Weak Definition and 473 Threads

A friend, well-read in popular accounts of physics, posted the following question to me: is the weak force attractive or repulsive? Now I have read about the weak interaction. I know that it violates parity, that it is involved in beta decay, that it unifies with the electromagnetic interaction...

Consider a scattering between two particles a and b that produces two particles c and d: d is stable, while c decays in two other different particles e and f. The first interaction is by strong force (time of interaction ##t_1\sim 10^{-23}s##, which is also the time of generation of c and d)...

Specifically this one: I've been asking several question's about the weak force to my professors, and both on here and PhysicsSE and it seems impossible to get a consistent answer as to what weak hypercharge, weak isospin actually are with any degree of physical-ity. So I suppose this thread...

Hi all, how much merit does this answer have on Quora? There also an identical answer on Physics Stack Exchange so it'd be nice to confirm or deny the validity of these. Thanks!

Homework Statement A particle of energy E moves in one dimension in a constant imaginary potential -iV where V << E. a) Find the particle's wavefunction \Psi(x,t) approximating to leading non-vanishing order in the small quantity \frac{V}{E} << 1. b) Calculate the probability current density...

"Calculated the total magnetic moment of a hydrogen atom in the ground state in a weak magnetic field which arises from hyper fine splitting of the ground state. How many beams does hydrogen produce from a Stern-Gerlach analyzer with a weak magnetic field?" I've calculated the magnetic moments...

Any recommedations for intro into the weak force? Also ones for the strong force?

We have the electric charge for the electromagnetic force, the color charge for the strong force. What is the charge for the weak force? Thank you. :)

Given a function in ##f \in L_2(\mathbb{R})-\{0\}## which is non-negative almost everywhere. Then ##w-lim_{n \to \infty} f_n = 0## with ##f_n(x):=f(x-n)##. Why? ##f\in L_2(\mathbb{R})## means ##f## is Lebesgue square integrable, i.e. ##\int_\mathbb{R} |f(x)|^2 \,dx< \infty ##. Weak convergence...

Wikipedia quotes weak isospin values for some particles and not for others. Why? Is the concept of weak isospin as an observable quantity not meaningful for, for example, pions?

Hi everyone. So I was studying and they say there is a force function (and a potential energy, I suppose) for every fundamental interaction. So, they always show the gravitational and electromagnetic force/potential energy functions for these, and they always mention the other two (plus the...

I've heard that the weak nuclear force is stronger than the electromagnetic force at distances of 10^-18 m. I've also heard that the strong force becomes repulsive at a distance of 0.7 fm. So if two quarks got to a distance of <<10^-18 m which force would win, the strong force or the weak force?

I have a few questions: Can a u quark turn into a d quark (heavier) via the weak interaction? If so, how is the mass/energy shortfall made up? How can the (supermassive) carrier bosons (W, Z) be called into being? Where does the energy come from? Or is the energy bill unpaid because they are...

I'm trying to find measurements for the weak interaction at various distances. Any suggests for search terms or relevant paper would be appreciated. Thanks, Dan

Hi all I got an exercise: Cells were floated in a mass in a solution with 150mM of NaCl (isotonic conditions). A weak acid was added to the solution with a pK of 7.0 and concentration of 50mM in the solution. What is the tonicity and osmoticity of the new solution if PH=4 I know that I should...

“If the weak gravity conjecture is right, loop quantum gravity is definitely wrong,” said Nima Arkani-Hamed, a professor at the Institute for Advanced Study who co-discovered the weak gravity conjecture. source...

Where is the electron-nucleon interaction? On the surface of the nucleus, or at the origin (R-0) ?

I have been using a way to verify the assumptions. For example let's say, If we add 200 mL of NaOH to 400 mL of HNO2 2M, The pH become 1.5 + (##pH_i##) calculate the concentration of NaOH. The usual way of doing is this: ## K_a = (0.02+x)[H^+]/(4/3-x) ## then find the x which most of the...

Homework Statement Let ##\{N_i ~|~ i \in I\}## be family of normal subgroups of G such that (i) ##G = \left\langle \bigcup_{i \in I} N_i \right\rangle## (ii) for each ##k \in I##, ##N_k \cap \left\langle \bigcup_{i \neq k} N_i \right\rangle = \{e\}## Then ##G \simeq \prod_{i \in I}^w...

What causes Strong and Weak Forces? I know that they bind certain things around in our universe but what causes them?

When there are EPR/Bell test inequality violations and no signal faster than light, the terms: Bell Non Locality, Quantum Non Locality, Weak Locality and the Cluster Decomposition Principle: Initial state of space like systems can be factorized. Subsystems remain space like separated. Then final...

Hello,I am reading the link http://math.mit.edu/~jspeck/18.152_Fall2011/Lecture%20notes/18152%20lecture%20notes%20-%204.pdfSays : w_t-D w_{xx}=f with f<0w at \bar{Q}_T has its maximum in \partial_p {Q}_T. If w is strictly negative at \partial_p {Q}_T then also is strictly negative in...

Homework Statement A tau neutrino with energy 1GeV interacts with a stationary neutron. Can the neutrino be detected via a charged current interaction? Take the mass of tau to be 1784MeV/c##^2##, 105MeV/c##^2## for the muon and 939MeV/##c^2## for the neutron. Homework EquationsThe Attempt at...

Im try to understand this paper http://citeseerx.ist.psu.edu/vie... and see if I correctly understand which processes are charge-current processes, and which are charge neutral, as listed in Figure 1. Thanks

Hello, I'm wondering how you would go about drawing a Feynman diagram for a weak charged current scattering interaction of a positron and a proton. I have attached a diagram of what I have tried but it doesn't conserve lepton number (I think this is a problem, from what I gather...

