AAA PHENOMENOLOGY AT THE LHC

Transcription

1 AAA PHENOMENOLOGY AT THE LHC Centre for Cosmology, Particle Physics and Phenomenology PRISMA - Mainz University 20 Nov 2013

2 PHENOMENOLOGY AUTOMATIC ACCURATE AUGMENTED new MC tools for hadron collider physics.

3 MichelangeloMangano Discoveries at hadron colliders

4 MichelangeloMangano peak pp H 4l Discoveries at hadron colliders easy Background directly measured from data. TH needed only for parameter extraction (Normalization, acceptance,...)

5 MichelangeloMangano Discoveries at hadron colliders peak pp H 4l shape ~~~~~~ pp gg,gq,qq jets+et / easy Background directly measured from data. TH needed only for parameter extraction (Normalization, acceptance,...) hard Background shapes needed. Flexible MC for both signal and background tuned and validated with data.

6 MichelangeloMangano Discoveries at hadron colliders peak pp H 4l shape ~~~~~~ pp gg,gq,qq jets+et / discriminant pp H W + W - easy Background directly measured from data. TH needed only for parameter extraction (Normalization, acceptance,...) hard Background shapes needed. Flexible MC for both signal and background tuned and validated with data. very hard Background normalization and shapes known very well. Interplay with the best theoretical predictions (via MC) and data.

7

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9 No sign of new physics (so far)!

10

11 MC developer

12 WHY HAPPY?

13 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out.

14 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery.

15 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery. Ingenuity/Creativity: From new signatures to smart and new analysis techniques (MVA), and combination with non-collider searches (DM, Flavor...).

16 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery. Ingenuity/Creativity: From new signatures to smart and new analysis techniques (MVA), and combination with non-collider searches (DM, Flavor...). Massification (the practice of making luxury products available to the mass market) : MC s in the hands of every th/exp might turn out to be the best overall strategy for discovering the Unexpected.

17 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery. Ingenuity/Creativity: From new signatures to smart and new analysis techniques (MVA), and combination with non-collider searches (DM, Flavor...). Massification (the practice of making luxury products available to the mass market) : MC s in the hands of every th/exp might turn out to be the best overall strategy for discovering the Unexpected. Flexibility: We need MC that are able to predict the pheno of the Unexpected.

18 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery. Ingenuity/Creativity: From new signatures to smart and new analysis techniques (MVA), and combination with non-collider searches (DM, Flavor...). Massification (the practice of making luxury products available to the mass market) : MC s in the hands of every th/exp might turn out to be the best overall strategy for discovering the Unexpected. Flexibility: We need MC that are able to predict the pheno of the Unexpected. Accuracy: accurate simulations for both SM and BSM are a must.

19 WHY HAPPY? Optimism: New Physics could be hiding there already, just need to dig it out. Democratization: No evidence of most beaten BSM proposals, means more and more room for diversification. Possibility for small teams to make a big discovery. Ingenuity/Creativity: From new signatures to smart and new analysis techniques (MVA), and combination with non-collider searches (DM, Flavor...). Massification (the practice of making luxury products available to the mass market) : MC s in the hands of every th/exp might turn out to be the best overall strategy for discovering the Unexpected. Flexibility: We need MC that are able to predict the pheno of the Unexpected. Accuracy: accurate simulations for both SM and BSM are a must.

20 ...SO HOW WE (USED TO) MAKE PREDICTIONS AT HADRON COLLIDERS?

