Andreas Crivellin. Flavor Physics beyond the Standard Model

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1 Andreas Crivellin Flavor Physics beyond the Standard Model

2 Outline: Introduction: Flavour anomalies * B D s h b a Possible New Physics Explanations Z Extended Higgs sector Leptoquarks Simultaneous Explanations of Anomalies and predictions Outlook and Conclusions 2

3 MSSM? New Physics Models No SUSY Particles No Direct Detection Signals Extra Dimension? No Kaluza Klein Excitations No 750 GeV excess What do we do now? Look at the experimental data and see what it suggests!

4 Flavour Anomalies 4

5 B * D Tree-level decays in the SM via W-boson R D * B B D D * * Combined 4σ deviation 5

6 b LQ R(D) Explanations Leptoquark (scalar or vector) Charged Higgs b H c c W??? c different differential distribution 6

7 B K*µµ 2-3 σ deviation from the SM mostly in P5 Can be explained by Descotes-Genon et al , Altmannshofer and DS , Beaujean et al New physics explanation is not easy (MSSM, 2HDM). Most natural explanation: Z Gauld et al , Buras et al , Subleading hadronic effects might be larger than expected 9 L Further supported by B s ϕμμ O s Pb R. Horgan, Z. Liu, S. Meinel, and M. Wingate (2015), arxiv:

8 R R R(K) = B Kµµ/B Kee Lepton flavour universality violation 2.6 σ deviation from the theoretically rather clean SM expectation SM K exp K Explanation: Leptoquarks e.g. G. Hiller, M.Schmaltz, Extra dimensions C. Niehoff, P. Stangl, D. Straub, arxiv: flavour non-universal Z W. Altmannshofer, et al Also LFV in B decays? LHCb

9 C 9 C9 9 b sμμ Global analysis give a very good fit to data Lepton Flavour Universality Violation Symmetry based solutions give a very good fit to data: 9 10 C C 9 10 C O s Pb 5 O s Pb L L Fit is 4-5 σ better than in the SM

10 b s b s Z explanations d 23 dl 2 2 C9 23 g m Z B d 23 M M b s 12 SM 12 B Z dl 2 23 s s mixing Z g d 23 m b s 2 2 Z U. Haisch et al W. Altmannshofer et al A. C. et al allowed regions 10

11 Leptoquarks B s B s mixing b b s LQ b LQ s s b LQ s Only weak constraints from other flavour observables (loop compared to tree) Possible effect in the anomalous magnetic moment of the muon Large production cross section at the LHC 11

12 h 2.6 σ difference from zero 11

13 h Can be explained in the effective field theory approach by Q fi e fei No dominant contribution from vector-like fermions A. Falkowski, D. M. Straub, and A. Vicente, Extended Higgs sector R. Harnik, J. Kopp, and J. Zupan, G. Blankenburg, J. Ellis, and G. Isidori, S. Davidson and P. Verdier, J. Heeck et al A. Greljo et al. arxiv: A. C. et al. arxiv:

14 Models for Simultaneous Explanations of Anomalies 13

15 2HDM with gauged L -L μ τ Vectorial U(1) gauge group: Q(e) = 0, Q(μ) = 1, Q(τ) = -1 b-s couplings generated with vector-like quarks Two Higgs doublets QL Yukawa couplings L 2 0 Y e e u d QY f fi 2ui QY f fi2di h.c.. Y f i fi 2 i R QL L 1 2 diagonalizes the τ-μ block of the mass matrix Z,, 15

16 2HDM with gauged L μ -L τ h 0 h 2 0 H 1 Z allowed by h allowed by excluded 16

17 Leptoquark Explanations of Tree-level contribution to loop effect in s can explain b sμμ and B D ( * ) τν a Anarchic flavor structure Tree-level contribution to and c b M. Bauer, M. Neubert arxiv: b but Hierarchical flavor structure, large third generations couplings, small first and second ones. b b c s 16

18 Tree-level Leptoquark Explanation Third generation couplings Misalignment between interaction and mass basis L. Calibbi, A.C. and T. Ota, PRL, arxiv:

19 2HDM of type X One Higgs doublet couples only to quarks the other Higgs doublet to leptons. Additional free parameters: tan v1/ v2 m, m, m, m H A H H u, fi u, u, q i i qi Y i Couplings to leptons are tan(β) enhanced Y q i q fi H 2 H 1 H 1 q f q f f

20 RD a 0 33 m H m A AC, Julian Heeck, Peter Stoffer. arxiv: PRL 2016

21 Prediction: t Hc Branching ratio can even reach the percent level AC, Julian Heeck, Peter Stoffer. arxiv: PRL 2016

22 L μ -L τ flavour symmetry Flavon mixes with the Higgs L a μ -L τ model for and is protected a h is not protected Effects in h 30

23 L a μ -L τ model for and Can also explainb s without violating 3 bound h : mixing among CP even Higgses m ma m 30

24 Outlook (personal view) Leptoquarks Bs b 2HDM X t Hc, Z Flavon model h bs R D a h R D s * a * bsh

25 e, 3e Any observation would directly prove NP currently best limit of clfv e 3e complementary to Z models Leptoquark explanations of Br e 0 (in general) Z models and motivate Br h 3e 0 e * B D bs 3 25

26 PEN and Muonic Lamb Shift B * D Also LFUV in? PEN R K h New Physics with muon but not with electrons? Connection to the proton radius problem??? Muonic Lamb Shift experiment e 26

27 b s b c Z gauge boson Leptoquarks Extended Higgs sector a h