Decay Definition and 998 Threads

As we all know radioactive isotopes have different half lives and different decay energies. Is there any tie between how long or short the half life is and the amount of energy of decay? I know that it will be a rather complex problem, especially for alpha decay where the mass of the...

Hi, How could I rearrange x=x0e^-lambda t into the form y=mx+c, where y is equal to ln x and x is equal to t? Thank you in advance I tried to solve the problem myself, by taking the natural log of both sides, this left me with: ln x = -lambda t * lnx0 However, I am not sure if this answer is...

1. If I throw sixty different dice (compared to an atomic nucleus) and each dice that gets a 3 is disintegrated and disappear before the next roll. Altogether I make ten roll, where each roll corresponds to one day. The result is illustrated in a graph: http://imgur.com/TbXF4mf click on the...

Homework Statement I am trying to calculate the ratio of the density of states factor, ##\rho(p)##, for the two decays: $$\pi^+\rightarrow e^++\nu_e~~$$ and $$\pi^+\rightarrow \mu^++\nu_{\mu}~~$$ Homework Equations ##\rho(p)~dp=\frac{V}{(2\pi\hbar)^3}p^2~dp~d\Omega## Which is the number...

Hello, Are there any anthropologists, archaeologists, or geologists around on this board for help? I am trying to teach myself about radioactive decay via beta emission whereby a neutron spontaneously transmutes into a proton, releasing an electron. But, I do not understand the practical side...

Hey, here's a quick question: What is the Hamiltonian operator corresponding to a decaying Carbon-14 atom. Any insight is quite appreciated!

As a physics A Level student, I am interested in understanding particle physics. Recently I have read that a W boson, as a relatively heavy particle, decays into one of three charged anti-leptons, and one of the three neutrinos. If a W boson decays to form an anti-tau lepton, it will also form a...

Is there any gamma decay or x-ray decay in Actinium series, Uranium series or Thorium series? On Wikipedia, it only shows alpha and beta decay, does it mean high energy photon decay (gamma or x-ray) exists in each process? Thank you! https://en.wikipedia.org/wiki/Decay_chain#Actinium_series

First of all let me tell that I am a high school student and I have no background in particle physics. If we apply the Heisenberg's uncertainty principle to an electron confined in the nucleus it tells us that the energy of the electron must be something like 3.8X10^8eV .. but in a beta decay...

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...

Homework Statement A radioactive material decays by simultaneous emission of two particles with respective half lives 1620 and 810 years. The time, in years, after which one-fourth of the material remains is: Homework EquationsThe Attempt at a Solution I'm confused whether the half lives...

Homework Statement The formula being derived is N=No*e^k*t, from the equation Nn=No/2^n where No is the initial number of particles and the lowercase n in the second equation is the number of half lives. The n in Nn just indicates the number of particles after so many half lives. You might also...

I'm looking for introductory references to the topic of time of tunnelling decay when besides the potential barrier there is also a magnetic field present. I have found a couple of articles about the topic but they treat complicated cases in condensed matter, I'm more interested in the basic of...

Considering a Z boson decay into a fermion-antifermion pair. How can i say if the process respect parity and charge conjugation?Thanks

Hello I was reading this post, https://www.physicsforums.com/threads/nuclear-decay-of-a-small-number-of-atoms-calculation.853664/ and I wander if the binomial distribution is still a good model if you have a small amount of nuclei, and in addition they can decay by different processes (each...

Hello everyone, I've been wondering for a while how is it possible to determine which decays are possible from a particle or, given a decay be sure that the given decay is possible and hence draw a Feynman diagram of it. I know I have to take into account conservation charge, energy...

Homework Statement A stationary nucleus undergoes radioactive decay. A beta particle and a neutrino are detected leaving the nucleus. What is the recoil velocity of the remaining nucleus? If the recoil velocity measured is significantly different from the calculated velocity, what conclusion...

