Heavy flavor physics at CMS and D0 Ivan Heredia de la Cruz - PowerPoint PPT Presentation

Heavy flavor physics at CMS and D0 Ivan Heredia de la Cruz CINVESTAV / CONACyT, Mexico RedFAE Workshop 2016 Nov 10 th 2016, Pachuca, Hgo.

Outline • Introduction • D0 & CMS detectors & the B physics program • CP-Violation in B 0 s . • B c meson decays. • B hadron properties. • Rare decays as new physics probes. • Exotic hadrons. • Summary and outlook Ivan Heredia RED-FAE 2016 2

Introduction LHC: pp collisions @ 7-8 (Run I) & 13 TeV (Run II) ⇒ large B • hadron production. D0/Tevatron shut down in 2012. B/QCD program still continues. • Precise measurements of B hadrons properties help to improve • or constrain QCD models, and could provide signs of new physics or constrain BSM models. CMS is able to provide several measurements of B hadrons • properties that are competitive with results from other experiments, such as in: o B mesons and baryons: masses, lifetimes, BRs, polarizations, etc. o CP-Violation in B mesons. o B rare decays: branching ratios, angular parameters. o Decays to exotic hadrons. B properties @ CMS -- Ivan Heredia 3

D0 and CMS detectors Muon Scintillation Scintillation Muon N N S S CMS B Physics program ⇿ Excellent µ ID + Forward Mini- Forward Mini- Counters Counters Muon Toroid Muon Toroid Drift Tubes Drift Tubes Track and vertex reconstruction PDTs PDTs Shielding Shielding CC CC EC EC EC EC Platform Platform Tracking System: Silicon, Fiber Tracker, Tracking System : Silicon, Fiber Tracker, Solenoid, Central & Forward Preshowers Solenoid, Central & Forward Preshowers Fiber Tracker/Preshower Fiber Tracker/ Preshower VLPC Readout System VLPC Readout System B properties @ CMS -- Ivan Heredia 4

B Physics Triggers (CMS/Run I) B properties @ CMS -- Ivan Heredia 5

B Physics Triggers (CMS/Run II) CMS-DP-2015-055 B properties @ CMS -- Ivan Heredia 6

B Physics Triggers (CMS/Run II) B 0 s ⇾ J/ψ φ (f 0 ) B c + ⇾ J/ψ n π ± Λ b ⇾ J/ψ Λ (*) B ⇾ K (*) µ + µ - B 0 (s) ⇾ µ + µ - CMS-DP-2015-055 B properties @ CMS -- Ivan Heredia 7

CPV in 
 B 0 s ⇾ J/ψ φ CPV phase φ s from interference btw direct and through mixing decays. • Non-standard particles in loops could change the SM prediction of φ s . • • 3+1 angular-time analysis to disentangle CP-odd/even contributions. CMS, PLB 757 (2016) 97–120 B 0 s ⇾ J/ψ φ: ATLAS, CDF, CMS, D0. B 0 s ⇾ J/ψKK: LHCb. Κ − where β s = arg ( − V ts V ∗ tb / V cs V ∗ cb ); B 0 s ⇾ J/ψππ: LHCb. B 0 s ⇾ J/ψ D s D s : LHCb. [http://www.slac.stanford.edu/xorg/hfag/osc/summer_2015/ HFAG_phis_inputs.pdf] B properties @ CMS -- Ivan Heredia 8

B 0 s ⇾ J/ψ f 0 (980) CMS: CPV analysis is simplified using B 0 s ⇾ J/ ψ f 0 ( π + π - ) wrt B 0 s ⇾ • J/ ψφ (K + K - ) decays. It is also a pure CP-odd eigenstate. o Region around the f 0 (980) can be used to measure τ (B 0 s ) CP-odd and φ s . B properties @ CMS -- Ivan Heredia 9

