Weak force Definition and 65 Threads

Which physics concepts and phenomena other than "CP violation" have to deal with the breaking (not validity) of "Invariance of Time Reversal", like for the Weak Force (e.g. for beta-decay)? The underlying mathematical and physical theory to this inquiry is based on advanced physics textbooks as...

Hello everyone I have been following Fermilab presentations by Dr Don Lincoln for some years. Recently he did a deeper review into the four fundamental forces. He explained why the weak force is relatively weak. The explanation given was that the “normal” mass of the W boson is relatively high...

If there are no flavor changing z0 weak interactions, how do we even know that the particle exists? I thought that we could only tell which particle was exchanged by the particles it decays into. Is this wrong?

Hi everyone, The four fundamental forces are gravity (I understand that G.R. does not look upon gravity as a force but I'm not worried about that here), the Lorentz force, the weak force, and the strong force. I'm familiar with the inverse square law for gravitation and the Lorentz force...

Hi! I could understand gravitational force as a force that move mass. I could understand electromagnetic force as a force that moves chaerged particles. I even could understand strong force as a force that atrack protons I could not understand the moment of what weak force changes. The moment...

Hello, I am a creative scifi writer and i only have basic quantum physics knowledge, if someone could answer my question please. I was wondering some type of weapon that uses weak force, therefore it would promote distorcions at weaf force field causing interaction with atoms My question is, if...

Hi All We know that beta decay is and ejection of an electron from nucleus, making a proton turn into a neutron (and a neutrino). Is it correct to say that is the weak force responsible for the increasing in the distance between electron and proton during this process (since the feel atracked...

Long time reader, first time posting here in physics forums. I know that according to relativity photons have no proper time. I also know that a photon of sufficient energy can interact with a nucleus's nuclear force via the weak interaction resulting in pair production. I was looking at a...

A reference please to a review paper, textbook, or website for an expression, or development of an expression for the field in Electro weak, similar to the A field in EM.

When learning about chirality I was very surprised to find that for QED and QCD the decay modes that would produce 2 particles with the same chirality had a Matrix Element of 0, which I took to mean that angular momentum was being conserved. Even the W only decay into RH antiparticles and LH...

This relates to the anthropic principle and the multiverse. Nuclear Processes in Other Universes: Varying the Strength of the Weak Force https://journals.aps.org/prd/pdf/10.1103/PhysRevD.98.063014 Nuclear processes in other universes: Varying the strength of the weak force Alex R. Howe, Evan...

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!

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

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 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...

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...

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...

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

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...

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

Why does the weak force only interact with left-handed particles or right-handed antiparticles? And does this mean that the particles that don't have those properties won't decay?

So - this may sound like an easily answered question - but with push-back on my part I hope I can get to the real crux of what I'm asking, in any replies you might be kind enough to provide. I hope the answer is not, eventually, simple. The crux of my issue is this: Why do we believe gravity...

What is the entropy of weak and strong force? Can we determine their entropy? If so, I would like to know the formula of determining this. Thanks:wink:

Hi there, so my question is as follows. I understand that only the weak interaction can change the flavour of a quark, but why? Idea 1: It's due to the change in flavour also meaning a change in mass, thus a massive exchange particle is needed (gravity is negligible so forget the massive...

This question straddles this forum and the "Beyond the Standard Model" one a bit, so if a mentor thinks it belongs better elsewhere, please feel free to move it. I've seen references in the "popular science" press about the possibility of indirectly detecting dark matter by looking for gamma...

Hello, I've been reading a book on particle physics for the general audience, and as you might expect, I was left with a slew of nagging unanswered questions. There was a chapter on gauge symmetry where the author described that the weak and the EM forces are the same force at some energy...

Hi. I need help please with a textbook illustration that has confused me. Is the caption a typo? Should be "neutrons into protons" instead? Thanks.

what property of elementary particles is reason for weak interaction? what I mean is as color charge is reason for strong force ,as electric charge is reason for EM force and as mass is reason for gravitational force what is reason for weak force?

Hi guys, Could someone with a better understanding of the standard model answer a question about the weak force? In a class I'm teaching, a question in the textbook asks if photons feel the weak force. My first thought was that it's fermions that feel the weak force and therefore the...

Hello! I have a question that has been bothering me for some time, and I thought this would be a good place to ask. This is my first posting on PF as well, so I hope this is well placed. There are force laws for the coulomb attraction and gravity. Are there similar force laws that can be...

Hi, I don't know very much about the weak force, but gravity, EM and the strong force all seem to apply an actual F = ma type of force (at least, I think the strong force does). But my limited knowledge of the weak force is just that it is involved in radioactive decay. Maybe this is why some...

In Deep Down Things, an excellent book of B Schumm, at page 288, he explains that the weak force is short range because the Weak quanta have a large mass. Using de Broglie wavelength relation: Lamda = h / p, he gets a wavelength of 10 ** -18 m, and he concludes that this is the W quanta range...

The W couples to left-handed particles only. What about the Z? Is it the same? Thanks in advance!

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...

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...

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...

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...

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...

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...

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

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...

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

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...