Scattering Definition and 820 Threads

Hello, does anybody know how to compare (at tree level) the two reactions e^- + e^+ \to \gamma^\ast \to e^- + e^+ and e^- + e^+ \to Z^\ast \to \nu + \bar{\nu} \;\;\; \text{and} \;\;\; e^- + e^+ \to W^\ast \to \nu_e + \bar{\nu}_e The first process is the so-called Bhabha...

Why is it that the formula for compton scattering does not include the binding energy for an electron to the nucleus? Seems like the scattered electron can have a continuous range of energies from 0 to h/mc. Why isn't this quantized?

Homework Statement In an experiment, an alpha particle of mass 6.7e-27 kg; charge 3.2e-19C travels in a straight line with a speed 2.0e7m/s towards the centre of a gold nucleus. Find: 1. The kinetic energy(KE) of the alpha particle; 2. The potential(V) at a distance 'x' from the centre of the...

Hi everyone. I was going through section 4.2 of Halzen and Martin, when I came across the following step \Box^2 A^{\mu} = j^{\mu}_{(2)} where j^{\mu}_{2} = -eN_{B}N_{D}(p_{D}+p_{B})^{\mu}e^{i(p_D-p_B)\cdot x} Now, according to the authors, Question 1: Shouldn't this be the solution in...

Homework Statement Consider a beam of neutrinos moving in the x direction at energy of 200 GeV, and passing through a block of iron. (a) The density of iron is ρ = 7.9gcm−3. In the rest frame of the neutrino, what is the flux of iron nuclei which are moving in its direction (give the...

Beta particles are fast moving electrons emitted by the nuclei of certain atoms. When beta particles enter a material they may be deflected, and after penetrating a short distance into the material, may be moving in any direction. Some of these particles may have their motion reversed by their...

I have yet another question... I was always thinking that the scattering amplitudes one computes in QFT are complex numbers of modulus between 0 and 1. And I was thinking that because it is supposed to be related to the probability of some transition between states happening. And then I tried...

Hi What is the best book about neutron scattering and diffusion? Regards

Hi, Following my recent https://www.physicsforums.com/showthread.php?t=375638" with density matrix formulations of scattering theory, here's a question I faced on yesterday's particle physics exam. I did some mechanical computation, but I am not fully convinced of what I did (basically computed...

Hi everyone, I'm looking for books or resources where I can read about things like measurement of cross section, cross-section asymmetry and polarization in the context of pion-neutron scattering, but also more generally in particle physics. By measurement, I don't mean experiments alone, but...

Hey guys, Im trying to derive the following equation (mc^2) [(1/E2)-(1/E1)]+cos(theta)-[((E1-E2)^2)/(2E1E2)]=1 E1 = Incident Photon's energy E2 = Scattered Photon's energy theta= scattering angle m = mass of electron c = s Using conservation of energy,conservation of mass, and...

Homework Statement Derive the equation non-relativistic equation for Compton scattering (mc^2) [(1/E2)-(1/E1)]+cos(theta)-[((E1-E2)^2)/(2E1E2)]=1 E1 = Incident Photon's energy E2 = Scattered Photon's energy theta= scattering angle m = mass of electron c = s Here is the lab In...

Hey folks, you don't happen to know where i can find a list of all possible Feynman diagrams contributing to a 5-gluon-amplitude? I am currently working on a comparison of beyond-feynman-graphs-techniques (colour-ordering, BCF, CSW, MHV,...) and old-school calculations using Feynman...

Can anyone help me to solve the PDE via Inverse Scattering transform method?

Trying to find the angle of the velocity vector from a recoiled electron after an impact from a photon. I have already found the initial energy of the photon, and the energy of the scattered photon, and so can calculate the momentums. I know the photon is scattered at an angle of 110...

Hi, I'm trying to derive a simple formula for 180° scattering. I've got to this stage and I really can't figure out how to simplify it further. \[ \frac{1}{\lambda}-\frac{1}{\lambda'} = \frac{2m_ec}{h} \] What I actually need is: \[ \lambda' - \lambda = \frac{2h}{m_ec} \] I'm...

