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--- 2015:groups:tools:vbb [2015/07/14 08:31]
philippe.gras Added instructions for CERN account
+++ 2015:groups:tools:vbb [2016/03/17 19:19]
christian.reuschle [Ongoing work and planned contributions:]
@@ Line 1: / Line 1: @@
 ====== A comparison of generators/fixed order predictions for Z+b(b) and W+b(b) among them and against data ======
+Papers:
+http://arxiv.org/pdf/1107.3714.pdf  (Campbell et al.)
 //If you are interested in contributing please subscribe to the [[https://e-groups.cern.ch/e-groups/EgroupsSearch.do?searchValue=houches-2015-topics-tools-vb|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.//
@@ Line 73: / Line 76: @@
   * _h_min_dR_ZB_boost: Differential cross section as a function of the angular variable $\mathrm{min}\Delta R_{\mathrm{ZB}}$
   * _h_A_ZBB_boost: Differential cross section as a function of the angular variable $\mathrm{A}_{\mathrm{ZBB}}$
+==== Ongoing work and planned contributions: ====
+=== Sherpa (Davide, Frank) ===
+ Samples:
+  * 4F MC@NLO (pp->Zbb)
+  * 5F MEPS@LO (pp->Z + pp->Zj+ pp-> Zjj + pp -> Z jjj) all processes at LO,
+  * 5F MEPS@NLO (pp->Z + pp->Zj+ pp-> Zjj) MC@NLO + (pp -> Z jjj)  at LO.
+ Notes:
+  * For the 5F_LO scheme different choices of mass treatment in the ME
+  * PDF variations: NNPDF30, CT14, MMHT14 (aS(mZ)=0.118)
+  * both parton and particle level
+  * Possibly Wbb too if enough time
+F Scheme Set Up:
+  * b-Mass     = 4.72 GeV
+  * Z-Mass     = 91.1876 GeV
+  * PDF_Set    = NNPDF30_nlo_as_0118_nf_4
+  * alphaS(mZ) = 0.118
+  * Events     = 400M (Weighted)
+F Scheme Set Up: (Both MEPS@LO and MEPS@NLO)
+  * PDF_Set      = NNPDF30_nnlo_as_0118
+  * alphaS(mZ)   = 0.118
+  * QCUT merging = 10.0 GeV
+  * Events       = 200M (LO) ~ 1B (NLO) (Weighted)
+ Preliminary Plots (may still change):
+  * ATLAS: https://users.hepforge.org/~dnapoletano/Lh_proceedings_Vbb/Zbb/ATLAS_2014_I1306294/index.html
+  * CMS  : https://users.hepforge.org/~dnapoletano/Lh_proceedings_Vbb/Zbb/CMS_TEST/index.html
+=== Powheg (Gionata, Carlo) ===
+  * W+bb and W+bb+j
+F scheme set up + matching with alphas and PDF with 5 flavours
+  * b-Mass     = 4.75 GeV
+  * Z-Mass     = 91.1876 GeV
+  * W-Width    = 2.1054 GeV
+  * CKM
+     - Vud=0.97428
+     - Vus=0.2253
+     - Vub=0.00347
+     - Vcd=0.2252
+     - Vcs=0.97345
+     - Vcb=0.0410
+     - Vtd=0.00862
+     - Vts=0.0403
+     - Vtb=0.999152
+  * PDF_Set  = MSTW2008  (21100 in the LHE numbering scheme)
+  * Results for W+bb+j:
+     * {{:2015:groups:tools:powheg-wbbj-d01-x01-y01.pdf|}}
+     * {{:2015:groups:tools:powheg-wbbj-d02-x01-y01.pdf|}}
+     * {{:2015:groups:tools:powheg-wbbj-d02-x02-y01.pdf|}}
+=== Herwig (Graeme, Christian) ===
+Preliminary results for Zbb production in the 5FS can be found on http://www.hep.man.ac.uk/u/graeme/public/LH_Vbb/preliminary/Zbb/
+  * Shown are the four matching-shower combinations of Herwig7, i.e.
+    - NLO$\oplus$QTilde aka MCatNLO-based matching with the angular-ordered shower,
+    - NLO$\oplus$Dipole aka MCatNLO-based matching with the dipole shower,
+    - NLO$\otimes$QTilde aka Powheg-based matching with the angular-ordered shower,
+    - NLO$\otimes$Dipole aka Powheg-based matching with the dipole shower.
+  * The uncertainty bands are purely from scale variations with respect to all scales in the hard sub-processes and in the shower, i.e. muR, muF (and the corresponding scales of $\alpha_s$ and PDF arguments in the shower) and muQ (shower start scale).
+  * The central scale choice is a fixed scale (Z mass) at the moment for muR=muF=muQ.
+  * The PDF sets being used are the default PDF sets to which the showers are tuned, i.e. MMHT2014lo68cl and MMHT2014nlo68cl.
+  * The underlying hard process is $p p \to e^+ e^- b \bar{b}$, with $b,\bar{b}\in p$ and we cut on the final state b quarks by requiring at least two jets, with a min. pT of 18 GeV and 15 GeV for the first and second jet respectively.
+  * Statistics: 40k, unweighted.
+Preliminary results for Zb production in the 5FS can be found on http://www.hep.man.ac.uk/u/graeme/public/LH_Vbb/preliminary/Zb/
+  * Description: see the first four main bullet points above.
