Pair Definition and 379 Threads

Two consecutive positive decimal integers are such that the sum of the digits of each of them is divisible by 11. Determine the minimum possible pair of such numbers.

Does anyone could indicate what is the best literature to learn about black hole pair production? Any textbook explaining the instanton derivation in detail for the case of black holes? Jan

Hello, how do the angular distributions of Bhabha Scattering e^+ e^- \Rightarrow e^+ e^- and Muon pair production e+ e- \Rightarrow \mu^+ \mu^- differ? Regards, Phileas Fogg

Say we have two electrons in a spin entangled state about the z-axis |01> + |10>. One electron travels off to our left, the other to our right. The right electron passes through an inhomogeneous magnetic field with gradient solely in the z direction (Stern-Gerlach type), and subsequently...

Hello, Im trying to find out if, since an electron positron pair can anhillate to produce a muon-anti muon pair by the weak interaction, can the same thing occur for the production of an electron/anti-electron pair? Or would it just happen by the electromagnetic force? Or both, with the weak...

A bit confused about how it works. Link - http://www.technologystudent.com/elec1/transis2.htm (3rd fig from top) The way I understand, transistor TR1's Base-emitter conducts, which fwd biases B-E junction of TR2. This in turn will turn on the lamp, but it won't be really bright. Once its...

I was just wondering how you might use Lewis theory to predict the reaction of molecules with an incomplete octet with a molecule that contains a lone pair? The idea is very abstract to me, I'd appreciate any ideas.

Hi guys I hope you can help. The other day I tried to explain to someone the mechanism behind 'stripes' in lightly doped cuprates that gives rise to the Mott insulator/ anti-ferromagnetic stuff. It quickly became clear that my understanding of super-conductivity differs considerably from the...

Homework Statement I have 2 questions from a practice test paper that I can't do (I missed the lessons) - I've attached them, the other questions I did fine. They should be quite basic but I'm not sure if what I'm doing is right (only done physics for 2 weeks). If anyone could correct my...

Homework Statement the 1.0kg block is tied to the wall with a rope. it sits on top of the 2.9kg block. the lower block si pulled to the right with a tension force of 20N. the coefficient of kinetic friction at both the lower and upper surfaces of the 2kg block is mk=.40. what is the tension in...

Hi! I have encountered many differential crossections: \frac{d\sigma}{dE_+d\Omega _+ d \Omega _-} (Pair production of electrons and positrons) Where E+ is energy of positron. However, in all of these crossections, the energy of the electron; E- is included in the formula, e.g eq 2.1.1...

Hi I am looking for a source which covers a differential crossection for pair production of electrons and positrons due to photons. \frac{d^2\sigma}{dEd\Omega} I need it to be valid for high relativistic energies of electrons/positrons and for all angels. I can only find formulas...

Homework Statement A pair of fair dice is rolled until the first 8 appears. What is the probability that a sum of 7 does not precede a sum of 8. Homework Equations Geometric series The Attempt at a Solution P(sum of 7 does not appear before sum of 8) = 5/36 + 5/36 * 25/36 +...

5. A photon of energy E strikes an electron at rest and undergoes pair production, producing a positron and an electron: photon + e * = e * + Positron + e * The two electrons and the positron move off with identical momenta in the direct ion of the init ial photon. Find the kinet ic...

I'm a little unsure about a certain part of this shown in a book. There is an electron and a positron moving in the +x direction. They annihilate each other and release 2 photons. to conserve momentum 1 moves in the -x and one in the +x direction. So then the first step is to do conservation...

I read about "pair production" how a photon can create and electron and a positron. I read the calculations and I understand how this is impossible unless something else (a nucleus) is present to take away some of the initial photon momentum, however, the book doesn't say exactly 'how' the...

Use of the term "pair" vs "ordered pair" Why is it that authors use the term "pair" and "ordered pair" interchangeably and, maybe I'm mistaken, a little imprecisely? For example, in listing the field axioms, the language "for every pair x and y" is usually used. However, surly the author means...

Homework Statement assume that two dipoles are placed back -t0 - back along axis as shown: ((-) a (+))(( +) a (-)) ------------------x axisr is oriented between ))(( but above, a distance...

how do we define the eccenticity of a pair of straight lines

why can't a gamma ray photon -->positron+electron? My notes simply say this would violate momentum conservation (you need a recoiling nucleus), but why? I mean, the photon WOULD have momentum (=E/c), so the sum of momentums of the positron and electron would just have be E/c..

Hi everyone Thanks for taking the time to read my first post. I was reading Bill Bryson's A short history of nearly everything (which may be like saying that I was reading cat in the hat in an english literature forum, but i shall see). Unfortunately I don't have the book here, or i would make...

Homework Statement To show that the minimum energy a photon must have to create an electron-positron pair in the presence of a stationary nucleus of mass M is 2mc^2[1 + (m/M)], m is the electron rest mass. Homework Equations Conservation of energy and momentum.Also the minimum energy a...

Say we have a BELL state |B00> = cos(a) |00>+ sin(a) |11> then for a (just one) pair of entangled particles, we keep one on location q, the other one in location w; the one in q forms a system Q, the one in w forms W. ( 'x' in a function like |v> x |w> indicates a tensor product)...

[SOLVED] Constructive and destructive interefernec and a pair of speakers Homework Statement Two loudspeakers, A and B, are driven by the same amplifier and emit sinusoidal waves in phase. Speaker B is 2.00 m to the right of speaker A. Consider point Q along the extension of the line...

