Kaon Definition and 32 Threads

https://home.cern/news/press-release/physics/na62-experiment-cern-observes-ultra-rare-particle-decay August 2024 - https://home.cern/news/news/physics/na62-announces-its-first-search-long-lived-particles

Below are the statements in the "David Griffiths, Introduction to Elementary Particles 2nd Edition, 147~148 p.": Evidently, the long-lived neutral kaon is not a perfect eigenstate of CP after all, but contains a small admixture of K1. The coefficient epsilon is a measure of nature's departure...

The phys.org summary had me intrigued and the resulting new paper makes for heavy reading at my level of knowledge, but it was the underlying reasoning of the methodology that I really question: One of the authors notes "It's so rare, that they should not have seen any." From that, the...

What would be reasonable preparation for reading the reference Kaon Physics https://arxiv.org/pdf/hep-ph/0401236.pdf I find I do not seem to be ready for this reading. I am familiar with quantum mechanics at the level of Schiff (an old text for first year graduate students) though perhaps rusty...

The weak interaction doesn't conserve CP, so it shouldn't care whether there are two neutral pions in the decay product or three. And the three-pion decay is slowed down by the lack of phase space since there is little mass in excess of that of three pions. So why don't we see more decays into...

Homework Statement We were supplied with several images of hydrogen bubble chamber tracks, from which we measured the length of the (invisible) K0 track, angles of departure from the K0 meson's track and curvature. As a way to limit the amount of data we're talking about, I'll only discuss the...

how could we produce a secondary beam consisted of long neutral koans using PS or SPS ? I mean is there any example of such an experiment? what are the conditions for conducting this such as the type of the primary beam, the type of the target and the momentum of the beam? I am interested to...

Hello everyone, If a nucleus consisting solely of mesons has enough mesons in it, will it be stable? Mesons are bosons, therefore (unlike baryons) they aren't effected by the pauli exclusion principle, so they all can acquire the lowest energy state. In theory, if there are enough mesons, the...

Hello, my question is, why does the decay of K⁺ -> π⁺ ν ν-bar require a loop to be allowed. See images below.* -What is it that makes the decay forbidden in figure 1.4 and not forbidden in figure 1.5? -What does being a first order weak decay and a second order weak decay mean? -I suspect...

what's the relation between kaon antikaon oscillation and two body problem . My teacher told me that I should learn kaon antikaon oscillation. . I can't find anything about it.

A kaon is a type of quark right? Is a way of thinking about it similar to the way a cell becomes specialized: a Kaon would be like a specialized quark?

Homework Statement A K0 particle is unstable and has a mass of 8.87x10-28 kg. It can decay into π+ and π- particles, each of mass 2.49x10-28 kg. Suppose that a K0 is moving in the +x direction and decays by this process, with the π+ moving off at 0.9c and the π- moving off at 0.8c. a) What was...

One of the possible decay modes of the neutral kaon is ## K^0 \rightarrow \pi^+ + \pi^- ## The rest masses of the K0 and pion are 498 MeV/c2 and 135 MeV/c2, respectively. In 2-dimensions (xz-plane), if the kaon has an initial momentum of 2000 MeV/c in the z direction, what is the momentum of...

I was recently reading an article that attempted to explain how the results of the Cronin-Fitch experiment illustrated CP violation. (http://hyperphysics.phy-astr.gsu.edu/hbase/particles/cronin.html) However, it wasn't very well explained. Could someone please explain this to me?

I was reading in Griffit's "Introduction to Elementary Particles" when I stumbled over the following Remark in chapter 4.4.3.1. CP eigenstates are constructed by |K_1> = \frac{1}{\sqrt{2}}(|K^0> - |\bar{K^0}) |K_2> = \frac{1}{\sqrt{2}}(|K^0> + |\bar{K^0}) and, assuming CP conservation...

Homework Statement (a) What is a meson? (b) State what these mesons are made up of and explain their quantum numbers and interactions. (c) Find the lifetimes of rho meson and kaon. (d) Find the dominant decay mode and explain why. (e) Why is decay to 2 neutral pions forbidden? (f) Explain how...