I came across a rather dubious question that a teacher had put in a power point. It said something like,"Given a sample of 100 atoms of isotope x, after one half life of the said isotope, how many atoms of the original isotope will be left?" My answer was that it was a trick question because...

Homework Statement The radionuclide 11C decays according to 116C → 115B + e+ + v Show that the disintegration energy is given by Q = (mC - mB - 2me) c2 Homework Equations Q = (mi - mf) c2 The Attempt at a Solution [/B] Q= (mC - mB - me) c2 Im probably missing something obvious but I can't...

Homework Statement I have a question regarding exercise 48.4-b in Srednicki's QFT book (the chapter is related to Yukawa theories). I have the official solution + explanation to the problem but I still do not fully understand the reasoning used in it, so perhaps you can help me. In the...

Beta decay, quantum fluctuations, even random vacuum polarizations are all manifestation of collapse, isn't it? The arguments being that in pure unitary wave function, there will be no phase randomization of any kind. Do you consider beta decay as example of decoherence? For decoherence to...

Homework Statement Hi- I've been doing some questions and came across the following A high energy particle, traveling towards an observer with velocity v decays to produce a photon with energy E in the rest frame of the particle. Find the frequency at which this photon would be detected by...

Hi all, I know that the dimension of a partial decay width or a cross section should be GeV or pb respectively. But what if i have a decay width probational to ## \Gamma = 10^{-3} GeV^3 G_\mu ## where I calculated all the masses and constants in ## \Gamma ##, ## G_\mu ## is the Fermi...

When a nucleus gamma decays, the gamma has its intrinsic spin of ##1\hbar##, but it can also carry away a significant amount of angular momentum in addition to that. Quadrupole radiation is very common, and in exceptional cases you can even get gammas with 5 or ##10\hbar##. Now suppose I do the...

Homework Statement Two isotopes N1, N2. You are given the value of the proportions N1(t1)/N2(t1) and N1(t2)/N2(t2). From this calculate Δt. Homework Equations dN/dt = -λN The Attempt at a Solution Solve dN1/N = -λdt and dN2/N = -λdt obtain: N1(t2) = N1(t1)exp(-λ1(t2-t1)) (1) and N2(t2) =...

Homework Statement A particular type of fundamental particle decays by transforming into an electron ##e^{-}## and a positron ##e^{+}##. Suppose the decaying particle is at rest in a uniform magnetic field of magnitude 3.53 mT and the ##e^{-}## and ##e^{+}## move away from the decay point in...

For instancr like neutron decaying into proton electron and antineutrino. I read it in a book that says that according to Fermi, each of these particles are vibrations in different quantum fields and that each field exerted a tiny influence on the others. Because of quantum mechanics, we can't...

Homework Statement What initial mass of 23592U is required to operate a 350 MW reactor for 3 yrs? Assume 46% efficiency. Homework Equations I used Mass* C* efficiency as a decimal= power (e^-6) * time (in seconds) and got 800 as the mass, however, this was incorrect The Attempt at a...

Homework Statement Assume that a 14 kg sample of 240Pu is used to produce electrical power from its α decay. If your device is 60% efficient in producing electrical power, how much power can be produced? (in watts) Homework Equations Q=mass of plutonium-mass alpha-mass daughter; 240 plutonium=...

A particle with mass M a rest decays into two particles a and b. I know that Ea + Eb = Mc2, from conservation of energy. But I'm pretty confused about signs in the conservation of momentum equation, and I've actually seen two versions! pa + pb = 0, so pa = - pb. But I've also seen pa = pb! I...

Homework Statement A particle with mass M at rest decays into two particles with masses ma=0.15M and mb=0.65M . i) Discuss the relative directions and magnitudes of the momenta of these two particles in the centre of mass reference frame. Homework EquationsThe Attempt at a Solution What's the...

Homework Statement I'm trying to confirm the speed of an antimuon in the \pi^+ \rightarrow \mu^+ \nu_{\mu} decay through the laws of conservation but it doesn't add up. Homework Equations [/B] 1.Energy-momentum relation: E^2 = (pc)^2 + (mc^2)^2 2. Rest masses: m_{\pi} = 139.6 \...

