Lifetime Definition and 145 Threads

Homework Statement I have to find the Fermi Coupling Constant using my measurement of the muon lifetime. My measurement is 2.1786x10^-6s Homework Equations G_F=\sqrt{\frac{192.pi^{3}}{\tau.m_{\mu}}} The Attempt at a Solution I tried plugging in the numbers that I have and I get...

Hi all Please take a look here (just read the first paragraph): http://hyperphysics.phy-astr.gsu.edu/Hbase/quantum/parlif.html I am a little uncertain of why it is that we equal the spread in time ∆t to the lifetime of the excited state (in the above link they denote the lifetime by Γ)...

Hello. The question states that We have a globular cluster with total mass 10^6 times sun's mass. Assume that the main sequence lifetime of a solar mass star is 10 giga year, and a main sequence lifetime scales with mass as M^-2. What is the mass of the most massive main sequence stars in...

Calculating the "proper mean lifetime" of pions Homework Statement The mean lifetime of pions at rest is to=2.6x10^-8. if a beam of pions has a speed v=0.85c a)what would their lifetime be in the laboratory? b)how far would they travel before they decay? c)what would your answer to b)...

For neutron we all know, it has the 15 minutes of fame before it decays, what is the theoretical bound on proton's lifetime outside the nucleus, and to what it should it be dacayed to? As far as I can tell electron is a point particle and cannot be dissolved into other parts, are there any...

Hi, I am trying to understand exactly how and why the lifetime, or decay rate, of an atomic level determines the spectral width of the transition to this level. Also I would like to understand why the natural lineshape is a Lorentzian. I am familiar with the vague explanations involving...

I am developing a cathode for studying the microwave induced magnetic isotope effect (MIMIE) in electrolytic reactions. My premise is that a cationic species and an electron donated by a cathode can be considered as a "quasi-radical pair," and that resonant magnetic pumping of the quasi-radical...

Homework Statement Three proton decays per cubic kilometer of water per year are detected by an array of photomultipliers immersed in the sea. Find the mean lifetime of the proton. Homework Equations t = 1 / lambda The Attempt at a Solution How is it possible to work this out...

In the recent past, I've leaned towards no. The reason being that space is a 4-dimensional haystack. Even if a region in that 4D space contains advanced extra terrestrials and we scan it, the extra terrestrials would not necessarily be using EM waves for communications. If extra terrestrials...

I have been doing an experiment on muon lifetime, and am wondering if my count rate is correct. A little about the experiment: I have two scintillators (plastic) set up above a lead glass absorber, and a third scintillator(plastic), under the lead glass to veto muons that do not stop in the...

could someone help me get started on a problem solving the photon lifetime in a cavity? i have 4 optical paths

Homework Statement The muon is an unstable particle that spontaneously decays into an electron and two neutrinos. If the number of muons at t = 0 is N_{o}, the number at time t is given by N = N_{0}e^{-t/\tau}, where \tau is the mean lifetime, equal to 2.2 \mu s. Suppose the muons move at a...

Homework Statement the nucleus of 227Th decays to 223Ra and \alpha. the daughter nucleus is left in a short lived excited state and decays down to the ground state with the emission of an 80 keV gamma ray. the natural line width of this gamma ray is .6 keV. what is the lifetime of the excited...

Homework Statement What is the speed of a pion if its average lifetime is measured to be 4.91E-8s? At rest, its average lifetime is 2.60E-6s. What is the particle's lifetime at rest? Homework Equations \Delta t = \Delta t0 / \sqrt{1-(v2/c2} The Attempt at a Solution I don't...

1. Calculate the main sequence lifetime in years of a 10-M\odot star if it has luminosity of 104L\odot and 10% of its mass will be converted from hydrogen to helium in the core. What will the end state of this star be? Ok so I wasn't really sure what to put for working here as I have no idea...

(*NOT HOMEWORK :) *) If I have a particle that oscillates between states A and B, and I calculate the probability of transition (or of rather being in state B after an IC of being in A @ t=0) and that probability goes like: Pb = C1 Sin^2 (C2 t) And I want to find the average/mean lifetime of...

I am inquiring if anyone here is qualified to numerically calculate the following equation: Fermi coupling constant and Muon decay lifetime: (ref. 1) \frac{G_F}{(\hbar c)^3} = \sqrt{\frac{192 \pi^3 \hbar}{(m_{\mu} c^2)^5 \tau_{\mu}} Muon decay lifetime: (ref. 2) \tau_{\mu} = 2.197034 \cdot...

[SOLVED] Lifetime & Branching ratio Hi! In my book Particle Physics by Martin & Shaw, eq 2.15: Lifetime: \tau _l = \dfrac{B(l^- \rightarrow e^-\bar{\nu }_e\nu _l )}{\Gamma (l^-\rightarrow e^-\bar{\nu }_e\nu _l )} Where B is branching ratio and Gamma the decay rate and l is a...

This is an interesting statistic I read recently... apparently, in 500 million years the atmospheric CO2 will have been vastly depleted due to it reacting with silicon and being stored underground. The CO2 levels will then be too low to allow photosynthesis to occur. This statistic, presumably...

Hi, I'm starting a prac on muon lifetimes and we have been asked to calculate the range of energies suitable for the experiment... Thinking about this, I was a bit stumped as to what we were supposed to be calculating... Is this a limitation of the detection equipment? Or do low energy...

[SOLVED] Restmass, lifetime of a meson Homework Statement A \rho meson is a highly unstable subatomic particle with a rest mass of 776 MeV/c^2 and a mean lifetime of 4\times10^{-24}s. What is the minimum uncertainty in the meson's energy? Homework Equations We know that rest energy...

