Interaction Definition and 713 Threads

Homework Statement Two charged objects Q1 = +4Q and Q2 = -Q are located on the x-axis. Q1 is at the origin and Q2 is at the x = +S m position. You also have a test charge +qo Homework Equations F = kQq/d2 The Attempt at a Solution So you find that qo is past Q2 on the x-axis...

Why is j=0 to j'=0 forbidden by the parity rule if spin orbit interaction is significant?

Homework Statement One of the mediators of the weak interactions is the Z boson, which has a mass of 91 GeV/c 2. Use this information to find an approximate value for the range of the weak interaction. Homework Equations This is the part that I am having trouble with. I don't know where to...

In my opinion, there should be a magnetic-dipole-dipole interaction between 2 1s-hydrogen atoms, but i could not find anything that confirms this. first of all i discovered this equation here: http://en.wikipedia.org/wiki/Magnetic_dipole%E2%80%93dipole_interaction the potential energy U = -...

I'm not sure what is the correct interaction hamiltonian between an electron in an atom and electromagnetic wave (described classically). According to me there exist two version of this hamiltonian which differ by factor 2: H_{int} = \vec{E_0} \vec{r} \cos(\omega t) or H_{int} =...

Homework Statement A harmonic oscillator starts in its ground state (n=0) at t=-infinity. A perturbation H = -xF(t) is applied between t= -infinity and t = T. (a) by considering the corresponding classical interaction explain why this represents the application of a time dependent force...

I'm working on a problem involving decay of a 2 strange/2 anti-strange tetraquark particle. 4 sample decay diagrams are given and I am to describe them and choose which is most prevalent. In on diagram, two of the strange/anti-strange quarks become two down/anti-down quarks via gluon through...

Just wondering... If the interactions between fermions are the emittance of a boson (from what I understand from the grand design book by stephen hawking) then when you punch someone, is it just high levels of bosons being emmited and clashing or are the actual boson particles colliding?

It's hard to me to understand about the interaction between protons and neutrons by the means of entropy. And Is it possible to know about an entropy of an interaction between protons and neutrons or between quarks:biggrin:?

Homework Statement state which one is dominant in Photoelectric effect, compton scattering, pair production, 1- Gamm rays in AL with 1MeV 2- Gamma rays in H with 100keV 3- Gamma rays in Iron with 100KeV 4- Gama rays in C with 10MeV 5- Gamma rays in Lead with 10MeV Homework...

Hi All, How can a high energy (above 1 MeV) gamma ray interact with a protium (hydrogen with only a proton in nucleus)? Does it only ionize it? Does it break it up? Does a chain reaction occur where antiparticles are formed and then annihilated, spitting out another gamma ray? I've been...

Please teach me this: Why point particle interaction(QTF theory) has UV divergences,but string interaction does not have UV divergences.Because I think that calculating the probability amplitude of a process,we must sum(or integrate) over all possible value of momentum.So how we avoid the UV...

Hi everybody, i have a question concerning potential energy (in all its forms, which basically means all forms of energy except the kinetic one). The kinetic energy of a system is always well defined: in the rest frame it is m² (convention c=1), in a frame moving at a relative speed v compared...

Homework Statement The flow of a single sphere translating at speed U in a fluid at rest far away from the sphere is given by the streamfunction, ψ(r,Θ) = (1/4)Ua2(3r/a - a/r)sin2Θ a=radius of sphere the origin is at the centre of the sphere and the axis Θ = 0 is...

- Lest say that we have a homogeneous liquid that is vibrated at a certain frequency so we get cavitation bubbles inside the liquid. Let's say that the cavitations lifetime is long enough to play with them. - Could we manipulate these cavitation bubbles so we can move them around and...

Looking thru some notes one this, I came across something which I can't get my head around. The Hamiltonian of the system (Helium atom) is H = H_1 + H_2 + W, the energies (kinetic and electron-nucleus) of electron 1, electron 2 and the interaction between the electrons themselves. To find...

