CKM * physics at hadron colliders Mat Charles (Sorbonne - PowerPoint PPT Presentation

CKM * physics at hadron colliders Mat Charles (Sorbonne Université/LPNHE) representing the LHCb collaboration * meaning here: flavour physics that lets us make serious, indirect tests of the SM either by itself or in combination with other measurements v4 1

Quick reminder of the players • At the Tevatron ( p p ): D0 & CDF • 1.96 TeV CM • At the LHC (pp): ATLAS, CMS & LHCb • 2010 and 2011: 7 TeV CM • 2012: 8 TeV CM • 2015-2018: 13 TeV CM • LHCb usually runs at a much lower luminosity/pile-up than ATLAS & CMS • LHCb recorded about 3 fb − 1 in Run1 (2010-2012) 
 Caution: Run2 and so far about 5 1 / 2 fb − 1 in Run2 (2015-2018) numbers are probably • ATLAS/CMS recorded about 26 fb − 1 in Run1 
 already out of date and so far about 137 fb − 1 in Run2 2

Back in 2016... • Barack Obama was the US president • France hadn't won the world cup in a generation • There were only 14 films in the Marvel Cinematic Universe • And at CKM, the overview talk covered: • CP viola*on in the interference between B -meson mixing and decay • CP viola*on in B -meson mixing • B -meson width and mass differences • Photon polarisa*on in B s à φγ • Tree-level determina*on of γ • Searches for CP viola*on in b baryons • Measurement of | V ub / V cb | • Leptonic and charmless hadronic rare decays • Angular analysis of B 0 à K* µ + µ � decays • Lepton Flavour Universality tests Vincenzo Vagnoni, CKM 2016 2 • What * have we learned since then? * in CKM physics 3

The classic Unitarity Triangle • Disclaimer: will use 𝛽 , 𝛾 , 𝛿 notation (rather than 𝜚 2,1,3 ) • Before BABAR & Belle, hoped for O(1) BSM effects • Today: triumph of CKM picture • Focus instead on over-constraining the triangle, looking for pieces that don't fit. • Requires many careful, precise measurements. 1.5 η e x γ c excluded area has CL > 0.95 l u d e d 1 γ a t C Fits from summer L summer16 > 1.0 0 . m & m 9 ∆ ∆ 5 s d Δ m β m d Δ d 2016. Hopefully it'll sin 2 β m Δ s 0.5 0.5 m ∆ be time for an d ε V α ε K ub K V β γ cb update soon! See η 0.0 0 α V α talks on Thursday ub -0.5 -0.5 BR(B ) → τ ν α morning [WG4/5]. ε γ K -1.0 CKM sol. w/ cos 2 β < 0 f i t t e r -1 (excl. at CL > 0.95) ICHEP 16 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 -1 -0.5 0 0.5 1 ρ ρ http://ckmfitter.in2p3.fr/ http://www.utfit.org/UTfit/ 4

The classic Unitarity Triangle • On LHCb side: • Many incremental improvements on 𝛿 • Constraints on 𝛾 • Also results from B-factories, notably on 𝛾 -- see next talk! • Let's walk through new LHCb inputs, starting with 𝛿 ... 1.5 η e x γ c excluded area has CL > 0.95 l u d e d 1 γ a t C Fits from summer L summer16 > 1.0 0 . m & m 9 ∆ ∆ 5 s d Δ m β m d Δ d 2016. Hopefully it'll sin 2 β m Δ s 0.5 0.5 m ∆ be time for an d ε V α ε K ub K V β γ cb update soon! See η 0.0 0 α V α talks on Thursday ub -0.5 -0.5 BR(B ) → τ ν α morning [WG4/5]. ε γ K -1.0 CKM sol. w/ cos 2 β < 0 f i t t e r -1 (excl. at CL > 0.95) ICHEP 16 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 -1 -0.5 0 0.5 1 ρ ρ http://ckmfitter.in2p3.fr/ http://www.utfit.org/UTfit/ 5