Can you please give me a hint to start this problem? The Einstein Aij coefficients are related to the lifetime an atom can spend in an excited state i before going to state j. Using Heisenberg’s Uncertainty Principle, show that large values of Aij lead to line profiles with large values of...

Hi all, I'm having trouble understanding the short lifetime on the neutral pion. I understand that in the residual strong interaction between nucleons, the range of the virtual pion is limited by Heisenberg's uncertainty relation for energy, which thus limits its lifetime. I don't...

A particle lives for a short time before breaking apart into other particles. Suppose it is moving at a speed of 0.996c, and an observer who is stationary in a laboratory measures the particle's lifetime to be 3.00 10-8 s. What is the lifetime according to a hypothetical person who is riding...

Theoratically a LED can last for 100,000 hours, but how can i prove that this is true? I've found out that the malfunction of a LED is caused by the degradation of the active region in it, but how can i determine when it is going to malfunction?

A (free) neutron has a lifetime of some 10 minutes or so, how come it is stable in a nucleus?

Preserving the lifetime of a bulb ? My father claims that is is better do leave a light bulb on rather than switch it on or off when used often because he says, "Electric charges are very fast and damages the filament inside with each flick of the switch closing the circuit, even more damage...

Homework Statement I just want to clear this up, I am a little confused: when an electric field is applied there is a force on the electron K-states thus displacing the fermi surface/sphere Is the relaxation time ( \tau)= lifetime of fermi sphere displacement or is lifetime of...

Homework Statement Draw a circuit the involves a battery and two identical bulbs that will maximize the lifetime of the battery. More specifically, draw a circuit that allows you to run the lights longest Homework Equations P = IV V = IR Series: R = R1 + R2 Parallel: R = 1/(1/R1 +...

Can anyone explain how to interpret Heisenberg's relation Delta(E)*Delta(t)>=hbar in case of "annihilation" and or "creation" of (elementary) particles: 1) in case of virtual particles 2) in case of antiparticles ? Is it eventually useful, if I may say so, to discriminate between the...

This probability problem is for my calculus class... a) A type of lightbulb is labeled as having an average lifetime of 1000 hours. It's reasonable to model the probability of failure of these bulbs by an exponential density function with mean = 1000. Use this model to find the probability...

Heres the question before I say anything else A beam of unknown elementary particles travels at a speed of 2.0 x 10^6 m/s. Their average lifetime in th ebeam is measrured to be 1.6 x 10^-8 s. Caclulate their average lifetime when at rest. hmm I have no examples to go by. I figure I will...

OK, I'm currently in the process of designing an experiment to measure the rest lifetime of the muon, using a vertical stack of four flat scintillation detectors separated by lead plates, and coincidence electronics, Time-Amplitude converter, etc. to acquire data from the cosmic ray muons...

I've recently purchased a laptop from ebay, it's in pretty good condition and runs great. However, I think that it's 2002 model and was wondering on how long will it continue to function without giving me any problems? Should I try to resell it, or is it worth the keep?

My question relates to calculating the decay lifetime of an unstable isotope. The information given is the average energy of the emitted gamma ray from the decay has an average energy of say 100kev and a line-width of 5 x 10^-6ev. From this information I need to work out the average lifetime for...

A newly discovered Θ meson has a rest mass energy of 1020 MeV, and electric charge of 0, and a measured energy width of 4 MeV a Using the uncertainty principle, calculate the lifetime of the Θ meson b A Θ meson at rest decays into K+ and K- mesons. Find the total KE of the kaons Thanks...

QFT states that all forces are due to the exchange of virtual particles, I'm interested in photons and their role in the EM force. I was wondering what the maximum time allowed for existence of an exchange photon is when it's emmitted from a proton in the nucleus of an atom. I'm thinkin' that...

for this question: a certain particle has a lifetime of 1*10^8 sec when measured at rest. How far does it go before decaying if its speed is 0.99c when it is created? my problem: because the particle is decaying, then its speed should be changing... then there's two variables in this...

Theoretically, could we (as a species) or could something else (as a species) evolve into something that lives a really really really really long time? I mean I really doubt that anything could actually become immortal because I think that the Universe will probably end at some point... But...

Note: You'll need the Normal Distribution Table. A certain type of light bulb has a lifetime in hours which is normally distributed with mean μ=650 and standard deviation σ=40. What is the probablility that a randomly selected light bulb has a lifetime in the range (700, 850)? Now this is...

I'm just being introduced to particle physics and wondering if I'm going about this correct..can someone help me? thanks The measured width of the J/ψ meson is 88 keV. Estimate its lifetime. Lifetime (s) of J/ψ meson is 8E-21 s Using uncertainty principle: ΔE = h/2πΔt isolate for delta...

Hi all. I'm wondering how people determine the lifetime of a light bulb. Do they really turn on the bulb and wait till it go down? Or there are special methods to shorten the duration of the testing experiment? Anyone know?

Need HELP! Muon Lifetime Experiment I just recently collected data from a muon lifetime determination experiment. The data was presented in the form of two columns: x = time (microseconds) and y = counts/bin. After plotting this xy into a graph I found that my muon lifetime was 2.12 (close...

Is the Scientific Revolution a given and the Information Revolution essential for maintaining the quality of life and perceived needs we have become used to? Otherwise, might they soon transform their basic principles to a philosophical paradigm more attuned to respecting unspoiled nature and...

Does any think or feel that we will be able to achive warp speed in my life time? I'm 30 years old.