Decay Definition and 998 Threads

The problem statement The Cobalt-60 isotope is often used in medicine. It has a half-life of 5.25 years. a) What is the activity of 1μg Cobalt in Bq (decays/second)? b) You find a sample of Cobalt that has a mass of 10 µg and has an activity of 5.0MBq. How old is that sample? This problem was...

Homework Statement A Phosphorous 34 decays and emits a particle. A JJ Thomson experiment is done to find out the charge to mass ratio of this particle. The particle moves undeflected through mutually perpendicular magnetic and electric fields of 2.00 x 10-3 T and 1.08 x 104 N/C, respectively...

Also, How do we know the radioactive decay is constant? I know that carbon dating cannot be 100% accurate because the rate of production fluctuates based on cosmic rays hitting our upper atmosphere. Why isn't this true with Earth metal isotopes? Is time truly constant? It seems like a lot...

Homework Statement What's up guys, I'm stuck on #2 of this worksheet,http://luc.edu/faculty/dslavsk/courses/phys111/homework/phys111-2015hw1.pdf The half - life of C - 14 is 5730 years. Determine the value of its decay constant (and express the answer in appropriate MKS units). 2.The attempt...

Homework Statement A Helium 5 at rest decays into Helium 4 and a neutron. Mass of Helium 4 = 6.648 x 10^-27 Mass of Neutron = 1.67493 x 10^-27 Helium 4 has a momentum of 1.903 x10^-20 and Ek 2.723x10^-14Homework Equations E=mc^2 v= square root of (E2/m) The Attempt at a Solution I have found...

Hello, I know that the gravitational force is the weakest of all forces (it is 10^-38 times weaker than the strong force), so it isn't possible a particle to decay through gravitational interaction. As far as I know, the strength of fundamental forces can change during different ages of the...

Hi Guys Is there a simple test by which one could determine the type of decay a radioactive specimen is undergoing? Thanks sonip

Hello, Let's say I have an ideal cylindrical pool (rigid, vertical walls) of diameter d, with water of depth h. Take the ratio of d:h to be around 5:1 - 10:1. If I press down on the surface with a plunger of width w, I cause a standing wave resembling a single-node Bessel function, like a...

What is so unstable about one particle that it only lasts a billionth of a second? Opposed to another particle that lasts much longer. What is so different between the two and why are there "timers" set when these particles created?

I'm trying to calculate the SU(5) model's prediction for the lower limit of a proton decay lifetime, for the channel p \rightarrow \pi^{0} e^{+}. I'm following this paper: arXiv:hep-ph/0504276v1 It contains the following equation: As far as I can tell this actually contains a prediction...

Hi everyone, i was reading the article of Cristenson,Cronin,Fitch and Turlay of 1964, the one that discovered CP violation in the system of neutral K mesons. There is one point in it that i don't get it. They say "the angle should be zero for two body decay and is, in general, different from...

what causes radioactive decay i mean i know throw decay could turn unstable to stable atom. But what cause it unstable?

I have some confusion over some diagrams involved in proton decays in SU(5). I've seen a few like this that look weird to me. Here is one I found where the colored Higgs triplet does the job: Straight away I don't know what to make of this because I've only ever seen diagrams where fermions are...

I'm trying to understand how the SU(5) prediction for the proton decay lifetime of \tau_{p} \sim10^{31} yr has been arrived at. I keep seeing it stated that \tau_{p} \sim \frac{4\pi}{g_{5}^{2}} \frac{M_{X}^{4}}{M_{p}^{5}} where g_{5} is the SU(5) coupling and M_{X,p} are the X boson and proton...

http://arxiv.org/abs/1507.05760 Higgs boson cosmology Ian G. Moss (Submitted on 21 Jul 2015) The discovery of the Standard Model Higgs boson opens up a range of speculative cosmological scenarios, from the formation of structure in the early universe immediately after the big bang, to relics...

Hello fellas! Ok, so we have the isotope Nickel-58 which can decay (still theoritically) to Iron-58 through double beta decay plus (bb+), my question is... imagine this decay is actually demonstrated (just figure it), so the transmutation into the iron isotope actually works... would the ejected...

it is said that the energy spectrum of two body and three body decay is discrete and continuous respectively.

Hi all, Hopefully this is the right subforum. I have a question related to Arduino sensors. Q:Generally, when do you need to be worried about losing data from having long wires from your sensor to your Arduino board? Details:For example, I've been looking at two sensors. Sensor 1: MLX90614...

