Gamma Definition and 714 Threads

Hello! I would like to know how to calculate the width of the two-photon channel of the SM Higgs. It seems to be quite a tedious calculation with a dimensional regularization to perform. There are two one-loop contributions (leptons and W). Thank you very much in advance for your help! B...

[SOLVED] Gamma radiation gamma radiation does anyone know how it is produced within the nucleus? and I know that gamma radiation takes place after a isotope has undergone a decay and is in an excited state. I know that what interest me is the very nature of the excited state! and how the...

\frac{\beta^\alpha \Gamma(\alpha + 1)}{\Gamma (\alpha) \beta^{\alpha+ 1}} = \frac{\alpha \Gamma (\alpha)}{ \beta \Gamma (\alpha)} = \frac{\alpha}{ \beta} This is the solution. In trying to get the middle expression out of the first I quickly end up with a mess. How should I approach this?

maple syntax: int(theta^y * exp(-theta*(1-alpha) ) , theta) I have a distribution that I need to integrate, and I know the result should have a gamma function in it. The only thing I have found helpful is: http://en.wikipedia.org/wiki/Gamma_function My function is kind of in that...

If the exploding star that caused the gamma ray burst on Wednesday had occurred as close to us as Alpha Centauri what would be the effect on Earth?

Many of us have seen how to find a vector satisfying the following conditions (i) magnitude is m (ii) makes angles alpha, beta and gamma with i,j,k vectors i.e. unit vectors along x,y and z axes. My question is can the angles be taken arbitrarily or they should satisfy some condition like...

How infinite does time get by gamma... So I was thinking, say you have a photon traveling at c. I would assume that the photon's own time frame would have time passing as normal. Now after a time t has passed in the photon's frame, some infinite amount of time would have passed say, on Earth...

Homework Statement Find the frequency and wavelength of a 100 MeV gamma ray photon Homework Equations 100 MeV=1.602 X 10^-11 The Attempt at a Solution I do not know how to do this. I am in a class for elementary teachers and we have to solve this problem.

Will some one help me to prove this identity G(n)+G(1-n)= pi/ sin npi 0<n<1 B(m,n) = (m-1)! / n(n+1)...(n+m+1) ,for beta function

The http://en.wikipedia.org/wiki/Gamma_function" is the integral \Gamma(z)=\int_{0}^{\infty}{dt\, t^{z-1}e^{-t}} . It has poles for integers of z less than 1 and is finite everywhere else. But to me it seems like it should be infinite for non integer values of z less than 0. My reasoning...

Homework Statement Need to prove these 2 identities of beta function & gamma function ? Homework Equations G(n)G(1-n)= pi/sin npi B(m,n) = (m-1)! / n (n+1)...(n+m+1) The Attempt at a Solution I tired using beta function in 1st one but did not get the solution .

[SOLVED] sum/integral/zeta functions/ Gamma functions ...problem solved. Question erased.

Does a gamma ray ray carry enough information to prove its source?

On February 1, 2007, the Konus-Wind, Integral, Messenger, and Swift gamma-ray satellites measured a short but intense outburst of energetic gamma rays originating in the direction of M31, the Andromeda galaxy, located 2.5 million light-years away. The majority of such short (less than two...

\Hi, I know the Gamma function has a first order pole at the negative integers, and the residue at -k is (-1)^k/k! So now I want to compute Gamma(-k)/Gamma(-l) , k and l positive integers, and I have a feeling it should be [ (-1)^k/k! ] / [ (-1)^l/l! ] =(-1)^{k+l} l!/k! What would be an...

[SOLVED] Regression Analysis for a Gamma function My regression analysis program that I developed in BASICS back in the 1980's applies for half a dozen linear equations some of which are transormed into log forms. I would like to modify my program to include this Gamma function...

Can anyone point to the current state of research about the relationship between antimatter clouds and gamma rays, specifically gamma ray bursts? There was a science.com article quoted in a Yahoo news story. If anyone has read the article, does it say anything pertinent on this question?

Hello, I need to compare an exponential integral -E_{-2k}(-m) -where k is a positive integer and m just a real number- to a Gamma function \frac{1}{m^{2k+1}}\Gamma(2k+1). I am using the notation from Mathworld here http://mathworld.wolfram.com/ExponentialIntegral.html...