21 LHC MASTER FORMULA

22 LHC MASTER FORMULA + x 1 E x 2 E p p

23 LHC MASTER FORMULA + µ F x1e x2e µ F p p

24 LHC MASTER FORMULA + µ F x1e x2e µ F p p σ X = a,b 1 0 dx 1 dx 2 f a (x 1,µ 2 F )f b (x 2,µ 2 F ) ˆσ ab X (x 1,x 2,α S (µ 2 R), Q2 µ 2 F, Q2 µ 2 R )

25 LHC MASTER FORMULA + µ F x1e x2e µ F p p σ X = a,b long distance 1 0 dx 1 dx 2 f a (x 1,µ 2 F )f b (x 2,µ 2 F ) long distance ˆσ ab X (x 1,x 2,α S (µ 2 R), Q2 µ 2 F, Q2 µ 2 R )

26 LHC MASTER FORMULA + µ F x1e x2e µ F p p σ X = a,b long distance 1 0 dx 1 dx 2 f a (x 1,µ 2 F )f b (x 2,µ 2 F ) long distance ˆσ ab X (x 1,x 2,α S (µ 2 R), Q2 µ 2 F, Q2 µ 2 R Pheno/Th exploit this formula to provide accurate and flexible predictions from a given model (SM, MSSM,...) )

27 HOW WE (USED TO) MAKE PREDICTIONS? First way: For low multiplicity include higher order terms in our fixed-order calculations (LO NLO NNLO...) ˆσ ab X = σ 0 + α S σ 1 + α 2 Sσ TH For high multiplicity use the tree-level results Comments: 1. The theoretical errors systematically decrease. 2. Pure theoretical point of view. 3. A lot of new techniques and universal algorithms have been developed. 4. Final description only in terms of partons and calculation of IR safe observables not directly useful for simulations

28 NLO BASICS NLO contributions have three parts

29 NLO BASICS NLO contributions have three parts σ NLO = m d (d) σ V + Virtual part

30 NLO BASICS NLO contributions have three parts σ NLO = m d (d) σ V + Virtual part d (d) σ R + m+1 Real emission part

31 NLO BASICS NLO contributions have three parts σ NLO = m d (d) σ V + Virtual part d (d) σ R + m+1 Real emission part m d (4) σ B Born

32 NLO BASICS NLO contributions have three parts σ NLO = m d (d) σ V + Virtual part d (d) σ R + m+1 Real emission part m d (4) σ B Born Loops have been for long the bottleneck of NLO computations Virtuals and Reals are each divergent and subtraction scheme need to be used (Dipoles, FKS, Antenna s) A lot of work is necessary for each computation

33 NLO BASICS NLO contributions have three parts σ NLO = m d (d) σ V + Virtual part d (d) σ R + m+1 Real emission part m d (4) σ B Born Loops have been for long the bottleneck of NLO computations Virtuals and Reals are each divergent and subtraction scheme need to be used (Dipoles, FKS, Antenna s) A lot of work is necessary for each computation The cost of a new prediction at NLO used to exceed 100k.

34 LOOP TECHNIQUES modified by the speaker

35 BEST EXAMPLE: MCFM Downloadable general purpose NLO code [Campbell, Ellis, Williams+collaborators] Final state Notes Reference W/Z diboson (W/Z/γ) Wbb photon fragmentation, anomalous couplings massless b-quark massive b quark hep-ph/ , arxiv: hep-ph/ arxiv: Zbb massless b-quark hep-ph/ W/Z+1 jet W/Z+2 jets hep-ph/ , hep-ph/ Wc massive c-quark hep-ph/ Zb 5-flavour scheme hep-ph/ Zb+jet 5-flavour scheme hep-ph/ recent additions, overall 30+ processes First results implemented in this is 13 years worth of work of several people (~5M$) Cross sections and parton-level distributions at NLO are provided One framework, however, each process implemented by hand. Final state Notes Reference H (gluon fusion) H+1 jet (g.f.) effective coupling H+2 jets (g.f.) effective coupling WH/ZH H (WBF) hep-ph/ , arxiv: hep-ph/ Hb 5-flavour scheme hep-ph/ t s- and t-channel (5F), top decay included t t-channel (4F) hep-ph/ arxiv: , arxiv: Wt 5-flavour scheme hep-ph/ top pairs top decay included

