Decay Definition and 998 Threads

Does neutron decay outside of the nucleus occur faster, slower, or at the same speed when the environment it is in is near absolute zero? Do any external factors affect the speed of a neutron decaying?

So I know that the total energy of the system initially is 775.5MeV, because the meson is at rest. Also by conservation of energy I know that the total final energy of the system is the same thing. I also know that the initial momentum of the system is 0 because the particle is at rest. This...

Hello! In the (famous) plot I attached we have the branches ratios for the Higgs decay for different Higgs masses. I am sure that sitting down and doing the Feynman diagram calculation (to 1 or 2 next to leading order?) I will get these curves. But I am a bit confused about the physics intuition...

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...

If you have a lump of the same species of radioactive isotopes, why can't the photons emitted from the radioactive decay of one nucleus cause spontaneous emission from other atoms? I presume it doesn't, because if it did, there would be a geometric effect of radioactive decay, which is not...

I know that, for charge conjugation, ##C_{\Phi} = -1##, ##C_{K^{+}} = 0##, ##C_{K^{-}} = 0##, but ##C_{\Phi} \neq C_{K^{+}}C_{K^{-}}##. How ##C_{tot}## is conserved in this interaction?

I started combining 2 pions: ##|\pi ^{0},\pi ^{0} >=\sqrt{\frac{2}{3}}|2,0>-\sqrt{\frac{1}{3}}|0,0>## What should i do now? Should i continue combining the third pion or can i already say that it's forbidden? If yes, why? Is it because the state antisymmetric, impossible for two bosons?

It is equally puzzling why we are confined to probability amplitudes for RD as in QM measurements. Newtonian determinism is undermined in both, so why were there still Newtonian determinists around when QM hit the scene? We still have deterministic equations for both ofc but they are limited to...

Hello physics gurus out there. Can someone please point me in the correct direction. I am looking for reasons why Hydrogen burning is NOT considered to be B+ decay in the standard CNO cycle? Thanks The forgetful one

Double-beta decay will emit two neutrinos. But, are they simultaneously released or separated?

I know that it has a cause! It happens to make the nucleus more stable. But some say it has no cause. I am confused actually.

Radioactive decay modes always release energy; but why can't nuclear fusion of light elements be a mode of radioactive decay? I guess because although such processes are exothermic, we need an inaccessible fairly high amount of energy to overcome the electrostatic repulsion barrier. But now...

I was learning about beta decay, and how a down quark decays into an up quark by emitting a W- boson which then becomes an electron and an electron antineutrino. I have two main questions - Firstly, how can the down quark be considered a fundamental particle, when it can break down to produce...

I measured the decay spectrum of Bi-207 as a beta source with scintillation detector and now I am trying to interpret the information given by the spectrum. As far as I know, the Bi-207 nuclei decay to the excited states of Pb-207 primarily via EC and a small beta+ branch, emitting beta...

Hello everybody! I have a question regarding the forbidden decay ##\rho^0 \rightarrow \pi^0\pi^0##, but it is a general doubt. My book states that one of the reasons why the decay is forbidden is Bose-Einstein statistics, the final state of two equal pions must be in an antisymmetric state...

What are the most likely modes of decay for ##\Omega ^{-}## into 2 hadrons? ##BR_{k}=\frac{\Gamma _{k}}{\Gamma}## ##\Gamma=\frac{\hbar}{\tau }## ##\Gamma _{k}=\Gamma _{if}=2\pi \rho|<\Psi _{i}|H_{Int}|\Psi _{f}>|^{2} (E_{f})## I took a look at the Particle Data Group, and the most likely modes...

My first idea was to find an expression of the muon momentum as a function of the angle and then maximaze the expression. But my attempts were not succesful. I report here my attempt. Set up (referring to the attached file "bettini.pdf"): $$ p = (\sqrt{p_k^2+m_k^2},0,0,p_k)$$ $$ k_1 =...

##\beta^{+}## decay (a proton decays to a neutron + positron + electron neutrino) is a decay in which mass energy is not conserved. I've been taught that if that ought to be the case for a decay/reaction, it would be forbidden (please see solution manual below): But ##\beta^{+}## decay is...

