Scattering Definition and 820 Threads

  1. amjad-sh

    A Scattering states at presence of interface with strong SOC

    This thread refers to a paper I am working on. The paper said in the model section that: In the complete set of scattering states we distinguish two orthogonal set of eigenfunctions: (i) the states − → ϕ incoming from the left, and (ii) the states ←− ϕ incoming from the right. Away from...
  2. K

    Scattering angle in relativistic kinematics

    Homework Statement Considering 2 scattering particles with momenta ##p_{1}, p_{2}##, where ##p_{2} = 0## in the Lab reference. The momenta of these 2 particles after elastic collision are ##p_{1}', p_{2}'##, respectively. Due to the 4-momentum relation, we have ##p_{1i}p_{1}^{'i} = e_{1}e_{1}'...
  3. Afina

    B Scattering of light in a strange fashion

    :smile::smile::smile::smile:Have you ever observe in night a source ( spherical) emitting light in strange fashion. If not then observe today. I saw that it was more towards the corner making plus sign or cross sign which can be seen through our eyes . Is there is something which is attracting...
  4. A

    Special relativity - inverse Compton scattering

    Homework Statement In the inverse Compton scattering there is a particle, with energy ##E## in the laboratory frame and mass at rest ##m##, which collide head on with a photon with energy ##E_\gamma##. Finding the maximum energy the photon can have after being scattered. The Attempt at a...
  5. A

    Special relativity - scattering angle

    Homework Statement Finding the maximum scattering angle of a particle whose mass in ##m_1## which hits with relativistic velocity ##v## a particle at rest with mass ##m_2<m_1##. The Attempt at a Solution I've written the 4-momenta (p before the collision, k after the collision and the z-axis...
  6. Decimal

    Rayleigh Scattering and linear polarization

    Hello, I am having a bit of trouble understanding the concept of Rayleigh scattering as it relates to light from the sun. My book states that unpolarized light will hit the atmosphere, and the scattered light will be mainly horizontally polarized, while the unscattered light remains...
  7. R

    Compton Scattering Homework: Wavelength & Angle Calculation

    Homework Statement In a Compton scattering experiment, an x-ray photon scatters through an angle of 17.40 from a free electron that is initially at rest. The electron recoils with a speed of 2180 km/s. Calculate (a) the wavelength of the incident photon and (b) the angle through which the...
  8. D

    Probability of spin-flip due to scattering

    Homework Statement A beam of spin-1/2 particles scatters off of a target consisting of spin-1/2 heavy nuclei. The interaction between the particle and nucleus is given by $$V(\vec{ r})= V_0~\delta (\vec{r})~ \vec{S}_1. \vec{S}_2$$ 1) Averaging over initial spin states, find the differential...
  9. Pushoam

    Compton Scattering: Solving for E with $\phi = 1/4\pi$

    Homework Statement Homework EquationsThe Attempt at a Solution ## \lambda' = 2 \lambda ## ## \lambda' - \lambda = \lambda = \frac { h} { mc} \cos{ \phi } ## Here, ## \phi = \frac { pi} 4 ## is the angle between photon's original line of motion and its line of motion after...
  10. Swamp Thing

    I Heuristic for simple two-photon scattering problems

    I'm afraid this question is going to be a bit hand-wavy, but I'm hoping for a way of thinking about two-photon scattering that would be helpful to a beginner but also give correct results. The starting point is that, for two photons in SPDC and other similar cases, the phase difference is a...
  11. A

    I Entropy of the last scattering surface and today's universe?

    Hi, I am quite confused about followed question, I think scientist think the last scattering surface was dense plasma at the temperature of 3000K. If the today's universe much cooler and less dense then "the last scattering surface" how can anyone says entropy increased by time? Isn't universe...
  12. I

    Classical ellipsoidal scattering Impact parameter

    Homework Statement (x^2 + y^2)/a^2 + z^2/c^2 = 1 Homework Equations [/B] The Attempt at a Solution the answer is : b(θ) = R / (f^2 * tan^2(θ/2) + 1)^0.5 I can't understand how to calculate this. My attempt : (x^2 + y^2)/a^2 + z^2/c^2 = 1 from this. b^2 + z^2/f^2 = a^2 , f = c/a, z =...
  13. A

    I Is the Compton scattering angle related to the incident energy?

