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Soft-Collinear-Effective Theory. and Jets at Colliders. Outline. Jets physics and precision QCD Theoretical tools Soft–Collinear–Effective–Theory (SCET) Overview of achievements Isolated Drell-Yan Top mass from invariant reconstruction Conclusion. LHC runs!. Jet Physics.
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Soft-Collinear-Effective Theory and Jets at Colliders 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Outline • Jets physics and precision QCD • Theoretical tools • Soft–Collinear–Effective–Theory (SCET) • Overview of achievements • Isolated Drell-Yan • Top mass from invariant reconstruction • Conclusion 6th Vienna Central European Seminar, Nov 27 - 29, 2009
LHC runs! 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Jet Physics Understanding of jets is essential in the search for the Higgs boson and for new physics at the LHC Not this kind of jets! 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Jet Physics Understanding of jets is essential in the search for the Higgs boson and for new physics at the LHC Jet: cluster of energetic hadrons leaving tracks xxx and energy deposits in the detectors. 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Jet Physics Understanding of jets is essential in the search for the Higgs boson and for new physics at the LHC QCD machinery 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Jet Physics Our level of understanding of jets at the conceptual level is reflected in our ability to do precision measurements of SM parameters: 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Jet Physics Our level of understanding of jets at the conceptual level is reflected in our ability to describe standard processes: ALEPH, DELPHI, L3, OPAL, SLD 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools QCD Factorization: e.g. Drell-Yan Collins, Soper,Sterman; Bodwin inclusive production perturbative short-distance cross section (process dependent) nonperturbative parton distributions (process independent) 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools QCD Factorization: e.g. Drell-Yan Collins, Soper,Sterman; Bodwin inclusive production Sterman; Catani, Trentadue near threshold 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools QCD Factorization: e.g. Drell-Yan Collins, Soper,Sterman; Bodwin inclusive production • not directly measurable (selection cuts, beam remnant) Sterman; Catani, Trentadue near threshold • very few events • size of power corrections 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools Monte Carlo Event Generators: Universal tool to describe/predict experimental distributions and rates depending on e.g. selection cuts. perturbative parton shower LL(+NLO) non-perturbative 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Theoretical Tools Monte Carlo Event Generators: Universal tool to describe/predict experimental distributions and rates depending on e.g. selection cuts. perturbative • relies on LL (partly NLO) parton shower approximation • shower cut represents an infrared regularization (factorization) scheme that is yet unspecified parton shower LL(+NLO) non-perturbative 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Monte Carlo Generators Strong coupling from event shapes: Almost all measurements from event shapes use the MC hadronization models to determine hadronization corrections to multiloop partonic computations. Herwig 6.2 Pythia 6.1 Q = 35 GeV (JADE) Dissertori, et al. hadron-level prediction Becher, Schwartz parton-level prediction 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Monte Carlo Generators Invariant mass reconstruction: Top mass measurements: jet scheme dependent jet jet b W t p p - t W - b jet 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Monte Carlo Generators Invariant mass reconstruction: Top mass measurements: jet jet jet b W t p p - t W - b jet 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Doing jet physics using the concept of mode and scale separation at the Lagrangian and operator level • Feynman rules • systematic power counting More transparent access to jet physics problems. SCET is an alternative approach to jet physics. IR-log resummation (soft+collinear) through renormalization. Easier (and field theoretic) access to power corrections and subleading twist terms. New proofs of factorization for processes not yet considered in the classic jet approach. Precision QCD at the LHC. 6th Vienna Central European Seminar, Nov 27 - 29, 2009
jet invariant mass Soft-Collinear-Effective Theory First developed for single jet problems in B-physics. Bauer, Fleming, Pirjol, Stewart 2000-2001 Light-cone coordinates: 6th Vienna Central European Seminar, Nov 27 - 29, 2009