𝛿 • Can make tree-level measurements of 𝛿 from interference of b → c (V cb ) and b → u (V ub ) decays • Use two-step decays, often: • B → D 0 X, D 0 → f • B → D 0 X, D 0 → f X D 0 • Many choices for X, f... D 0 V cb → f γ = arg [ − V ud V * B f cb ] ub V ub f → X D 0 V cd V * 0 D • Aside: loop-level measurements of 𝛿 also possible (see talks on Tuesday morning, WG 5) 6

LHCb-CONF-2018-002 𝛿 • No single dominant mode. • Game instead is to make many individual measurements, combine them. Recent LHCb combination: ("last combination" † B decay D decay Method Ref. Dataset Status since last = April 2017) combination [3] B + → DK + D → h + h � PLB 777 (2018) 16 GLW [14] Run 1 & 2 Minor update B + → DK + D → h + h � PLB 760 (2016) 117 ADS [15] Run 1 As before B + → DK + D → h + π � π + π � GLW/ADS [15] Run 1 As before B + → DK + D → h + h � π 0 GLW/ADS [16] Run 1 As before PRD 91, 112014 (2015) B + → DK + D → K 0 S h + h � GGSZ [17] Run 1 As before JHEP 10 (2014) 097 B + → DK + D → K 0 S h + h � arXiv:1806.01202 GGSZ [18] Run 2 New B + → DK + D → K 0 S K + π � PLB 733C (2014) 36 GLS [19] Run 1 As before B + → D ⇤ K + D → h + h � GLW [14] Run 1 & 2 Minor update B + → DK ⇤ + D → h + h � GLW/ADS [20] Run 1 & 2 Updated results JHEP 11 (2017) 156 B + → DK ⇤ + D → h + π � π + π � GLW/ADS [20] Run 1 & 2 New B + → DK + π + π � D → h + h � GLW/ADS [21] Run 1 As before PRD 92, 112005 (2015) B 0 → DK ⇤ 0 D → K + π � ADS [22] Run 1 As before PRD 90, 112002 (2014) B 0 → DK + π � D → h + h � GLW-Dalitz [23] Run 1 As before PRD 93, 112018 (2016) JHEP 08 (2016) 137 B 0 → DK ⇤ 0 D → K 0 S π + π � GGSZ [24] Run 1 As before s K ± JHEP 03 (2018) 059 B 0 D + s → h + h � π + TD [25] Run 1 Updated results s → D ⌥ B 0 → D ⌥ π ± D + → K + π � π + TD [26] Run 1 New JHEP 06 (2018) 084 • Won't go through them individually, but just to illustrate... � 1 † 7

𝛿 from B + → D K + , D → K S h + h − • GGSZ method, using CLEO-c input for phase variation across Dalitz plot (a.k.a. "model-independent") • LHCb Run2 data (2015+2016): 
 ∘ γ = ( 87 +11 − 12 ) ∘ Combined with prior Run1 result: γ = ( 80 +10 − 9 ) ] ] 4 4 3 3 /c /c LHCb LHCb 2 2 ) [GeV ) [GeV B + → DK + B + → DK − 2 2 + − π π S S 0 0 K K ( ( 2 2 m m 1 1 1 2 3 1 2 3 With infinite apologies to 0 2 4 0 − 2 4 2 + m ( K ) [GeV /c ] m 2 ( K ) [GeV /c ] the London Palladium π π S S 0.2 0.2 + − y y Run 1 LHCb LHCb 2015 & 2016 data Good agreement Combined result 0.1 0.1 between Run1 0 0 and Run2 results. Run 1 − 0.1 0.1 − 2015 & 2016 data Combined result contours hold 68%, 95% CL contours hold 68%, 95% CL 0.2 arXiv:1806.01202 − − 0.2 − 0.2 − 0.1 0 0.1 0.2 0.2 0.1 0 0.1 0.2 − − 8 x x + −

