====== NLO EW technical comparisons ====== //If you are interested in contributing please subscribe to the [[https://e-groups.cern.ch/e-groups/EgroupsSearch.do?searchValue=houches-2015-topics-xwg-ewk-corrections|mailing list]]. You will be asked to log in with your CERN account. If you don't have a CERN account, please fill [[https://account.cern.ch/account/Externals/RegisterAccount.aspx|this form]] to create a lightweight account.// ===== Working plan: ===== ==== 1) Summary of codes for EW automation ==== Contributions from GOSAM, MadGraph5_aMC@NLO, OPENLOOPS, Recola, ... ==== 2) Technical comparison of EW NLO cross sections ==== Processes: pp -> lljj arXiv:1411.0916, table 3 (and optionally table 4) and some related cumulative histograms contributers (contact persons): Recola (denner@physik.uni-wuerzburg.de) OPENLOOPS (lindert@physik.uzh.ch) ... pp -> lvjj arXiv:1412.5157 table 3 contributers (contact persons): OPENLOOPS (lindert@physik.uzh.ch), MadGraph5_aMC@NLO?, GOSAM (nicolas.greiner@desy.de) ... pp -> ttH arXiv:1504.03446 table 3/4 for 13 TeV (or more energies) contributers (contact persons): MadGraph5_aMC@NLO (davide.pagani@uclouvain.be) OPENLOOPS (lindert@physik.uzh.ch) ... ==== 3) Comparison of Sudakov approximation with EW NLO corrections for distributions ==== Processes: pp -> lljj arXiv:1411.0916, table 3 and/or 4 contributers (contact persons): Recola (denner@physik.uni-wuerzburg.de) Chiesa et al. (mauro.chiesa@pv.infn.it; fulvio.piccinini@pv.infn.it) Sherpa (jennifer.thompson@durham.ac.uk) pp -> lvjj arXiv:1412.5157 table 3 contributers (contact persons): OPENLOOPS (lindert@physik.uzh.ch) Chiesa et al. (mauro.chiesa@pv.infn.it; fulvio.piccinini@pv.infn.it) Sherpa (jennifer.thompson@durham.ac.uk) ==== 4) Calculation of the ratio for sigma(pp -> Z/gamma*+jets)/sigma(pp -> gamma+jets) and comparison to data ==== contributors (contact persons): CMS (vitaliano.ciulli@cern.ch) OPENLOOPS (lindert@physik.uzh.ch) Chiesa et al. (mauro.chiesa@pv.infn.it; fulvio.piccinini@pv.infn.it) Sherpa (jennifer.thompson@durham.ac.uk) Parameters according to CMS paper [[http://arxiv.org/abs/1505.06520|arXiv.1505.06250]], now published [[http://dx.doi.org/10.1007/JHEP10(2015)128|JHEP 10 (2015) 128]] **NEW!** Link to the Rivet analysis file and plots (last updated 01-03-2016):{{:2015:groups:sm:cms_2015_i1372730_v2.tar|}} * There are three plugins: * CMS_2015_I1372730_Z: Z only plots * CMS_2015_I1372730_G: gamma only plots * CMS_2015_I1372730: all plots including ratios * the plugin with the ratio plots can only be run on a sample with both Z and gamma events with correct relative cross-section * otherwise to get the ratio plots one should run the first two plugins and then make the ratio (will try to provide a script, but just send the plots to vitaliano.ciulli@cern.ch and I will do it) Selection cuts for the ratio plots: * For $Z/\gamma^{*}$ plus jets events we select: * two same flavour opposite sign leptons with $p_{T} > 20$ GeV and $|\eta| < 2.4$ and $71 < M_{\ell\ell} < 111 $ GeV and $p_{T}^{\ell\ell} > 100$ GeV * leptons are "dressed" with all photons in a cone of radius $\Delta R = 0.1$ * at least one jet, jet selection $p_{T} > 30$ GeV and $|\eta| < 2.4$, we remove jets within a radius of $\Delta R < 0.5$ with respect to the axes of each lepton * for the ratio plots a cut on Z rapidity |y|<1.4 is also applied * For $\gamma$ plus jets events we select: * at least a prompt photon with $p_{T} > 100$ GeV and $|\eta| < 1.4$ (in case there is more than one photon the leading one satisfying all cuts is used) * the photon must be isolated, i.e. the scalar sum of the $p_T$ of all stable particle in a cone of radius $\Delta R = 0.4$ is less then 5 GeV * at least one jet, jet selection $p_{T} > 30$ GeV and $|\eta| < 2.4$ , we remove jets within a radius of $\Delta R < 0.5$ with respect to the axis of the