jet invariant mass Soft-Collinear-Effective Theory First developed for single jet problems in B-physics. Bauer, Fleming, Pirjol, Stewart 2000-2001 Separation of modes: 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Bauer, Fleming, Pirjol, Stewart Lagrangian: similar to QCD Lagrangian Collinear Lagrangian: small large 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Currents: jet field n-collinear Wilson line Jet fields are gauge invariant under collinear gauge transformations. 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Factorization: Soft field redefinition: soft-collinear decoupling 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Factorization: Soft field redefinition: soft-collinear decoupling soft-collinear decoupling at the operator level 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Soft-Collinear-Effective Theory Factorization: Soft field redefinition: soft-collinear decoupling • applies to any number of final state jets • can be generalized to initial state jets (SCET-II) soft-collinear decoupling at the operator level 6th Vienna Central European Seminar, Nov 27 - 29, 2009
SCET: Conceptual Work Glauber gluons: Bauer, Fleming, Pirjol, Stewart 0011336 Bauer, Stewart 0107001 Idilbi, Majumder 0808.1087 Liu, Ma 0802.2973 Bauer, Pirjol, Stewart 0109045 Renormalons: Hoang, Stewart 0709.3519 Subleading Power: Bauer, Pirjol, Stewart 0011336 All order infrared structure: Pirjol, Stewart 0211251 Becher, Neubert 0903.1126 Beneke, Feldmann 0008255 Becher, Neubert 0904.1021 Beneke, Chapovsky, etal 0206152 Feroglia, Neubert, etal 0908.3676 Chay, Kim 0205117 Feroglia, Neubert, etal 0908.3676 SCET with mass: k factorization: T Leibovich, Ligeti, Wise 0303099 Nandi, Li 0704.3790 Boos, Feldmann, Mannel 0504005 Chay 0711.4296 0-bin subtraction: Parton shower: Manohar, Stewart 0605001 Bauer, Schwartz 0607296 Idilbi, Mehen 0707.1101 Bauer, Tackmann, Thaler 0705.1719 Bauer, Tackmann 0801.4028 Chiu, Fuhrer, Hoang etal 0901.1332 6th Vienna Central European Seminar, Nov 27 - 29, 2009
SCET: Collider Applications Idilbi, Ji, Ma, Yuan 0509294 Idilbi, Ji 0501006 Ahrens, Becher, etal 0809.4298 Becher, Neubert, Xu 0710.0680 Zu, Sheng, etal 0903.5047 Stewart, Tackmann, etal 0910.0467 Mantry, Petriello 0911.4135 Manohar 0309176 Chiu, Kelley, Manohar 0709.2709 Chay, Kim 0511066 Chiu, Kelley, Manohar 0712.0396 Chen, Idilbi, Ji 0607003 Chiu, Kelley, Manohar 0806.1240 Becher, Neubert, Pejak 0607228 Chiu, Fuehrer, etal 0909.0947 Chay, Kim 0205117 Fleming, Hoang, etal 0703207 Bauer, Lee, Manohar, etal 0309278 Fleming, Hoang, etal 0711.2079 Schwartz 0709.2866 Jain, Scimemi, Stewart 0801.0743 Hoang, Stewart 0709.3519 Bauer, Fleming,Lee etal 0801.4569 Leibovich, Liu 0705.3230 Becher, Schwartz 0803.0342 Hoang, Kluth 0806.3852 Fleming, Leibovich,etal 0607121 Hornig, Lee, Ovanesyan 0901.3780 Bauer, Lange 0905.4739 Becher, Schwartz 0911.0681 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Isolated Drell-Yan Stewart, Tackmann, Waalewijn Drell-Yan with central jet veto. 0910.0467 Beam thrust: • event-shape-like and suitable for analytic computations • contribution of unmeasured beam remnant negligible • cut on vetoes high p jets T • factorization for • related to initial state parton shower PDF beam functions 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Top Reconstruction and Event Shapes . Fleming, Mantry, Stewart, AHH Possibility to define reconstruction prescription such that non-perturbative effects can be extracted from event shapes. 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Top Reconstruction and Event Shapes . Invariant mass distribution Jet mass, thrust distribution for thrust, jet masses 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Top Reconstruction and Event Shapes . Fleming, Mantry, Stewart, AHH Top Quark universal ! Light quarks 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Top Reconstruction and Event Shapes . Fleming, Mantry, Stewart, AHH Top Quark universal ! Light quarks 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Invariant Mass Peak and Top Mass Fleming, Mantry, Stewart, AHH best mass scheme: jet mass first moment of the soft function 6th Vienna Central European Seminar, Nov 27 - 29, 2009
. Abbate, Fickinger, Mateu, Stewart, AHH NNNLL’ NNNLL NNLL’NNLLNLL’ preliminary 488 bins 6th Vienna Central European Seminar, Nov 27 - 29, 2009
Conclusions Soft-Collinear-Effective-Theory: • Approach to jet physics and high energy scattering processes using effective field theory. • Alternative and compatible approach to classic jet physics. • Modularity: SCET can be combined with HQET, NRQCD, Chiral p.th. • Initiates novel applications (conceptual & computational). • Aim: Precision QCD Physics at LHC Stay tuned! 6th Vienna Central European Seminar, Nov 27 - 29, 2009