Coulomb Definition and 219 Threads

I am trying to find out what is the correct way to write the mathematical demarkation for the Coulomb Barrier. You know, if I wanted to write the symbol for the radius of the coulomb barrier. If anyone could show me it in the correct font that would be great. NO, this isn't for...

I have seen the Fourier transform of the coulomb potential quite often. However, I have come across a sum expression for an electrostatic potential V_{cb}(r-r') = \frac{1}{V}\sum_{q \neq 0} \frac{4\pi}{q^2}e^{iq(r-r')} It is equation (2.6) here...

Hi, I have a question about the divergence of forward Coulomb (Bhabha/Moller) scattering. I guess the classical analog of it is the Rutherford cross-section divergence, but that can be explained by the infinite impact parameter. In the QED version - the Bhabha/Moller scattering, it is...

Is the Jellium model only suitable for an electron gas of infinite volume? If I confined a gas to a finite volume using an infinite potential well, is there still a way to cancel out the infinities in the coulomb interactions between electrons?

Homework Statement Show that the expectation value of the Coulomb potential v(\vec{r_1},\vec{r_2})=\frac{e^2}{|\vec{r_1}-\vec{r_2}|}, between two electrons depends on the relative orientation of spin of the two electrons. Assume each electron is in the product state form...

Homework Statement In the absence of the Pauli principle, the Coulomb force would not be saturated, and the energy of a system containing N atoms would vary as N^(5/3). Show that a system of 2N atoms would have an energy lower than that of two N - atom systems. Homework Equations E...

Is there a general analytic solution to the classical motion of a relativistic charged particle in a static Coulomb potential? Of course, the non-relativistic limit is simply Kepler's problem. Quantum effects should be ignored, but relativistic effects (such as E field transforming into B field)...

Hello I am re-reading some of my old textbooks and have come across a simplified (non-relativistic) term used to correct the beta decay spectrum for the coulomb effect of the nucleus on the ejected beta particle. The expression is; F(Z,E) = (2*Pi*n) / (1 - exp(-2*Pi*n)) where n =...

The result is well known, but i need more details about the integral below \int \mathrm{d}^2x \frac{1}{|\mathbf{x}|} e^{- \mathrm{i} \mathbf{q} \cdot \mathbf{x}} = \frac{2 \pi}{q} I've done the Fourier transform of the Coulomb potential in 3D. But failed to get the right answer in 2D...

Homework Statement Three positive point charges (with charge and mass given) A (+3q, 2m),B (+q, m) ,C(+4q, 7m/31) can move in a line under the coulomb repelling of one another. The movement begins when all are at rest. Initial distance are (left to right lie A, B, C) AB = r, BC = 2r. Then...

The Coulomb potential energy between two point charges is defined as: V=[(q_1)(q_2)]/[(k*r)] Suppose that you have two equal, like charges at a distance L, then V_like=q2/(k*L) Similarly, for two equal, opposite charges, V_opp=-q2/(k*L)=-V_like Both situations experience a force of...

Hi there, I'm studying the interaction of one electron atom with an electromagnetic field. In every textbook the starting point is the hamiltonian of the system containing the scalar potential and the vector potential. But then the scalar potential is ignored and I don't understand why. I've...

Towards the end of my atomic and quantum course my lecturer makes a note of residual Coulomb interaction and does a few graphs to show the concequences of it are (such as some states not being allowed do to symmetry) and that they favour larger values of angular momentum, but doesn't really...

Homework Statement Find the deflection angle of a particle moving in a repulsive Coulomb field. Homework Equations The Attempt at a Solution Hi everyone, I can do this no problem if I just knew the equation for a repulsive Coulomb field! Can anyone please help me with this? Thanks

Hi all, I am just new to work on NLO in QCD. I need to know how a Coulomb singularity in QCD is defined? What is the form/expression of this singularity term? Can anyone explain with an example of any Feynman diagram? I am interested in the case of a quarkonium with two gluons in final state...

I have read that charge is supposed to be invariant under time reversal. Now, if I consider two like charges placed some distance from each other, I expect them to repel and go away from each other. In a time-reversed frame, I expect them to approach each other. Since the separation is...