LHCb-CONF-2018-002 LHCb 𝛿 combination 1 Preliminary CL 0 γ = (74 . 0 +5 . 0 LHCb B decays � 5 . 8 ) � s − 0 B decays 1 Preliminary 0.8 + B decays Combination 110 ) 0.6 o ( LHCb γ 100 Preliminary 0.4 90 68.3% 80 0.2 70 95.5% 60 0 0 50 100 150 50 [ ] γ ° 40 2013 2014 2015 2016 2017 2018 2019 • We are used to saying " 𝛿 , the least-well-known angle of the CKM triangle". • ... but uncertainties on 𝛽 around 5°, depending on statistical treatment. Being overtaken by 𝛿 ! ∘ e.g. HFLAV average: α = ( 84.9 +5.1 − 4.5 ) 9

𝛾 from B 0 → J/ 𝜔 K S , B 0 → 𝜔 (2S) K S • Classic time-dependent CPV measurement, golden mode for the B-factories. • This analysis: J/ 𝜔 → e + e − , 𝜔 (2S) → 𝜈 + 𝜈 − with Run1 • ... since J/ 𝜔 → 𝜈 + 𝜈 − done previously, PRL 115, 031601 (2015) S ( t ) ≡ Γ ( B 0 ( t ) → [ cc ] K 0 S ) − Γ ( B 0 ( t ) → [ cc ] K 0 S ) A [ cc ] K 0 Γ ( B 0 ( t ) → [ cc ] K 0 S ) + Γ ( B 0 ( t ) → [ cc ] K 0 S ) (taking ∆Γ =0) S sin( ∆ m t ) − C cos( ∆ m t ) = cosh( ∆Γ t/ 2) + A ∆Γ sinh( ∆Γ t/ 2) ≈ S sin( ∆ m t ) − C cos( ∆ m t ) C: CPV in direct J / ψ K 0 ψ (2 S ) K 0 S S decay (expect 0) Candidates / (2 . 5 MeV / c 2 ) Candidates / (4 . 5 MeV / c 2 ) 10 3 10 3 LHCb LHCb B 0 → J/ ψ K 0 B 0 → ψ (2 S ) K 0 S S B 0 s → J/ ψ K 0 B 0 s → ψ (2 S ) K 0 S S Comb. background Comb. background S=sin2 𝛾 : CPV Run1 10 2 10 2 in interference 10 10 JHEP 11 (2017) 170 5200 5300 5400 5500 5600 5200 5250 5300 5350 5400 5450 m ( J/ ψ K 0 S ) [MeV / c 2 ] m ( ψ (2 S ) K 0 S ) [MeV / c 2 ] 10

𝛾 from B 0 → J/ 𝜔 K S , B 0 → 𝜔 (2S) K S • Flavour tagging needed to measure TD asymmetry • Opposite-side (muon; electron; kaon; charges of all tracks; charm) • Same-side (pion; proton) JHEP 11 (2017) 170 • Event-by-event mistag estimate ( 𝜃 ) 
 Effective tagging efficiencies (%) calibrated with control channels to 
 B 0 → J/ ψ K 0 B 0 → ψ (2 S ) K 0 Tagger S S OS 3 . 60(13) 2 . 46(5) obtain mistag probability ( 𝜕 ) SS 2 . 40(28) 1 . 07(8) • B + → J/ 𝜔 K + for OS, B 0 → J/ 𝜔 K *0 for SS OS + SS 5 . 93(29) 3 . 42(9) • Simultaneous fit, sharing ∆ m, 𝜐 but not CP observables. Signal yield asymmetry Signal yield asymmetry Run1 Run1 LHCb LHCb 0.2 0.2 0 0 -0.2 -0.2 B 0 → J/ ψ K 0 B 0 → ψ (2 S ) K 0 S S 5 10 15 5 10 15 Decay time [ps] Decay time [ps] 11