I found an article, titled Electromagnetic Decay of the Σ0(1385) to Λγ , in the arXiv telling that the reaction Σ0→Λ+γ can happen through electromagnetic interaction. However, if I examine the conservation of parity. Parity on the left side is even(P(Σ0)=+), but that on the right side is...

Homework Statement A muon decays to an electron, an electron neutrino and a muon neutrino. ## \mu \rightarrow e \ \nu_\mu \ \nu_e## .The matrix element of the process is ## |\mathcal{M}|^2 = G^2_F (m^2-2mE)mE## with ##m## being the mass of the muon and ##E## the energy of the resulting...

Among the radioactive products emitted in the 1986 Chernobyl reactor accident were 131I ( t1/2 = 8.0 d) and 137Cs (t1/2 = 30 y). There are about five times as many 137Cs atoms as 131I atoms produced in fission. (a) Which isotope contributes the greater activity to the radiation cloud? Assume the...

I am familiar with the proton:neutron ratio and stability but what about this instability actually causes a quark to emit a boson and change flavour? And what does this have to do with the weak nuclear force? Thanks

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...

Homework Statement [/B] You find a 1kg piece of rock containing 3 elements: Fakium with 50 protons and 52 neutrons imaginium with 52 protons and 48 neutrons madeupium with 51 protons and 51 neutrons Fakium is known to be radio active, Which of the other two elements could be the decay product...

Homework Statement Charred wood remains were found in Conimbriga, probably with Roman origin. When measured at 14C activity in these remnants, it afforded 10.8 disintegrations per second per gram. The half-processing 14C is 5730 ± 30 years and the activity of this isotope in the atmosphere and...

Hello everyone, I found in the PDG booklet that pi 0 decay into e+ e- gamma is more likely to happen than to e+ e- only ..is there a reason that favorises the first decay?

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...

Hi guys, in my plot I have an unstable isotope of an alien element and I was wondering wouldn't it be nice if most of the particles generated from the decaying are entangled, how do you think, does it sound silly and totally impossible? If it is a good idea, then how such a property can be used...

Hello, In my understanding, decay of quarks should give leptons of the same generation as the quark has, like in a basic way, neutron decaying into proton and an electron. Because of this I have trouble understanding why the strange quark turns directy into up quark, an electron and an electron...

Hello, Why is there a decay mode of omega baryon that creates unnecessary particles? sss -> uds + u(bar)s and why not just sss -> dss ?

Hi, I have a question regarding decay of matter. Let's say I have a block of lead. Now imagine I sit it in a vacuum - given infinite time. What will happen to it - will it ever degrade or change. In another way does matter last forever? Also what is the correct physics term for what I am...

Fluorine ions are negatively charged, and help prevent tooth decay by forming fluoraptite when substituting the lost hydroxide ions in the tooth enamel. Since they are both negative, it is successfully substituted. However, it was told that acid on the tooth causes that decay. My question is...

Hello everyone! I had a question about a particle (say a proton) with relativistic energies interacts with a magnetic field (in the z direction). As it is accelerates the particle emits synchrotron radiation. Naturally I assume that this emission of photons reduces the particle's energy. My...

I am trying to solve the following problem for my graduate course in isotope geochemistry. If 1 g of 226Ra is separated from its decay products and then placed in a vessel, how much helium (cm3) will accumulate in the vessel in 60 days? Here is what I know. The decay series from 226Ra to Lead...

Homework Statement Are the number of electrons on both sides of the radioactive decay balanced? Homework Equations For example, consider an alpha decay. ZPA → Z-2DA-4 + 2He4 For P, Number of Neutrons = A - Z Number of Protons = Z Number of Electrons = Z For D, Number of Neutrons = [A - 4] - [Z...

What is so special about the Higgs field that causes protons to decay?