Considered a simple system composed by 2 electrons, like the H2 molecule, the exchange interaction is isotropic: there's no preferential direction of the spins in physical space. What is the reason? Maybe the fact that the exchange interaction deals with only with the Pauli exclusion prinicple...

Homework Statement Im being asked what is the minimum energy requiered for the process e + p -> nutrino + nutron assumptions are: 1. Kinetic energy of proton is much lower from his rest mass, not true for the electron. 2. border line case is when nutrino energy is close to zero...

Well, it seems that the chances of a catastrophic interaction with another star (dead or alive) is very minimal. We also know that the chances of this interaction are still minimal once the Milky Way will collide with the Andromeda galaxy (this may increase the total number of stars by a factor...

Homework Statement The spin-orbit interaction splits the hydrogen 4f state into many (a) Identify these states and rank them in order of increasing energy. (b) If a weak external magnetic field were now introduced (weak enough that it does not disturb the spin-orbit coupling), into how many...

In peskin chap 4 on interaction field theory, he first introduced some basics about interaction picture(mostly in pg. 83~87) , it seems he assumed the Hamiltonians H=H_0+H_int in Schrodinger picture are all time-independent, because he used quite a lot of notations like exp(iHt), exp(iH_0t) and...

Suppose that the interaction energy between two atoms is given by: E(R)=-A/(R^2)+B/(R^10) The atoms form a stable molecule with an inter- nuclear distance of 0.3nm and a dissociation energy of 4 eV. a) Determine A and B. b) Calculate the force required to break the molecule. What is the...

According to wikipedia http://en.wikipedia.org/wiki/Diproton "Diprotons are not stable; this is due to spin-spin interactions in the nuclear force, and the Pauli exclusion principle, which forces the two protons to have anti-aligned spins and gives the diproton a negative binding energy."...

Hello all, i wonder if you can help me with a problem I am having. I have a disc and three planes (representing a road, building and roof). For this problem, the disc can be considered a plane. http://i3.photobucket.com/albums/y60/con20or/Fig1.png I know the orientation of each of the...

- We know that for closed systems, energy transfer between the system and the environment can be in the form of heat or work. -We know that for open systems or control volumes, energy transfer between the system and the environment can in the form of heat, work, or mass flow. Let's say we have...

Hello. I'm new so I am uncertain to which forum this post should be posted in so I'll just leave this here. Anyways, I was reading about the four fundamental forces and it came to my mind that the W boson is 80.4 GeV, whilst the two lepton that are excreted upon destruction are 0.511 MeV...

An experiment performed by a German king in the 13th century made me think. He put several babies into a cell with no social interaction but to feed them. They all died with no apparent reason. My question is, why was that? How can the body simply shut down if no social interaction is attained?

Why doesn't dark matter affect the movement of solar system bodies as it does with the galaxies and stars movement?. Is it possible that dark matter affects only at galaxies scales or that the heliosphere interferes with the interaction of dark matter at solar systems scales (I say this because...

Homework Statement Given an interaction lagrangian L = i \, g \, \bar \psi(x)_i (\lambda^a)_{ij} \gamma_5 \, \psi(x)_j \phi(x)_a where \psi_i are three Dirac fermions with mass M and \phi_a are eight real scalar fields of mass m and \lambda_a are the generators of SU(3). I have to find...

In the position representation, its true that we can use operators to represent the coulombic interaction between the proton and electron of a Hydrogen atom. I've never actually given any thought as to what the elements of such an operator would be (in matrix form of course). I know these...

For a leptonic weak interaction diagram, we have an election converted into a neutino and emitting a w- particle. But only left handed part should undergo weak interaction. So basically you should have the left handed part of electron converted into a neutrino(left handed) emitting a w-...

Say we have two complex fields, f_1 and f_2 which each are solutions of the D'Alembert operator or the wave operator in three space dimensions. Say we subtract the square of the magnitude of the difference of f_1 and f_2 from the Lagrangian for the fields f_1 and f_2. In that case the Lagrangian...

