Flavor Physics: Past, Present, Future Indirect Searches for NP at the Time of LHC GGI, Florence, Italy, 22-24 March 2010 Yossi Nir ( Weizmann Institute of Science ) Flavor Physics 1/37
Thanks to my collaborators: Kfir Blum, Jonathan Feng, Sky French, Oram Gedalia, Eilam Gross, Daniel Grossman, Yuval Grossman, Gudrun Hiller, Yonit Hochberg, Gino Isidori, David Kirkby, Christopher Lester, Zoltan Ligeti, Gilad Perez, Yael Shadmi, Jesse Thaler, Ofer Vitells, Tomer Volansky, Jure Zupan Flavor Physics 2/37
Flavor Physics Plan of Talk 1. Introduction 2. Past: What have we learned? Lessons from the B-factories 3. Present: Open questions • The NP flavor puzzle • The SM flavor puzzle 4. Future: What will we learn? Flavor@LHC Flavor Physics 3/37
Flavor Physics Introduction Flavor Physics 4/37
Introduction Why is flavor physics interesting? • Flavor physics is sensitive to new physics at Λ NP ≫ E experiment FCNC suppressed within the SM by α n W , | V ij | , m f • The Standard Model flavor puzzle: Why are the flavor parameters small and hierarchical? (Why) are the neutrino flavor parameters different? • The New Physics flavor puzzle: If there is NP at the TeV scale, why are FCNC so small? The solution = ⇒ Clues for the subtle structure of the NP Flavor Physics 5/37
Introduction A brief history of FV • Γ( K → µµ ) ≪ Γ( K → µν ) = ⇒ Charm [GIM, 1970] • ∆ m K = ⇒ m c ∼ 1 . 5 GeV [Gaillard-Lee, 1974] • ε K � = 0 = ⇒ Third generation [KM, 1973] • ∆ m B = ⇒ m t ≫ m W [Various, 1986] Flavor Physics 6/37
Introduction Flavor@GeV = ⇒ NP@TeV A recent example [Blum et al, PRL 102, 211802 (2009)] ∆ m K = (7 . 01 ± 0 . 01) × 10 − 15 ; ǫ K = (2 . 23 ± 0 . 01) × 10 − 3 • m K ∆ m D m D = (8 . 6 ± 2 . 1) × 10 − 15 ; A Γ = (1 . 2 ± 2 . 5) × 10 − 3 • � � 2 1 • Consider Q Li ( X Q ) ij γ µ Q Lj TeV 2 X Q = V † Y u = V † λ u , • Take Y d = λ d , d diag( λ 1 , λ 2 ) V d • K + D = ⇒ Degeneracy: λ 2 − λ 1 ≤ 0 . 004 − 0 . 0005 m ˜ Q 2 − m ˜ Q 1 – Supersymmetry: Q 1 ≤ 0 . 27 − 0 . 034 m ˜ Q 2 + m ˜ � TeV < 0 . 06 − 0 . 02. – RS-I: m KK f Q 2 ∼ Flavor Physics 7/37
Introduction Why is CPV interesting? • Within the SM, a single CP violating parameter η : In addition, QCD = CP invariant ( θ QCD irrelevant) Strong predictive power (correlations + zeros) Excellent tests of the flavor sector • η cannot explain the baryon asymmetry – a puzzle: There must exist new sources of CPV Electroweak baryogenesis? (Testable at the LHC) Leptogenesis? (Window to Λ seesaw ) Flavor Physics 8/37
Introduction A brief history of CPV • 1964 − 2000 • | ε | = (2 . 284 ± 0 . 014) × 10 − 3 ; R e ( ε ′ /ε ) = (1 . 67 ± 0 . 26) × 10 − 3 Flavor Physics 9/37