ℬ (B 0 s ⇾ ψf 0 (ππ))/ ℬ (B 0 s ⇾ ψφ(KK)) CMS, PLB 756 (2016) 84–112 Experiments measure R in diff. M( π + π - ) ranges. • LHCb [PRD 86, 052006 (2012)]* LHCb [PLB 698 (2011) 115–122] * CDF (PRD 84, R f0/φ ≈ 0.2 [Stone & Zhang, PRD 79, 074024 (2009)]. 052012 (2011)) D0 [PRD 85, 400 -1 (a) Signal -1 (b) 011103(R) Signal 350 3 Cross-feed 10 (2012)] Cross-feed Combinatorial Combinatorial 300 + B contamination m) + ) B contamination 2 Events / (20 MeV/c µ Total 250 Events / (100 Total 2 10 -1 DØ, 10.4 fb Signal 140 200 Background 120 Total ) 2 Events / ( 20 MeV/c 100 Next important • 150 80 60 40 10 property is Bs CP- 100 20 0 0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 - 2 Invariant Mass + [GeV/c ] π π 50 odd lifetime. 0 1 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 0.05 0.1 0.15 0.2 0.25 0.3 • At DØ it was 0 - - 2 + + Invariant Mass B ( ) [GeV/c ] π π s Proper Transverse Decay Length [cm] measured: τ ð B 0 D0, PRD 94, 012001 (2016) s Þ ¼ 1 . 70 � 0 . 14 ð stat Þ � 0 . 05 ð syst Þ ps ; B properties @ CMS -- Ivan Heredia 10

+ ⇾ J/ψ n π ± B c Unique lab to study HQ dynamics. • b and c quarks competing in decay. • Measurements in a kin. region • complementary to LHCb. LHCb, p T > 4 GeV, 2.5 < | η | < 4.5, • measures R c/u = 0.68 ± 0.10 ± 0.03 ± 0.05 [PRL 109 (2012) 232001]. Difference + ) � < � p T (B + ) � in expected since � p T (B c central region. LHCb measures R B c = 2.41 ± 0.30 ± 0.33 • [ PRL 108 (2012) 251802 ]. First +* Predictions of R B c , assuming B c ⇾ J/ ψ W • confirmation +* ⇾ n π + , btw = 1.5 – 2.3 [ PRD 81 and W (2010) 014005, PRD 81 (2010) 014015 ]. CMS, JHEP 01 (2015) 063 B properties @ CMS -- Ivan Heredia 11

B hadron lifetimes J/ ψ c c ¯ B-lifetimes determine importance of • b non-spectator contributions. s Λ b u Λ CMS about to publish precise • u d d measurements: X.X PDG = c τ B + 491.6 ± 0.8 (stat) ± 1.8 (syst) µ m 491.1 ± 1.2 Not approved yet 455.4 ± 1.5 453.8 ± 1.6 (stat) ± 2.1 (syst) µ m ( in J / ψ K ∗ 0 ) = c τ B 0 455.4 ± 1.5 455.4 ± 2.7 (stat) ± 2.6 (syst) µ m ( in J / ψ K 0 c τ B 0 = S ) 509.0 ± 12.0 504.3 ± 10.3 (stat) ± 3.3 (syst) µ m ( in J / ψπ + π − ) c τ B 0 = 434.9 ± 3.8 s = 443.6 ± 2.0 (stat) ± 2.2 (syst) µ m ( in J / ψφ ) c τ B 0 443.4 ± 3.6 ± s = c τ Λ 0 442.1 ± 8.1 (stat) ± 2.5 (syst) µ m 434.9 ± 3.8 b 152.0 ± 2.7 c τ B + c = 163.9 ± 7.4(stat) ± 3.0 (syst) µ m D0: 2nd. most precise -1 -1 • D0 Epoch IV, 2.0 fb D0 Epoch IV, 2.0 fb , , 2 2 /dof = 1.18 /dof = 1.18 χ χ 1 þ ð ΔΓ s = 2 Γ s Þ 2 3 3 s Þ ¼ 1 10 10 Data Data m m τ fs ð B 0 1 − ð ΔΓ s = 2 Γ s Þ 2 ; µ µ Total fit projection Total fit projection Candidates per 20 Candidates per 20 Signal fit projection Signal fit projection τ (B s ) in flavor-specific 2 2 Γ s 10 10 Background fit projection Background fit projection - μ + ν X. 10 10 Þ ¼ 443 . 3 � 2 . 9 ð stat Þ � 6 . 3 ð syst Þ μ m, B s ⇾ D s consistent with the current world average of vs. W.A. 453.0 ± 4.2 µm. 1 1 D0, PRL 114, 062001 (2015) data data 4 4 2 2 B properties @ CMS -- Ivan Heredia 12 0 0 (data-fit)/ (data-fit)/ 2 2 − − 4 4 − − 0.1 0.1 0.05 0.05 0 0 0.05 0.05 0.1 0.1 0.15 0.15 0.2 0.2 0.25 0.25 0.3 0.3 0.35 0.35 0.4 0.4 − − − − Pseudo Proper Decay Length (cm) Pseudo Proper Decay Length (cm)

