b s b c anomalies anomalies Found by LHCb (and perhaps Found by - - PowerPoint PPT Presentation

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Oct 25, 2023 141 likes •344 views

b s b c anomalies anomalies Found by LHCb (and perhaps Found by several experiments hinted by Belle) (LHCb, BaBar and Belle) Many observables: global pattern Two observables: R(D) and R(D*) Neutral current Charged current 1-loop

SLIDE 1

b → s anomalies b → c anomalies

Found by LHCb (and perhaps hinted by Belle) Neutral current 1-loop (and CKM-suppressed) in the SM The New Physics can be heavy Many observables: global pattern Found by several experiments (LHCb, BaBar and Belle) Charged current Tree-level in the SM The New Physics must be light Two observables: R(D) and R(D*)

SLIDE 2

The anomalies

SLIDE 3

Avelino Vicente - BSM Journal Club 3 IFIC, 20/09/17

Episode V: LHCb strikes back

2014 : Lepton universality violation

[LHCb, 2014] arXiv:1406.6482

The anomalies

SLIDE 4

Avelino Vicente - BSM Journal Club 4 IFIC, 20/09/17

The anomalies

2.6 s 2.2 s 2.4 s

LHCb measurement SM prediction Important: LFUV ratios are clean observables, free from hadronic uncertainties If confirmed: dramatic implications for New Physics Run-2 update eagerly awaited

SLIDE 5

The anomalies

SLIDE 6

Avelino Vicente - BSM Journal Club 6 IFIC, 20/09/17

The anomalies

BaBar + Belle + LHCb

Another hint of lepton universality violation?

Deviation from the SM at the 4 s level

SLIDE 7

Avelino Vicente - BSM Journal Club 7 IFIC, 20/09/17

The anomalies

SLIDE 8

New Physics explanations

SLIDE 9

Avelino Vicente - BSM Journal Club 9 IFIC, 20/09/17

New Physics explanations

Neutral current Charged current

Z’ boson, leptoquarks, compositeness, RPV loops Charged Higgs, leptoquarks, compositeness, W’ boson, RPV sfermions

SLIDE 10

Avelino Vicente - BSM Journal Club 10 IFIC, 20/09/17

Leptoquarks

Alonso, Grinstein, Martin-Camalich [1505.05164]

Simultaneous explanation of both puzzles: leptoquarks?

Barbieri, Isidori, Pattori, Senia [1512.01560]

However: leptoquarks added to the models without a clear theoretical motivation... ad-hoc

Example:

Other leptoquarks have also been proposed

... and others

SLIDE 11

Backup slides

SLIDE 12

Avelino Vicente - BSM Journal Club 12 IFIC, 20/09/17

The anomalies

2013 - Episode IV: A new hope 2014 - Episode V: LHCb strikes back 2015 - Episode VI: Return of the anomalies 2016 - Episode I: The Belle menace 2017 - Episode II: Attack of RK* 2018 - Episode III: ???

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Avelino Vicente - BSM Journal Club 13 IFIC, 20/09/17

Episode IV: A new hope

2013 : First anomalies found by LHCb

Data collected:
Decrease (w.r.t. the SM) in several branching ratios
Several anomalies in angular observables

[LHCb, 2013] 1305.2168, 1308.1707, 1403.8044 arXiv:1308.1707

The anomalies

SLIDE 14

Avelino Vicente - BSM Journal Club 14 IFIC, 20/09/17

Optimized observables

[Descotes-Genon et al, 2012, 2013]

differential angular distribution

[Figure borrowed from Javier Virto]

The anomalies

SLIDE 15

Avelino Vicente - BSM Journal Club 15 IFIC, 20/09/17

Episode VI: Return of the anomalies

2015 : LHCb confirms first anomalies

[LHCb, 2015] 1512.04442 [ Complete LHC Run I dataset ]

Errors shrunk... ... anomalies persist

The anomalies

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Avelino Vicente - BSM Journal Club 16 IFIC, 20/09/17

The anomalies

P5’ anomaly confirmed Little LFVU indication

[Belle, 2016] 1612.05014

Episode I: The Belle menace

2016 : Belle finds additional hints

SLIDE 17

Avelino Vicente - BSM Journal Club 17 IFIC, 20/09/17

The anomalies

[LHCb, 2017] Talk by S. Bifani April 18th 1705.05802

Episode II: Attack of RK*

2017 : More universality violation in LHCb

low bin central bin

SLIDE 18

Avelino Vicente - BSM Journal Club 18 IFIC, 20/09/17

Interpreting the anomalies

Effective hamiltonian

[ analogous for primed operators ]

: Wilson coefficients : Operators

SLIDE 19

Avelino Vicente - BSM Journal Club 19 IFIC, 20/09/17

Table from Capdevila et al, 1704.05340

Global fits

All observables Only LFUV observables

New Physics hypothesis preferred over SM by more than 5 s (4 s if only LFUV) The C9m coefficient seems to be crucial Qualitatively similar results in 1704.05435 and 1704.05438 “clean” + “dirty” “clean”