Download presentation
Presentation is loading. Please wait.
Published byKarin Lucas Modified over 8 years ago
1
Probing Flavor Structure in Supersymmetric Theories Shaaban Khalil Ain Shams University, Cairo, Egypt
2
I. Introduction The recent results on the mixing-induced asymmetries of B → φ K and B → ή K are: Belle BaBar These observations are considered as signals to new physics. →→ The direct CP violation in B 0 → K - π + and B - → K - π 0 :
3
To accommodate the CP asymmetries of B decays, SUSY models with flavor non-universal soft breaking terms are favored. The squark mixings are classified as i) LL and RR mixings given by (δ u,d LL ) ij and (δ u,d RR ) ij. ii) LR and RL mixings given by (δ u,d LR ) ij and (δ u,d RL ) ij. Constraints are more stringent on the LR (RL) mass insertions than the LL (RR) mass insertions. MIs between 1st & 2nd generations are severely constrained more than MIs between 1st or 2nd & 3rd generations. This gives the hope that SUSY contributions to the B-system.
4
II. Squark Mixing: LL versus LR The EDM constraints severely restrict the LL and RR mass insertions: (δ d LR ) 22eff ≈ (δ d LR ) 22 +(δ d LL ) 23 (δ d LR ) 33 (δ d RR ) 32 ≈ 10 -2 (δ d LL ) 23 (δ d RR ) 32 (for neg. (δ d LR ) 22 ). ≈ 10 -2 (δ d LL ) 23 (δ d RR ) 32 (for neg. (δ d LR ) 22 ). From Hg EDM: Im(δ d LR ) 22 < 5.6 x 10 -6. The SUSY contributions to the decay amplitudes B → φ K and ή K: R φ = -0.14 e -i0.1 (δ d LL ) 23 -127 e -i0.08 (δ d LR ) 23 +(L ↔ R), R ή = -0.07 e -i0.24 (δ d LL ) 23 - 64 (δ d LR ) 23 - (L ↔ R).
5
The CP asymmetries S φK and S ήK can not be accommodated simultaneously by dominant (δ d LL ) 23 or (δ d RR ) 23. SφK and SήK Combining the effects of LL and RR MIs, we can fit the exp. data of SφK and SήK. However, the Hg EDM exceeds with many order of magnitudes its exp. Bound.
6
Thus, SUSY models with dominant LR and RL may be the most favorite scenario. However, it is difficult to arrange for (δ d LR ) 23 ≈ O(10 -2 ) whilst (δ d LR ) 12 remains small: From ΔM K and έ/ε: Re (δ d LR ) 12 < O(10 -4 ) & Im (δ d LR ) 12 < O(10 -5 ).
7
The MI (δ d LR ) ij are given by (δ d LR ) ij ≈ [V d+ L. (Y d A d ). V d R ] ij. The factorizable A-term is an example of a specific texture to satisfy this hierarchy between (δ d LR ) 12 and (δ d LR ) 23. With intermediate/large tanβ, an effective (δ d LR ) 23 can be obtained: (δ d LR ) 23 eff = (δ d LR ) 23 + (δ d LL ) 23 (δ d LR ) 33 For negligible (δ d LR ) 23, we find
8
Thus if (δ d LL ) 23 ≈ 10 -2, we get (δ d LR ) 23eff ≈ O(10 -2 – 10 -3 ). These contributions are considered as LL (or RR). The main effect is still due to the Wilson coefficient C 8g of the chromomagnetic operator. Although (δ d LL ) 23 ≈ 10 -2 is not enough to explain the CP asymmetries of B-decays. Still it can induce an effective LR mixing that accounts for these results.
9
Suggested supersymmetric flavor model As an example, we consider the following SUSY model: M 1 =M 2 =M 3 = M 1/2 A u = A d = A 0 M U 2 = M D 2 = m 0 2 m H1 2 = m H2 2 = m 0 2 The masses of the squark doublets are given by tan β=15, m 0 =M 1/2 =A 0 =250 → a ≤5
10
The Yukawa textures play an important rule in the CP and flavour supersymmetric results. Y u= 1/v sinβ diag(m u,m c,m t ) Y d =1/vsinβ V + CKM. diag(m d,m s,m b ). V CKM Although, it is hierarchical texture, it lads to a good mixing between the second and third generations. The LL down MIs are given by: (δ d LL ) ij =1/m q 2 [V L d+ (M d ) 2 LL V d L ] ij With a=5 → (δ d LL ) 23 ~ 0.08 e 0.4 I Thus, one gets: (δ d LR ) 23eff ~ O (10 -2 -10 -3 ). The corresponding single LR MI is negligible due to the degeneracy of the A-terms.
11
Contribution to S φK and S ήK Gluino exchanges give the dominant contribution to the CP asymmetries: S φK and S ήK. S ήK 1 σ constraints on S ήK leads to a lower bound on a: a ≥ 3. SφK and SήK With a large a, it is quite possible to account simultaneously for the experimental results SφK and SήK.
12
Contribution to B→ K π The direct CP asymmetries of B→ K π are given by: A CP K - π + ~ 2 r T sin δ T sin(θ P + γ) + 2r EW C sin δ EW C sin(θ P -θ EW C ), A CP K - π 0 ~ 2 r T sin δ T sin(θ P + γ) - 2 r EW sin δ EW sin(θ P -θ EW ). The parameters θ P, θ EW C, θ EW and δ T, δ EW, δ EW C are the CP violating and CP conserving phases respectively. The parameter r T measures the relative size of the tree and QCD penguin contributions. The parameter, r EW, r EW C measure the relative size of the electroweak and QCD contributions.
13
P e θ P = P sm (1+k e θ’ P ), r EW e δ EW e θ EW = r EW sm e δ EW (1+ l e θ’ EW ),r EW C e δ EW C e θ EW C =(r EW C ) sm e δ EW C (1+m e θ’ EW C ), r T e δ T =(r T e δ T ) sm /|1+ k e θ’ P | k,l,m are given by (m g = m q =500, M 2 =200, μ =400): k e θ’ P = -0.0019 tan β (δ u LL ) 32 - 35.0 (δ d LR ) 23 +0.061 (δ u LR ) 32 l e θ’ EW = 0.0528 tan β (δ u LL ) 32 - 2.78 (δ d LR ) 23 +1.11(δ u LR ) 32 m e θ’ EW C =0.134 tan β (δ u LL ) 32 + 26.4 (δ d LR ) 23 +1.62 (δ u LR ) 32. a=5, m 0 =M 1/2 =A 0 =250 GeV → (δd LR ) 23 ~ 0.006xe -2.7i. Thus: K~0.2, l~ 0.009, m ~0.16 → r EW ~ 0.13, r c EW ~ 0.012, r T ~ 0.16 → A CP K - π + ~ -0.113 and A CP K - π 0 < A CP K - π +
14
Conclusions We studied the possibility of probing SUSY flavor structure using K, B CP asymmetries constraints & EDM. One possibility: large LR and/or RL sector. Second possibility: large LL combined with a very small RR and also intermediate or large tan β. Large LR requires a specific pattern for A terms. Large LL seems quite natural and can be obtained by a non- universality between the squark masses. As an example, a SUSY model with a non-universal left squark masses is considered. one gets effective (δ d LR ) 23 that leads to a significant SUSY contributions to the CP asymmetries of B decays.
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.