    The Compton equation determines the shift of the wave-length of the scattered photon as a function of the ##cos\theta## of the scattered photon. It does not depend on the energy of the incident photon. With some manipulation using the equations of conservation of the momentum and energy, one...
  14. V

    Interpret constraints on scattering amplitude

    Homework Statement For the following theory: ##\mathcal{L}=\frac{1}{2}[(\partial \phi)^2-m^2\phi^2+(\partial\Phi)^2-M^2\Phi^2]+g\phi^2 \Phi^2## Compute s-channel amplitude for process ##\phi\phi \rightarrow \phi\phi##. Interpret result for ##M>2m##. Homework Equations Scattering amplitude...
  15. T

    What is the necessary correction factor for Rutherford scattering in 3D?

    Homework Statement So I recently carried out an experiment for Rutherford scattering. From my lab script is states the following 'Recording the scattering rate as function of angle In order to compare your results with “Rutherford’s scattering formula”, you must first make a correction for the...
  16. J

    Finding bound state and scattering matrix of Hamiltonian

    Given that the Hamiltonian is H = P^2/(2m) + aδ(X − x(naught)) + bδ(X + x(naught), where x(naught) is a positive number. Find the conditions for bound states to exist and calculate their energies. Find the scattering matrix for arbitrary values of a and b. Can someone help me solve this please.
  17. C

    Transmission over a linear barrier (QM)

    Homework Statement Suppose we have a potential such that $$ V = \left\{ \! \begin{aligned} 0 & \text{ if } x<0\\ \mathcal{E}x & \text{ if } x>0, x<L\\ \mathcal{E}L & \text{ if } x>L \end{aligned} \right. $$ for some electric field ##\mathcal{E}##. I'm trying to find the transmission...
  18. C

    B Question regarding Light by Light Scattering

    I recently read this article from Science Alert regarding Light by Light Scattering (http://www.sciencealert.com/light-continues-to-behave-really-weirdly-in-the-large-hadron-collider). They seemed to be astonished to witness light actually bouncing off each other, as they state that photons pass...
  19. Ken Gallock

    I Wick's theorem and Nucleon scattering

    Hi. My question is about nucleon-nucleon scattering. In David Tong's lecture note, he discusses Wick's theorem and nucleon scattering (page 58-60). My problem is that I don't know how to calculate the second line of eq(3.48): \begin{equation} <p'_1, p'_2|:\psi^\dagger (x_1) \psi (x_1)...
  20. R

    Understanding Rayleigh Scattering and Changing Sky Colors

    Rayleigh scattering is what caused the sky to be blue.. what elements must be replaced to make the sky orange, or yellow or other colors? Is there a list of elements somewhere for the different colors?
  21. A

    Relativistic scattering - determining bound on initial momentum

    Homework Statement A high-energy photon collides with a proton at rest. A neutral pi meson is produced according to the reaction ##\gamma + p \to p + \pi^{0}##. What is the minimum energy the photon must have for this reaction to occur? (The rest mass of a proton is ##938\ \text{MeV/c}^{2}##...
  22. P

    2-body scattering and Mandelstam Variables

    Homework Statement In a 2-body scattering event, A + B → C + D, it is convenient to introduce the Mandelstam variables, s ≡ −(PA + PB)2 , t ≡ −(PA − PC) 2 , u ≡ −(PA − PD) 2 , where PA,...,D are the 4-momenta of the particles A, . . . , D respectively, (· · ·) 2 = (· · ·) · (· · ·) denotes a...
  23. Pouyan

    Calculating the Wavelength of Monochromatic Radiation in Compton Scattering

    Homework Statement Compton scattering can be used both to measure the direction and energy of photons in nuclear physics experiments. For a particular preparation a spectrum of Compton scattered electrons was measured which clearly corresponded to a generally monochromatic gamma radiation. The...
  24. bananabandana

    Thomson Scattering In the Early Universe

    Homework Statement Why does Thomson scattering occur in the early universe? Homework Equations $$ e^{-} + \gamma \rightarrow e^{-} + \gamma $$ is a Thomson scattering process if: $$ E_{\gamma} << m_{e}c^{2}$$ (Electrons are essenitally stationary) The Attempt at a Solution [/B] Very confused...
  25. Daniel Petka

    B Is Inverse Compton Scattering Related to the Doppler Effect?

