Weak Definition and 473 Threads

Homework Statement So I'm looking at the spectrochemical series of ligands which has that I- < Br- < Cl- < F- < OH- < ox2- < H20 < NH3 < en <bpy< phen <CN- Where the left side are weak field ligands and the right side are strong field ligands. A lot of my homework problems involve...

So according to the rules of solubility all ionic compounds containing acetate are soluble in water. However acetic acid is a weak acid. Why is this if acetate is dissolved in water?

Well, I was looking at the beta decay of neutron, and I thought that the weak interaction can be seen in analogue to QED, where you have an electron that emits(or absorbs) a photon and gets scattered. In the same way, couldn't we say that a Neutron is scattered to a Proton (I see them as the...

Homework Statement Let ##U\subset\mathbb{R}^n## be a bounded open set with smooth boundary ##\partial U##. Consider the boundary value problem $$\begin{cases}\bigtriangleup^2u=f&\text{on }U\\u=\frac{\partial u}{\partial n}=0&\text{on }\partial U\end{cases}$$where ##n## is the outward pointing...

Apologies if this is rather trivial. I'm having a hard time wrapping my mind around the mathematics of energy bands and periodic potentials. I understand that an electron in a periodic potential will be of the form \phi_k(r) = e^{ik.r}u_k(r) . This wavefunction has periodicity of the...

I am confused about when and to what extent parity is violated in weak decays. On the one hand, there's Wu's famous experiment where electrons are emitted preferentially in one direction. This parity violation can be said to be maximal, since all electrons are emitted in one direction...

Homework Statement I am confused about parity violation in weak decays. I learned about Wu's famous experiment and how it demonstrates that parity is violated in weak decays. However, when I am doing a course problem on nuclear β-decay, then it still necessary to conserve parity...

Buffer (pH of a weak acid decreases when we add NaOH! Yes, really.. This is not homework, but just something that I find not following general rule. Just wondering why. So We have the titration of 20.0 mL of .100M HF with .100M NaOH With 0mLof NaOH, the pH=2.08 (by calculating) But...

That is if a tissue paper is wet,it is easier for us to "separate" into many small portions than in dry condition does. Why? Sorry for my poor english,i don't know how to express it well, but i hope it is understandable.

Homework Statement Recall that log 2 = \int_0^1 1/(x+1) dx. Hence, by using a uniform(0,1) generator, apprximate log 2. Obtain an error of estimation in terms of a large sample 95% confidence interval. If you have access to the statistical package R, write an R function for the estimate and the...

Provided they aren't in an excited state (which would allow a decay via EM or strong). I had a question asking why the neutral lambda particle, consisting of uds quarks, has a lifetime characteristic of the weak. The answer being that it must decay via the weak to change the s-quark flavour into...

I know there are four different forces in the universe and they all affect us. I know that gravity is the force of objects' mass interacting I know electromagnetic is the force carried by photons and is the cause of electromagnetic waves I know that the strong nuclear i responsible for the...

I just came across the following Quote in an introductory Quantum physics book"There are certain experiments in which behave differently in their mirror image form, this is called the Parity Violation in." Can anybody explain in detail what parity violation is and what mathematical description...

A long wavelength light has too little energy to knock out electrons, so how do scinetists detect them? and how does a light with low energy ever cease to exist since it can never be absorbed?

Homework Statement Determine the pH at the equivalence point after 20.00mL of a 3.75 M NaF(aq) solution is titrated with 3.25 M HI(aq) Homework Equations ##k_a = \frac{[A^-][H^+]}{[HA]}## The Attempt at a Solution The first thing I noted was that NaF ##\rightarrow## Na+(aq) +...

Hello, I have to calculate the gravitational field strength g given by the De Sitter-Schwarzschild spacetime. If G=c=1 I get: R_{00}\simeq -kT_{00}+\frac{1}{2}kT\eta_{00}+\Lambda \eta_{00}\simeq -kT_{00}+\frac{1}{2}kT_{00}\eta^{00}\eta_{00} +\Lambda \eta_{00}\simeq...

1. Yukawa Potential So reading about the yukawa potential I notice that the constant k is related to the inverse of the effective distance of the force from what I've been reading. Thing is everything I read about the strong force states it has infinite range but simply has a maximum potential...