Homework Statement Estimate the radius of the last scattering surface, using the age of the Universe. Why might this underestimate the true value? Homework Equations For a matter dominated universe particle horizon distance = 3ct The Attempt at a Solution I assumed the way to do...

Hi, see attachment for questions/equations and my attempt. I have had a go at this question but cannot get the correct answer, could someone be kind enough to point out my mistake and point me in the right direction. Cheers (sorry for poor pic quality)

I'm trying to understand Central Force problems and Scattering (from a central force) but the website of my course (I'm studying Analytical Mechanics) doesn't offer very good matterial on the subject. Can anyone suggest good papers about it, accompanied by problems and their solutions? Thanks.

Hi everyone.Electon-electron or Moller Scattering is the topic of my homework and i also have to derive the differential cross section equation/formula. The problem is i do not know how to start it and continue. Please help me and show me a path.It also may work if you have already worked...

I'm wanting to get another optics book. I'm interested in finding a book that gives insight into how light waves interact with surfaces such as in reflection and x-ray diffraction and things like that using sufficient diagrams of the wavefronts and particles and rayleigh scattering. I want to...

Hi! I have the following problem: Example: collision of 2 electrons For non-relativistic scattering it is easy to show that the speed of the CM frame with respect to the lab frame is equal to the speed of the electrons in the CM frame, expoloiting the fact that in the lab frame, one of the...

I have a problem here that has me a bit suck: In scattering between incident neutrons and target protons at rest, show that the angle between the two scattered particles is always 90 degrees. I have set up the conservation of energy and momentum equations and have: Energy: Tn=T'n+Tp...

What's wrong with this MATLAB code for Rutherford scattering, it won't run for me! :( Hi, I can't do matlab...and have to plot the trajectory of alpha particles in rutherford scattering. I've made an attempt, but i know I've gone wrong somewhere. Could someone tell me how to fix it? I'd be...

I just need an explanation of this. Found it in a question. :smile: Also, photons when absorb by an electron in an atom, does the energy (if less than the ionisation energy) have to be exactly equivalent to one of the energy states and if it isn't what happens? You probably think I suck at...

Homework Statement A beam of particles strike a wall containing 2 x 10^29 atoms per m^3. each atom behaves like a sphere of radius 3 x 10^-15 m. Find the thickness of the wall that exactly half the particles will penetrate without scattering. What thickness would be needed to stop all but...

Homework Statement Consider the situation where high-energy gamma rays are striking a detector after scattering off of the electrons in the material surrounding a detector. Show that if the gamma rays are perfectly back-scattered by the material, such that the scattering angle is θ = 180...

Homework Statement photon scatter angle is theta, electron recoil angle is phi prove tan(phi) = (1+hf/mc^2)^-1 cot(theta/2) Homework Equations The Attempt at a Solution Conservation of energy is the same as in here: http://en.wikipedia.org/wiki/Compton_scattering...

Dear participants of a forum. The phenomenon of quantum entanglement arises only when there is the INTERACTION between two objects of a microcosm. However there is a question: What is such INTERACTION? Whether the scattering matrix is the key moment in such interaction...

This is not a homework problem, just a question I encountered I thought I should figure out. Homework Statement ....__... _______ ..._____...|..|_ ..|-------------Energy ....|_|...|_| ...A...B.C.D..E...FEdited due to formatting of my picture. Please ignore the periods I had to use them to...

hi, here's the problem: imagine a heavy nucleus and an electron approaching it with some momentum pi. it scatters elastically off the nucleus at some angle \theta and momentum pf. the nucleus can be considered to remain at rest, since it is so massive. I have to start with the definition...

First off, this is not a request for a numerical answer. We've started discussing scattering matrices in my High frequency engineering class, and I'm having some trouble understanding wave mechanics. This got no attention in the homework forum, so I'll just copy paste from there. In a 2x2...

Homework Statement Alpha particles of kinetic energy 9.6MeV are incident on a silver foil of thickness 7.0 micro meters. For a certain value of the impact parameter, the alpha particles lose exactly half their incident kinetic energy when they reach their minimum separation from the...

Hello, I want to do a scattering calculation with two particles scattering to two (other) particles relativistically. Is it correct to use the following conservation laws? \vec{p}_1+\vec{p}_2=\vec{p}_3+\vec{p}_4 \gamma_1 m_1c^2+\gamma_2 m_2c^2=\gamma_3 m_3c^2+\gamma_4 m_4c^2 where the...

