Recent content by Hepth

You're all right, I'm wrong completely. I think I'm remembering some identities for building up operator expectation values that restricts what the momenta can be, or what vector or tensor objects can be as a result of like an HQET operator. Obviously the null vector kills these identities...

Basically yes, if you want a way to think about it then imagine that whatever field your working with is unbound, and so has some plane-like wavefunction. Then these derivatives are basically creating interaction terms that have a proportionality to the momentum of the field. Since it...

vecs[[j, all]] should translate to vecs(j,:) or vecs(:,j). the semi-colon tells MATLAB to select all of the elements in that dimension (j,:) being everything in the jth row, and (:,j) being everything in the jth column. So something like sum = []; for j = 1:10 sum = sum + sqrt(vals(j) .*...

It's about the parity conservation. The K has negative parity, as does the pion (pseudoscalars). On the right hand side, two electrons have positive parity, so the current should have negative parity, -1*-1=1. Then for the PS to PS decay you have a final state with negative parity, so only...

That's what I was finding, even if I'm restricted to 0 to 1 for example, there numerically will exist a a single real positive solution; but analytically I don't think there's a solution.

$$ y == x*Tanh[x]$$ Solve for "x". Does this exist? Even in terms of more complicated functions like Lambert W, or possibly recursive solutions/geometric series/etc. Thanks, if anyone can point me in the right direction!

Sorry, let's say that I can command a pressure only rather than flow rate.

I should be able to do this, but its been a while and maybe I'm making this more difficult that it should be. Assume you have a cylinder nearly sealed but with an outlet hole at the top. I want to pump a fluid into the canister, pushing the air out of the hole, and time how long it takes. The...

Yeah, I think they were recording only the Plenary speakers at the last ICHEP, our parallel sessions were not. But usually even the video takes time to be put on the website. A lot of the slides, especially those with preliminary experimental results, might not be made public either.

Honestly I felt that the Doom 3 experience was entirely based on how good of a computer, monitor and sound system you had. I played it on my poor machine and it just felt slow and clunky, but when i played it on a friends rig in his basement with a nice surround system and top-of-the-line...

So assume a decaying pseudoscalar to 4 leptons (or neutrinos), and you want to calculate the partial width. I have calculated this before, and basically you get integrable divergences when you try to integrate (due to the denominator's energies) that can be removed by changes of coordinates of...

Does anyone have suggestions on the strategies for a four-body decay's kinematics? I'm just wondering what is out there. Last time I had to calculate something I just did it straightforward, but I know there must be other methods. (Like preferring to work in energies over invariants). I usually...

Test NIntegrate with different methods NIntegrate[___, Method-> "MonteCarlo"] "GlobalAdaptive" [default] "DuffyCoordinates" "MonteCarlo" "QuasiMonteCarlo" "AdaptiveMonteCarlo" "AdaptiveQuasiMonteCarlo" "DoubleExponential" you might have to add MaxPoints-> 10^7 Plain montecarlo seems to do the...

No problem, its actually quite an interesting problem and perhaps I'll look into it further, though I need to finish up these 3 other projects first.

I've basically transitioned to using LaTeX for nearly everything now; cover letters, articles, resume/cv, publication list, presentations To be honest I feel like its more portable than doing things in Word or Powerpoint, its easier to change things, styles etc. once you know all of the...