As it's written in the following article, nuclear binding energy is always a positive number; thus it takes energy to disassemble a nucleus into its nucleons. ...The binding energy is always a positive number, as we need to spend energy in moving these nucleons, attracted to each other by the...

Moderator's note: This is spin-off from https://www.physicsforums.com/threads/why-randomness-means-incomplete-understanding.975227 Reading this thread I would like to point out one aspect that makes me wonder personally and has also been mentioned here by other users. The decay of atoms...

First of, I have no idea what I'm supposed to do with the neutrinos and the photons. Can somebody explain how to handle these? The rest of what I tried is quite straight forward $$\begin{align*}\Delta E &= 4M_p - M_{He} - 2 M_e + E_{\text{Neutrino and Photons}}\\&= 4M_p - (2[M_p+M_n]-E_B) - 2...

Attempt at solution: By conservation of momentum: $$P = (M,0,0,0) = p_1 + p_2 = (E_1 + E_2, 0, 0,0)$$ thus $$ M = E_1 + E_2 = 2k^2 + m_1^2 + m_2^2$$ Now $$E_1^2 - E_2^2 = m_1^2 - m_2^2 = (m_1 + m_2)(m_1-m_2)$$ $$ = M(m_1-m_2) = (2k^2+m_1^2+m_2^2)(m_1-m_2)$$ Isolating k: $$ k =...

Hello! In Modern Particle Physics by Mark Thomson, in the Electroweak Unification chapter, pg. 412 he talks about the branching ration of the W decay to quarks. And for this he includes both the ##W\to q \bar{q'}## and ##W\to q \bar{q'}g## i.e. the state with a gluon and 2 quarks in the final...

Since we are looking for K total, I summed the given kinetic energy for lead and the typical kinetic energy of an alpha particle: 0.12 + 5 = 5.12 MeV. My answer is definitely wrong, but I don't how I should approach the problem.

Problem Statement: In beta-decay, a gamma ray that is a fast moving electron is emitted due to the conversion of a neutron to a proton and an electron to increase the stability. As a result, the atomic number increases while the mass number remains the same. But when the atomic no. increases as...

So I worked out the first part and obtained ##E_1 = 478.8MeV##, ##E_2 = 459.4MeV## and ##p = 0.49 MeV/c## but I can't quite wrap my head around the second part. Normally, I'd use the equation for s but I'm confused since I don't know the angle between the gamma rays.

As mentioned above I'm unable to begin because I don't know the relevant equations or method.

I was looking up stuff for relativistic two-body decay, and I came across this pdf: https://indico.cern.ch/event/391122/contributions/928962/attachments/782786/1073126/twoBodyDecay.pdf which says that because ##p_2^2=P^2−2P\cdot p_1+p_1^2## we apparently have ##m_2^2=M^2−2ME_1+m_1^2##. But this...

I understand that In general, the branching ratio for a particular decay mode is defined as the ratio of the number of atoms decaying by that decay mode to the number decaying in total. But I can’t get this specific branching ratio.

QED predicts photon-photon scattering, via a fourth-order Feynman diagram with four external photon legs connected to an electron loop. It seems to me that the same diagram should also predict a process where a single incoming photon decays spontaneously into three photons. This is not forbidden...

Hello! Given an excited state of a nucleon, such as the ##\Delta## baryon (and here I mean all its 4 version ##\Delta^{++}##, ##\Delta^{+}##, ##\Delta^{0}##, ##\Delta^{-}##), the decay channel is (in this case) to a pion and a nucleon. I was wondering, is the decay probability the same for all 4...

In a https://jila.colorado.edu/thompson/sites/default/files/pdf/PhysRevLett.113.154101_0.pdf on quantum synchronization, they introduce the setup given in the attached 'Fig1.png'. I would like confirm a few concepts regarding this setup. The setup is described in the following way: The general...