    Isn't Inverse Compton scattering just the Doppler's effect? A fast moving electron gets slowed down by a photon. This photon then becomes blue shifted, becoming a gamma ray. Kinda makes sense.
  26. Albi Mema

    Consider Compton scattering of a photon by a moving electron

    Homework Statement Consider Compton scattering of a photon by a moving electron. Before the collision the photon has wavelength λ and is moving in the +x-direction, and the electron is moving in the −x-direction with total energy E (including its rest energy mc2). The photon and the electron...
  27. K

    Rutherford scattering and momentum

    I read from a text that Rutherford found out that all the mass must be concentrated in the middle of the atom due to fast-moving alpa ( high momentum) is deflected back at 180 degrees. I am wondering if there is going to be no contact collision due to the the kinetic energy being converted...
  28. S

    A Relative sign in diagrams for ##Z##-boson exchange for ##WW## scattering

    Consider the scattering process ##W^{+}W^{-} \to W^{+}W^{-}##. This process is mediated in the Standard Model by 1. a four-##W## scattering, 2. ##Z##-boson exchange, 3. Higgs exchange...
  29. A

    A What Happens When Particles Travel in Non-Crystal Directions?

    Can someone explain this paragraph especially the bold part in simpler language: "If it is not in a major crystal direction or plane ("random direction", Fig. 2), it is much more likely to undergo large-angle scattering and hence its final mean penetration depth is likely to be shorter." full...
  30. A

    Why Does X-Ray Scatter at Angle 2dsinθ?

    This question is as dumb and simple as it can be: Why is the path difference 2dsinθ? Or better said: Why x-ray scatters like in the image? (Couldn't there be another scattering angle for both atoms other than θ?)
  31. J

    I Positron/Proton Scattering Weak Charged Current

    Hello, I'm wondering how you would go about drawing a Feynman diagram for a weak charged current scattering interaction of a positron and a proton. I have attached a diagram of what I have tried but it doesn't conserve lepton number (I think this is a problem, from what I gather...
  32. Muthumanimaran

    Finding the scattering cross section

    Homework Statement In an experiment carried out with a beam of thermal neutrons it is found that on traversing a 2mm thick foil of 197Au, some 70% of the neutrons are removed. What is the total thermal neutron cross-section for this isotope of gold? Comment on the result of the cross-section...
  33. H

    Compton Scattering Angle Calculation

    Homework Statement A photon with wavelength 0.1385 nm scatters from an electron that is initially at rest. What must be the angle between the direction of propagation of the incident and scattered photons if the speed of the electron immediately after the collision is 9.30×106 m/s? Homework...
  34. J

    Electron Scattering and Bragg's law

    Homework Statement A beam of thermal neutrons (K = 0.025 eV) scatters from a crystal with interatomic spacing 0.45 nm. What is the φ angle of the first order Bragg peak? (as defined in figure 5.11, φ and the scattering angle add up to 180 degrees). Homework Equations nλ = 2dsinθ = DsinΦ d...
  35. cdot1989

    I Photoelectric absorption versus Compton scattering

    During the photoelectric process, photons are absorbed and electrons are ejected. In Compton scattering, photons are scattered rather than absorbed. My textbook (Quantum Physics of Atoms,Molecules,Solids,Nuclei, and Particles) explains that absorption occurs in the photoelectric process because...
  36. G

    B Does Deep Inelastic Scattering Reveal the True Nature of Baryons?

