Scattering is a general term for several physical processes in which radiation of some sort changes direction due to an interaction with a particle. Scattering can be classified by the type of radiation (ie, electromagnetic, x-ray, neutron), or by the relative sizes of the wave and the particle (ie, ...

learn more… | top users | synonyms

0
votes
0answers
29 views

Free particle scattering in 2D using polar coordinates

The free particle hamiltonian commutes with the angular momentum operator L and Lz, so we can use a spherical wave basis instead of the regular plane-wave basis |k>, using spherical Bessel function ...
2
votes
1answer
30 views

Feshbach resonance in simple terms

I was reading up Feshbach resonances in cold atoms and I was unable to grasp the concept. I will tell you what I have understood. We consider two body scattering processes elastic as well as ...
2
votes
3answers
57 views

Why stars are white? According to Rayleigh Scattering

According to Rayleigh Scattering, the red waves are capable of travelling a long distance, so that only we are seeing the Sun as reddish during Sunset and Sunrise. If this was true then all other ...
0
votes
1answer
21 views

What is the charge/matter distribution?

I am a mathematics student who is doing an introductory course in nuclear physics and since the course is rather elementary a lot of the definitions/derivations are skipped which makes it quite tough ...
0
votes
0answers
18 views

Correlation function and scattering amplitude in critical phenomena

When we use scattering radiation to probe critical phenomena, we have the usual Bragg relation for constructive interference $$|\vec{k}|=\frac{4\pi}{\lambda}sin\frac{\theta}{2}$$ where $\vec{k}$ is ...
6
votes
0answers
80 views

What is the physical interpretation of the automorphism on bounded operators induced by an S matrix?

In a QFT, the S-matrix $S$ is a unitary operator, that fixes the vacuum and commutes with the unitary operators implementing the action of the Poincare group on an appropriate Hilbert space $H$. ...
1
vote
0answers
40 views

The interaction between waves and particles according to their wavelength [duplicate]

Why do EM waves with a large wavelength like those in the red range (and radio waves) interact with particles less than those in the blue range? That is the reason why the sky is blue, is that right? ...
5
votes
1answer
360 views

Why can't Compton scattering happen in leading order of perturbation theory?

Why is the matrix element of Compton scattering in leading order of perturbation theory equal to zero? Why can this process only be described in second order of perturbation theory, i.e. with exchange ...
1
vote
0answers
46 views

potential barrier scattering when particle energy equals to the barrier height

What happens if we have $E=V$, where $E$ is the energy of a incoming particle and $V$ is the height of a square potential barrier? This wiki page actually gives a finite transmission probability for ...
0
votes
1answer
46 views

Finding finite square well width and depth from transmission resonance

For an electron incident a one-dimensional finite square well the transmission probability is $\approx$1 for electron energies $E_1=0.6 \textbf{ eV}$, $E_2=1.9 \textbf{ eV}$ and $E_3=3.4 \textbf{ ...
4
votes
1answer
29 views

What causes these rainbow effects using a polarizing filter on an airplane?

I know that light reflected from a surface at 45° is polarized and that for a similar reason skylight arriving from a direction orthogonal to the sun is polarized too. Photographers make use of this ...
0
votes
0answers
13 views

plane wave state used for scattering calculation

When we do scattering calculation off a potential barrier, normally we would assume some incident plane wave and then make use of the boundary conditions. But how is this corresponding to the ...
0
votes
2answers
49 views

One dimensional scattering cross section

My quantum mechanics book (http://www-thphys.physics.ox.ac.uk/people/JamesBinney/qb.pdf, pages 94-95 of the pdf, or 86-87 of the book) considers the one dimensional step potential ...
1
vote
1answer
68 views

Altarelli-Parisi Splitting Function $P_{qq}(z)$ vanishing integral if and only if quark flavour sum rules and equivalence

Question 1: I believe both questions are in the context of Deep Inelastic Scattering. I've been given the expression for $F_{2}^{ep}(x)=(\frac{2}{3})^2[u(x)+\bar{u}(x)] +(\frac{1}{3})^2[d(x) + ...
2
votes
0answers
25 views

Model of scattering in wet things

You know that clothes and some surfaces become darker when wet (covered in an earlier question: why wet is dark?), because of the disordered reflections or of the refractive index of water or ...
4
votes
5answers
2k views

Why is the sky of the moon always dark?