36 Events at hadron colliders Sherpa s artist

37 Events at hadron colliders High Q 2 Sherpa s artist

38 HOW WE (USED TO) MAKE PREDICTIONS? Second way: Describe final states with high multiplicities starting from 2 1 or 2 2 procs, using parton showers, and then an hadronization model. EXP Comments: 1. Fully exclusive final state description for detector simulations 2. Normalization is very uncertain 3. Very crude kinematic distributions for multi-parton final states 4. Improvements are only at the model level. most known and used : PYTHIA, HERWIG, SHERPA

39 SM STATUS 10 YEARS AGO pp n particles

40 SM STATUS 10 YEARS AGO pp n particles complexity [n]

41 SM STATUS 10 YEARS AGO accuracy pp n particles [loops] complexity [n]

42 SM STATUS 10 YEARS AGO accuracy pp n particles [loops] fully inclusive parton-level 2 fully exclusive complexity [n]

43 SM STATUS 10 YEARS AGO accuracy pp n particles [loops] fully inclusive parton-level 2 fully exclusive complexity [n]

44 WHAT ABOUT NEW PHYSICS? b - b g g g~ g~ g~ ~ b ~ u χ 0 2 χ 0 1 χ 0 1 ū u

45 BSM (=SUSY)STATUS 10 YEARS AGO accuracy pp n particles [loops] fully inclusive parton-level 2 fully exclusive complexity [n]

46 BSM (=SUSY)STATUS 10 YEARS AGO accuracy pp n particles [loops] fully inclusive parton-level 2 fully exclusive Prospino! complexity [n]

47 th/exp interactions ante LHC TH Idea

48 th/exp interactions ante LHC TH Idea Lagrangian Feyn. Rules Amplitudes x secs Paper

49 th/exp interactions ante LHC TH PHENO Idea Lagrangian Feyn. Rules Amplitudes x secs Paper

50 th/exp interactions ante LHC TH PHENO Idea Lagrangian Feyn. Rules Amplitudes x secs Paper

51 th/exp interactions ante LHC TH PHENO Idea Lagrangian Feyn. Rules Amplitudes x secs Aut. Feyn. Rules Any amplitude Any x-sec partonic events Pythia PGS Paper Paper

52 TH Idea Lagrangian Feyn. Rules Amplitudes x secs Paper th/exp interactions ante LHC PHENO Aut. Feyn. Rules Any amplitude Any x-sec partonic events Pythia PGS Paper EXP

53 TH Idea Lagrangian Feyn. Rules Amplitudes x secs Paper th/exp interactions ante LHC PHENO Aut. Feyn. Rules Any amplitude Any x-sec partonic events Pythia PGS Paper EXP

54 TH Idea Lagrangian Feyn. Rules Amplitudes th/exp interactions ante LHC PHENO Aut. Feyn. Rules Any amplitude EXP x secs Paper Any x-sec partonic events Pythia PGS Paper New MC Pythia

55 TH Idea Lagrangian Feyn. Rules Amplitudes th/exp interactions ante LHC PHENO Aut. Feyn. Rules Any amplitude EXP Amps 2 2 x secs Any x-sec partonic events New MC Pythia PGS Pythia New Pythia Paper Paper

56 TH Idea Lagrangian Feyn. Rules Amplitudes th/exp interactions ante LHC PHENO Aut. Feyn. Rules Any amplitude EXP Amps 2 2 x secs Any x-sec partonic events New MC Pythia Pythia New Pythia PGS Detec. Sim. Paper Paper Paper Data

57 BSM TH/EXP INTERACTIONS : THE OLD WAY Workload is tripled! Long delays due to localized expertise and error prone. Painful validations are necessary at each step. It leads to a proliferation of private MC tools/sample productions impossible to maintain, document and reproduce on the mid- and long- term. Just publications is a very inefficient way of communicating between TH/PHENO/EXP.

58 GAP ANALYSIS (ANTE LHC) We would like to:

59 GAP ANALYSIS (ANTE LHC) We would like to:

60 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks).

61 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues.