The neutral pion is dominantly decaying to 2 photons via electromagnetic interaction \pi^0 \rightarrow 2 \gamma. However if one allows for P-violation in electromagnetic interactions, he will also get C violation (due to CPT theorem). In that case a decay of the form \pi^0 \rightarrow 3 \gamma...

My background of some introductory courses in particle physics has left me with severe shortcomings. Say we start from a hadron, which decays purely to other hadrons. My question is this: through which interaction does the process take place? Is there a preferred interaction, and why/why not...

Homework Statement An unstable ion of mass ##M##, energy ##E## emits a massless particle of energy ##E_\nu## at angle ##\theta##. In the rest frame of the ion, find ##E_\nu^*## and ##cos \theta^*##. Ions are now accelerated to ##\gamma=100## and a detector with radius ##r=20m## is placed...

Hi all, I'm attempting to write something on proton decay (specifically in the p \rightarrow K^{+} \nu channel) and need to understand some theory that predicts it. I'm under the impression that the MSSM is the most straightforward theory. However, I look through introductory texts/documents...

Homework Statement I am trying to solve problem 5.4(a) in Peskin & Schroeder. I am requested to calculate the decay rate of a ##1S_0## positronium state into two photons. Obviously, we have to sum over all photon polarizations eventually to get the total decay rate. However, I do not understand...

Hi, I'm looking for the momentum so that the decay length of a tau (mean lifetime ##t_{lft}=2.9 \times 10^{-13}s##) can be ##2mm##. I was wondering whether someone can use the formula I got: l_{lab}= t_{lab} u = \gamma u t_{lft} \Rightarrow pc= m \gamma u = m \frac{l_{lab}}{t_{lft}}? (Looking...

Homework Statement An initially pure 3.4 g sample of Ga-67, an isotope with a half life of 78 hr. What is its initial decay rate? Note: Molar Mass values given in tables for chemical elements are for natural mix isotopic ratios. (i.e. the relative percentages of each isotope normally present...

Homework Statement 1) Calculate the Q-value for the electron emission beta decay of Co-60 * 2) Calculate the Q-value for the positron emission beta decay of Mg-23 * * (both correct to 6 significant figures) Atomic Masses (u) electron = 0.0005485803 Co-60 = 59.9338222 Ni-60 = 59.9307906...

Homework Statement A beam of pion mesons travels down a tube at the CERN accelerator moving at v/c=0.95 with respect to the laboratory. (i) Compute the γ factor for these pions. (ii) The pion lifetime is 2.6 × 10−8 s, what is the lifetime measured at the laboratory? (iii) The pions travel 50...

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

Homework Statement Homework Equations Please see below. The Attempt at a Solution I'm pretty sure my method is correct but I'm getting small answers: $$ COM \\ \\ E_{6}= E_{2}+E_{\alpha} \\ \\ Minus \ E_{2} \ and \ square \ both\ sides\\ \\ E_{6}^{2}+E_{2}^{2}-2E_{2}E_{6}=E_{\alpha}^{2}\\...

Take some unstable particle species, and put two of them into an exotic atom or exotic molecule, such that the two bound particles fully occupy a 1s orbital. For example, two negative muons orbiting an alpha particle, or two mesons orbiting a massive baryon. Decay of either orbiting particle...

Hi there, my question is along the lines of the following. I understand that in an experiment we obtain a distribution of masses for a given particle, due to the finite resolution of the detectors. In terms of a fundamental (if that even makes sense) decay width, what is the decay width? Is it...

Homework Statement Homework EquationsThe Attempt at a Solution I've started from writing out the amplitude. Here I know that fermion has definite helicity so I can't sum over spins but I should input explicit forms of spinors. Am I correct? How to do this? I would be grateful for helping me...

Both ##^{87}_{37}Rb## and ##^{87}_{38}Sr## are odd-even nuclei, so we can ignore the pairing term ##\delta##. I tried to calculate the most stable Z for a given A by finding ##\frac{\partial B}{\partial Z} = 0##. That gives the most Z-stable value of ##Z_0 = \frac{2\gamma A}{4\gamma + \epsilon...