photon A Rivet analysis is being prepared to provide direct comparison with data at full particle level Plots for the ratio: * Z boson differential transverse momentum cross-section in an inclusive $Z/\gamma^{*}+\mathrm{jets}$ * $\gamma$ differential transverse momentum cross-section in an inclusive $\gamma+\mathrm{jets}$ in the following kinematic ranges: * $N_{jets} \geq1$ * $N_{jets} \geq2$ * $N_{jets} \geq3$ * $H_{T} > 300$ GeV, $N_{\mathrm{jets}}\geq 1$ Points open for discussion/inputs: * are scale uncertainties correlated among the two processes? * is someone interested in having a Rivet routine which runs at parton level? Comparison of LO + approx EWK (M. Chiesa et al) to CMS Z/gamma ratio: * {{:2015:groups:sm:rzg1_alpgen.pdf|V +>= 1 jet}} * {{:2015:groups:sm:rzg2_alpgen.pdf|V +>= 2 jet}} * {{:2015:groups:sm:rzg3_alpgen.pdf|V +>= 3 jet}} ===== Input parameters ===== as defined in the relevant papers: ^ Parameters etc. ^ lljj ^ lvjj ^ ttH ^ | order of LO contribution | all | all | O(alphas**2 alpha) and O(alphas alpha**2) | | order of NLO corrections | O(alpha**3 alphas**2)|O(alpha**2 alphas**3) and O(alpha**3 alphas**2) | NLO EW O(alphas**2 alpha**2) and NLO QCD | | renormalisation scheme | G_mu scheme | G_mu scheme | alpha(MZ) | | complex/real masses | complex-mass scheme | complex-mass scheme | real masses | | jet algorithm | anti-kT R=0.4 | anti-kT R=0.4 | - | | partons clustered for | abs(y) < 5 | abs(y) < infinity | - | | photon/jet separation | democratic clustering+ fragmentation | fermion-photon recombination and democratic clustering | - | | MAX(E_gamma/(E_gamma+E_jet) | 0.7 | 0.5 | - | | PDFs | MSTW2008LO PDF | NNPDF2.3QED PDF | NNPDF2.3QED PDF | | factorization scale | MZ_pole | Hhat_T / 2 (scalar sum of all partonic E_T) | H_T / 2 | | renormalization scale | MZ_pole | Hhat_T / 2 (scalar sum of all partonic E_T) | H_T / 2 | | partons at LO | g,u,c,d,s,b | g,u,c,d,s,b,gamma | g,u,c,d,s,b,gamma | | partons at NLO | g,u,c,d,s | g,u,c,d,s,b | g,u,c,d,s,b,gamma | | gamma-induced contributions | none | only at LO | all and none (PDF set to zero) | | collider energy[TeV] | 13 | 13 | 13 | | alpha_s | from PDFs, 0.139395..| from PDF, 0.118 | from PDF, 0.118 | | G_mu | 1.1663787e-5 GeV**-2 | 1.16637e-5 | from alpha | | alpha | calculated from G_mu| calculated from G_mu | 1/128.93 | | MZ_onshell | 91.1876 GeV | 91.1876 GeV | 91.188 GeV | | GZ_onshell | 2.4952 GeV | 2.4955 GeV | 0 GeV | | MZ_pole, GZ_pole | calculated | - | - | | MW_onshell | 80.385 GeV | 80.385 GeV | 80.385 GeV | | GW_onshell | 2.085 GeV | 2.0897 GeV | 0 GeV | | MW_pole, GW_pole | calculated | - | - | | complex masses | defined from pole masses | defined from on-shell masses | - | | mb | 0 GeV | 0 GeV | 0 GeV | | mt | 173.2 GeV | 173.2 | 173.3 GeV | | Gamma_t | 0 GeV | 1.339 | 0 GeV | | MH | 125 GeV | 125 GeV | 125 GeV | | Gamma_H | 0 GeV | 4.07 MeV | 0 GeV | | basic cuts | pt_j > 30 GeV | pt_j > 30 GeV | | | | abs(y_j) < 4.5 | abs(eta_j) < 4.5 | | | | pt_l > 20 GeV | pt_l > 25 GeV | | | | abs(y_l) < 2.5 | abs(eta_l) < 2.5 | | | | dR_ll > 0.2 | dR_jl > 0.5 | | | | dR_jl > 0.5 | M_TW > 40 GeV | | | | 66 GeV < M_ll < 116 GeV| missing_ET > 25 GeV | | | | | | | | cumulative histogram 1 | pT(j1) > 0.25,0.5,0.75,1 TeV| pT(j1) > 0.5, 1 TeV | pt(H) and pt(t) and pt(tbar) > 200 GeV | | cumulative histogram 2 | M_jj > 0.50,1,2,4 TeV | missing_ET > 0.5, 1 TeV | pt(H) and pt(t) and pt(tbar) > 400 GeV | | cumulative histogram 3 | pT(l-) > 0.25,0.5,0.75,1 TeV| pT(l) > 0.5, 1 TeV | pt(H) > 500 GeV | | cumulative histogram 4 | pT(ll) > 0.25,0.5,0.75,1 TeV | | abs( y(t) ) > 2.5 | | cumulative histogram 5 | HT > 0.50,1,1.5,2 TeV | HT > 0.5,1,2 TeV | | Alternative lljj analysis: same as above with M_ll cut replaced by the following VBF cuts: M_jj > 600 GeV; abs(y_j1-y_j2) < 4.5; y_j1 * y_j2 < 0; min(y_j1,y_j2) < y_l < max(y_j1,y_j2).