Measurement of sin2 b with charmonium decays and gluonic penguin decays
Theoretical study of rare B/D decays - HKUST Jockey Club...
Transcript of Theoretical study of rare B/D decays - HKUST Jockey Club...
![Page 1: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/1.jpg)
1
Theoretical study of rare B/D decays
Cai-Dian Lü(吕才典)
CFHEP, Institute of High Energy Physics, Beijing
51
![Page 2: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/2.jpg)
2
Outline n Introduction/Motivation n Theory of non-leptonic B/D decays n Factorization assisted topological diagram
approach for hadronic B/D decays n Summary
51
![Page 3: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/3.jpg)
Flavor physics is important
3 51
![Page 4: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/4.jpg)
CKM triangle measurement
4 51
![Page 5: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/5.jpg)
5 51
![Page 6: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/6.jpg)
6
![Page 7: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/7.jpg)
7 51
![Page 8: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/8.jpg)
51 8
FlavorphysicsatCEPCasasuperZfactoryOnthewaytotheCEPCproposedasaHiggsfactory,itstartswithaZ0factory&veryhighluminosity,whichteststhedetector.Luminosity:8x1035cm-2s-1Integrated:40ab-1in2yearscomparablewithsuperBfactoryAdvantageatBs/Bc,tau,Dphysics
![Page 9: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/9.jpg)
It makes even more sense to measure CP asymmetries in many-body final states , especially in Bs decays
51 9
![Page 10: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/10.jpg)
Recently many CP measurements for 3-body B decays
第3页 10 51
![Page 11: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/11.jpg)
In perturbative QCD approach
S-wave resonant states ……….
W.F Wang, H.n. Li, Wei Wang, CDL, PRD91 (2015) 9, 094024
第5页 11 51
![Page 12: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/12.jpg)
12
BcMeson/UniquefromsuperBfactory
51
![Page 13: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/13.jpg)
13
Current new physics signal in B physics
51
![Page 14: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/14.jpg)
14 51
![Page 15: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/15.jpg)
15 51
![Page 16: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/16.jpg)
16 51
![Page 17: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/17.jpg)
17
b W u B π d(s) π (K) W
b t B π
In experiments, we can only observe hadrons
The standard model describes interactions amongst quarks and leptons
π (K)
Rich physics in hadronic B decays
How can we test the standard model without solving QCD? 51
![Page 18: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/18.jpg)
Perturbative calculations n In principle, all hadronic physics should be
calculated by QCD n In fact, you can always use QCD to calculate
any process, provided you can renormalize the infinities and
do all order calculations.
18 51
![Page 19: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/19.jpg)
Divergences n Perturbation calculation means order by order n Involving loop diagrams n Therefore divergences unavoidable n Ultraviolet divergences à renormalization n Infrared divergences ? Infrared divergence in
virtual corrections should be canceled by real emission
n In exclusive QCD processes à factorization 19 51
![Page 20: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/20.jpg)
20
It is very difficult for exclusive processes
n infrared finite seems not possible, no free gluon can be emitted
n Infrared divergence should be absorbed into meson wave function (distribution amplitude)
n This is called factorization
51
![Page 21: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/21.jpg)
21
Factorization can only be proved in power expansion by operator product expansion. To
achieve that, we need a hard scale Q
• In the certain order of 1/Q expansion, the hard dynamics characterized by Q and the soft dynamic factorize
• The former into hard kernel H and the latter into distribution amplitude ϕ
• Factorization theorem holds up to all orders in αs, but to certain power in 1/Q
• H is process-dependent, but calculable • ϕ are universal (process-independent) predictive
power of factorization theorem • In B decays the hard scale Q is just the b quark mass
51
![Page 22: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/22.jpg)
✤ QCD-methods based on factorization work well for many processes Perturbative QCD approach based on kT factorization [Keum, Li, Sanda, 00’; Lu, Ukai, Yang, 00’] n collinear QCD Factorization approach
[Beneke, Buchalla, Neubert, Sachrajda, 99’] n Soft-Collinear Effective Theory
[Bauer, Pirjol, Stewart, 01’]
✦ Unavailable for 1/mb power corrections
✤ Topological diagrammatic approach
[Chau, Cheng, et al, 91’; Chiang, Rosner, et al, 04’]
✤ Work well for most of charmless B decays, except for pi K puzzle etc.
