1 Quark flavour observables in 331 models in the flavour precision era Quark flavour observables in 331 models in the flavour precision era Fulvia De Fazio INFN- Bari Fulvia De Fazio INFN- Bari the flavour precision era a NP scenario to look at flavour observables: 331 model conclusions the flavour precision era a NP scenario to look at flavour observables: 331 model conclusions Based on A.J. Buras, J. Girrbach, M.V. Carlucci,FDF JHEP 1302 (2013) 023 Based on A.J. Buras, J. Girrbach, M.V. Carlucci,FDF JHEP 1302 (2013) 023 EPS HEP 2013 Stockholm

2 Flavour Precision Era (FPE): working assumptions CKM parameters have been determined by means of tree-level decays Non-perturbative parameters are affected by very small uncertainties and fixed CKM parameters have been determined by means of tree-level decays Non-perturbative parameters are affected by very small uncertainties and fixed Two scenarios 1.|Vub| fixed to the exclusive (smaller) value 2. |Vub| fixed to the inclusive (larger) value 1.|Vub| fixed to the exclusive (smaller) value 2. |Vub| fixed to the inclusive (larger) value Using  |V ub | in scenario 1 |V ub | in scenario 2 requires NP enhancing B(B    ) no NP required for B(B    ) reproduces the experimental value for S J/  Ks S J/  Ks higher than experiment suppresses  K w.r.t. experiment  K consistent with experiment  M s,d agree within uncertainties, slightly preferring models predicting a small suppression |V ub | in scenario 1 |V ub | in scenario 2 requires NP enhancing B(B    ) no NP required for B(B    ) reproduces the experimental value for S J/  Ks S J/  Ks higher than experiment suppresses  K w.r.t. experiment  K consistent with experiment  M s,d agree within uncertainties, slightly preferring models predicting a small suppression

3 331 Model: general features Gauge group: SU(3) C X SU(3) L X U(1) X Spontaneously broken to SU(3) C X SU(2) L X U(1) X Spontaneously broken to SU(3) C X U(1) Q Nice features: Nice features: requirement of anomaly cancelation + asympotic freedom of QCD implies number of generations= number of colors two quark generations transform as triplets under SU(3) L, one as an antitriplet this may allow to understand why top mass is so large requirement of anomaly cancelation + asympotic freedom of QCD implies number of generations= number of colors two quark generations transform as triplets under SU(3) L, one as an antitriplet this may allow to understand why top mass is so large Fundamental relation: Key parameter: defines the variant of the model  =1   3 (331 variant) leads to interesting phenomenology new gauge bosons have integer charges Key parameter: defines the variant of the model  =1   3 (331 variant) leads to interesting phenomenology new gauge bosons have integer charges P. Frampton, PRL 69 (92) 2889 F. Pisano & V. Pleitez, PRD 46 (92) 410 P. Frampton, PRL 69 (92) 2889 F. Pisano & V. Pleitez, PRD 46 (92) 410

4 331 Model: new particle content New Gauge Bosons Singly charged Neutral Mediates tree level FCNC in the quark sector (couplings to leptons are universal) Mediates tree level FCNC in the quark sector (couplings to leptons are universal) Extended Higgs sector Three SU(3) L triplets, one sextet New heavy fermions D,S new heavy quarks with Q=-1/3 T new heavy quark with Q=2/3 E l new heavy neutrinos (both L & R) D,S new heavy quarks with Q=-1/3 T new heavy quark with Q=2/3 E l new heavy neutrinos (both L & R)

5 331 Model: quark mixing Quark mass eigenstates defined upon rotation through two unitary matrices U L & V L In contrast to SM only one of them can be traded for VCKM, the other one enters in Z’ couplings to quarks

6 331 Model: Z’ couplings to quarks The case of B d,B s,K systems depend only on four new parameters: stringent correlations between observables expected B d system  only on s 13 and  1 B s system  only on s 23 and  2 K system  on s 13, s 23 and  2 -  1 FCNC involve only left-handed quarks FCNC involve only left-handed quarks We fix 1  M Z’  3 TeV

7 Oases in the parameter space from  F=2 observables Oases in the parameter space from  F=2 observables Imposing the experimental constraints: One finds the allowed oases for the parameters s 13, s 23 >0 & 0<  23 <2  0<  13 <2  Example of NP contribution: The case of B d mixing Example of NP contribution: The case of B d mixing  M s Mass difference in the B̅ s –B s system S  CP asymmetry in B s  J/    M d Mass difference in the B̅ d –B d system S  Ks CP asymmetry in B d  J/  K s

8 Oases in the parameter space from  F=2 observables A1 A3 A2 A4 A1 B1 B3 B4 B2 Small oases in B s case can be eliminated by data on the mixing phase and on  K Other observables should be considered to find the optimal oasis Blue regions  S  Red ones   M s Blue regions  S  Red ones   M s Blue regions  S  Ks Red ones   M d Blue regions  S  Ks Red ones   M d

9 The decay B s   +  - SM effective hamiltonian  one master function Y 0 (x t ) Z’ contribution modifies this function to: a new phase independent on the decaying meson and on the lepton flavour Theoretically clean observable: the new phase involved LHCb SM phase of the function S entering in the box diagram vanishes in SM phase of the function S entering in the box diagram vanishes in SM Analogous observables can be considered in the B d case

10 Searching for the optimal oasis A1,B3 A1,B1 A3,B3 A3,B1 B1B3 From both B s and B d systems Observables in B d system

11 Searching for the optimal oasis A3 A1 Triple correlation in B s system Test of the model: Once the sign of S s  +  - is determined the model uniquely predicts the correlation between S  and B(Bs   +  -)

12 Correlations with  K It is possible to reproduce  M s,  M d and find  K consistent with experiment It is possible to reproduce  M s,  M d and find  K consistent with experiment

13 Conclusions Dominant NP contributions in 331 model come from tree-level Z’ exchanges The model can remove the tensions between SM and experiment when 1 TeV  M Z’  3 TeV The parameters of the model reproduce  F=2 observables in restricted oases The optimal oasis can be selected looking at other obervables and correlations among them A triple correlation in the Bs system has been identified as a valuable test of the model Increasing the mass of Z’ it is still possible to find oases where the  F=2 constraints are OK however some observables receive very small NP contributions (rare decays) Dominant NP contributions in 331 model come from tree-level Z’ exchanges The model can remove the tensions between SM and experiment when 1 TeV  M Z’  3 TeV The parameters of the model reproduce  F=2 observables in restricted oases The optimal oasis can be selected looking at other obervables and correlations among them A triple correlation in the Bs system has been identified as a valuable test of the model Increasing the mass of Z’ it is still possible to find oases where the  F=2 constraints are OK however some observables receive very small NP contributions (rare decays)