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