Homework Statement Prove ln(1+x)>=(x)/Sqrt(1+x) Prove (x-1)^2>=x((ln(x))^2) For x>0 Homework Equations The Attempt at a Solution I have tried using MVT, but i only end up with more inequalities that i cannot seem to prove... Another idea that works but i cannot prove exactly...

Why is the nn-pair unbound? I don't seem to find the answer in any of my textbooks =/

Homework Statement Is it possible for pair production to occur without interacting mwith matter? Homework Equations E+ + E- = E(gamma) - 2*m_e*c^2 The Attempt at a Solution In the Coulomb field of nucleus (or electron), the incident photon energy can be converted to the...

Homework Statement Show that the creation of an electron-positron pair (or any particle-antiparticle pair, for that matter) by a single photon is not possible in isolation, ie, that additional mass (or radiation) must be present. (Hint: Consider the reaction at threshold, then apply...

which pair of elements is most apt to form an ionic compound with each other? nitrogen and hydrogen or barium and bromine? please explain

I have read in a book by Jonathan Allday (Quarks, Leptons and the Big Bang, Institute of Physics Publishing Bristol and Philadelphia), the following The positron electron pair which are materialized out of the vacuum are being created by the energy stored in the vacuum(zero point energy) and...

How does string explains pair creation and annihilation ?

Here is a question, which may seem dumb: Consider an electron and a positron that annihilate, both of which are non-relativistic (taking the observer's frame of reference to be the center of mass frame of the electron-positron pair) so that we only consider their electric fields for simplicity...

How did they experimentally verify that there is pair creation and annihilation in the vacuum? What kind of particles usually pops in and out of the vacuum?

study of brane decay that results in a brane/antibrane "pair"? I have heard of anti-branes and have a few questions. Has there to anyone's knowledge been any study of brane decay that results in a brane/antibrane "pair"? Is such theoretically possible?

Homework Statement I'd like to prove a F/T pair and to confim if they are correct. s(t) = A Sin[w0 t] * rect[t/T - T/2] ... (1) it's Fourier transform is S(f) = exp(-j w T)*T/2*A* {Sinc[(w+w0)T/2/Pi] + Sinc[(w-w0)T/2/Pi]} ...(2) where rect is rectangular function Homework...

Ok, so I know the difference between bonding and antibonding orbitals (one the electrons add destructively and the other they add constructively) but what I don’t understand is how we know which electrons will add destructively and which electrons will add destructively. For this wouldn’t we...

Hi! A question from a beginner in quantum physics... If the quantum field randomly produces an electron-positron pair, and the pair annhialate, a gamma ray photon is produced. The net result of this process is gamma ray photons coming out of the quantum field at random. This means the...

Homework Statement A photon of energy E strikes an electron at rest and undergoes pair production, producing a positron and an electron: photon + (e-) = (e+) + (e-) + (e-) The two electrons and the positron move off with identical momenta in the direction of the initial photon. Find...

Dirac's theory of the electron predicted that there were identical particles of equal mass but of negative energy. He appealed to the Pauli exclusion principle and proposed that there was a negative energy 'sea' of electrons that was full up to -2mc^2 in order to answer critics that positive...

Hi, I have a little circuit board that drives some solenoids that keeps going bad. It belongs to a scale that is made by a company that is now bankrupt so they aren't much help. They used a photocoupler (Sharp PC844 - IRED coupled to phototransistor) and an NPN transistor (2N4401) to create a...

Hello everyone, Another example from the book I'm going over and I'm not exactly sure how they got their answer: The game of poker is played with an ordinary deck of cards. Various five-card holdings are given special names. a. how many 5 card poker hands contain two pair? Well I'm...

Why does pair production cannot occur except in the presence of another body? The explanation is so that linear momentum is conserved but why does a photon must first collide with something? I can see how linear momentum is conserved without a collision first. i.e. the two particles move with...

A concept I don't understand is the force exerted by one block of mass m1 on a block of mass m2 and vice versa when a force F is applied to m1. What I mean is, say you have to blocks next to each other and a force F is applied to m1. My physics teacher says m1 will accelerate, but m2 will...

hi i have a question if in a question, and they ask, action/reaction pair of the force lets say a man is swimming..and they say name the action/reaction pair of the force, of the force that causes the man to accelerate..how would i reply?

The correct way is \left(\begin{array}{cc}13\\1\end{array}\right \left(\begin{array}{cc}4\\2\end{array}\right (12;3)(4;1)(4;1)(4;1) But why does (13;1)(4;2)(48;1)(44;1)(40;1) fail? I would have thought that after you get the two that match there are 48 left to choose from that don't macht...

Hi there, This question is giving me some trouble... 1.1-6 A game consists of rolling a pair of dice and moving a game piece the number of spaces according to the total number of dots on the dice. In order to move the game piece on a player's first turn, the player must roll a 1 or a 6...

Can an e-p pair be created simply from field interactions rather than brute force collisions of atomic nuclei?

Why can an ordered pair (x, y) be defined as a set {{x}, {x, y}}? Further on, (x, y, z) can de defined as {{x}, {{x}, {{y}, {y, z}}}}... I don't quite understand this.

A) By definition linear charge density is Q/L. So for the inner conductor with 2λ I want to say it is 2Q/infinity but this cannot be right. I am sure using Guass's law produces a correct answer but I cannot see anyway to relate it to λ or length of the conductors for that matter B) For...

I have some questions about mesons. I don't really understand why they are build up from a quark-antiquark pair. I know from the theory that one can classify the mesons by considering the tensor product of the fundamental representation [3] and the representation [3'] (the prime for denoting...