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 Consider; p+p \rightarrow d + e^+ + \nu_e Assume the binding energy of deuteron is 2.2MeV, calculate the maximum energy that the positron can have. Homework Equations m_p=938.28MeV/c^2 m_n=939.566MeV/c^2 m_d=1875.6MeV/c^2 The Attempt at a Solution Assuming the neutrino was...

Hello all, please forgive me if I seem somewhat unaccustomed to this site, I have just registered. I suffer from an illness called catastrophic thinking syndrome, simply put this means that I turn everything I read into a disaster until I become ill due to anxiety / depression . I recently...

If you consider the ##\chi_0 ## with a mass of ## 3.4 GeV/c^2## meson, why doesn't it decay to a pair of charged leptons? Technically it is possible though the weak interaction (Z boson) or EM interaction, right? Is it because it is so heavily suppressed because the strong interactions are...

The following equation is written in my book: 204Pb→4α + 200Hg If an alpha particle is a helium nucleus, why doesn't it have a +2 charge and why doesn't Hg have a -2 charge? Did my text just omit the charge?

Homework Statement Find the velocity field u(x,t) Homework Equations \rho = constant u(0,t)=0 u(0,L)=0 \frac{\partial u}{\partial t} = \nu \frac{\partial ^{2}u}{\partial x^{2}} u(x,0)=U_{o}[sin(\frac{3\pi x}{L})+0.7sin(\frac{9\pi x}{L})] The Attempt at a Solution I have absolutely no idea...

p+p→Σ+ + n + K0 + π0 + π+ right hand side has more energy

In the text-book example of CP violation in the kaon system, the usual statement is that the KS decays much faster than the KL because the phase space is larger for a decay into two pions, compared to three pions. (See, for example, Griffiths or "Modern Particle Physics" by Thomson.) I was...

How the relative angular momentum of two particles can be detect by detector in two particle decay (center of mass frame)? I am curious about the signatures/differentiation between different relative momenta, means how one can decide that it is L=0, L=1,2,3,...? Of course the distribution would...

I'm sorry for posting this another thread, but I accidentally posted under to wrong forum initially and could not figure out how to delete it :-(1. Homework Statement Find the missing isotope: Iodine-127 (n, alpha) My answer is Sb- 122 but it was wrong. Also, how would I go about finding the...

Decay \eta\to\pi^0\gamma is forbidden by C parity. But why this decay is also forbidden by statistics (J)? pi^0 spin is 0 photon spin is 1 But there are can be different situations with full orbital angular momentum of pi^0\gamma. J=L+S and must be 0. Look like L is 0. But why? Why we can't...

Homework Statement (a) Explain spin and parity of mesons (b) State their quark content (c) Draw a feynman diagram of J/psi decay (d) Why doesn't ##\chi## undergo leptonic decay? (e) What is the minimum centre of mass? [/B] Homework EquationsThe Attempt at a Solution Part(a)[/B] Spin is...

Hi there, In a two body decay process like ## B \to l \nu ##, there is a factor ##| \bar{l} (1-\gamma_5)\nu|^2 ## in the matrix element amplitude, in which equals ##| \bar{l} (1-\gamma_5)\nu|^2 = (/\!\!\! p_l+m_l) (1-\gamma_5) /\!\!\! p_\nu(1+\gamma_5) = 2(/\!\!\! p_l+m_l) /\!\!\...

Homework Statement (a) What processes changes atomic number by 1? What are the favourable conditions? How do you tell a neutrino is involved? How can we use this to understand the mass of this particle? (b) Use semi empirical mass formula to explain why odd-odd isobars are unlikely, while...

Homework Statement (a) Show maximum energy transferred in compton scattering is as such. (b) Identify what the peaks are and why some decays are suppressed. (c) How do you distinguish between these 2 decays[/B] Homework EquationsThe Attempt at a Solution Part(a) Bookwork. For completeness...

Hi, 1. Homework Statement In the calculation of the matrix element amplitude of ## B \to l \nu ##, I got a factor ## \bar{l} (1-\gamma_5)\nu ## as in [hep-ph/0306037v2]. For ##|M|^2## I made : ##| \bar{l} (1-\gamma_5)\nu|^2 = (/\!\!\! p_l+m_l) (1-\gamma_5) /\!\!\! p_\nu(1+\gamma_5) =...

Hello everyone, Can a hadron be in an excited stage? If yes, can neutrons -the element- neutronium have a nuclear isomer in a metastable stage, making it have a longer half life?