Decay Definition and 998 Threads

Homework Statement (b) A nuclear research reactor produces radiation for neutron scattering measurements. A safety procedure shuts the reactor down if a radiation level monitoring detector measures more than 3 counts per minute. In a test, 156 counts are recorded during a random 24 hour...

Homework Statement Many heavy nuclei undergo spontaneous "alpha decay," in which the original nucleus emits an alpha particle (a helium nucleus containing two protons and two neutrons), leaving behind a "daughter" nucleus that has two fewer protons and two fewer neutrons than the original...

If I put a dosimeter 1 meter away from a gamma sample that starts decaying at the moment I switch on the dosimeter then how would I measure the dose level received by the dosimeter, would it gradually decrease over the first half life or would it stay the same throughout the first half life...

Apologies for this question, but I'm trying to understand what I'm looking at here and was unable to find an answer online. From my understanding, this is a decay scheme that shows the percentage of each energy level at which the disintegrated mother nucleus has reached after the...

I wish to draw the proton momentum spectrum by transforming the energy spectrum of recoil protons. I have calculated the energy spectrum using Nachtmann's spectrum: wp=g1[T]+a*g2[T] Where: g1[T]=(1 - x2/σ[T])2 * Sqrt[1 - σ[T]] * (4*(1 + x2/σ[T]) - (4/3*(σ[T] - x2)/σ[T])*(1 - σ[T])); g2[T]=(1 -...

Homework Statement Consider nucleus A decaying to B with decay constant D1, B decays to either X or Y (decay constants D2 and D3). at t=0, number of nuclei of A,B,X and Y are J,J,0 and 0. and N1,N2,N3 and N4 are the number of nuclei of A,B,X and Y at any instant. My question is, what is the...

Homework Statement I want to know why probability disintegration per second of a radioactive nucleus does not depend on time lived by it. Homework Equations N/N(initial)=e^(-λt) The Attempt at a Solution According to the above equation, the probability should increase with the passage of...

Homework Statement I need to calculate the muon decay rate, ignoring the mass of the outgoing particles. Homework Equations ##d\Gamma = \frac{1}{2E_1}|M|^2d\Pi_{LIPS}## The Attempt at a Solution I am actually having problem with the math at a point. I reached this...

Homework Statement A beam of light of vacuum wavelength λ = 550nm passes from water (refractive index 1.33) into air (refractive index 1.00). (a) What is the critical angle? (b) Suppose the beam is totally internally reflected. At what angle of incidence would the decay length of the...

When looking at the FFT spectrum of a sonometer, I noticed that the harmonics decayed faster than the fundamental. Why is this?

https://phys.org/news/2018-08-long-sought-higgs-boson.html

Geiger–Nuttall rule relates the decay constant of a radioactive isotope with the energy of the alpha particles emitted. Roughly speaking, it states that short-lived isotopes emit more energetic alpha particles than long-lived ones. - wiki I am trying to understand why there is an inverse...

What causes an elementary particle to "decay" into other elementary particles? And where do these particles come from if they were not part of the original particle?

Homework Statement An antiproton of energy 35 ##GeV## from a source outside the solar system interacts with a proton in the upper atmosphere traveling on a trajectory which is radial with respect to the centre of the Earth. The antiproton annihilates the proton with the final outcome that two...

Homework Statement An antimuon and electron may bind together via Coulomb attraction and then decay, but is the following process possible? (µ+e-) → νe + νµ_bar *The νµ_bar is the antiparticle of the muon neutrino - the antimuon neutrino More than one answer (below) may be correct. a)...

Consider chain of two radioactive decays ##A \to B\to C##. The equation that regulates ##N_B## is $${\frac {\mathrm {d} N_{B}}{\mathrm {d} t}}=-\lambda _{B}N_{B}+\lambda _{A}N_{A}$$ I can't understand why the activity of ##B## is get as ##\lambda_B N_B##, for example at page 20 here...

Regarding the Quantum Anti-Zeno effect (AZE), we know that frequent measurements of a decaying system (such as a decaying radioactive nucleus) can induce greater decay rates. However, if I understand correctly, you can change the percentage of change in the decay rate. For example, if you have...

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)...

is the amplitude of pure leptonic decay of pseudo scalar meson(say K→ee), while is the amplitude of the semileptonic decay of K→π ee. Kindly explain why does sd replace sγ5d ee in the amplitude?

I recently read about a beta decay isotope (Rhenium-187),whose half life was changed from 42 X 109 years to 33 years, just by stripping the nucleus of all it's electrons. Why does this allow for a faster decay, and does this apply to all beta decay nuclei, or just Rhenium 187?

I am trying to solve for the theoretical relative decay rates of the various (m,n) modes of an ideal circular membrane, if that membrane is excited momentarily by an impulse or deformation. I would ideally like the decays of the (m,n) modes in dB/s. Imagine a simple isolated drum head being...

Hey everyone, I have a question about how "viable" the Quantum Anti-Zeno Effect (AZE) is at lowering decay rates in radioactive nuclei. We know that the AZE can, in fact, reduce the half life of radioactive isotopes, but there seems to be a barrier to that. AZE states that decay can be...

I recently started learning about quarks and leptons and was wondering what happens to the fermions (specifically the quarks and leptons) during a beta decay. How is the electron/positron created and what causes the up quarks and down quarks to change flavours? If this is a bad question please...

Homework Statement [/B] The problem states that 24 11Na is radioactive. The question asks if it's a β- or β+ emitter. The 24 is the atomic mass number and the 11 is the atomic number. Homework Equations I know that in β- decay, the atomic number increases by 1 and it emits an electron and...

Hey everyone, I've learned about double beta decay and neutrinoless double beta decay recently. So we have two "conditions" for decay, 2v decay and 0v decay. Now, to the question I have: There have been a lot of experiments measuring 2v decay rates, and there have been many experiments...