+  * The underlying hard process is $p p \to e^+ e^- {b,\bar{b}}$, with $b,\bar{b}\in p$ and we cut on the final state b quark by requiring at least one jet, with a min. pT of 18 GeV for the first jet.
+  * We cut on the invariant mass of the charged-lepton pair, with a min. inv. mass of 60 GeV and a max. inv. mass of 120 GeV.
+  * Statistics: 100k, unweighted.
+Preliminary results for Zbb production in the 4FS can be found on http://www.hep.fsu.edu/~creuschle/public/.Plots_2016_LHVbb_Preliminary/plots_Zbb_4FS_MMHTnf5_BnotinJ_0Jet_NoBCut_WeightedOff_FixedScale/
+  * Shown is NLO$\oplus$QTilde (MCatNLO-DefaultShower) and NLO$\otimes$QTilde (Powheg-DefaultShower).
+  * Scale choices, scale variations and choice of PDF sets as described above.
+  * The underlying hard process is $p p \to e^+ e^- b \bar{b}$, with $b,\bar{b}\notin p$. There are no cuts on the b quarks.
+  * We cut on the invariant mass of the charged-lepton pair, with a min. inv. mass of 60 GeV and a max. inv. mass of 120 GeV.
+  * We cut slightly on the charged leptons, with a min. pT of 5 GeV and a rapidity range between -4 and 4.
+  * Statistics: 100k, unweighted.
+Preliminary results for Wbb production in the 4FS can be found on http://www.hep.fsu.edu/~creuschle/public/.Plots_2016_LHVbb_Preliminary/plots_Wbb_4FS_MMHTnf5_BnotinJ_0Jet_NoBCut_WeightedOff_FixedScale/
+  * Shown is NLO$\oplus$QTilde (MCatNLO-DefaultShower) and NLO$\otimes$QTilde (Powheg-DefaultShower).
+  * The central scale choice is a fixed scale (W mass) at the moment for muR=muF=muQ.
+  * Scale variations and choice of PDF sets as described above.
+  * The underlying hard process is $p p \to l \nu b \bar{b}$, considering $e^{\pm},\mu^{\pm}\in l$. There are no cuts on the b quarks.
+  * We cut on the transverse mass of the W, with a min. trans. mass of 20 GeV.
+  * We cut slightly on the charged lepton, with a min. pT of 5 GeV and a rapidity range between -4 and 4.
+  * Statistics: 100k, unweighted.
+Further studies on Zbb production in the 4FS, for a different PDF choice, can be found on https://www.itp.kit.edu/~reuschle/.Plots_2016_LHVbb_Preliminary/Zbb4FS/plots_NNPDFnf4_BnotinJ_0Jet_MCatNLO-DefaultShower_WeightedOn_Central/
+  * Shown is the NLO$\oplus$QTilde aka MCatNLO-based matching with the angular ordered shower.
+  * No scale variations.
+  * The central scale choice is a fixed scale (Z mass) at the moment for muR=muF=muQ.
+  * The PDF set being used is NNPDF30_nlo_as_0118_nf_4.
+  * Statistics: 1M, weighted.
+Further studies on Wbb production in the 4FS, for varying PDF choices, can be found on https://www.itp.kit.edu/~reuschle/.Plots_2016_LHVbb_Preliminary/Wbb4FS/plots_AllPDFs_BinJ_1Jet_MCatNLO-DefaultShower_WeightedOff_Central/ or similarly for on https://www.itp.kit.edu/~reuschle/.Plots_2016_LHVbb_Preliminary/Wbb4FS/plots_AllPDFs_BnotinJ_0Jet_MCatNLO-DefaultShower_WeightedOff_Central/
+  * The difference between the two is that for one we require one jet (which may contain a b quark) with a certain min pT (first link), for the other we don't cut on the b quarks at all (second link).
+  * Shown is the NLO$\oplus$QTilde aka MCatNLO-based matching with the angular ordered shower.
+  * No scale variations.
+  * The central scale choice is a fixed scale (W mass) at the moment for muR=muF=muQ.
+  * There is a choice of different PDF sets being used, i.e.
+    - MMHTnf5: MMHT2014lo68cl and MMHT2014nlo68cl,
+    - MMHTnf4: MMHT2014nlo68cl_nf4,
+    - NNPDFnf5: NNPDF30_lo_as_0118 and NNPDF30_nlo_as_0118,
+    - NNPDFnf4: NNPDF30_lo_as_0118_nf_4 and NNPDF30_nlo_as_0118_nf_4.
+  * Statistics: 100k, unweighted.
+The remaining parts of the description of the run setups can be found in the vbb.pdf file in the draft for the proceedings.
+==== github instructions ====
+To setup your local repository
+  - go to github.com and get an account
+  - log in, go to https://github.com/vciulli/leshouches_vbb
+  - In the top-right corner of the page, click Fork
+  - open a shell where git is available
+  - clone the repository with the command: git clone git@github.com:your_git_username/leshouches_vbb.git
+    - if you have problems with ssh publickey try: git clone https://github.com/your_git_username/leshouches_vbb.git
+  - enjoy
+To start contributing
+  - modify/add a file
+  - add file(s) to local repository: git add filename.bla
+  - commit file(s) to local repository: git commit -m "commit messate" filename.bla
+  - "push" modifications to your remote (i.e. github) repository : git push
+  - inform Vitaliano to include your modifications to the main repositiry
+To synch your repository with the main repository
+  - git pull https://github.com/vciulli/leshouches_vbb master

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