particle decay

  1. F

    Relativistic decay

    1. Homework Statement A Sigma^+ decays at rest into a neutron and a pion^+ meson, i.e. according to the reaction $$\Sigma \rightarrow n + \pi$$ The n and π masses are assumed known. The kinetic energy of the π + is measured to be 92 MeV. Determine the momentum of the pion. 2. Homework...
  2. J

    I On the decay of the neutral Sigma particle

    Hello! I wanted to ask why does the neutral Σ decay almost always to one γ(or two) and a neutral Λ. Why can't it decay to anything else? Thanks!
  3. referframe

    I Conservation laws during particle decay?

    I believe that conservation laws, like for energy and momentum, are obeyed during the particle decay process, e.g. the total energy of the new output particles is equal to the energy of the one input particle. But is that relationship subject to quantum fuzziness? Suppose we, somehow, prepare...
  4. E

    A Hadrons with significant branching ratios to muons

    Hi, I'm undergraduate researcher and my professor is interested in the answer to this question. He's kind of left me in the dark on why this is important to us, but that is another matter. We want hadrons that are produced at LHC conditions and decay before reaching the detector. So far all...
  5. R

    Energy of the photon emitted in a gamma ray decay

    1. Homework Statement An Fe nucleus (A=57) decays from an excited stated to the ground state by emitting a gamma ray. The energy of the photon is 14.4 KeV when the nucleus is held fixed. If the nucleus is free to recoil then the energy of the photon emitted will be? 2. Homework Equations ## E...
  6. R

    Calculating the energy of anti neutrino

    1. Homework Statement A free neutron is unstable and decays into proton electron and an anti neutrino. The rest masses of these particles are ##m_n = 939.6 MeV, m_p = 938.3 MeV m_e = 0.51 MeV ##and ##m_{\nu} = 0 ## so that the change in the total rest mass in the decay is 0.79 MeV. If in a...
  7. Elvis 123456789

    Another relativistic particle decay question

    1. Homework Statement Unstable particles cannot live very long. Their mean life time t is defined by N(t) = N0e−t/τ , i.e., after a time of t, the number of particles left is N0/e. (For muons, τ=2.2µs.) Due to time dilation and length contraction, unstable particles can still travel far if...
  8. Elvis 123456789

    Relativistic particle decay

    1. Homework Statement Unstable particles cannot live very long. Their mean life time t is defined by N(t) = N0e−t/τ , i.e., after a time of t, the number of particles left is N0/e. (For muons, τ=2.2µs.) Due to time dilation and length contraction, unstable particles can still travel far if...
  9. R

    I Entropy and particle decay

    Maybe my question is a bit more philosophical than scientific. In the macroscopic world entropy means that things become more chaotic and less orderly as they decay. It seems to me somewhat paradoxical that in the quantum world lower generation particles "decay" into the first generation...
  10. P

    Calculate the energy of the neutrino in the following decay

    1. Homework Statement Stopped pions provide a useful mono-energetic source of neutrinos. For a pion at rest, calculate the energy of the neutrino in the decay $$\pi^+\rightarrow \mu^++\nu_{\mu}$$ You do not need to consider the subsequent decay of the ##\mu^+## and you can assume that the...
  11. Xico Sim

    I Method to know if a reaction is allowed

    Hi guys. This is my first post here. Here it goes. I'm attending an introductory course on particle physics. By now, I'm supposed to know how to find out if a given reaction, say νμ+p→μ++n (for example) is possible or not. Unfortunately, the rules by which a reaction must abide are still foggy...
  12. JG1009

    CP Violation in Neutral Kaon Decays

    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?
  13. QuantumKangaroo

    Difference between Photons and the Higgs Boson?

    I'm new to quantum physics, and this might be a stupid question. What is the difference between Photons and the Higgs Boson? I know that neither of them interact with the Higgs field. And that when CERN found the Higgs Boson, it decayed into other particles INCLUDING photons. So what's the...
  14. Dilatino

    Why can the omega meson not decay to 3 neutral pions?

    What reasons prevent the decay $\omega \rightarrow \pi^0 \pi^0 \pi^0$ from happening?
  15. U

    Tau leptonic decay - Lifetimes and modes

    1. Homework Statement (a) Explain lepton universality. (b) Explain why decay mode is forbidden and find hadronic branching ratios. (c) Find the lifetime of tau lepton. (d) What tau decay mode would be suitable? (e) Find the precision. (f) How do you improve the results? (g) Why is it much...
  16. U

    Why is this tau decay not allowed?

    Why is the decay ##\tau^{-} \rightarrow \mu^+ + \mu^- + \mu^-## not allowed? Charge, lepton number are conserved. I have a feeling it is something really basic. I'm thinking in weak interactions you only go from a ##l^- \rightarrow \nu_{l}## and not 'hop' from one muon to another non-neutrino muon.
  17. ORF

    Can we find EM radiation in charged particle's decays?

    Hello. I was taught that a charge which changes its velocity must radiate (at least, in classical electrodynamics). Let's consider a charged particle which decays into another charged particle (and, maybe, others neutral particles; but not photons). In this case, can we find electromagnetic...
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