Homework Statement A hypertriton (a bound system with a L hyperon together with a deuteron core (proton and neutron) is produced at the origin of the coordinate, (x,y)=(0,0) with a velocity of 0.94c (beta=0.94), flying along the x-axis. The mass of the hypertriton is 2.991 GeV/c2 . It decays...

In a typical resonant bandpass filter, resonance is set as none at 0 and full at 1, such that the filter rings infinitely at 1 and not at all at 0. If there is a two-pole resonant bandpass filter, with an impulse excitation to a maximum amplitude of "1" and a resonance setting between 0 and 1...

Hello! I am reading about Time Dependent Perturbation Theory from Griffiths book on QM. He derives the fact that for a system with 2 levels with energies ##E_b > E_a##, if you send light to it (or a sinusoidal perturbation) the probability of an electron going from state a to state b is the same...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] Question: An experiment is proposed to directly measure the width (Γ) and mass (m_H) of the Higgs boson via the reaction: muon+ + muon- > H. Sketch a graph of the expected cross section...

Homework Statement I have a lambda decaying into a pion and a proton. The lambda is moving with velocity 0.9c and I know the mass of the lambda as well as the pion and proton (these are known constants). I need to find the momentum of the pion and the proton after the decay happens. Homework...

Homework Statement I have a mother particle at rest, which decays to a daughter particle. The daughter has mass m, momentum p and energy E and is at an angle θ1. Now I have to assume that the daughter is emitted at an angle θ2, and the mother is moving along the x-axis with velocity βc. I need...

Homework Statement A particle A (mother particle) with a mass of mA decays to two particles B and C (daughter particles) with mass values of respectively mB and mC. Calculate momentum of the two daughter particles, pB and pC. (at first the mother particle is at rest) Homework Equations The...

Hi all, I'm just curious about the weak force and how it works. If quarks and electrons both have weak iso-spin and are constantly whizzing about next to their neighbour's (especially so inside a nucleon), what prevents say, the up quarks from emitting a W- boson everytime they are near a down...

This is not a physics question. Each time a ball bounces it will bounce to, let's say 75% of its previous height. (I am not interested in the time, energy or velocity, of the ball.) So if we drop it from 100 cm it will bounce back up to 75 cm, and on the next bounce it goes up to 56.25 cm and...

Homework Statement For a medium of conductivity ##\sigma##: $$ \nabla^2 \vec{B} = \sigma \mu \mu_0 \frac{\partial \vec{B}}{\partial t} + \mu \mu_0 \epsilon \epsilon_0 \frac{\partial^2 \vec{B}}{\partial^2 t} $$ A long solenoid with ##r=b## has n turns per unit length of superconducting wire anc...

Hi there, not sure whether this is in the right section but: I've made two runs of a radioactive decay experiment where I've got a log(N) vs. time plots. From this I've got the decay constants and hence the half-life. I've averaged these two half-lives ( = 160 secs) and now I'm trying to work...

Homework Statement Show that it is impossible for an ultra-relativistic particle with ##pc>>Mc^2## to disintegrate into two identical massive particles of mass m. Homework Equations Conservation of four momentum The Attempt at a Solution The four momentum of the ultra-relativistic particle...

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. Homework Equations...

I read from various sources that Non-baryonic matter (primarily WIMPs) is the best candidate to explain a number of cosmological phenomena. Why would the phenomenon of radioactive decay not be attributed to these abundant (over 1/4 of the mass-energy of the universe) particles? I'm not trying to...

I presume they cannot as they are fundamental particles? But then a meson can decay into a lepton?

Proton decay has not been observed and has been constrained to be extremely rare in ordinary low temperature situations, if it happens at all (the Standard Model says it doesn't happen at all, because there are no lighter decay products that would not violate conservation of baryon number)...

Homework Statement I'm trying to compute the square amplitude ## |\mathcal{M}|^2 ## for a decay process in which a Majorana fermion, call it ## \chi_2 ##, decays into another Majorana fermion, ## \chi_1 ##, and a vector boson denoted by ## A^{\mu} ##. The model is such that the mass of the two...

Homework Statement How can I estimate the decay coefficient in Ae^-at for this graph I know the equilibrium position Homework Equations damped oscillation The Attempt at a Solution not sure if this is right.[/B]

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...

1. Create and solve differential equations for the number of different amounts of isotopes, which change through time in the decay chain X -> Y -> Z, where X and Y are radioactive atoms, and Z is a stable atom. 2. Make a mathematical analysis of how the different amounts of isotopes from 1 mg...

Homework Statement A nucleus A decays into two nuclei B and C. The two nuclei have a combined kinetic energy of 581.9 MeV. What is the difference between the rest mass of the parent nucleus A and the combined rest mass of the two produced nuclei? Give your answer in atomic mass units u, with...

Homework Statement I found an answer on the internet for this problem, but I'm not sure on one of the steps. The solution says, "Take ln of both sides to get rid of Ae. If we do that, then the right side will be ln(Ae^t/T). I don't see how using ln will get rid of Ae? Homework Equations Refer...

I am having a question in mind that why π+ decays to muon and muonic neutrino ,why no electron and electronic neutrino?

Homework Statement The radioactive isotope radon-222 may decay spontaneously by emitting an alpha particle. The daughter nucleus is an isotope of polonium. The atomic masses of these isotopes are: Rn-222 : 222.0157 u Po : 218.00896 u He : 4.00260 u A sample of radon-222 contains 3.0 x 107...

Hello all, I have a data which look like reversed exponentially modified Gaussian (EMG) function and interested to fit the data with with reversed EMG function. After searching on internet I found the EMG function, which is given below...