Celebration of Panofsky Prize Jonathan Dorfan David Hitlin Fumihiko Takasaki Stephen Olsen “For leadership in the BaBar and Belle Experiments, which established the violation of CP symmetry in B-meson decay, and furthered our understanding of quark mixing and quantum chromodynamics.”
57
Embed
Celebration of Panofsky Prize - … · Celebration of Panofsky Prize Jonathan Dorfan David Hitlin Fumihiko Takasaki Stephen Olsen “For leadership in the BaBar and Belle Experiments,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Celebration of Panofsky Prize
Jonathan Dorfan David Hitlin Fumihiko Takasaki Stephen Olsen
“For leadership in the BaBar and Belle Experiments, which established theviolation of CP symmetry in B-meson decay, and furthered our understanding of
quark mixing and quantum chromodynamics.”
B-factory Science ImpactZoltan Ligeti
Celebration of Dorfan/Hitlin Panofsky Prize
SLAC, January 13, 2016
Personal recollections
• I met Dave when as a postdoc at Caltech (1994–97); was fun to think independentof the available data (then mostly CLEO), imagining the huge future data sets
Some were done by BABAR & Belle: B → Xsγ spectrum and moments, B →Xc`ν moments and |Vcb|, B → Xu`ν hadron mass spectrum, B → D∗∗`ν (LLSW)
Some are still left for the future: B → Xsνν, B → Xcτ ν, etc.
• Discussions with Dave — remember vividly being stunned by deep commentsat a level as if he has been working on the same problem, immediate picture ofdecay properties that he heard about for the first time
• The BABAR workshops took place in my 3rd year at CaltechI went to Rome, Princeton, Paris...
Z L – p. 1
Personal recollections
• I met Dave when as a postdoc at Caltech (1994–97); was fun to think independentof the available data (then mostly CLEO), imagining the huge future data sets
Some were done by BABAR & Belle: B → Xsγ spectrum and moments, B →Xc`ν moments and |Vcb|, B → Xu`ν hadron mass spectrum, B → D∗∗`ν (LLSW)
Some are still left for the future: B → Xsνν, B → Xcτ ν, etc.
• Discussions with Dave — remember vividly being stunned by deep commentsat a level as if he has been working on the same problem, immediate picture ofdecay properties that he heard about for the first time
• The BABAR workshops took place in my 3rd year at CaltechI went to Rome, Princeton, Paris...
• Once, on a weekend, jump-starting Dave’s porschefrom my crappy nissan sentra
Z L – p. 1
Personal recollections
• I met Dave when as a postdoc at Caltech (1994–97); was fun to think independentof the available data (then mostly CLEO), imagining the huge future data sets
Some were done by BABAR & Belle: B → Xsγ spectrum and moments, B →Xc`ν moments and |Vcb|, B → Xu`ν hadron mass spectrum, B → D∗∗`ν (LLSW)
Some are still left for the future: B → Xsνν, B → Xcτ ν, etc.
• Discussions with Dave — remember vividly being stunned by deep commentsat a level as if he has been working on the same problem, immediate picture ofdecay properties that he heard about for the first time
• The BABAR workshops took place in my 3rd year at CaltechI went to Rome, Princeton, Paris...
• Once, on a weekend, jump-starting Dave’s porschefrom my crappy nissan sentra
Z L – p. 1
Summary — version one
• Flavor physics was crucial for the development of the standard model(KL → µµ⇒ GIM, charm; εK ⇒ 3rd generation; ∆mK ⇒mc; ∆mB ⇒heavy mt)
• LEP & SLC in the 90s probed the gauge sectorto better than 1%, testing the theory at one-loop level
Nobel Prize, 1999⇒
• Before 1999, ε was the only unambiguous measurement of CP violationCould be fit with KM phase, but O(1) deviations in SM flavor sector were allowed
• BABAR and Belle probed the Yukawa sector much better
Nobel Prize, 2008⇒
• However, O(20%) BSM contributions to FCNC processesstill allowed — lot of room for Belle II & LHCb to find NP
Z L – p. 2
Large impacts on theory
• Flavor physics triggered lots of developments + testing grounds for new methods
FCNC motivated: Heff at high orders, multi-loop perturbative calculations
Heavy quark symmetry: symmetries, HQET at high orders, many applications
Operator product expansions: Develop / use / test expansions to high orders
Soft-collinear effective theory: Started with B → Xsγ and semileptonic
[Developments continue, expect a lot more, data always motivate theory]
BSM: Hundreds of papers motivated by anomalies, elaboration of MFV, GMSB,other frameworks to address lack of NP signals in flavor [all started pre-BABAR]
• Broad impacts: perturbative / nonperturbative / logs vs fixed order / interfacesBroad impacts: (LHC jet vetos, cross sections, jet substructure, EFT for DM signals, ... )
Z L – p. 3
Rough outline
• B physics before BABAR + progress since
• New measurements at BABAR not done / seen beforeNew measurements at BABAR some impacts constraining BSM
• Future: Belle II, LHCb, current anomalies, prospects
Z L – p. 4
Rough outline
• B physics before BABAR + progress since
• New measurements at BABAR not done / seen beforeNew measurements at BABAR some impacts constraining BSM
• Future: Belle II, LHCb, current anomalies, prospects
Disclaimers
I’ll mostly say BABAR throughout this talk — comparable results from Belle
Focus on topics relevant to understand short-distance physics
Thousands of missing references...