62 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues. 3.have the needed accuracy of NLO prediction with the flexibility of parton shower/hadronization.

63 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues. 3.have the needed accuracy of NLO prediction with the flexibility of parton shower/hadronization. 4.have the above for ANY SM background as well as for ANY BSM signals.

64 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues. 3.have the needed accuracy of NLO prediction with the flexibility of parton shower/hadronization. 4.have the above for ANY SM background as well as for ANY BSM signals. 5. have them all available at the touch of a button.

65 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues. 3.have the needed accuracy of NLO prediction with the flexibility of parton shower/hadronization. 4.have the above for ANY SM background as well as for ANY BSM signals. 5. have them all available at the touch of a button. OK?

66 GAP ANALYSIS (ANTE LHC) We would like to: 1.have the possibility of making collider studies for any BSM theory by knowing the Lagrangian (and benchmarks). 2.that our EXP/TH results could be directly used by the TH/EXP colleagues. 3.have the needed accuracy of NLO prediction with the flexibility of parton shower/hadronization. 4.have the above for ANY SM background as well as for ANY BSM signals. 5. have them all available at the touch of a button. OK?

67 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

68 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

69 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

70 ME with PS [Mangano] [Catani, Krauss, Kuhn, Webber] [Frixione, Nason, Webber] Matrix Element Shower MC 1. parton-level description 1. hadron-level description 2. fixed order calculation 2. resums large logs 3. quantum interference exact 3. quantum interference 4. valid when partons are hard and well separated 5. needed for multi-jet description through angular ordering 4. valid when partons are collinear and/or soft 5. nedeed for realistic studies.

71 ME with PS [Mangano] [Catani, Krauss, Kuhn, Webber] [Frixione, Nason, Webber] Matrix Element Shower MC 1. parton-level description 1. hadron-level description 2. fixed order calculation 2. resums large logs 3. quantum interference exact 3. quantum interference 4. valid when partons are hard and well separated 5. needed for multi-jet description through angular ordering 4. valid when partons are collinear and/or soft 5. nedeed for realistic studies Approaches are complementary:. merge them!

72 ME with PS [Mangano] [Catani, Krauss, Kuhn, Webber] [Frixione, Nason, Webber] Matrix Element Shower MC 1. parton-level description 1. hadron-level description 2. fixed order calculation 2. resums large logs 3. quantum interference exact 3. quantum interference 4. valid when partons are hard and well separated 5. needed for multi-jet description through angular ordering 4. valid when partons are collinear and/or soft 5. nedeed for realistic studies Approaches are complementary:. merge them! Difficulty: avoid double counting

73 Merging fixed order with PS Parton shower Matrix elements

74 Merging fixed order with PS Parton shower Matrix elements

75 Merging fixed order with PS Parton shower Matrix elements

76 Merging fixed order with PS Parton shower Matrix elements

77 Merging fixed order with PS Parton shower Matrix elements

78 Merging fixed order with PS Parton shower Matrix elements

79 Merging fixed order with PS Parton shower Matrix elements

80 Merging fixed order with PS Parton shower Matrix elements

81 Merging fixed order with PS Parton shower Matrix elements

82 Merging fixed order with PS Parton shower Matrix elements Possible double counting between partons from matrix elements and parton shower easily avoided by applying a cut in phase space

83 Merging fixed order with PS Parton shower Matrix elements kt > Q c kt < Q c kt < Q c kt > Q c... kt < Qc kt < Q c kt > Q c kt > Q c... Possible double counting between partons from matrix elements and parton shower easily avoided by applying a cut in phase space

84 V+JETS AT THE LHC Working amazingly well!

85 V+JETS AT THE LHC Working amazingly well!

86 WHAT ABOUT NLO? dσ NLOwPS NAIVE = dφ B (B(Φ B )+V + S int ct ) I n MC + dφ B dφ R B (R S ct ) I n+1 MC This simple approach does not work: Instability: weights associated to I n MC and I n+1 MC are divergent pointwise (infinite weights). Double counting: dσ naive NLOwPS expanded at NLO does not coincide with NLO rate. Some configurations are dealt with by both the NLO and the PSMC. Currently, two solutions available