I've hit a problem trying to sample an inverse gamma distribution, 'scaled' using a temperature variable, T. If my distribution is defined as (where the normalising constant k=(b^a)/Gamma(a) ): IG(x|a,b) = k * x^(-a-1) * exp(-b/x) then the scaled version is (IG(x|a,b))^(1/T) = k^(1/T) *...

Hi all, I have a set of samples and I would like to detect the probability distribution that best represents the data. I'm using the kolmogorov-Smirnov test to verify the goodness-of-fit for some well-known distributions, like Gamma, exponential and Weibull. Since I don't know the...

How do escape peaks occure? I mean peaks originating from a gamma ray located at the Energy value of \ E_{peak} \equiv E_{gamma}-511KeV. I read that an annihilation process takes place and one of the annihilation photons escapes detection.To arive at detecting an Energy of E_{peak} the...

Looking for a "mainstream" explanation for gamma gays and nuetron capture signatures. One of Elizabeth's homework problems got me to thinking: Now if Elizabeth is reading this thread, please note that the "correct" answer (in mainstream thinking today) is probably a). However...

Homework Statement Show that tr(\gamma^{\mu}\gamma^{\nu}\gamma^{5}) = 0 Homework Equations (anti-)commutation rules for the gammas, trace is cyclic The Attempt at a Solution I can do tr(\gamma^{\mu}\gamma^{\nu}\gamma^{5}) = -tr(\gamma^{\mu}\gamma^{5}\gamma^{\nu}) = -...

Haven't been able to find the answer anywhere IRL yet, so I thought I'd see if someone in the PhysicsForums could help me with this one. When doing SEM/EDS (EDX/EDXS) (~equivalent to x-ray fluorescence) analysis it looks as if my europium containing samples contain copper as well, which'd...

Is there a way to measure the atomic number of a source using gamma spectroscopy? Like, I know that if you have different back scattering material, it will produced different intensity backscattering peaks, but is there a formula that relates intensity of backscattered peaks to the atomic number?

http://www.sciencedaily.com/releases/2005/05/050502190314.htm ScienceDaily (May 2, 2005) — DURHAM, N.C. -- Duke University engineers have led the most detailed analyses of links between some lightning events and mysterious gamma ray emissions that emanate from Earth's own atmosphere. Their...

Hey guys having a bit of problem with my year 1 essay. Would really appreciate any help :) What are the main sources of gamma ray bursts both short and long duration? I know some are from supernovae but where do others come from?

I've looked around and not found any good sources on the gamma energies from fast neutron activation. I need to find the characteristic gamma rays for an MCNP project and currently, I'm relying on energies I get from running some simple cases I set up for the element of interest. Does anyone...

I was watching a show on Discovery about things that could end the Earth and one of them was a Gamma Ray Burst. They said on the show that by the time we knew it was coming towards us, it would be too late but if it moves a the speed of light or slower wouldn't that mean that we would see the...

I don't know if you've heard the latest news from the MAGIC telescope researchers, but they may possibly have come across evidence of Quantum Foam: http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/ Gamma rays were apparently found to have...

http://www.universetoday.com/2007/10/03/high-energy-gamma-rays-go-slower-than-the-speed-of-light/ Bad news or bad journalism?

Do all types of supernovae emit gamma rays? If so, is it an initial burst, or does the GRB last as long as the visible light? If so, is the GRB in all directions or just in jets? Thanks.

please reference the link here This is the gamma spectrum for Co-60 from the wikipedia site:http://en.wikipedia.org/wiki/Gamma_spectroscopy though wikipedia might not be the best of sources, I was just wondering a few things. The two peaks around channel 700 and 800 are referred to as a...

Homework Statement "Use the binomial expansion to derive the following results for values of v << c. a) γ ~= 1 + 1/2 v2/c2 b) γ ~= 1 - 1/2 v2/c2 c) γ - 1 ~= 1 - 1/γ =1/2 v2/c2" (where ~= is approximately equal to) Homework Equations As far as I can tell, just γ = (1-v2/c2)-1/2The Attempt at a...

