“fourth generation”: from b factories, to colliders and to the cosmos amarjit soni het, bnl...
DESCRIPTION
Motivation Seen 3; why not 4? Enhanced prospects for DEWSB Enhanced prospects for baryogenesis NFC: built in Cannot be just simple SM4: DM link? Readily accounts for B-CP-anomalies 4G2HDM:Bar-Shalom,Nandi,AS’11 IMPLICATIONS EPS'11, Grenoble A. Soni3TRANSCRIPT
“Fourth Generation”: From B Factories, to Colliders and to
the CosmosAmarjit SoniHET, BNL
EPS’11, Grenoble
EPS'11, Grenoble A. Soni 1
Outline
• Motivation• Hints• Implications for the High Intensity
Frontier• Implications for High Energy Frontier• DM possibilities• Summary & Outlook
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Motivation• Seen 3; why not 4?• Enhanced prospects for DEWSB
• Enhanced prospects for baryogenesis
• NFC: built in• Cannot be just simple SM4: DM link?
• Readily accounts for B-CP-anomalies
4G2HDM:Bar-Shalom,Nandi,AS’11IMPLICATIONS
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CAN NOT BE JUST SM4• Neutrino4 must be very heavy• 4G fermions very likely play important
role IN DEWSB -> likely a strongly coupled 4G
• Generic models [see Bar-Shalom, Nandi and A. S ‘11] suggest significant differences in search strategies from SM4
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HINTS
Based on Enrico Lunghi+AS0707.0212; 0803.4340; 0903.5059;0912.0002
1010.6069
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Delta K pi
•
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Important to Examine only DeltaF=2 observables:Leave out Vub sin 2 β = 0.87+-.09{Lunghi+AS,hep-ph/08034340}
( became possible only due significantly reduced error in BK)
Gamiz et al;Becirevic;
Tantalo.
Antonio et al(RBC-UKQCD)
0702042
2.1-2.7 σ- deviation from the directly measured values of sin 2 β requires careful follow-up
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Predict sin2β & fBEPS'11, Grenoble A. Soni 9
Inputs: S(Bd->ψK), εK, ΔMs, ΔMd, Vcb, γ
Predict: Br(B->τν) & fB
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PHENO'11; 5/9/11 A. Soni 14
Mawhinney, plenary LAT’11
HUGE STRIDES IN LATTICE
CALCULATION OF BK!
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In a nutshell• Bulk of NP effects is in Bd,Bs mixing &
in sin2β {CONFIRMS our 2008 findings}• Bulk of NP NOT in B->τν, or in εK
[Presence of subdominant effects therein certainly possible]
• Many, many checks for robustness of the conclusions
• VERY DIFFICULT to RECONCILE RESULTS with CKM-SM
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Overall perspective• Sin 2 β from “penguin” dominated modes (ΦKS ,ηKS, …..) tends to be even smaller than from “gold-plated” mode• ΔACP (K π) = ACP (K+ π0) - ACP (K+ π -) is nowhere near zero (~14.4%) and rather difficult to
understand. . Also CDF, D0: S(ψΦ) mild indication….unsettled . D0, dimuon asymmetry exptal analysis extremely
difficult -> NEEDS confirmationImplications of our analysis is that such nonSM
effects requiring the presence of NP with a new CP-odd phase should persist
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4G & BCP-anomalies
A.S. et al ‘10; Nandi & A.S’10;Buras et al’10; Hou & Ma’10
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A. S et al 0807.1971; 1002.0595 {Note constraints from S,T, b -> s gamma,K-> pi nu nu ….are all included} C ALSO A.Buras et al 1002.2126
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Predicted range of S(psiKs) in SM4 (with mt’=400 GeV) is (shown in red) comparedwith the experimentally measured value via the psi Ks mode (1 sigma error) and
with the SM (1 sigma)
SM4 seems to predict sin2 beta around 0.70 with an error of about 0.06;S. Nandi and A.S, 1011.6091
World Average
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Recent D0 result is vertical axis and combined D0, CDF each For SM4 error on Delta_Gamma_s is increased
by a factor of two resulting in ~50% increase in a_sl^s
S.Nandi and A.S,1011.6091
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Br(Bs->µµ): a very clean processIMPORTANT Correlation with S(psi phi)
SM4 may increase or decreaseBr by ~ O(3)
Current <3.60X10-8
CDF,HFAG
CDF UPDATE ‘11
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Detection of 4G quarks[Atwood, Gupta, AS’11]
• An important feature: To a rather good approximation, pair production is
near threshold . Using this feature showed robust signals:
1)Single lepton2)Opposite sign leptons3) Same sign dileptonsAll 3 viable
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Search for 4th generation at hadron colliders
An important caveat:• B-CP anomalies only need a
heavy top-like quark possessing akin to charged weak interactions: the underlying theory need not be simple SM4
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4G2HDM:LEET for DEWSB[Bar-Shalom,Nandi, A.S ‘11]
• 2 Higgs doublet model for the 4th ; 2nd doublet with v2/v1 >> 1 couples only to 4th gen
• FCNC only among 3rd and 4th gen• Significant modifications to t’, b’ decays• t’->t h, b h+ very large BR, similarly for b’• Requires modification to search strategies
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Phenomenology of type-I 4G2HDM
• FCNC effects only in t’ t & b’ b transitions
e.g.,
• Enhanced htt Yukawa interaction while suppressed ht’t’ one:
Bar-Shalom
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t’ decay pattern
t’ decays:
Bar-Sahlom
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b’ decay pattern
b’ decays:
Bar-Shalom
Summary & Outlook• 4G is well motivated for DEWB, baryogeneses,
alleviates B-CP anomalies & possibly dark matter connection.
Cannot be just simple SM4Heaviness of t’ may imply it may be strongly
coupledDecay pattern of t’, b’ may be quite different from
SM4
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Urgent questions for experiments
• ATLAS,CMS: Φ, W’,Z’,G; t’, b’ exist?• LHCb [CDF,D0]: S(Bs->ψφ), as
sl ; adsl ;
S(Φ KS), AFB(K*ll) …….• BABAR,BELLE updates for ad
sl very useful• BELLE (UPS5S run and nearby): as
sl and linear combination
• BELLEII; SBF: S(η’KS, φKS, KSKSKS), Br(B->τν), ad
sl, assl (?); S(Bd(s)->K* γ; …);
S(D0); asl(D0)…