Introduction A brief history of CPV • 1964 − 2000 • | ε | = (2 . 284 ± 0 . 014) × 10 − 3 ; R e ( ε ′ /ε ) = (1 . 67 ± 0 . 26) × 10 − 3 • 2000 − 2010 • S ψK S = +0 . 67 ± 0 . 02 • S η ′ K S = +0 . 59 ± 0 . 07, S π 0 K S = +0 . 57 ± 0 . 17, S f 0 K S = +0 . 60 ± 0 . 12 • S K + K − K S = − 0 . 82 ± 0 . 07, S K S K S K S = +0 . 74 ± 0 . 17 • S π + π − = − 0 . 65 ± 0 . 07, C π + π − = − 0 . 38 ± 0 . 06 • S ψπ 0 = − 0 . 93 ± 0 . 15, S DD = − 0 . 89 ± 0 . 26, S D ∗ D ∗ = − 0 . 77 ± 0 . 14 • A K ∓ ρ 0 = +0 . 37 ± 0 . 11, A ηK ∓ = − 0 . 37 ± 0 . 09, A f 2 K ∓ = − 0 . 68 ± 0 . 20 • A K ∓ π ± = − 0 . 098 ± 0 . 012, A ηK ∗ 0 = +0 . 19 ± 0 . 05 • . . . Flavor Physics 9/37
Flavor Physics What have we learned? Flavor Physics 10/37
What have we learned? Testing CKM – Take I • Assume: CKM matrix is the only source of FV and CPV • λ known from K → πℓν A known from b → cℓν • Many observables are f ( ρ, η ): ⇒ ∝ | V ub /V cb | 2 ∝ ρ 2 + η 2 – b → uℓν = ⇒ ∝ | V td /V ts | 2 ∝ (1 − ρ ) 2 + η 2 – ∆ m B d / ∆ m B s = 2 η (1 − ρ ) – S ψK S = ⇒ (1 − ρ ) 2 + η 2 – S ρρ ( α ) – A DK ( γ ) – ǫ K Flavor Physics 11/37
What have we learned? The B-factories Plot 1.5 excluded at CL > 0.95 excluded area has CL > 0.95 γ 1.0 ∆ m & ∆ m s d sin 2 β 0.5 m ∆ d ε α K γ β η 0.0 α V ub α -0.5 ε -1.0 K CKM γ sol. w/ cos 2 < 0 f i t t e r β (excl. at CL > 0.95) ICHEP 08 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 ρ CKMFitter Very likely, the CKM mechanism dominates FV and CPV Flavor Physics 12/37
What have we learned? Testing CKM - take II • Assume: New Physics in leading tree decays - negligible • Allow arbitrary new physics in loop processes 0 mixing • Use only tree decays and B 0 − B • Define h d e 2 iσ d = A NP ( B 0 → B ) A SM ( B 0 → B ) • Use | V ub /V cb | , A DK , S ψK , S ρρ , ∆ m B d , A d SL • Fit to η , ρ , h d , σ d • Find whether η = 0 is allowed If not = ⇒ The KM mechanism is at work • Find whether h d ≫ 1 is allowed If not = ⇒ The KM mechanism is dominant Flavor Physics 13/37
What have we learned? η � = 0 ? 1-CL 1.5 1.5 CKM 0.9 f i t t e r FPCP 2007 1 1 0.8 0.7 0.5 0.5 0.6 α γ β 0.5 η η 0 0 0.4 -0.5 -0.5 0.3 0.2 -1 -1 0.1 -1.5 -1.5 0 -1 -1 -0.5 -0.5 0 0 0.5 0.5 1 1 1.5 1.5 2 2 ρ ρ • The KM mechanism is at work Flavor Physics 14/37
What have we learned? h d ≪ 1 ? 1-CL 3 3 CKM 0.9 f i t t e r FPCP 2007 0.8 2.5 2.5 0.7 2 2 0.6 d d 0.5 σ σ 1.5 1.5 0.4 1 1 0.3 0.2 0.5 0.5 0.1 0 0 0 0 0 0.5 0.5 1 1 1.5 1.5 2 2 2.5 2.5 3 3 h h d d • The KM mechanism dominates CP violation • The CKM mechanism is a major player in flavor violation Flavor Physics 15/37
What have we learned? Intermediate summary • The KM phase is different from zero (SM violates CP) • The KM mechanism is the dominant source of the CP violation observed in meson decays • Complete alternatives to the KM mechanism are excluded (Superweak, Approximate CP) • No evidence for corrections to CKM • NP contributions to the observed FCNC are at most comparable to the CKM contributions • NP contributions are very small in s → d , c → u , b → d , b → s Flavor Physics 16/37