Is there a way to calculate the wavelength, frequency or energy (per photon) of the virtual photons that charges exchange to account for the Coulomb force? This is assuming that it's always the same wavelength, of course.

im generating potentials, however the coulomb is proving tricky. stumbling block is finding a way to write A coth(2x) + B cosech(2x)= (A+B)/2 tanh(x)+(A_B)/2 coth(x) i am at the RHS and need to get the tanh to come out which I am told can be done. the a's and b's might not be quite right...

Hi everybody, I'd like to pose a few questions that I've had for ages. I haven't found any answers except "read some Quantum Field Theory" so I'd appreciate an explanation in layman's (or in "science educated but not at all expert") terms. Suppose we have two small charges, one positive and...

I find Maxwell's equations insufficient and superfluous having the Lorentz & Coulomb's force equations. As far as I see magnetic (Lorentz force) and electric (Coulomb's force) interaction is best defined by these two equations themselves, and although Maxwell's equations can describe quite a few...

I have a question regarding the Coulomb interaction in spaces with non-trivial topology. Suppose we have D large spatial dimensions (D>2). Then the Coulomb potential is VC(r) ~ 1/rD-2. Usually one shows in three dimensions that the Coulomb potential VC(r) is nothing else but the Fourier...

I'm trying to find the experimental evidence for quantum tunneling during a fusion reaction. Take the simple D + D -> T + P reaction. I know that the energies required to make this happen are much lower in actual experiment than what would be predicted by Coulomb's model of the electrical...

Homework Statement q1=q3=5uC,q2=-2uC q2 and q3 have d distance so q2 with q1 d=0.1m q3 and q1 have √2d Homework Equations |q1||q2| F=k---------- r^2The Attempt at a Solution :S

Coulomb gauge fixes gauge by setting div(A)=0. What has it to do with adding a gradient to A and subtract a partial time derivative from V?

¿what is the domain of validity of inverse square laws of Newton and coulomb? I think (correct me if this is false) that at the small scale these laws have been verified accurately , but ¿what happens with large distances? :rolleyes: . ¿Have been done an experiment which measured the...

I am wondering why both Coulomb and Classical Gravity follow 1/r^2 laws. Weak and Nuclear force fall off at much faster distance scales! Does anyone know why it is that both Coulomb and Gravity have 1/r^2 strength, while the other forces have different distance scales?

Or how did Coulomb measure quantity of electricity while doing his experiments that leads him to claim his famous Coulomb's law. F=k\frac{q_1 q_2}{r^2} You can measure F and r for sure. But how about q1 and q2 ?

Ok not 100% if this is right place but it's not homework so... What the hell is a coulomb I've looked everywhere and everything seems to be different. So is it the charge on electrons? Or is it a packet of electrons? 6 million million million electrons = coulomb?!?? Sorry if this...

1. The problem statement, all variables, equations and given/known data ¨ Hi guys. I am working on solving the stationary Schrôdinger equation of the Helium atom by the variational method using a Slater determinant constructed from Slater type 1s orbitals, and in that respect i need to solve...

Given a set of a scalar function V and a vector function, how does one recognize that it is a coulomb gauge or lorentz gauge transformation? Actually there is a method that i use but i am not sure if it is always true: what i do is to make an electric field (from that set and using known gauge...

Hi. Landau and Lifgarbages give an equation describing the angle of deflection of a charged particle of a given initial velocity and impact parameter. It's given on page 102 of their Classical Theory of Fields, available here...

Homework Statement In frame S, two identical point charges q move abreast along lines parallel to the x-axis, a distance r apart and with speed v. Determine the force in S that each exerts on the other: a) using the lorentz force in conjunction with the field of a moving charged particle...

Do you know if someone already found a link between Newton : F = G mm'/r^2 and Coulomb : F = K qq'/r^2 laws ?

in a mass of 12g of carbon there are NA= 6.02215x1023 atoms, each atom has 6 electrons, 6 protons and 6 neutrons. each electron has a charge of -1.6x10-19C and each proton has a charge of 1.6x10-19C, each neutron has no charge. if all the electrons were at the north pole and all the protons at...