I just read some basic concepts on General Relativity, and this idea pops up: I know we should use variations of metrics for gravitational field in the Lagrangian. But considering the resemblance of gravitational field(weak-field) to electromagnetic field, can we construct a 4-potential similar...

I read in a paper http://nngroup.physics.sunysb.edu/~nngroup/misc/Documents/NeutrinoReactionsAtAcceleratorEnergies.pdf that delta_I = 1/2 rule of the strangeness-changing weak current implies the ratio of cross section of proton->Ʃ0 process to neutron->Ʃ- process to be 1/2. The delta_I = 1/2...

I read in a paper that delta_I = 1/2 rule of the strangeness-changing weak current implies the ratio of cross section of proton->Sigma0 process to neutron->Sigma- process to be 1/2. I do not understand what is this selection rule and how does it effect the cross section ratio of the 2 processes...

The strong interaction has color ''charge'',the electromagnetic interaction has electric charge,the gravity interaction has mass ''charge'',then what is the charge in weak interaction? Each interaction corresponds to a symmetry.Symmetry SU(3) for strong interaction, SU(2)xU(1) for...

I ran across the following passage in the Wikipedia article on mass-energy equivalence: This level of physics is way over my head, but I'm wondering: "What happens to the quarks that comprise the protons and neutrons?" Are they conserved in the neutrinos and antielectrons? Chris

Hello, I'm looking to amplify a very weak AC signal using op-amps. The problem I'm running into is that I can only operate using a +5V supply voltage, no negative voltages. My AC signal is about 5mV and I need it to be about +2.5V. The AC signal is initally DC baised and is at +3.5V, so I put a...

Folks, I am struggling to see what is happening here particularly when ## \displaystyle \sum_{i=1}^{n-1}## transforms into ##\displaystyle \int_{x_1^e}^{x_{n}^e}## ##\displaystyle 0=\sum_{i=1}^{n-1} \left [ \int_{x_i^e}^{x_{i+1}^e} (a \frac{dw}{dx} \frac{du}{dx}+cwu-wf )dx- \left [ w(x)...

Is the weak force really a "force"? I have seen that gravity, electromagnetism and the strong force are described by physicists in detail in the sense that specific things can be said about what is attracted and/or repulsed and under what circumstances these forces are manifested. All we ever...

Does anybody could help me to state if the following particles experience strong interactions, weak interactions, both interactions or neither of the two interactions? This is what I think: electron = strong interactions and weak interactions boson = weak interactions down quark = strong...

I'm still highly confused about the weak force. Every time I read about it I get something along the lines of it is responsible for beta decay which to my understanding is when a proton or a neutron exits from the atom's nucleus. One thing I have trouble understanding is that if the strong...

1. Homework Statement and attempt at a solution Considering that the ground state of the beryllium atom is 2s^2 and the first excited state is 2s2p, I was wondering in how many lines would the emission/absorption spectrum be modified in a weak magnetic field. I know that if there's no...

Homework Statement Weak Duality Theorem. If x ε ℝn is feasible for P and x ε ℝm is feasible for D, then cTx ≤ yTAx ≤ bTy. Thus, if P is unbounded, then D is necessarily infeasible, and if D is unbounded, then P is necessarily infeasible. Moreover, if cTx = bTy with x feasible for P and y...

With beta decay a down quark turns into a up quark + W- results in e- and (anti-neutrino) and up quark turns into a down quark + W+ produces e+ + (neutrino), does the W- and W+ get emitted and then turn into e- + (anti-neutrino) or e+ + (neutrino) or do they stay in the nucleus? How does the Z...

Hi all, For my studies I'm currently looking into Weak anti localisation. I've come across a lot of articles making use of this effect, but none of them describe the concept of WAL. So far I've been unable to find it in my books. I hope one of you can help me with this.

So I am wondering about one thing. The charged propagators in weak theory are W+- bosons. The mathematical expression for them, while drawing the Feynman diagrams is: -i\frac{g_{\mu\nu}-\frac{q_\mu q_\nu}{m_W^2}}{q^2-m_w^2}. The problems that are usually given to me are simple and involve...