87 WHAT ABOUT NLO? dσ NLOwPS NAIVE = dφ B (B(Φ B )+V + S int ct ) I n MC + dφ B dφ R B (R S ct ) I n+1 MC This simple approach does not work: Instability: weights associated to I n MC and I n+1 MC are divergent pointwise (infinite weights). Double counting: dσ naive NLOwPS expanded at NLO does not coincide with NLO rate. Some configurations are dealt with by both the NLO and the PSMC. Currently, two solutions available

88 NLO+PS in a nutshell dσ NLO+PS =dφ B Bs (Φ B ) with B s = B(Φ B )+ V (Φ B )+ R(Φ R )=R s (Φ R )+R f (Φ R ) s (p min R s (Φ R ) )+dφ R B B(Φ B ) s (p T (Φ)) integrates to 1 (unitarity) dφ R B R s (Φ R B ) +dφ R R f (Φ R ) Full cross section (if F=1) at fixed Born kinematics This formula is valid both for both MC@NLO and POWHEG MC@NLO: POWHEG: R s (Φ) = P (Φ R B ) B(Φ B ) R s (Φ) = FR(Φ),R f (Φ) = (1 F )R(Φ) Needs exact mapping (ΦB,ΦR) Φ F=1 = Exponentiates the Real. It can be damped by hand.

89 AND POWHEG

90 AND POWHEG [Frixione, Webber, 2002; Frixione, Nason, Webber, 2003] - Matches NLO to HERWIG and HERWIG++ angular-ordered PS. - Some events have negative weights. - Large and well tested library of processes. - Now available also for Pythia8, HW++ [Torrielli, Frixione, ] - Now automatized [Frederix, Frixione, Torrielli] - Available in amc@nlo (see later) and also in SHERPA

91 AND POWHEG [Frixione, Webber, 2002; Frixione, Nason, Webber, 2003] - Matches NLO to HERWIG and HERWIG++ angular-ordered PS. - Some events have negative weights. - Large and well tested library of processes. - Now available also for Pythia8, HW++ [Torrielli, Frixione, ] - Now automatized [Frederix, Frixione, Torrielli] - Available in amc@nlo (see later) and also in SHERPA POWHEG [Nason 2004; Frixione, Nason, Oleari, 2007] - Is independent* of the PS. It can be interfaced to PYTHIA and HERWIG - Generates only* positive unit weights. - Can use existing NLO results via the POWHEG-Box [Aioli, Nason, Oleari, Re et al. 2009]

92 AUTOMATION

93 AUTOMATION Genius: 1% inspiration and 99% perspiration. [Thomas Edison]

94 AUTOMATION Genius: 1% inspiration and 99% perspiration. [Thomas Edison] True, but perspiration can be automated!

95 AUTOMATION

96 AUTOMATION Cost saving Trade human time and expertise spent on computing process at the time with time on physics and pheno. one

97 AUTOMATION Cost saving Trade human time and expertise spent on computing process at the time with time on physics and pheno. one Robustness Programs are modular and computations based on elements that can be systematically and extensively checked. Trust can be easily built.

98 AUTOMATION Cost saving Trade human time and expertise spent on computing process at the time with time on physics and pheno. one Robustness Programs are modular and computations based on elements that can be systematically and extensively checked. Trust can be easily built. Wide accessibility One framework for all. Available to everybody for an unlimited set of applications for all. Augmented TH/EXP collaboration.