Why is the sky of the moon always dark compared to the sky of the earth, doesn't it have day and night like earth?
0
votes
0answers
19 views

How much of the sunshine is scattered into the space?

How much more sunshine will the earth ground receive if without the atmosphere?
2
votes
1answer
59 views

Probability current in scattering problems

This is a section from Wikipedia: In regions where a step potential or potential barrier occurs, the probability current is related to the transmission and reflection coefficients, respectively ...
0
votes
0answers
35 views

Does photon polarization take place without scattering processes?

Behind two perpendicular crossed polarisation filters (for visible light) the intensity of light will be zero. After installing a third filter between the two others non parallel to each of them some ...
0
votes
1answer
24 views

What is the reduced width amplitude of an unstable state?

Particularly used in nuclear physics when describing the lifetime (i.e. partial decay width) of a resonant state (a.k.a resonance) is the term "reduced width amplitude". I have searched online, and ...
0
votes
0answers
11 views

Solution for elastic wave on plane of ideal contact between two half spaces of elastic, homogeneous, isotropic, linear solids

Please give the solution for elastic wave of arbitrary polarization incident at arbitrary angle on plane of ideal contact (meaning no slip, homothermal, nondissipative, and no transfer of material ...
5
votes
1answer
31 views

How would a huge ball of air look in space from outside and from inside?

If you replaced the Earth (except the atmosphere) with air and kept the pressure linear to the center (of the now non-existing Earth) while ignoring the effects this would have on gravity and leaving ...
1
vote
1answer
37 views

Resonant vs. Non-resonant Raman

What does it mean to say that the conventional Raman effect is non-resonant? And, how/why does resonant Raman give a stronger signal than the non-resonant type?
1
vote
1answer
71 views

Relation between scattering matrix and an effective Hamiltonian

Could somebody provide the proof (or reference to some accessible literature) of relation $$S(E) = 1 + 2πiW^{†} (H_M − E − iπW W^{†} )^{−1} W \tag{2}$$ of arXiv:0806.4889, which relates $S$-matrix to ...
1
vote
0answers
23 views

Mie's scattering Theory Problem

Is Mie's theory which describes the scattering of EM wave off sphere , possible to extend to spheroidal ? object or arbitrary shape with finite series expression ? I tried to replace the radial ...
1
vote
1answer
140 views

Are reflection and transmission coefficents real or complex?

Is it common practice to give reflection and transmission coefficients as the ratio of the respective waves with respect to the incident wave when written in complex form or real form? I have seen ...
1
vote
0answers
26 views

Tadpole-free condition

Tadpole-free is a very important condition for perturbative string theory (which is equivalent to the theory to be expanded around the "right" vacuum). For simplicity, let's consider closed string ...
0
votes
1answer
38 views

A conjecture about the Møller operator

Consider the Møller operator $$ \Omega_+ = \lim_{t \rightarrow -\infty } e^{i H t } e^{- i H_0 t } , $$ Now, suppose a state $\psi $ is located far away from the potential $V = H- H_0$. I feel that ...
0
votes
2answers
88 views

What is the necessity of wave packet in studying matter wave?

I am new to this realm of physics. I have literally understood the matter wave, wave function; read the trapped electron in an infinite potential-well. But what I didn't understand is the concept of ...
0
votes
0answers
35 views

Differential Cross sections from amplitude scattering matrix

How can I get the differential cross sections from the amplitude scattering matrix, $S$ (2x2 matrix)? I've seen this in a Mie solution solver: Parallel Polarized Light: dCsdOp = $\frac{2}{\pi k} ...
2
votes
3answers
134 views

Could the sky on a planet theoretically be any color?

The sky on the Earth is blue. Could the color of the sky on a planet with an atmosphere be of any color theoretically? Which colors are the most likely? I think it would be really awesome to have ...
1
vote
1answer
39 views

Why ingoing and outgoing impact parameters equal in elastic scattering?