Someone told me that the film badges used in nuclear plants respond to microwave radiation from microwave ovens, as well as to the ionizing radiation they're intended for. I don't understand how this could work. Can someone explain it, or is it just not true?

Hello you guys. I was wondering about the energy limits of the gamma rays. I allready know that the gamma ray spectrum varies from some MeV to 50 MeV (approximately). Does anyone know how can these limits be justified?

IF nothing can escape from a black hole's event horizon, then how do x-rays and Gamma rays escape? and how does it emits light? it says in "Brief History of Time" that the light it emits is just at the boundary of the event horizon. So then how does it escape the gravity and reach earth...

Hi The compound summation formula v = \frac{(m + l)!(al + a + cm)}{m!(l + 1)!} listed in the "Solve v = f(x) for x" thread uses factorials and in an effort to extend it to non-integral values of "m" and "l", I stumbled across the gamma function http://en.wikipedia.org/wiki/Gamma_function" ...

Hello Guys! Please help me in this question: What is the nature of the gamma ray bursts? Why do they last for mo only 2 seconds? thx!

Homework Statement I have a doubt in the following problem. I get an answer which is slightly different from the book answer. 1) A 6 MeV gamma ray is absorbed and dissociates a deuteron into a proton and a neutron. If the neutron makes an angle of 90 degrees with the direction of gamma ray...

Hello everybody, I have to calculate the matrix element of the process gg-->ttbar-->lnub lnub (ttbar dileptonic decay) using FORM. I have three feynman dyagrams for such a process. When I calculate the interference term i have as output thousands of terms with Levi civita tensors inside (but...

First post,a good begin. As far as I know,the band gap is generated from the bragg reflection at the BZ boundary.So I think we just need the special K-point at the surface of 1BZ,and also the band gap(direct or indirect) is at the special K-point on the surface. But it seems not real in most...

I was just doing a little test and one question that I got wrong and can't seem to rationalise the supposed correct in a satisfactory way involved gamma decay and binding energy. What it basically asked was, if gamma decay occurs, and hence energy is released, how is the binding energy per...

If X and Y are gamma distributed random variables, then the ratio X/Y, I was told follows a beta distribution, but all I can find so for is that the ratio X/(X+Y) follows a beta distrinbution. So is it true that X/Y follows a beta distribution?

When an electron and anti-electron come together a gamma ray is produced. So are gamma ray bursts just the product of lots of electrons and anti-electrons coming together? I gather that at least twice the mass of our Sun is required for a gamma ray burster to form,so if we have two masses and...

Homework Statement so, I'm given some sample data: electricity consumption on randomly selected n days, and asked to model the problem using Gamma distribution, then the question is to estimate percentage of days on which consumption was > 10 by using moment estimates. So, I can find the...

Has anyone seen this representation for gamma function before? \Gamma(z) = \int_0^1\ dt\,\, t^{z-1}(e^{-t}\, -\, \sum_{n=0}^N\frac{(-t)^{n}}{n!})\,\, +\,\, \sum_{n=0}^N\frac{(-1)^{n}}{n!}\frac{1}{z+n}\,\, +\,\, \int_1^\infty dt\,\, e^{-t}\,t^{z-1} for Re(z) > -N-1 I can't figure out how...

Homework Statement Calculate \int_0^{\frac{\pi}{2}} \frac{1}{\sqrt{1+\sin^2 x}} dx expressing its solution in terms of the gamma function. It's suggested to first use the change of variable \sin x = t Homework Equations The gamma function is defined as p>0, \Gamma(p)=\int_0^\infty x^{p-1}...

For starters... What does "data reduction" mean? The book starts throwing around this term (which is also part of the book's title) without even defining it. homework question: Show by numerical calculation that, for the Gaussian probability distribution, the full-width at half maximum...

Hey , i am in grade 11 not yet studied gamma function, and not sure if it will be in the program but i have studied it a bit on my own f(x) = gamma(x) x = 1 : y = 1 x = 2 : y = 1 x = 3 : y = 2 x = 4 : y = 6 x = 5 : y = 24 x = 6 : y = 120 and i found a pattern : 1 * 1 = 1 2 * 1 = 2 3 * 2 = 6...