Hi every one this is the first time in this wonderful forum :) and i have a question i hope i find an answer ? how can the additiona of a smalll (c/r square)term to the coulomb potential removes the degnerecay of states with different (small) L. (quantum defect)? :confused: thanks

Homework Statement We have a source charge that is a uniform sphere with a radius a (centered at origin) and uniform charge density, \rho. There is a line charge with a length L that begins at Z0 and ends at Z0 + L (lies on the Z axis). This line charge has a uniform charge density of...

The coulomb force is given by k*q1*q2/r^2 so if there are two charges that have negative signs, then the force would be negative. Having said that, a "negative force" would then signal an attractive force since opposites attract. F=-dU/dx, so a negative force would result in a "positive...

The laws of Coulomb versus Ampere and the electromagnetic Machian "paradox" Here's an apparent paradox that has been tunneling about in my little mind lately. Maybe someone out there can help me with it. Imagine if you will, a vast empty region of space devoid of any visible distant...

Hello! Can someone please enlighten me about coulomb blockade & how its relevant to Single Electron Transistors? Thanks :))

The field intencity around a little spherical conductor changes with reverse ratio to the square of their distance. Then let us put another little spherical charged conductor in field of first one. The field lines are no more change with the reverse ratio to the square of their distance(they are...

ive just come across gauge transformations on maxwells equations, and mathematically its all pretty straightforward, however, i then come across choices of gauge, with the simplest being the coulomb gauge which is to set devirgence of A = 0 (A vector potential), youve also got the lorentz gauge...

Homework Statement Hi 1) I read the following article: http://pdg.lbl.gov/2005/reviews/passagerpp.pdf On page 12 of the .pdf there is a figure, figure 27.8, which shows how a charged particle deviates from it's path when scattered by the Coulomb force that comes from the nuclei of the matter...

about coloumb? i wonder why two point charge whose magnitude 0 and +q(or smt different from zero charge) exert a coloumb force to one another .formula says there shoud be no force acting to each other(because of multiplication q1.q2=0) but there is an atraction between them . if this force...

Homework Statement There is a propagating planar wave of the Coulomb potential, \phi = sin(kx - \omega t) . What other fields result when it is assume the magnetic potential, \textbf{A} is everywhere constant? \phi, Coulomb potential \textbf{B}, magnetic field strength \textbf{E}...

If I describe a system by a Lagrange's function L=-\frac{1}{2}\int d^3x\;(\partial_{\mu}A_{\nu}(x))(\partial^{\mu} A^{\nu}(x)) - \sum_{k=1}^N \Big(q_k A^0(x_k) - q_k v_k\cdot A(x_k) + m_k\sqrt{1-|v_k|^2}\Big) (I'm just coping this from my notes. I'm sure the not gauge fixing Lagrangian with...

Homework Statement I'm sure I'm missing something simple here, but to the point: I calculate the electric field a distance r from a uniform straight infinite line charge using Gauss' Law and get an answer; I do the same calculation using Coulomb's law and get the same answer but a pi...

Homework Statement For the potentials: V(\vec{r}, t) = ct \vec{A}(\vec{r}, t) = -\frac{K}{c} x \^x c being velocity of light in a vacuum, determine the constant K assuming the potentials satisfy the Lorentz gauge. b) Do these potentials satisfy the Coulomb gauge as well? c) Show that for a...

I recently had a test question posed to me that asked firstly for an explanation of the terms in the semi empircal mass forumla (which I gave correctly) but then went on to ask: For ^{40}_{20}Ca and ^{208}_{96}Pb estimate the fraction of the binding energy provided by the surface and...

Biot-Savart + Coulomb + Charge Conservation = Maxwell?? Do the Biot-Savart Law, Coulomb's Law, and the Law of Charge Conservation contain the same information as Maxwell's Equations? i.e. \begin{cases} d\vec{B} = \frac{\mu_o}{4\pi} \frac{I d\vec{l} \times \hat r }{r^2} \\ \vec{E}=...

Questions on reversed "Coulomb" force. I've seen that with Moeller scattering, the attractive force between the nucleus and the electron can become repulsive at high relativistic velocities of the electron. What are the energies required for this to occur? Is there an analogous result between...