99 SM STATUS ANTE LHC accuracy pp n particles [loops] fully inclusive parton-level 2 fully exclusive complexity [n]

100 SM STATUS ANTE LHC accuracy pp n particles [loops] fully inclusive parton-level fully exclusive 2 fully exclusive and automatic complexity [n]

101 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

102 NEW LOOP TECHNIQUES For the calculation of one-loop matrix elements, several methods are now established : Generalized Unitarity (ex. BlackHat, Rocket,...) [Bern, Dixon, Dunbar, Kosower, hep-ph/ ; Ellis, Giele, Kunszt , +Melnikov ] Integrand Reduction (ex. CutTools, Samurai) [Ossola, Papadopolulos, Pittau, hep-ph/ ; del Aguila, Pittau, hep-ph/ ; Mastrolia, Ossola, Reiter, Tramontano, ] Tensor Reduction (ex. Golem, GoSam) [Passarino, Veltman, 1979; Denner, Dittmaier, hep-ph/ , Binoth, Guillet, Heinrivh, Pilon, Reiter ]

103 Predictions at NLO modified by the speaker

104 Predictions at NLO Generalized Unitarity (ex. BlackHat, Rocket,...) Integrand Reduction (ex. CutTools, Samurai) Tensor Reduction (ex. GoSam) modified by the speaker

105 Predictions at NLO Generalized Unitarity (ex. BlackHat, Rocket,...) Integrand Reduction (ex. CutTools, Samurai) Tensor Reduction (ex. GoSam) modified by the speaker Thanks to new amazing results, some of them inspired by string theory developments, now the computation of loops has been extended to high-multiplicity processes or/and automated.

106 COMPARISON WITH DATA W+5 jets 5 jets [Bern et al., ] [Badger et al ]

107 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

108 BSM TH/EXP INTERACTIONS : THE OLD WAY TH Idea Lagrangian Feyn. Rules Amplitudes PHENO Aut. Feyn. Rules Any amplitude EXP Amps 2 2 x secs Any x-sec partonic events New MC Pythia Pythia New Pythia PGS Detec. Sim. Paper Paper Paper Data

109 BSM TH/EXP INTERACTIONS : THE OLD WAY TH Idea Lagrangian PHENO Aut. Feyn. Rules Any amplitude Any x-sec partonic events EXP Pythia Detec. Sim. Data

110 BSM TH/EXP INTERACTIONS AUGMENTED TH EXP Idea Lagrangian FeynRules/LanHEP/Sarah DM tools ME Generator Signal & Bkg Events PS+Had Delphes/Sim Data

111 BSM TH/EXP INTERACTIONS AUGMENTED TH Idea Lagrangian EXP One path for all Physics and software validations streamlined Robust and efficient Th/Exp communication It works top-down and bottom-up FeynRules/LanHEP/Sarah DM tools ME Generator Signal & Bkg Events PS+Had Delphes/Sim Data

112 BSM TH/EXP INTERACTIONS AUGMENTED TH Idea Lagrangian EXP One path for all Physics and software validations streamlined Robust and efficient Th/Exp communication It works top-down and bottom-up FeynRules/LanHEP/Sarah DM tools ME Generator Signal & Bkg Complete automatization LO (and now NLO) calculations available, including merging with the parton shower in multi-jet final states, for SM as well as for BSM physics. Events PS+Had Delphes/Sim Data

113 THE FEYNRULES PROJECT [Alloul, Christensen, Degrande, Duhr, Fuks] Model-file Particles, parameters,... Lagrangian FeynRules TeX Feynman Rules Interfaces or UFO FeynArts CalcHep Sherpa Golem Whizard MadGraph 5 HERWIG

114 THE FEYNRULES PROJECT

115 THE FEYNRULES PROJECT

116 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

117 NEW CODES FOR AUTOMATIC LOOP AMPLITUDES MadLoop : Hirschi et al., , based on MadGraph + CutTools HELAC-NLO : Bevilacqua et al., , based on HELAC + CutTools GoSam : Cullen et al., , based on QGRAF+SAMURAI+Golem Open Loops : Cascioli et al., , based on the combination of several approaches

118 NEW CODES FOR AUTOMATIC LOOP AMPLITUDES MadLoop : Hirschi et al., , based on MadGraph + CutTools HELAC-NLO : Bevilacqua et al., , based on HELAC + CutTools GoSam : Cullen et al., , based on QGRAF+SAMURAI+Golem Open Loops : Cascioli et al., , based on the combination of several approaches Limitations on applications (i.e. number of external partons or BSM) are systematically and quickly overcome: the wave function of the automatic loop effort has collapsed!