    Hi, There's a pic on wiki page (Feynman type) showing deep inelastic scattering where a fast lepton interacts with a quark in a baryon by a virtual photon (clearly that doesn't change particle type) then there's an arrow labelled X that I guess is maybe a stream of other hadrons (mesons mostly I...
  37. PedroBittar

    I Graviton Scattering: Compute Amplitudes w/Einstein Gravity

    Is it possible to compute scattering amplitudes of a graviton interaction taking Einstein gravity as an effective field theory at low energies? I did not study qft the proper way yet, so any clarifications on the subject would be welcome.
  38. A

    Does Scattering Involve Absorption

    Hi, I read that scattering is just hitting a particle and bouncing off at some other direction. But I also read that scattering involves the complete absorption and emission of a particle/wave. Is this part correct? I have been unable to find that bit of information anywhere else.
  39. T

    Calculating Bragg Angles for X-Ray Scattering from Table Salt Crystal

    Homework Statement The Spacing between the Na and Cl atoms in table salt (NaCl) is ##d=2.82x10^{-10}m##, which was first deduced from Bragg scattering. For an experiment where X-rays of energy 20 eV are produced, what are the corresponding Bragg angles below ##90^{\circ}## for scattering from a...
  40. J

    I Difference between Scattering and Emission of Photons

    Hello, Ok, so I’ve been searching about this for a while and there seems to be a difference in explanations that confuses me. What concerns me is the exact detailed physical mechanism that makes particles cause a scatter of a photon and an emission of a photon. The Wiki page about scattering...
  41. M

    I Difference between absorption and scattering cross sections

    Hi. I'm trying to model the attenuation (extinction) of a weak laser through a gas sample using the Beer-Lambert law. I've found that the attenuation cross section can be written as the sum of both a scattering and absorption cross section, however I'm having difficulty finding a source that...
  42. F

    Correcting results to fit Rutherford's Scattering Formula

    I'm a Physics undergraduate at University and in my labs module I had to recreate the Rutherford Scattering experiment. The basic setup was similar to this: My problem is that this setup only records data in one plane and not 3D. In reality the particles are scattered in a sort of cone...
  43. binbagsss

    I Scattering, 4 point correlator, number of distinct Feynman diagrams

    In order to compute the scattering probability that two particles of type 1 (associated to ##\phi_1(x)##) which come from the far past with the momenta ##p1## and## p2##, to scatter and evolve into two particles of type 2 (associated to ##\phi_2(x)##) with the momenta ##p3## and ##p4## , I am...
  44. C

    Quantum What is the Born approximation and how does it relate to quantum scattering?

    Hi i am trying to understand Borh's scattering but i need article that will teach me step by step. Do you know any?
  45. E

    How Is Scattered Flux Density Measured from a Ruby Laser in the Atmosphere?

    Homework Statement [/B] An unpolarized ruby laser operated at 0.7 μm is projected vertically into a clear sky to investigate the density of the atmosphere. A detector located 10 km from the base of the laser is used to receive the flux density scattered from the laser beam by air molecules...
  46. N

    Shield against induction of sounds from remote source of RF

    It has been demonstrated that it is possible to make humans hear sounds using waves. Abstract From Journal of Applied Physiology Is there a practical method for shielding? I mean using materials for simple attenuation, and/or altering characteristics of waves (frequency, phase and/or amplitude).
  47. G

    Difference between elastic and coherent scattering

    Hi everyone! What is the difference between coherent and elastic scattering. Maybe the elastic scattering implies that there is not loss of energy, whereas the coherent scattering implies that the wavelength of a ray (or rays) is the same before and after the scattering? Thank you in advance.
  48. Bloopy

    B Doubt regarding Rutherford's Alpha Scattering Experiment and Impact Parameter

    It is mentioned in my Textbook that if alpha-particle has large impact parameter, it gets scattered through small angles and vice versa. I understand that impact parameter is defined as the perpendicular distance between the path of a projectile and the center of the nucleus. I am unsure how...
  49. mfb

    I Evidence of Light-by-light scattering by ATLAS

    For centuries, scientists argued whether light was waves or particles. Light scattering with other light would favor the particle concept. Today we know both models are wrong, but quantum electrodynamics also predicts this scattering - just with an incredibly tiny rate, so it has never been...
  50. P

    What is the Fraction of Energy Lost by an Electron in Elastic Scattering?

    Homework Statement An electron collides with a particle with mass M at rest and scatters elastically through an angle θ (assume electron mass negligible). Show that the fraction of energy lost by the e- is: (Ee - Ee')/Ee = 1/[1+ Mc2/Ee(1-cosθ)] Homework Equations Conservation of Energy: Ee +...
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