Weak Definition and 473 Threads

Hi guys, Problem: Let {Xn},{Yn} - real-valued random variables. {Xn}-->{X} - weakly; {Yn}-->{Y} weakly. Assume that Xn and Yn - independent for all n and that X and Y - are independent. Fact that {Xn+Yn}-->{X+Y} weakly, can be shown using characteristic functions and Levy's theorem...

Please teach me this: How can we unify electromagnetic and weak interactions?Is it correct that the SU(2) symmetry(flavor symmetry of fermions) is spontaniously broken(by Higgs Field) and the symmetry(be broken) ''become'' U(1)xSU(2) symmetry that is the symmetry of electroweak interaction...

The notations are: W^+, W^-, and Z^0. I'm assuming the W stands for Weak. But, why Z for the neutral one? Is there even a reason?

Firstly: Does anyone know at our current level of technology what "small enough not to detect tidal forces" equates to? Near the surface of the earth(as it probably depends on the amount of curvature of space). Secondly: Does anyone know at out current level of technology what the minimum...

Is a weak acids concentration determined from when it is in equilibrium, or if it hasn't dissociated at all? i.e. 0.100M CH3COOH. Would this be the concentration of CH3COOH during it's equilibrium: CH3COOH <-|-> CH3COO- + H+ Or just by itself? Thanks!

Homework Statement A satellite is in circular polar orbit radius r around Earth (radius R, mass M). Clocks C on satellite and C0 on south pole of earth. Show the ratio of the rate of C to C0 is approximately 1 +\dfrac{GM}{Rc^2} - \dfrac{3GM}{2rc^2} Homework Equations d\tau =...

Hi all, Im an EE major and am getting ready to pick spring classes tomorrow. My only option for Calc 3 which will fit into my schedule seems to be the easiest professor possible (aka they give over 30% A's, which I found from the rating website, I have also heard from other students that it is...

i can understand the weak large number law however, what does strong large number law mean? i cannot see the difference between the two ps: i do physics, not maths

Hi physics forum, I have been reading David Griffith's book "intro to elementary particles" and he describes the decay of the pi-meson as "pure axial vector" Can someone tell me what this means, in terms of the weak force vertex consisting of this factor γu(1-γ5) Thanks, Mark

Hi forum, The weak force vertex factor is γu(1-γ5). Am I right that the axial component only couples to left handed fermions? Does the vector component couple to both left and right-handed fermions? Thanks, Mark

Hi I don't understand my textbook 100% when it comes to this: Weak nuclear force: The force that affects leptons and quarks. Uhm, how? They tried to illustrate this with an example of a beta-decay, but I didn't get it. Some W- particle was created when an d quark went over to an u quark...

How do you determine in a particle interaction which force is responsible? For example a K- meson is found to decay into three charged pi mesons what force is involved? The answer here is a weak interaction but why?

My first question, so sorry if it's in the wrong forum. I'm trying to understand the Newtonian weak field approximations to general relativity. I can't see why, if the Schwarzschild metric (which can describe the gravitational field around the Sun) is a vacuum solution (T_{\mu\nu}=0 ) , do...

say we have a sequence of probability measures on R, such that each one is abs. continuous wrt the Lebesgue measure... is it possible that these measures converge weakly to a measure which is _not_ abs. continuous wrt the Lebesgue measure?

Does this ever happen? p + \gamma \rightarrow n + e+ + \nu_e It seems possible, if the \gamma has enough energy, but I wonder if anyone can confirm that it happens.

I have started with the space-time metric in a weak gravitational field (with the assumption of low velocity): ds^2=-(1+2\phi)dt^2+(1-2\phi)(dx^2+dy^2+dz^2) Where \phi<<1 is the gravitational potential. Using the standard form for the Christoffel symbols have found: \Gamma^0_{00}=\phi_{,0}...

Why is gravity thought to be a week force? I would agree that at the surface of our Earth it would appear to be week, after all we can stand on the surface of the Earth without risk of being pulled into it core. But a black hole is another kettle of fish altogether, it's almost an atomic...

Say I have a primal LOP K and a dual LOP D If D is bounded, which means it is feasible, does that mean P is also bounded? Because if P is unbounded, then D is infeasible Likewise if D is unbounded, P is infeasible So D is bounded, P is feasible? Make sense?

Homework Statement Prove that weak induction is equivalent to strong induction. Homework Equations To prove this...we assume weak induction. That is (i) 1 \in S (ii) n\in S \Rightarrow n+1 \in S for all n in N The Attempt at a Solution So to prove strong induction we...

Yeah, desk shook a little and everything. It kinda freaked me out. Was there a big earthquake somewhere else in the world just now?

Hi, If the weak interaction obeys CP symmetry but violates P symmetry does that mean that it must also violate C symmetry? John

Hi PF I was wondering today about the origin of the fundamental forces. Now gravity comes from mass (lets call this massive charge), electromagnetism comes from electrical charge and the strong force comes from color charge. These are all kinds of "charges", but what kind of "charge" gives...

Hi guys How can we correct week metalization in PCB plating? please help me

Are there any W^\pm or Z^0 interactions that change lepton flavor? For example, turn an electron into a muon or vice versa? Thanks!

Hello all, I received my PhD in a physical science field in December, and am currently 6 months into a 1-year (renewable) post-doc. I am unsure if I will remain in my current position at the end of this year, and am looking critically at my future career prospects. I find myself in the...