My understanding of colour so far is that if we had, say, a baryon with quark content uuu, we would need to invoke a new quantum number that would allow each quark not to be in the same quantum state to avoid violating the Pauli principle. Now apparently this new quantum number is called colour...

What is a CS course that covers how software and hardware are connected? This probably seems simple to most but I have no clue as to how this interaction works. A lot of the courses I've looked up seem to be either hardware or software only. Also, is there a name for this area of CS so I can...

Gravitational force between masses is given by the law of universal gravitation. Electrodynamics force between electric charges is the Lorentz force. Nuclear force between nucleons falls off exponentially with rising the distance. The force between quarks grows in proportion to the distance. Can...

When a charged particle moves through a magnetic field, the field excerts a force in the normal-direction (90 degrees).. Is this caused by magnetic-magnetic interaction? I.e. a charged moving particle sets ut a circular magnetic field, is it this field which interacts with the magnetic...

Homework Statement A dipole p is directed in the positive z direction at the origin. The force on a dipole p in an electric field E is F=(p\cdot\nabla)E If a second dipole is placed at (r, \theta), by what factor must r increase – in terms of p, \theta and r – so that the net force between...

In the semi-classical treatment of light-Atom interaction, light is treated as an electromagnetic wave while atom is thought of as a quantized harmonic oscillator with discrete energy eigenfunctions, the atom can absorb energy from the incident wave and become excited under certain conditions...

Hello, I came to consider the following problem, and cannot seem to find the right way to tackle it. It is not homework, merely a question I'd like to address out of personal curiosity: Consider two volumes V1 and V2, each assumed adiabatic, and linked with a valve. V1 is considered...

hi, let's suppose 2 electrons are far away each other and therefore they interact very weakly. i wonder if in such case there are as many virtual photons in the case they are very close to each other? because i know that only 1 electron in complete vacuum generates an electromagnetic field and...

pan proto experientialism and the quantum exchange interaction. Would the quantum exchange interaction explain how (proto)experiences among particles are intimately shared to form what we perceive as an experience?

I am trying to calculate the excionic and biexcitonic energies in quantum dots using Configuration interaction method. I tried to calculate the two electron integrals for configuration interaction method. The integrals are of the form: \int\int dr_1 dr_2 \Psi_1(r_1)...

I have read so much, please put me straight on "photon interaction" 1. My photon hits matter. 2. It interacts with the atoms of that matter. 3. The electron (say) energy level transition (High->Low) spawns photon(s) of lower energy levels? 4. My photon is now other photon(s) but...

Say you have two magnetic dipole moments, say p1 and p2, which are separated by a distance r, with no external magnetic fields. If you want to figure out the energy of their magnetic interaction, is it valid to figure out the energy of p1 in the magnetic field generated by p2, or vice versa...

Photon interaction cross section? What?!? Hey guys-- I'm practicing for the GRE, and I came across a question that has stuff that's not even in my textbook! I haven't found much from googling either. Here is the question: My instinct was to guess (C) because graphs I had seen of the...

When exciting a phonon mode with an evanescent wave possessing a wavevector ~100-200X larger than freespace but still ~10X smaller than fermi wavevector, would one expect a different resonance frequency for the phonon mode? I would think not.. but experiment seems to say yes. More specifically...

Does anyone know how to construct Fock space in an interacting theory? I am confused by the concept of Fock space in interacting theories, please tell me where is wrong in my following argument: Consider an interacting theory of non-derivative interaction, say, a simple \phi^4 theory...

hi everyone! I am so confused about interaction energy! as you know, in many statistical mechanics books we see there are equations which are taken in a non-interacting system. for example for a two particle system, you can see the total energy is: E = E1 +E2 +E12 while E12 is the...

Hi, I'm Chen. Recently I was trying to study the neutrino interaction with electron. Question: can Pythia generate the event of ( e , neutrino ->...) ? if so, please help me for input program. thanks Chen

The total electric field is the vector sum of electric fields- is this the case with magnetic fields? Experience tells me a vector magnetic field can alter another vector magnetic field- for example, when you push two magnets together.