Homework Statement A possible decay mode a of a positive Kaon in the production of three Pions as shown below:. K+ → π+ + π+ + π− Whats is the maximum Kinetic energy that anyone of the pions can have? The kaon is a rest when...

I was looking at this old chart (before the standard model was completed) and this thing with Kaon notations was confusing. So I understand that the top right number on a particle denotes charge, but what is subscript? Does that denote the number, as in which exact particle it refers to? Because...

Homework Statement One of the following equations represent a possible decay of the K + kaon. K+ → π+ + π0 K+ → μ+ + νμ State, with a reason, which one of these decays is not possible.The Attempt at a Solution At first i thought the first decay was not possible, however, i recently learned...

Homework Statement Ok, so I need to make a software that will simulate a neutral kaon system, and I only have the following data about the masses and decay widths: gammaS = 580*gammaL {S = short lived state, L = long lived state} mS - mL = 0.477*gammaS Homework Equations How...

Homework Statement A Kaon (k0) decays into two charged pions (π+ & π-), what is the minimum momentum required for the kaon so that none of the pions move backwards (in the opposite direction of the kaon) in the laboratory frame. Homework Equations Conservation of momentum...

Hey, I'm trying to get my head around neutral Kaon oscillations. As far as I understand it neutral Kaons can change between K^0 and \overline{K^0} as they propagate. Going through the quantum mechanics of this implies that this oscillation must be facilitated by a mass difference between the...

Homework Statement I am asked to draw a feynman diagram of K^- \rightarrow \mu \nu Homework Equations K^- consist of s\bar{u} The Attempt at a Solution I wonder what the direcion of the arrows should be, my guess is something like the attached image. edit: Ah, where the left u shoudl be an...

Homework Statement Ok so a Kaon (m = 500MeV) is accelerated from rest along the z-axis to a final energy of 5GeV, I need to find two factors of a lorrentz transformation β and γ and write a four vector for this. Homework Equations β=p/E γ=E/m The Attempt at a Solution I have...

Kaon discovered by "the unusual fork" So historically (reading about it in Griffiths) the (neutral) kaon was discovered by noting that there was some neutral particle decaying into a positive and neutral pion. But how did they know at the time (1947) that it was not the neutron doing this...

Homework Statement Draw the lowest-order Feynman diagram for the decay: K^+ \rightarrow l^+\nu_l Homework Equations Kaon structure is given as u\bar{s} The Attempt at a Solution So I know that you can get a lepton and an associated neutrino from a W decay, where the strange...

Homework Statement Homework Equations http://img42.imageshack.us/img42/7931/image24yc.jpg The Attempt at a Solution To make things easier I just scanned my work - I'm at a loss of what to do next :( [PLAIN][PLAIN]http://img816.imageshack.us/img816/6139/image25t.jpg Thanks a...

Hi, very simple question: What is the parity of the anti neutral kaon?

Hi everybody,i'm worried about some calculation. I have to write down the amplitude for the neutral Kaon oscillation. There are two Box diagrams which are depicted here: http://upload.wikimedia.org/wikipedia/de/9/92/FeynmanKaon.png The two diagrams come along with a combinatorical factor of...

I understand that K_l = \frac{d\bar{s} + s\bar{d}}{\sqrt{2}} K_s = \frac{d\bar{s} - s\bar{d}}{\sqrt{2}} This happens because K_0 is oscillating into its own antiparticle. My question is, why the same is not applicable to the neutrinos? They do oscillate. So instead of ‘pure’ e, mu, tau...

Homework Statement a neutral kaon at rest decays to pion- and pion+ , if kaon rest mass is 497.7MeV/c^2, and the pions rest mass is 139.6MeV/c^2, what are the kinetic energies of the resulting pions? Im very stuck with this, and not sure where to start, how can i find Ek of pions, if i don't...

First of all, many books assume first that K_S and K_L are CP eigenstates. They then tell that by observation that cannot be true. Is that relevant to the CP violation? Why don't the authors just tell that K_L is a mixed state with only a small amount of CP=+1 eigenstate? Second, observing...