Homework Statement I'm supposed to calculate the scattering amplitudes of some spherically symmetric potentials in the Born approximation and just trying to figure out how that works in general and what a scattering amplitude is actually. Homework Equations 1+1=2 The Attempt at a...

Homework Statement If the maximum kinetic energy given to the electrons in a Compton scattering experiment is 10 keV, what is the wavelength of the incident X-Rays? Homework Equations \Delta\lambda = (h/mc)*(1-cos\theta) E = hc/\lambda \Delta\lambda = \lambdascattered - \lambdaincident...

I'm reading through the Introduction to Quantum Mechanics book by Griffiths (2nd edition) and it is describing delta-function potential wells. When it describes how to find bound states the energy is E < 0 (negative) in the region x < 0 (negative). It says the general solution is: \psi (x)...

Hi For example in e-e- -> e-e- scattering (electron-electron scattering) the differential cross section goes to infinity as theta goes to zero. Consequently the cross section is infinite. But how can we measure and interpret the cross section/differential cross section and interpret it as a...

This is actually for a graduate course but it's a basic special relativity problem, i.e. undergraduate-level material, so I'm posting it here... Homework Statement Homework Equations U^{\mu} = (1, 0, 0, 0) (in the observer's rest frame) V^{\mu} = (\gamma, \gamma \vec{v}) P^{\mu} =...

I can't find the value of the Yukawa coupling g, for neutron-proton scattering for example, where the Yukawa potential reads - g^2 exp(-m*r) / r. Can some1 tell me at least an approximate value?

I'm reviewing my scattering processes and can't quite pin down the difference between raman and compton... It sounds like Compton scattering is exactly the same as Raman scattering (with inverse-compton = raman stokes scattering; and normal compton = raman anti-stokes scattering). Also, just...

Homework Statement A photon whose energy equals the rest energy of the electron undergoes a Compton collision with an electron if the electron moves off at an angle of 40 degrees with the original photon direction, what is the energy of the scattered photon.Homework Equations E2 = (m0c2)2 +...

Homework Statement Using energy and momentum conservation requirements, show that a free electron cannot absorb all the energy of a photon. Homework Equations Einstein energy-momentum formula: (E)² = (mc²)² - (cp)², where m = mass, E = energy, c = speed of light, and p =...

Homework Statement 48. If a 6.0 keV photon scatters from a free proton at rest, what is the change in the photon's wavelength if the photon recoils at 90 degrees? 52. A gamma ray of 700 keV energy compton-scatters from an electron. Find the energy of the photon scattered at 110 degrees...

Hi, I have a question regarding the Electron scattering angel Teta in formula in: http://www.whfreeman.com/MODPHYSICS/PDF/3-2bw.pdf which indicates Compton wavelength shift by: labda2 - lamda1 = (h/mc)(1 - cos(Teta)). (3.40) With Teta = 0 we get labda2 = lamda1 (no change of energy by the...

Perhaps this question is silly, but I don't entirely understand how elastic scattering of photons is even possible given that the directions of the incident/scattered photon differ. If there is a change in direction of the photons momentum, then there must be some momentum transferred to the...

A 0.88Mev photon is scattered by a free electron initially at rest such that the scattering angle of the scattered electron is equal to the scattered photon.How to find the angle??

Pion Nucleon Scattering and a bit about group theory/ representations Hello everybody, I am going through Ryder's book about Quantum Field Theory right now. In the chapter about Pion Nucleon scattering he writes the interaction term like L_{int}=ig \bar{\psi} \gamma_5 \tau_a \psi \phi^a...

I need to know the magnitude of the velocity perturbations (peculiar velocities) dv at time of last scattering as function of the multipole moment. The temperature power spectrum of CMB shows temperature fluctuations dT/T ~ 10^-5. That naively suggests the peculiar velocities were dv/c ~...

In air, high angle scattering of alpha radiation from Am241 is almost non existent. When a sample is pulled away from a detector the detection rate drops as 1/r^2. But if a thin aluminium foil is inserted in the path almost half of the radiation disappears somewhere else, it do not reach...