the lab frame): \frac{\mbox d^2\sigma}{\mbox d E^\prime\mbox...

Does anybody know where to get the expected cross section for Z at the LHC (pp at 14 TeV)? (it would be great if you could provide a reference).

In this problem, you will estimate the cross section for an earth-asteroid collision. In all that follows, assume that the Earth is fixed in space and that the radius of the asteroid is much less than the radius R of the earth. The mass of the Earth is M_e, and the mass of the asteroid is m. Use...

I'm going through my intro to mechanical engineering material and there was one thing I was never clear on: If you have a cross section of a rod, why isn't its' area at a cross section pi * r^2 as a opposed to piD^2/4, where D is the diameter?

Is anyone familiar with Breit-Wigner Cross section? Say, for a reaction with 2 particles in the initial state, 1 intermediate and 2 final: \sigma = \frac{g \pi \lambda^2 \Gamma_i \Gamma_f}{(E-E_0)^2 + \frac{\Gamma^2}{4}} I can't see why for the wavelength we should use the momentum of...

I'm looking either for online resources or reference to a good book. I've been trying to help someone with a homework problem in a course entitled, Elements of Mechanical Design which uses Mechanical Design of Machine Elements and Machines by Jack A. Collins. The book sucks. The system...

What is the differential cross section for photo-electric effect? Is there a paper that explains this in more detail? Thanks in advance for any responses!

Area moment of inertia--circular cross section From the bending beam calculation, the moment of inertia of the cross section with regard to a coplanor axis of rotation is used. If we have a circular "beam", the area moment of inertia of a circular disk of radius a about a diameter is I_d =...

Can someone explain what absorption cross section is and how it's figured into an equation? And what is irradiation?

If the area enclosed by an ellipse 4x^2+y^2=1 and its cross section is perpendicular to the x-axis then its volume is? I don't have the slightest clue how to do this? Maybe solve for 2y^2=1-4x^2 set the integral equal to pi times the intergral of 1/4 to 1 of 1-4x^2?