Flavor Physics The NP Flavor Puzzle Flavor Physics 17/37
The NP flavor puzzle The SM = Low energy effective theory ⇒ Λ Planck ∼ 10 19 GeV 1. Gravity = ⇒ Λ Seesaw ≤ 10 15 GeV 2. m ν � = 0 = 3. m 2 H -fine tuning; Dark matter = ⇒ Λ NP ∼ TeV ⇓ • The SM = Low energy effective theory • Must write non-renormalizable terms suppressed by Λ d − 4 NP y ν ij • L d =5 = Λ seesaw L i L j φφ • L d =6 contains many flavor changing operators Flavor Physics 18/37
The NP flavor puzzle New Physics • The effects of new physics at a high energy scale Λ NP can be presented as higher dimension operators • For example, we expect the following dimension-six operators: NP ( d L γ µ s L ) 2 + z cu NP ( c L γ µ u L ) 2 + z bd NP ( d L γ µ b L ) 2 + z sd z bs NP ( s L γ µ b L ) 2 Λ 2 Λ 2 Λ 2 Λ 2 • New contribution to neutral meson mixing, e.g. m B ∼ f 2 3 × | z bd | ∆ m B B Λ 2 NP • Generic flavor structure ≡ z ij ∼ 1 or, perhaps, loop − factor Flavor Physics 19/37
The NP flavor puzzle Some data 7 . 0 × 10 − 15 ∆ m K /m K 8 . 7 × 10 − 15 ∆ m D /m D 6 . 3 × 10 − 14 ∆ m B /m B 2 . 1 × 10 − 12 ∆ m B s /m B s 2 . 3 × 10 − 3 ǫ K A Γ /y CP ≤ 0 . 2 S ψK S 0 . 67 ± 0 . 02 S ψφ ≤ 1 Flavor Physics 20/37
The NP flavor puzzle High Scale? 10 − 4 > √ • For z ij ∼ 1 (and I m ( z ij ) ∼ 1), Λ NP ∼ ∆ m/m TeV Λ CPC Λ CPV > > Mixing ∼ ∼ NP NP K − K 1000 TeV 20000 TeV D − D 1000 TeV 3000 TeV B − B 400 TeV 800 TeV B s − B s 70 TeV 70 TeV Flavor Physics 21/37
The NP flavor puzzle High Scale? 10 − 4 > √ • For z ij ∼ 1 (and I m ( z ij ) ∼ 1), Λ NP ∼ ∆ m/m TeV Λ CPC Λ CPV > > Mixing ∼ ∼ NP NP K − K 1000 TeV 20000 TeV D − D 1000 TeV 3000 TeV B − B 400 TeV 800 TeV B s − B s 70 TeV 70 TeV Did we misinterpret the Higgs fine tuning problem? Did we misinterpret the dark matter puzzle? Flavor Physics 21/37
The NP flavor puzzle Small (hierachical?) flavor parameters? < 10 8 (∆ m ij /m ) • For Λ NP ∼ 1 TeV , z ij ∼ < < Mixing | z ij | ∼ I m ( z ij ) ∼ 8 × 10 − 7 6 × 10 − 9 K − K 5 × 10 − 7 1 × 10 − 7 D − D 5 × 10 − 6 1 × 10 − 6 B − B 2 × 10 − 4 2 × 10 − 4 B s − B s Flavor Physics 22/37
The NP flavor puzzle Small (hierachical?) flavor parameters? < 10 8 (∆ m ij /m ) • For Λ NP ∼ 1 TeV , z ij ∼ < < Mixing | z ij | ∼ I m ( z ij ) ∼ 8 × 10 − 7 6 × 10 − 9 K − K 5 × 10 − 7 1 × 10 − 7 D − D 5 × 10 − 6 1 × 10 − 6 B − B 2 × 10 − 4 2 × 10 − 4 B s − B s The flavor structure of NP@TeV must be highly non-generic How? Why? = The NP flavor puzzle Flavor Physics 22/37
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