Take the Rutherford scattering, as for example in this picture: What is the easiest way to show that the impact parameter "b" (see picture) is the same for the ingoing and outgoing trajectories? ...
0
votes
0answers
35 views

Scattering of slow neutrons

I've here a spectrum which was obtained from the scattering of slow neutrons on uran. But I'm not sure what I'm actually see there. Can someone explain the "scattering of slow neutrons"? Edit: ...
1
vote
0answers
37 views

Deriving general boundary conditions from first principles for elastodynamic scattering

It seems that most of the relevant books only give the linear case and the rest say something along the lines of "here are common examples of boundary conditions." What are the most general boundary ...
0
votes
0answers
39 views

Angles in Born approximation Spherical Potential

I have a question concerning (in my opinion) strange notation that arose in both the book by Shankar and Sakurai in the same manner. Where i am very confused by them both seemingly using the same name ...
1
vote
0answers
26 views

How to write down the Lippmann-Schwinger equation for such a problem? [closed]

Suppose there are three particles, 1, 2, 3. Initially, particle 2 and particle 3 form a bound state. Particle 1 is free. Now we want to study the scattering of particle 1 against the 2-3 bound system. ...
4
votes
0answers
83 views

Derivation of the Lippmann-Schwinger equation

I was trying to understand the derivation of the Lippmann-Schwinger equation in Sakurai's Modern Quantum Mechanics, Section 6.1. Our teacher presented a much simpler derivation, similar to that on ...
2
votes
1answer
45 views

Scattering Matrix of a Given Circuit - Microwave

This might be an easy question but I couldn't find it in our course book[Microwave Engineering, Pozar, 4th ed] or on internet. I have a homework and one of the questions asks me to find the S-Matrix ...
2
votes
1answer
34 views

Space-like pion electromagnetic form factor

The 1986's publication "A measurement of the space-like pion electromagnetic form factor" (http://dx.doi.org/10.1016/0550-3213(86)90437-2) starts with: The pion form factor has been measured in ...
1
vote
1answer
119 views

What is the most accurate experimental confirmation of Rutherford's $\sin^{-4}\phi/2$ law?

What is the most accurate experimental confirmation to date of Rutherford's $\sin^{-4}\phi/2$ law, where $\phi$ is the scattering angle?
1
vote
0answers
19 views

QM scattering in a finite-sized box

Background Consider a non-relativistic particle in a one-dimensional box of length $L$ with (for definiteness) an attractive delta function at the origin: $H = \frac{P^2}{2m} -|c|\delta(x), \qquad ...
2
votes
2answers
125 views

Rainbow reflected on TV screen? (pic attached)

According to wikipedia, A rainbow is an optical and meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets... Given that we require ...
0
votes
0answers
19 views

Why we're using Rollnik type potentials in non relativistic scattering?

I'm studying non relativistic scattering theory and I just started the section relative to time independent scattering with one-particle potential. According to my lecture notes, a potential is ...
0
votes
1answer
26 views

Thomson scattering: radiation scattered in one direction or all directions?

I have a question about how Thomson scattering takes place. Say X-rays hit a bound electron in a crystal. (These electrons aren't "free", but the energy difference is so large that the scattering is ...
1
vote
0answers
32 views

X-rays scattered at righ angles of the incident ones: are they polarised?

Basic books dealing with the interaction of X-rays with matter ussually don't mention anything about the polarisation, but I read somewhere that X-rays scattered in matter are linearly polarized, ...
2
votes
1answer
48 views

Intensity of light wave penetrating soft tissue

I'm studying for a medical physics exam and I'm struggling with the following question: Calculate the fraction of energy which penetrates to a depth of 3cm in soft tissue for a beam of light at a ...
0
votes
0answers
18 views

Relation between Compton Wavelength and Bound States

In their paper, "A Theory of Dark Matter" (http://arxiv.org/pdf/0810.0713v3.pdf), the authors in a section argue that if there is a massive dark matter particle $\chi$ which interacts via a force ...
1
vote
0answers
29 views

Why organic materials' hole mobility is usually higher than electron mobility?

Most of OFETs, and in particular OTFTs, are p-type (p-channel devices), because the hole mobility is higher than the electron mobility in most organic materials (wikipedia). What is the reason for ...
1
vote
1answer
90 views

Boundary Conditions in a Step Potential

I'm trying to solve problem 2.35 in Griffith's Introduction to Quantum Mechanics (2nd edition), but it left me rather confused, so I hope you can help me to understand this a little bit better. The ...
3
votes
1answer
62 views

Scattering amplitude with on-shell virtual photon

Let's assume electron-electron scattering in QED in second order of perturbation theory. Then in the corresponding scattering amplitude there will appear photon propagator $$ D_{\mu \nu}(q = p_{i} - ...