Hadronic matrix elements calculations
22
![Page 23: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/23.jpg)
23
CP Violation in Bà π π (K) (real prediction before exp.)
CP(%) FA BBNS PQCD Exp
π +K – +9±3 +5±9 –17±5 –9.7±1.2
π +π – –5±3 –6±12 +30±10 +38±7
(2001) (2004)
Annihilation type diagram play a very important role in direct CP violation of B decays by providing the necessary strong phase. (Phys.Lett. B504 (2001) 6;Phys.Rev. D63 (2001) 074009)
51
![Page 24: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/24.jpg)
pseudo-scalar B requires spins in opposite directions, namely, helicity conservation
momentum
B fermion flow
spin (this configuration is not allowed)
p1 p2
Annihilation suppression ~ 1/mB ~ 10%
Like Bàe νe
For (V-A)(V-A), left-handed current
24 51
![Page 25: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/25.jpg)
Annihilation-Type diagrams
••
••
W annihilation W exchange
Time-like penguin Space-like penguin
W W
W
W
25
Penguin type annihilation not suppressed
51
![Page 26: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/26.jpg)
Pure annihilation type decay Bsàπ+π-
n Very rare decay predicted in PRD76, 074018 (2008)
n BR=(5.7 ± 1.7)x10-7
n No one expected to be measured
π+
π-
26
••
Time-like penguin
Bs W
51
![Page 27: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/27.jpg)
CDF Results
F.Ruffini, 1107.5760ex
27
Later also measured by LHCb
51
![Page 28: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/28.jpg)
n High precision measurements of B/D decays already by BaBar, Belle, BESIII and LHCb, and to be pushed by LHCb upgrade and Belle-II.
n High precision in theoretical calculation is urged
n Theore7cally,itisnotsa7sfied,sincetherearemostlymodelcalculaQons,someQCDsumrulescalculaQonorrelyonLaSceQCD:anulQmatetoolbutaformidabletasknow
n Charmquarkmassisnotlargeenoughforheavyquarkexpansion
28
Hadronic decays with charm quark in the final states or initial state
51
![Page 29: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/29.jpg)
Topological diagrammatic approach
n Distinct by weak interaction and flavor flows with all
strong interaction encoded, including non-perturbative ones. Model-independent
n Based on flavor SU(3) symmetry. Amplitudes with strong phases extracted from data. SU(3) breaking was lost.
n DP, D*P and DV fitted separately, 5 parameters for each category of decay modes. Less predictive.