Compared to, for example, electromagnetic interactions. Are the "weakness" and "slowness" perhaps somehow related? Perhaps both "weakness" and "slowness" can both be reformulated as "having a low probability of occurring", making the "slowness" apparent, and making the "weakness" a...

the spin orbit coupling removes the degeneracy but not completely, should we still use the degenerate perturbation theory. is it because of relativistic corrections? Thanks!

Sorry it's my first time posting so I am not sure if latex works here... I have been trying to understand the proof of WLLN using Chebychev's inequalities, and here are my problems: I know for the Strong Law of Large Numbers, if n→∞, Ʃ(1 to n) σi ^2 / i^2 < ∞ => SLLN is satisfied...

Weak eigenstates d', s', b' are a mixture of mass eigenstates. For example, s'=V_cd*d+V_cs*s+V_cb*b This doesn't seem to be the case for u, c, t quarks. For example, there is no c'=V_su*u+V_sc*c+V_st*t Why is that?

I seem to have read something once that suggested that gravity may be leaking into other dimensions/branes, this could explain why this force is so weak. I've been left thinking that it makes sense as a possibility. If it turns out to be the case, could Dark Energy then be leaked gravitational...

Hello. I'm trying to grasp the notation for the definition of something called the weak q-norm, defined as \|x\|_{q,w}^q = \sup\limits_{\epsilon > 0} \epsilon^q \left| \Big\{i \,|\, |x_i| > \epsilon \Big\} \right| I don't come from a pure math background so I've never seen this...

In the limit of weak coupling, G\overline{ρ}<<1, the BCS pairing gap equation gives that Δ \propto exp(-1/G\overline{ρ}). \overline{ρ} is the level density.This cannot be developed as a power series in the interaction strength G. Does this imply that there is a phase transition between a...

I have a question about Feynman Diagrams: let's say we have a process: up antidown -> W+ -> up antidown... the first vertex is like V_CKM G PL ( mixing, gamma, projector) the second is the same..only with the complex conjugate CKM matrix... but why?... If I compute the M* I have to...

Two Questions: 1. I am new to electrical engineering but I want to know how I would Invert a signal. By this I mean, how do I turn a weak signal from, let's say a walkie-talkie, and turn that "weakening" signal into a "strengthening" signal. I would like for the signals to be inverted, in...

Strong or weak force?? Homework Statement So all I want to know is how you tell if it is a strong or weak force interaction. e.g. K^+ = pi^0 + pi^0 + pi^+ (all mesons) So i determined that the energy was concerved: 493.7-135-135-139.6=84.1MeV baryon and Lepton numbers are also...

Dear Physics Forum, I am a little confused about conservation of charge vs. charge conjugation. I'm reading David Griffith's book "Intro. to Elementary Particles"... pg. 81 "All three interactions (weak, strong, EM), of course, conserve electric charge. In the case of weak interactions...

Relevant equations: V = I*R ε = I*(R+r) Then, V = {ε/(R+r)}*r V = potential difference, ε = electromotive force, R = resistance of external load resistor, r = internal resistance of the battery. So say the external load resistor's resistance is a constant for two batteries of the...

Hello, I am struggling to understand why L1 is not weakly compact, while Lp, p>1, is. The example I have seen put forward is the function u_n (x) = n if x belongs to (0, 1/n), 0 otherwise, the function being defined on (0,1). It is shown this u_n converging to the Dirac measure, and...

Hi, I am hoping someone could clear up a few things about neutrinos oscillations for me. For the sake of this dicussion let's set up the neutrino mixing equations in such a way that the flavor eigenstates are a superposition of mass eigenstates. So now for example we have...

how can boric acid be a weak monobasic acid?i thought it was tribasic.

I am currently reading E=Mc^2 and have a quick question regarding some of the nuclear fusion they describe that takes place in stars: When proton fusion occurs, one of the protons decays into a neutron + positron + neutrino – due to the weak interaction. And the proton and neutron , acted...

Please teach me this: Why is CP symmetry violated in electro-weak interaction? Is it correct that because of the mass of neutrino is zero(so that the left and righ neutrinos do not mix with each other)? Thank you very much in advance.

So, I've found the result that orthonormal sequences in Hilbert spaces always converge weakly to zero. I've only found wikipedia's "small proof" of this statement, though I have found the statement itself in many places, textbooks and such. I've come to understand that this property follows...