Theoretical Physics Theoretical Physics Help Forum Aug 2nd 2013, 03:24 AM #1 Junior Member   Join Date: Aug 2013 Posts: 2 Higgs production and pDF Hi all, I try to calculate the Higgs production cross section by Mathematica using for example the formula in [arXiv:hep-ph/0503172]. The problem comes when I calculate " σ_0 " it's of order 10^-10 pb at mh = 125 GeV, then when I convolute with the parton distribution function to get the pp -> H production according to equ.( 3.58) it gives me of order 10^-7 pb !! while in the plot (3.18) pp -> H is around 50 pb. Here is my calculation; for σ0: σ0[mh_] : = ( ( c^2)/ (256 *Pi)) *(1/2)^2* ( ((Yht)/(mT))* At [mh])^2 where c = 0.117, Yht= mt/v, v= 174 and At is the fermion loop function. For σ(pp -> h) I used: LogPlot[ {σ0[mh]*(q)* NIntegrate[(1/x)* pdf[iset, iparton, x, 14000] * pdf[iset, iparton, (q/x), 14000], {x, q, 1}], {mh, 100, 200}] With iset = 1; (* CTEQ5M*) iparton = 0; q := mh^2/14000^2; I don't know what is the problem I have, any help please, Thanks, Safinaz   Aug 3rd 2013, 12:04 PM   #2

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 Hi all, I try to calculate the Higgs production cross section by Mathematica using for example the formula in [arXiv:hep-ph/0503172]. The problem comes when I calculate " σ_0 " it's of order 10^-10 pb at mh = 125 GeV, then when I convolute with the parton distribution function to get the pp -> H production according to equ.( 3.58) it gives me of order 10^-7 pb !! while in the plot (3.18) pp -> H is around 50 pb. Here is my calculation; for σ0: σ0[mh_] : = ( ( c^2)/ (256 *Pi)) *(1/2)^2* ( ((Yht)/(mT))* At [mh])^2 where c = 0.117, Yht= mt/v, v= 174 and At is the fermion loop function. For σ(pp -> h) I used: LogPlot[ {σ0[mh]*(q)* NIntegrate[(1/x)* pdf[iset, iparton, x, 14000] * pdf[iset, iparton, (q/x), 14000], {x, q, 1}], {mh, 100, 200}] With iset = 1; (* CTEQ5M*) iparton = 0; q := mh^2/14000^2; I don't know what is the problem I have, any help please, Thanks, Safinaz
I can't seem to get arXiv to reference that paper itself...it keeps sending me to the Cornell U. library and it won't let me view the article.

Question: The 50 pb...is this a measurement or is it a theoretical calculation? I would like to see how you did the calculation if so.

-Dan
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See the forum rules here.   Aug 4th 2013, 12:05 AM #3 Junior Member   Join Date: Aug 2013 Posts: 2 Hi, I went on the theoretical calculation with no problem and get σ0[mh_] : = ( ( \alpha_s^2)/ (256 *Pi)) *(1/2)^2* ( ((Yht)/(mT))* At [mh])^2 This consists with the formula look for example J.M.S. Wu, Phys. Rev. D 86, 033003(2012) My main problem is to dealing with the PDF to get \sigma(pp -> H) at last. I can send you the Math. file in which I tried but please let me know your mail. Best, S.  Tags higgs, pdf, production Thread Tools Show Printable Version Email this Page Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post topsquark Quantum Physics 10 Nov 18th 2014 02:04 PM hassan89 Electricity and Magnetism 1 Jan 26th 2009 08:22 AM 