Weak measurement show that you can get "partial/probabilistic" which-way info and get a "partial" interference pattern. Deduction 1: Does this mean that weak measurements prove that we can control the degree of randomness? (either of individual photons or average of a thousands of photons)...

Does it explain what occur during strong measurement or "approximately" solve the measurement problem? I'm asking because below it is mentioned that "it is this uncertainty that creates the uncontrollable, irreversible disturbance associated with measurement". Does it mean that measurement...

i'm trying to dissolve an unknown acid salt and it is not soluble in water at stp. it does dissolve, however, when it undergoes heat and some stirring. is this property representative of most weak acids, that they are not easily miscible in water?

Z° and weak isopsin The Z° is a mixture of the B (iso-scalar) and the W° (iso-triplet with T³=0). Is it OK to say that the Z° still has T³=0? Or is this meaningless due to the breaking of the original SUwI(2) * UY(1) to Uem(1) and the mixing in the Z°?

So I've seen the distinction one makes in case of infinite-dimensional Hilbert spaces. Weak convergence versus strong convergence of sequences. I cannot think of an example of sequence of vectors in L^2(R) which converges with respect to the scalar product, but not with respect to the norm...

Hi, I came across a problem, which I might have solved a few years ago when I had studied Chemistry, but now I am totally stumped. Would appreciate some quick solutions. I have 25 ml of 0.1 M NaOH, and a volume of 0.1 M of Ethanoic Acid. What volume of ethanoic acid would neutralize the 25...

Homework Statement In order to achieve a high result in this chemistry assignment, I need to have demonstrated a knowledge of challenging content not discussed in class. Every other part of this assignment I've covered (Intro, method, discussion etc), I am just stuck with the calculations...

In another thread, it's considered a generally accepted fact that the WEP is not valid anymore the way it was initially postulated: I find this surprising, because such a change in the principles of the theory should be more stressed in introductory GR textbooks, and kind of disturbing...

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...

I have read about Wu et al. and their experiments with Co 60 that showed that the weak interaction violates parity. I don't quite get it tho. 6 So they aligned Co atoms in a magnetic field. Some of the nuclei decay and emit neutrinos and electrons. It was observed that an equal number of the...

So the pion(+)n is made up of an up quark and a down antiquark. And somehow, it emits a W+ boson, which then turns into a muon and a muon-neutrino. From the Wiki article, "W bosons can decay to a lepton and neutrino or to an up-type quark and a down-type quark." Does this mean that the...

I'm preparing for a chemistry lab relating to "Determination of the dissociation constant of a eak acid". In part of the lab, I will b doing the following for measuring "Ka" for ethanoic acid using the indicator method: 1- Mix ethanoic acid (0.02M, 5cm3) and sodium ethanoate (0.02M, 5cm3)...

Hello there, I was wondering if anybody could indicate me a reference with regards to the following problem. In general, the Euler - Lagrange equation can be used to find a necessary condition for a smooth function to be a minimizer. Can the Euler - Lagrange approach be enriched to cover...

We had a physics lesson today on nuclear binding energy, where we looked at the mass of two protons and two neutrons independently and compared it with the mass of a helium nuclei, and were told how the discrepancy related to the release of energy during nuclear fusion. The first question in...

Hello, Chitose here while I'm learn about hand in hand combat, someone told me that to always protect my chin. "No matter how strong, big or well train people are, getting direct hit at chin will take him down instantly" in boxing, both fighter are also protect and try to hit each other...

Is the weak force responsible for all radioactive decay, or just beta? If it is also responsible for alpha and gamma, how does it work? If not, what causes the other two? (Also, related to this, I know that alpha radiation is two protons and two neutrons being expelled from the nucleus, and...

In A First Course in General Relativity, the use of the weak field approximation is confusing to me. I constantly get confused when the term "f(x) is only valid to first order in f..." for the Newtonian potential in the metric comes up. At a certain point the book states: ...1/2(-1/(1 +...

Hey, For a problem I am working on I need to know if the energy-momentum tensor of the Reissner- Nordstrom metric obeys the weak energy condition. Since I need the result for the following calculations, I just want to be sure that it is correct. Does anyone of you know the correct answer and...

Homework Statement If .0200L of .100M nitrous acid is titrated using .200M NaOH solution, what will the pH be at equivalence? Homework Equations The Attempt at a Solution I figured out that the volume of NaOH at equivalence is .01L, however I do not know what to do after that...

Homework Statement I need an example of the math Homework Equations The Attempt at a Solution

So, it's for Mastering Chemistry and I need to sort out the strong acids weak acids strong bases and weak bases. It says that two are wrong though I've looked them all up and don't know which ones are wrong. [PLAIN]http://bit.ly/fREfFS

I believe the neutron decays with a half life around 12 minutes via the weak mechanism. I'm wondering what causes a particular neutron to decay. At the moment the neutron decays, has it encountered (run into) a stray weak field? Or ... does the neutron decay just because of internal forces...

Probability - A and B are two weak students... Homework Statement A and b are two weak students in Mathematics. The chances of their solving a problem correctly is 1/8 and 1/12. The probability of them making a common mistake is 1/1001 and they obtain the same answer. Find the chance that...

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...

Such an equilibrium problem involves 3 equilibria: a weak acid, a weak base, and water autoionization. I find in various texts that several assumptions are made in dealing with this class of equilibria problems (ignore water's autoionization, conversion of the weak acid is on the order of...