Hi, I want to develop a Monte Carlo simulation to determine the temperature of a beta radioisotope (Sr-90) of a given mass for my master thesis in Computational Physics. I am rookie to simulations. How much time will take to develop such a code. Thnaks a lot

In Beta+ decay, a W+ boson is created and it decays into positron and electron neutrino. Mass of W+ boson is ~ 80 GeV/c^2, however, the total mass of positron and electron neutrino is very small compared to it. So, what happens to the rest of the mass? Is it converted into kinetic energy of...

What is the significance of the radioactive decay constant?

Take one radioactive element and put a detector all around it so that you can immediately detect whenever it will undergo radioactive decay. Have a clock connected to the detector to note the "exact" instant at which the atom decays. Let's say that after 3min after the clock started counting the...

Hi, I was trying to see where the equation N = No e-λt came from and it is derived from dN/dt = -λN which is discussed very well in this thread in post #2 (https://www.physicsforums.com/threads/derivations-of-the-decay-constant-equation.213312/). I understand the steps except for the reason why...

Hi, Suppose I had a pair of protons that are entangled, and one or both of those protons decayed( https://en.wikipedia.org/wiki/Proton_decay ) over time, does that mean the entanglement between the protons does not exist anymore, and would it be fair to say that the entanglement decayed over time?

Homework Statement U - 238 is undergoing alpha emission into Th - 234. U - 238 has half – life of 109 years. Calculate the emission rate of alpha when uranium has mass of 10 grams Homework Equations A = λN A = A0 (1/2)n , n = t / half - life The Attempt at a Solution Not sure how to do it but...

Take 60Fe found in meteorites. Does it start to decay the moment it is created. Or does it start to decay when it cools to a solid (a meteorite)? Does heat have anything to do with it? Thanks

Hi, I have questions on the neutron decay What prevent the neutron to decay in udc or udt except mass/energy consideration ? If we do the assumption that (udc) and (udt) have the same mass than the proton (yes I know, this doesn't make sense) the three decay (p, udc, udt) woulld have the same...

Would a proton decay into smaller particles if you accelerate it into higher speeds without colliding it into another proton?

Homework Statement You have 0.0625 grams of an unstable element and 0.9375 grams of the stable daughter product. How many half-lives has it undergone？ Homework Equations N=No (1/2)^(t/(t1/2)) In which N represents the final activity for a period of time No is the original activity t...

Could there be a connection between Robert Zimmermann's work (McMaster Univ. Toronto) on Vector Plasma, and Jenkins and Fischbach's (Perdue Univ.) work on variations in the rate of radioactive decay for elements on Earth in relation to solar activity? Only looking for a confirmation that their...

Let's say you have an impulse of noise, eg. via a guitar string, or a resonant bandpass filter, and it decays naturally. If "1" is the maximum initial amplitude of sound, and "0" is no sound at all, what is the equation for decay of sound over time (x)? Is it: y = 1/c^x Or y = 1/(x+1)^c I...

Before you report this, yes I do know there was already another post like this one, but I don't feel like it fully answered the question. Note that I really don't know anything about quantum anything, but I'm trying to do some reading up on "randomness" and the consensus seems to be that this...

The atomic nuclei consist out electrons, protons and neutrons (with only exception of hydrogen, that does have a neutron). Thus, it would be straightforward, that there existed a corresponding radiation for each nucleus component, when a nucleus decays. There is an electron radiation (beta...

Homework Statement Homework Equations (1) E2 = p2c2 + m02c4 (2) E = γm0c2 (3) E = Eγ1 - Eγ2 (4) p = E / c (5) E = hf (6) λ = c / f The Attempt at a Solution a) Using eqn (1), rearranged p = (E - m0c2) / c , I obtained 2.9 MeV c-1. Not sure if I have the right answer here as I...

Homework Statement Given a coupling h \; \partial_\mu \phi^a \partial^\mu \phi^a , meant to model the first order interaction of the Higgs field h to boson fields \phi^a , compute the width \Gamma(h \rightarrow \phi^3 \phi^3) of the Higgs particle to decay to two longitudinal (say)...