-- Compton scattering data from CERN LEP -- arxiv.org/abs/hep-ex/0504012 -- Data from Table 4, page 11. -- x is cos(theta) x = ( -0.74, -0.60, -0.47, -0.34, -0.20, -0.07, 0.06, 0.20, 0.33, 0.46, 0.60, 0.73) -- y is cross section y = ( 13380, 7720, 6360, 4600, 4310, 3700, 3640, 3340, 3500, 3010, 3310, 3330) "picobarn" "Predicted values" alpha = 7.2973525643 10^(-3) c = 299792458.0 meter / second h = 6.62607015 10^(-34) joule second hbar = h / float(2 pi) eV = 1.602176634 10^(-19) joule s = (40.0 10^9 eV)^2 C1 = float(pi) alpha^2 / s C2 = (h c)^2 -- should be hbar instead of h, error in arxiv paper? C3 = 10^40 "picobarn" / meter^2 -- convert square meters to picobarns yhat = C1 ((x + 1) / 2 + 2 / (x + 1)) C2 C3 yhat "Coefficient of determination (R squared)" ybar = sum(y) / dim(y) RSS = sum((y - yhat)^2) -- residual sum of squares TSS = sum((y - ybar)^2) -- total sum of squares 1 - RSS / TSS Run