B baryons Apart from lifetime, • CMS, PLB 714, (hadro-)production measurements. 136 (2012) HQ-Drag 1.5 fm 1.8 (F) 0.5 D0 σ 1.6 Signal (B)/ 0.4 CMS Background σ 1.4 R= 0.3 HQ Drag LHCb 1.2 HQ Recomb 0.2 y (Tevatron) = 7.64 1 y (LHC) = 8.92 0.1 A 0.8 0 D0, PRD 91, 0.6 -0.1 072008 (2015) 0.4 -0.2 -1 D0 Run II, 10.4 fb R ¼ 0 . 92 � 0 . 12 ð stat Þ � 0 . 04 ð syst Þ , -0.3 0.2 the value of R . . stat 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 0 0 1 2 3 4 5 6 7 8 9 10 | y | y(beam) - y( Λ b) B properties @ CMS -- Ivan Heredia 13

B baryons (II) CMS PAS BPH-15-002 p ˆ z 1 In CMS we measured the Lb polarization θ p • n ˆ φ p Λ µ + θ Λ ˆ y 1 ˆ x 1 J/ ψ and decay parameters of Λ b ⇾ J/ ψ Λ . ˆ y 2 θ µ π Λ b n ˆ ˆ z 2 φ µ ˆ µ − x 2 Z π Z π d Γ d Γ p p ( θ Λ , θ p , θ µ ) = � � θ Λ , θ p , θ µ , φ p , φ µ d φ p d φ µ d Ω 3 d Ω 5 − π − π _1 _1 8 19.7 fb -1 (8TeV) + 5.2 fb -1 (7TeV) 19.7 fb (8TeV) + 5.2 fb (7TeV) 350 Events / ( 0.002 GeV ) Events / ( 0.2 ) ∑ � | T ++ | 2 , | T + 0 | 2 , | T − 0 | 2 , | T −− | 2 � c i ( P , α Λ ) f i � � η i θ Λ , θ p , θ µ . CMS 800 CMS ∼ 300 Preliminary Preliminary 700 i = 1 data 250 data fit 600 fit signal model signal model bkg model bkg model 500 200 i η i c i f i 400 150 300 1 1 1 1 100 200 50 100 2 α 2 α Λ cos θ p 0 0 5.58 5.6 5.62 5.64 5.66 − 1 − 0.8 − 0.6 − 0.4 − 0.2 0 0.2 0.4 0.6 0.8 1 3 − α 1 P cos θ Λ m(J/ )[GeV] cos θ ψ Λ p _1 _1 -1 -1 19.7 fb (8TeV) + 5.2 fb (7TeV) 19.7 fb (8TeV) + 5.2 fb (7TeV) − ( 1 + 2 γ 0 ) /3 4 α Λ P cos θ Λ cos θ p Events / ( 0.2 ) Events / ( 0.2 ) 450 500 3 cos 2 θ µ − 1 � � 5 γ 0 /2 1 /2 400 400 350 3 cos 2 θ µ − 1 � � 6 ( 3 α 1 − α 2 ) /4 cos θ p /2 α Λ 300 300 250 3 cos 2 θ µ − 1 data � � 7 ( α 1 − 3 α 2 ) /4 P cos θ Λ /2 CMS CMS 200 data fit 200 fit signal model Preliminary Preliminary 150 signal model bkg model 3 cos 2 θ µ − 1 bkg model � � ( γ 0 − 4 ) /6 8 α Λ P cos θ Λ cos θ p /2 100 100 50 0 0 1 0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8 1 1 0.8 0.6 0.4 0.2 0 0.2 0.4 0.6 0.8 1 − − − − − − − − − − cos cos P = 0.00 ± 0.06 ( stat ) ± 0.02 ( syst ) , θ θ µ Λ | T − 0 | 2 = 0.51 ± 0.03 ( stat ) ± 0.02 ( syst ) , α 1 = 0.12 ± 0.13 ( stat ) ± 0.06 ( syst ) , | T + 0 | 2 = − 0.02 ± 0.03 ( stat ) ± 0.02 ( syst ) , α 2 = − 0.93 ± 0.04 ( stat ) ± 0.04 ( syst ) , | T −− | 2 = 0.46 ± 0.02 ( stat ) ± 0.02 ( syst ) , γ 0 = − 0.46 ± 0.07 ( stat ) ± 0.04 ( syst ) , | T ++ | 2 = 0.05 ± 0.04 ( stat ) ± 0.02 ( syst ) . B properties @ CMS -- Ivan Heredia 14