Z L – p. 4
Started before BABAR
Discovery of B0–B0 mixing, 1987
• ARGUS: At much higher rate than expected
• Preceded by: discovery of Υ
Preceded by: long B lifetime
• Flurry of theory papers, SM interpretation:
– Probably mt > mW ⇒ no top hadrons– Expect Bs mixing near maximal
• SM predicts large CP violationSM predicts large FCNC B decay rates
Dashed arrows show anticipated improvements in next generation of experiments
– Proton decay already ruled out simplest version of grand unification
– Neutrino experiments hope to probe see-saw mechanism
– Flavor physics probes TeV-scale new physics with even SM-like suppressions
– LHC was in a unique situation that a discovery was virtually guaranteed (known since 80’s)
Z L – p. i
Push Bs,d→ µ+µ− to theory limit
• For Bd, CMS (LHCb) expect ultimately 15–20% (30–40%) precision at SM level
SM uncertainty ' (2%)⊕ f2Bq⊕ CKM [Bobeth, FPCP’15]
]9−[10)−µ+µ→0BB(0 0.2 0.4 0.6 0.8
LlnΔ2−
0
2
4
6
8
10SM
]9−[10)−µ+µ→s0BB(
0 2 4 6 8
LlnΔ2−
0
10
20
30
40SM
]9−[10)−µ+µ→s0BB(
0 1 2 3 4 5 6 7 8 9
]9−[1
0)− µ
+ µ→
0B
B(
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
68.27%
95.45%
99.73% 5−10
×6.3
−1
7−10
×5.7
−1
9−10
×2−1
SM
CMS and LHCb (LHC run I)
a
b
c
[LHCb & CMS, 1411.4413]
• Theoretically cleanest |Vub| I know, only isospin: B(Bu → `ν)/B(Bd → µ+µ−)
• A decay with mass-scale sensitivity (dim.-6 operator) that competes w/ K → πνν
Z L – p. ii
Bound on vector-like fermions
• Do not make hierarchy problem worse; vector-like fermions can Yukawa couple tothe SM fermions via the Higgs in 11 models (⇒ FCNC Z couplings) [Ishiwata, ZL, Wise]
ModelQuantum Present bounds on M/TeV and λiλj for each ij pair
• Want observables: (i) sensitive to different NP, (ii) measurements can improve byan order of magnitude, and (iii) not limited by hadronic uncertainties:
• Difference of CP asymmetries, SψKS − SφKS• γ from CP asymmetries in tree-level decays vs. γ from SψKS and ∆md/∆ms
• Search for charged lepton flavor violation, τ → µγ, τ → 3µ, and similar modes
• Search for CP violation in D0 −D0 mixing
• The CP asymmetry in semileptonic decay, ASL
• The CP asymmetry in the radiative decay, SK∗γ
• Search for not yet seen FCNC decays and refinements: b→ sνν, B → τ ν, etc.
• Any one of these measurements has the potential to establish new physics
Z L – p. v
Some theory challenges
• New methods & ideas: recall that the best α and γ measurements are in modesproposed in light of Belle & BABAR data (i.e., not in the BABAR Physics Book)
– Better SM upper bounds on Sη′KS − SψKS, SφKS − SψKS, and Sπ0KS− SψKS
– (and similarly in Bs decays)
– How big can CP violation be in D0 –D0 mixing (and in D decays) in the SM?
– Better understanding of semileptonic form factors; bound on SKSπ0γ in SM?
– Inclusive & exclusive semileptonic decays
– Many lattice QCD calculations (operators within and beyond SM)
– Factorization at subleading order (different approaches), charm loops
– Can direct CP asymmetries in nonleptonic modes be understood enough to– make them “discovery modes”? [SU(3), the heavy quark limit, etc.]
• We know how to make progress on some + discover new frameworks / methods?
Z L – p. vi
Charged lepton flavor violation
• SM predicted lepton flavor conservation with mν = 0
Given mν 6= 0, no reason to impose it as a symmetry
• If new TeV-scale particles carry lepton number(e.g., sleptons), then they have their own mixingmatrices⇒ charged lepton flavor violation