119 NEW NLO+PS FRAMEWORKS POWHEG-BOX and applications: Alioli et al, , , , , , , , : Framework which allows to promote a standard NLO calculation into a MC at NLO generator. Very popular choice. More than ~20 processes implemented in the last two years. Similar in spirit to MCFM. NEW SHERPA Hoeche et al, , , : Flexible framework having both MC@NLO and POWHEG methods based on CS dipoles, needs virtuals. Fully automatic except for virtuals. HERWIG++ D Errico et Richardson , , Hamilton et al , , , : POWHEG method, several processes implemented. Need the NLO elements. POWHEL Papadopoulous, Garzelli, Kardos Trocsanyi, , : HELAC-NLO + POWHEG-Box

120 THE JOINT VENTURE

121 THE JOINT VENTURE MadGraph

122 THE JOINT VENTURE MadGraph CutTools

123 THE JOINT VENTURE MadGraph FKS CutTools

124 THE JOINT VENTURE MadGraph FKS CutTools

125 THE JOINT VENTURE MadGraph FKS FKS CutTools

126 THE JOINT VENTURE Modular structure: MadGraph FKS MadLoop or External Tool (via Binoth LH accord) FKS MadFKS CutTools counterterms Interfaced to Herwig++ and Pythia8

127 THE JOINT VENTURE Modular structure: MadGraph FKS MadLoop or External Tool (via Binoth LH accord) FKS MadFKS CutTools counterterms Interfaced to Herwig++ and Pythia8

128 AUTOMATIC NLO+PS IN 2011 [Hirshi, Frederix, Frixione, FM, Torrielli,]. Total cross sections at the LHC for 26 sample procs Very loose cuts just when needed Running time: Two weeks on a 150+ node cluster Proof of efficient EPS handling. Successful cross-check against known results (and small bugs found in other NLO codes Zjj, W + jj)

129 AUTOMATIC MC S AT NLO Suppose now you are interested in multi-lepton backgrounds to SUSY. You might want to check: or./bin/mg5 > define Wpm = W+ W- > generate p p > t t~ Wpm [QCD] > output ttw > launch./bin/mg5 > define V = W+ W- Z > generate p p > V V [QCD] > output VV > launch where heavy states can also be decayed keeping spin correlations.

130 AUTOMATIC NLO IN SM (2013) ~15 NLO publications since 2011 Public release of (beta) 8 Nov 2012 Improved functionalities (OpenLoops method, automatic uncertainties, Pythia8 interface, speed-up) Running/validating now a wide range of sample SM processes: Release of MadGraph5_aMC@NLO before the end of the year!

131 SM STATUS : YEAR 2011 accuracy pp n particles [loops] fully inclusive parton-level fully exclusive 2 fully exclusive and automatic complexity [n]

132 SM STATUS : YEAR 2011 accuracy pp n particles [loops] fully inclusive parton-level fully exclusive 2 fully exclusive and automatic 1 amc@nlo, Sherpa, POWHEL, complexity [n]

133 BOTTOM LINE NNLO and NLO+PS stay to the LHC era as NLO and LO+PS stayed to the Tevatron era

134 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

135 MULTI-JET NLO The problem consists in merging samples for S+0j, S+1j, S+2j, S+...j computed at NLO consistently without double counting (where S can be a Higgs, a ttbar pair, a W-boson, etc.) Sherpa approach: Hoeche et al., CKKW-L approach: Lavesson, Lonnblad, , Lonnblad, Prestel, Geneva approach : Alioli et al and see also (with NNLO proposal) FxFx approach (with MC@NLO) : Frederix and Frixione

