Connecting b->s anomalies with neutrino masses, dark matter and - PowerPoint PPT Presentation

Connecting b->s anomalies with neutrino masses, dark matter and charged LFV Based on: JHEP 1811 (2018) 011 Chandan Hati arXiv:1806.10146 Laboratoire de Physique de Clermont In collaboration with G. Kumar, J. Orloff, and A. M. Teixeira Electroweak Interactions and Unified Theories 16 to 23 March 2019

Introduction The Standard Model (SM): Highly successful but incomplete … Neutrino Oscillation-> neutrino masses => New physics beyond the SM (SM neutrinos are strictly massless) Matter-antimatter asymmetry Dark matter candidate Hundreds of theoretical models with various motivations ! Flavour puzzle Unification of interactions Hierarchy Problem … Guidance from experimental anomalies: B-decays, (g-2) , … 1

Beyond the Standard Model: for the hints Hints of significant deviations from the SM predictions in B meson decays=> New physics ? [JHEP 08 (2017) 055] 2

A phenomenological approach to LFUV: connection to available data and experimental prospects Some popular solutions to the LFUV: Scalar leptoquark triplet: (3, 3, 1/3); Vector leptoquark singlet: (3,1,2/3); … Constraints/Predictions SM+ Scalar LQ triplet+ Motivation ?? Neutrino masses and oscillation data Unification? Collider Baryogenesis? EDM? … 3 …

A working example: SM + 2 Scalar LQ + T riplet Majorana fermion (3 gen) The symmetry gives a viable dark matter candidate The standard type III seesaw is forbidden! 4

Radiative neutrino masses and a parametrisation to fit oscillation data Topologically similar to Krauss, Nasri, Trodden PRD 2013, ordinary scalars and singlet DM in the loop h − 1 / 3 h − 1 / 3 1 1 see talk of Rachik Soualah h − 1 / 3 h − 1 / 3 2 2 d C d C ν C Σ 0 d R d L ν L L R L A parameterisation à la Casas-Ibarra is a complex orthogonal matrix Using this parametrisation one can can easily fit oscillation data! 5

A viable dark matter candidate Electroweak radiative corrections: m( Σ ± ) − m( Σ 0 ) ∼ 166 MeV Cirelli, Fornengo, Strumia NPB 2006 Z 2 symmetry => Σ R is odd => Σ 0 (the lightest "exotic" stable state) => a viable dark matter candidate Σ R co-annihilate via gauge interactions s -channel t -channel 6

Neutral current anomalies: R K and R K* Relevant operators for: Taking the 1 σ best fit to R K and R K* data Hiller, Nisandzic 2017, Capdevila et al. 2018 Hurth et al. 2016, Be č irevi ć et al. 2015, … 7

Charged current anomalies: R D and R D ∗ = Using ~ SM like after taking into account the constraints from flavour changing process Belle Collaboration: If this signal is confirmed then this minimal model needs to be extended! See for example: Becirevic et al. 18 Include additional leptoquark R2 = (3, 2, 7/6) / S1= (3, 1, 1/3) ? Crivellin et al. 17 8

A “peek” into the flavour structure of scalar triplet LQ How to implement a flavour structure for y? Can be inspired by Froggatt-Nielsen/flavor symmetry/… To select a benchmark ε we parametrise R K( ∗ ) data best fit value as ( m h 1 ∼ 1.5 TeV) => ∼ 0.215 ! ∼ Textures consistent with all the constraints from flavour violation: amongst the most stringent constraints 9

Prospects for flavour violating processes Cr ( μ -> e,N ) K + →π + νν K L →π 0 νν νν / 10 10 μ -> eee τ -> μμμ K L →μ e B s →μ e μ -> e γ τ -> μ γ τ -> e γ R K (* � ⇓ ⇓ ⇓ ⇓ ⇓ ⇓ Current upper bound 10 - 8 ▲ ↓ ↓ ↓ ↓ Future sensitivity ■ ⇓ ▲ ■ ▲ ■ ▼ ▼ ▲ ▼ ⇓ 10 - 10 ★ ⇑ ★ ▲ ▼ ■ ★ ■ ▼ ⇑ Current lower bound Branching ratio ⇓ ■ ▼ 10 - 12 ⇓ ⇓ ▼ ▲ ⇓ ■ ▼ ▲ ▲ ■ ▲ ▲ ■ ▼ Texture I ↓ ▼ ▲ ■ ▼ ■ 10 - 14 ▲ ▼ Texture II ↓ 10 - 16 ■ Texture III ↓ 10 - 18 ★ SM prediction K L →μ e B s →μ e μ -> e γ τ -> μ γ τ -> e γ μ -> eee τ -> μμμ Cr ( μ -> e,N ) K + →π + νν K L →π 0 νν νν / 10 10 R K (* � Exciting possibilities to probe leptoquark coupling textures at experiments! 10

Connection between LFUV and charged LFV The textures give a direct correlation between LFUV data with charged LFV �� [ μ→ � γ ] �� [ μ→ ��� ] �� [ μ - ���� ] �� [ � + →π + νν ] 10 - 9 10 - 11 10 - 13 10 - 15 2000 4000 6000 8000 10000 m h 1 ( GeV ) The current upper limits on Charged LFV processes translates into an upper bound on leptoquark masses within collider reach 11

What about neutrino oscillation data? Recall: Three generations m Σ : 2.5, 3.5, 4.5 TeV 3 TeV Lightest neutrino mass 0.001 eV Global best fit values for other oscillation parameters Scan for a complex consistent with the perturbativity limits Ruled out ! 12


 
 
 Concluding Remarks We considered a simple scalar leptoquark extension [SM + 2 Scalar LQ + Triplet Majorana fermion (3 gen)] allowing to 1. Accommodate the latest data on neutrino oscillation parameters 2. Explain the R K ( ∗ ) anomalies 3. Account for a correct relic abundance for dark matter 4. Consistent with the bounds on the leptoquark couplings from the relevant leptonic and semi-leptonic meson decays, neutral meson anti-meson oscillations, and CLFV processes 5. Exciting prospects for probing the model in future CLFV experiments : μ − e conversion in nuclei and radiative decays μ → e γ , τ → μγ , e γ , μ → 3e and τ → 3 μ 
 Source: Symmetry Some open issues A consistent UV completion Implementing a mechanism for baryogenesis Computation of EDMs (two-loop ) Thanks a lot for your attention!

Backup I: Full Lagrangian

Backup II: Relevant Lagrangian for neutrino masses h − 1 / 3 h − 1 / 3 1 1 h − 1 / 3 h − 1 / 3 2 2 d C d C ν C Σ 0 d R d L ν L L R L U is the PMNS mixing matrix is a complex orthogonal matrix

Backup III: Dark matter co-annihilation channels s -channel t -channel

Backup IV: Some important constraints from the mesonic observables 10

Backup V: LFV: current limits and future sensitivities Conversion 11