29
[Chiang, Senaha, 07’]
T C E A
51
![Page 30: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/30.jpg)
Ø Effective Hamiltonian: For the color favored diagram (T), it is proved factorization to all order of αs expansion in soft-collinear effective theory, The decay amplitudes is just the decay constants and form factors times Wilson coeficients of four quark operators. The SU(3) breaking effect is automatically kept
30
No free parameter
51
![Page 31: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/31.jpg)
Ø Effective Hamiltonian: For other diagrams, we extract the amplitude and strong phase from experimental data by χ2 fit We factorize out the decay constants and form factor to keep the SU(3) breaking effect
31 51
![Page 32: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/32.jpg)
Global Fit for all BàDP, D*P and DV decays (PRD92, 094016 (2015))
n 31 measured modes induced by b→c transitions
32
Topological amplitudes
χ2 is much smaller than previous topology diagram approach
Large strong phase
51
![Page 33: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/33.jpg)
BàDP
X
33 51
![Page 34: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/34.jpg)
BàD*P
X
34 51
![Page 35: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/35.jpg)
BàDV
35 51
![Page 36: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/36.jpg)
Nonperturbative parameters 𝜒C, 𝜙C, 𝜒E, 𝜙E
are universal for all the DP, D*P and DV modes
36
factorization
![Page 37: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/37.jpg)
GlobalfitforhadronicDdecays(Phys.Rev. D86 (2012) 036012)
• 12 free parameters are extracted from 28 experimental data of D->PP branching ratios
• Λ describes the soft momentum in D meson • The value of Glauber phase is consistent with the
value extracted from B->πK data, resolving the puzzle for direct CP asymmetry in this mode [H.n Li, S. Mishima, 0901.1272]
37 51
![Page 38: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/38.jpg)
TopologydiagramsforBRs • According to weak
interactions and flavor flows • Include all strong interaction
effects, involving final state interaction (FSI) effects
• Magnitude and phase are introduced to each topology
• This is a complete set • Penguins are neglected for
BRs due to suppression of CKM matrix elements
38 51
![Page 39: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/39.jpg)
EvoluQonscale n ImportantflavorSU(3)breakingeffectsn Non-negligiblemassraQosn SuggestedbythePQCDapproach,thescaleissettotheenergyreleasedependingonmassesoffinalstates
n :themomentumofso`degreesoffreedom,afreeparametertobedetermined
39 51
![Page 40: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/40.jpg)
Singly Cabibbo-suppressed decays (10-3), better agreement with data
40 51
![Page 41: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/41.jpg)
41 Phys.Rev. D89 (2014) 5, 054006 51
![Page 42: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/42.jpg)
PenguinparameterizaQon n Usethelong-distancehadronicparametersfixedbythedataofbranchingraQos
n TrytoformulatepenguincontribuQonwithoutintroducingaddiQonalfreeparameters
n Thetreeoperatorsareall(V-A)(V-A)n Forpenguins,thehadronicmatrixelementswith(V-A)(V-A)operatorsarethesameastreeleveloperators
42 51
![Page 43: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/43.jpg)
Predictions of Direct CP asymmetries
43 51
![Page 44: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/44.jpg)
44
12.03.13 Moriond QCD 2013, La Thuile 17
LHCb combination
● The two measurement are compatible at the 3 % level
● χ2 = 4.85
● Naive average (neglecting indirect CP violation)
LHCb-PAPER-2013-003
LHCb-CONF-2013-003
Semileptonic:
Prompt:(preliminary)
51
![Page 45: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/45.jpg)
Charmless B decays
n Famous pi K puzzle not well explained n Tree + penguin contribution, complicated
45 51
![Page 46: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/46.jpg)
Large color suppressed tree diagram contribution together with large strong phase also expected
46 51
![Page 47: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/47.jpg)
Preliminary results
47 51
![Page 48: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/48.jpg)
Charmless Bc decays
51 48
Only annihilation type diagrams contribute, and experimentally not accessible by super B factory
![Page 49: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/49.jpg)
Results from pQCD based on kT factorization
51 49
![Page 50: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/50.jpg)
Summary
n High-energy QCD processes must involve both perturbative and nonperturbative dynamics.
n At leading power, the two dramatically different dynamics factorize.
n Theoretical study of non-leptonic D/B meson decays making great improvement with helping from rich experimental data
n Flavor sector has only been tested at the 10% level and can be done much better
n We are still waiting for a clear New physics signal in the heavy flavor sector
50 51
![Page 51: Theoretical study of rare B/D decays - HKUST Jockey Club ...ias.ust.hk/program/shared_doc/2016/201601hep/Lu_Caidian_160114.pdf · n High precision measurements of B/D decays already](https://reader036.fdocuments.net/reader036/viewer/2022081521/5cdc112488c99373238b5428/html5/thumbnails/51.jpg)
51
Thanks!
51