136 MULTI-JET NLO The problem consists in merging samples for S+0j, S+1j, S+2j, S+...j computed at NLO consistently without double counting (where S can be a Higgs, a ttbar pair, a W-boson, etc.) Sherpa approach: Hoeche et al., CKKW-L approach: Lavesson, Lonnblad, , Lonnblad, Prestel, Geneva approach : Alioli et al and see also (with NNLO proposal) FxFx approach (with MC@NLO) : Frederix and Frixione The wave function of the merging at NLO effort has collapsed in 2012

137 MULTI-JET NLO [Hoeche et al., ] [Frederix, Frixione, ] Jet rates Up to 3 extra jets at NLO Various approaches give consistent results Differential jet rates Matching up to 1 extra jet at NLO Method works for H+jets and W+jets equally well.

138 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS

139 PREDICTIVE MC (SIMPLIFIED) PROGRESS Automatic NLO+PS Merging and matching: ME+PS NLO+PS New Loop techniques BSM framework Merging at NLO BSM at NLO+PS The next wave-function collapse is in progress...

140 AUTOMATIC SUSY AT NLO WITH MADGOLEM [Goncalves-Netto et al., , , I ] MadGraph 4 Mad dipoles MadGolem FKS Golem All pp to sparticle-sparticle channels available No events, but completely differential in partonic observables. Shapes very similar to those obtained with ME+PS merging at LO.

141 BSM STATUS AND OUTLOOK accuracy [loops] pp n particles fully inclusive parton-level fully exclusive 2 fully exclusive and automatic: C coming up done complexity [n]

142 WHAT S NEXT Automation of high-parton multiplicity final states [e.g., Becker et al, ,...] Automation of EW corrections [e.g., Actis et al, ,...] Process-independent algorithms for NNLO [e.g., Czakon et al , Currie et al , Boughezal, ,... ] NNLO+PS [e.g., Alioli et al, ]...

143 CONCLUSIONS

144 CONCLUSIONS The need for better description and more reliable predictions for SM processes for the LHC has motivated a significant increase of theoretical and phenomenological activity in the last years, leading to several important achievements.

145 CONCLUSIONS The need for better description and more reliable predictions for SM processes for the LHC has motivated a significant increase of theoretical and phenomenological activity in the last years, leading to several important achievements. A new generation of tools and techniques is now available. Full Automation of Accurate (NLO) computations at fixed order as well as their the matching to parton-shower has been proven for the SM. The frontier is now at NNLO.

146 CONCLUSIONS The need for better description and more reliable predictions for SM processes for the LHC has motivated a significant increase of theoretical and phenomenological activity in the last years, leading to several important achievements. A new generation of tools and techniques is now available. Full Automation of Accurate (NLO) computations at fixed order as well as their the matching to parton-shower has been proven for the SM. The frontier is now at NNLO. Amazingly efficient, flexible and robust BSM simulation chain available and being continuously improved. Same level of sophistication as SM processes can be attained. Both top-down and bottom-up approaches included.

147 CONCLUSIONS The need for better description and more reliable predictions for SM processes for the LHC has motivated a significant increase of theoretical and phenomenological activity in the last years, leading to several important achievements. A new generation of tools and techniques is now available. Full Automation A of Accurate (NLO) computations at fixed order as well as their the matching to parton-shower has been proven for the SM. The frontier is now at NNLO. Amazingly efficient, flexible and robust BSM simulation chain available and being continuously improved. Same level of sophistication as SM processes can be attained. Both top-down and bottom-up approaches included. A Augmented EXP/TH interactions in the new framework and not limited anymore by the burden of heavy/long and inefficient calculations...

148 A Accurate A Automation Augmented

149 A A A Accurate Automation Augmented

150 AAA PHENOMENOLOGY AT THE LHC EWSB Λ NEW PHYSICS DARK MATTER HIGGS LHC SUSY NATURALNESS TOP QUARK Free to Pheno