Hello, From my understanding, the weak interaction only acts of Left-Handed Chiral Particles, and Right-Handed Chiral Anti Particles. There have been observed fermions (other than neutrinos, where all observed neutrinos are Left Handed Chiral) where some are left handed and some are right...

I am familiar with the following equation which relates weak isospin (T3) and weak hypercharge (YW): YW = 2(Q-T3) (Where Q is electric charge) However, while this can be used to calculate YW from T3 and vice versa, how do you calculate each of these properties individually, without using the other?

Hi! I want to clarify what will happen if you mix two acids. One is stronger and One is less stronger. What will be the pH level result? for example if the acid is the juice from lemon which is at 2.0 be mix with orange ph level of 3.0, will it be greater than less than 2.0? or will it be 2.5...

I have a glass of water at room temperature. The electromagnetic force is at play between the electrons and nucleus of the atoms, the strong nuclear force is at play holding the nucleus together, the force of gravity weak as it may be is at play between the various particles - electrons, quarks...

What are the weak isospins (T3 values) of various hadrons, including the proton, neutron, mesons, hyperons and other hadrons? How is the weak isospin calculated for any hadron? Published sources provide T3 only for fundamental fermions, that is, quarks and leptons. In the fundamental bosonic...

Do we need more proof of dark matter than this?: https://en.wikipedia.org/wiki/Weak_gravitational_lensing

Which of the following statements about weak acids and weak bases are false? (i) The strength of a weak acid decreases as itspKa decreases. (ii) Weak bases react with water to produce a small amount of a strong base. (iii) The strength of a base decreases as the strength of its conjugate acid...

Okay, I'm following a series of video lectures on applications of finite element method to engineering, and the tutor started by demonstrating the mathematical background of FEM using a simple heat transfer problem. He derived the governing equation (in just one dimension): (1)...

Reading this article - http://hyperphysics.phy-astr.gsu.edu/hbase/particles/proton.html#c4 there is a statement - "A free neutron will decay with a half-life of about 10.3 minutes but it is stable if combined into a nucleus." So is it only free neutrons that decay into protons? In...

some inquiries 1. Is it possible parity being violated by the weak force is because of further symmetry breaking of SU(2)xU(1) (besides the higgs field) ? Any papers about this? 2. I read in wiki that that mirror matter can recover the symmetry. What else (beside mirror matter) could restore...

When does GR apply in gravitational fields as opposed to Newtonian gravitation? Another words, what would be the strength of the graviatational field before we abandon Newtonian gravity and start implementing GR? 10 g's, 20 g's?

I'm reviewing this book Warped Passages by Lisa Randall and a sentence caused me some incomprehension. Somewhere in it she stated: "The weak gauge boson masses tell us the precise value of the energy at which the weak force symmetry is spontaneously broken. That energy is 250 GeV, the weak...

Why is the weak field a force of nature.. while the higgs field is not a force of nature.. what is the signature or things to look for before a field can be considered as a force of nature?

Do the weak isospins of the w1 and w2 bosons combine as their fields combine?

Homework Statement Homework Equations Henderson-Hasselbalch Equation The Attempt at a Solution Sorry for the huge picture, but the number says 0.007558 mol. Is my ICE table correct? Equation: 7.42 = 6.85 + log((0.007558-x)/x) (0.007558-x)/x = 3.715 x = 0.00160 mol H+/(0.07483 L + 0.01339 L)...

Does a 'weak measurement' on the spin of an electron in a pure state put the electron in a mixed state of the previous state and the state of the measurement axis of the measurement?

Homework Statement I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently...

If gravity is a weak force , then How it holds planets , stars and galaxies together ? let me know if i am right..? Gravity only attracts there is no negative version of the force to push things apart and while gravity is powerful enough to hold galaxies together, it is so weak that you...

Homework Statement An example of a weak decay of a nucleus is (Z, A) → (Z +1, A) + τ- + ντ-bar where (Z,A) represents a nucleus with Z protons and A−Z neutrons. (d) Suppose the gauge boson in the above process is produced at rest. Assuming the neutrino is massless, what must the 3-momenta of...

In the case of two protons in the nucleus. I've seen charts with that info, but I don't know how... How can I calculate that ratio? I've looked everywhere, and I can't find anything... Thanks

I stumbled upon this concept when studying gas dynamics. What I get from my readings it must occur when Mach number is really close to 1. But I didn't understand how the property relations across a shock wave is affected by it.

Since Acetic Acid is a weak acid, it has a low Ka which means that the forward reaction is not favored as much as the reverse reaction. However, the Kb is even lower than the Ka...how is this possible? Shouldn't the Kb be higher to indicate that the reverse reaction is favored?

Im reading Carroll's Spacetime and Geometry section 4.2 where he claims the following as the weak energy condition: Given a energy momentum tensor T and a timelike vector t then Tμν tμ tν ≥ 0. He claims that for a perfect fluid this is equivalent to the statement that ρ ≥ 0 and (ρ+P) ≥ 0...

Dear all Do we have chiral symmetry for weak interaction? I know that weak interaction is chiral. thank you

I'm trying to understand a paper which uses weak-* topology. (Unfortunately, the paper was given to me confidentially, so I can't provide a link.) My specific question concerns a use of weak-* topology, and interpretation/use of neighborhoods in that topology. First, I'll summarize the context...