future prospects for b physics at a super b factory
DESCRIPTION
Future Prospects for B Physics at a Super B Factory. M. Hazumi M. Yamauchi T. Browder and many others. Thanks to:. Hitoshi Yamamoto Tohoku University DIF06, Frascati, March 2, 2006. Evidence for direct CP violation in B g K + p -. Observation of CP violation in B meson system. - PowerPoint PPT PresentationTRANSCRIPT
Future Prospects for B Physics at a Super B Factory
Hitoshi YamamotoTohoku University
DIF06, Frascati, March 2, 2006
Thanks to:
M. HazumiM. YamauchiT. Browder and many others
Observation of CP violation in B meson system
Observation of CP violation in B meson system
Evidence for direct CP violation in B K+
Evidence for direct CP violation in B K+
We have done quite well so far ...
PEPII,KEK-B both exceededdesign lum. ~0.8 ab-1total
Main Aim of B-factories :To test the CKM mechanism of CPV
€
Vaba Lγμ bL W μ (a = u,c, t; b = d, s,b)
CPV by the irreducible complex phases in quark-W coupling:
€
α /φ2 ≡ argVtdVtb
*
−VudVub*
, β /φ1 ≡ argVcdVcb
*
−VtdVtb*
, γ /φ3 ≡ argVudVub
*
−VcdVcb*
Unitarity of V(Unitarity triangle)
Measure the sides and angles in different modes
V: CKM matrix
Status of Unitarity Triangle
Summer 2005
‘Lines’ by sin2 Vub/Vcb. α and ms,d all cross at a single point!
Striking confirmationof the CKM paradigm. A part of SM.
(Normalized to the length of the bottom)
■ Quadratic divergence of Higgs mass correction.◆ Indicates new physics in TeV scale.
SUSY? Little Higgs?■ Pattern of CKM matrix is not explained.
◆ Underlining mechanism by new physics implied.◆ Why 3 generations?
■ Cannot explain the matter excess of universe.◆ CKM not enough. Other source of CPV implied.
■ Does not have dark matter candidates WMAP : ~1/4 of universe is dark matter◆ Implies new particles (e.g. SUSY has).
Problems of Standard Model
■ Standard Model quark-W coupling◆ Left-handed coupling only◆ Pattern of Cabibbo suppressions in CKM matrix◆ No additional CPV phases
■ New flavor structures◆ Could be right-handed◆ Pattern of mixing matrix element different from CKM◆ New CPV phases
New Physics : New Flavor Structure
€
m112 m12
2 m132 m14
2
m212 m22
2 m232 m34
2
m312 m32
2 m332 m34
2
m412 m42
2 m432 m44
2
⎛
⎝
⎜ ⎜ ⎜ ⎜
⎞
⎠
⎟ ⎟ ⎟ ⎟
Mass matrix(general)
High-luminosityFlavor physics
Energy frontiers(LHC, ILC)
For example : MSSM
Super B factory
Down type squark mass matrix
Need for a Super B Factory
■ New flavor physics would be likely to appear in loops of b→s,d transitions.
■ B→s,d transitions currently limited by statistics.■ Increasing the statistics by ~100 (thereby reducing the
error by 1/10) is imperative.■ → Super B-factory.
◆ Preparations/studies underway in Japan, US, and Europe.
Super KEK-B
■ Luminosity ~ 4cm2s◆ 40KEKB design luminosity (25achieved peak)◆ 5 BB pairs/yr◆ 4 pairs/yr, 5 cc pairs/yr
A super B factory is a super tau-charm factory
■ LOI in 2004◆ http://belle.kek.jp/superb/loi◆ “Physics at Super B Factory” hep-ex/0406071
■ Official Budget request submitted to Japanese government in Aug 2005.(Not approved yet)
SuperKEKB41035 cm2s1
In order to increase the luminosity. . .
Interaction RegionCrab crossing
=30mrad.y*=3mm
New QCS
Linac upgrade
More RF power
Damping ring
New Beam pipe
Super KEK-B Upgrades
Probes for New Flavor Structure
■ New CPV phase in b→sqqTime-dependent CPV analsysis (tCPV)
■ Right-handed current in b→stCPV
■ Lepton AFB in b→sll■ LFV in decays■ Charged Higgs in B → D ■ ...and many more b→s
Time-dependent decay distribution on Y4S
€
ACP (Δt)
S
A
€
ΓB,B (Δt)∝ e−γ |Δt|[1± (S sin ΔmΔt + AcosΔmΔt)]
S: t±asymmetry, A: tag area difference
€
B, B
A C
H. Miyake
Current status of b→sqq
S= fsin2 for J/KS,L
f : CP eigenvalue)Define sin2
eff= fS sin2
eff sin2eff sin2
bbsqq at Super B Factorysqq at Super B Factory
SM predictions
SK0 (July 2005)
SK0 (SuperKEKB)50ab-1
summer 2005
∆S(Ks) at 50ab1
= XX 0.03(stat) 0.01(syst) 0.04(th)
∆S(Ks) at 50ab1
= XX 0.03(stat) 0.01(syst) 0.04(th)
assumingpresent WA
KsKsSummer 2005
based onS.Khalil and E.Kou PRD67, 055009 (2003)and SuperKEKB LoI
How can it constrain theories?
Mass matrix elementsbetween andare constrained.
€
˜ s L,R
€
˜ b R,L
KsKs
Theory may need somemechanism to explain suppressed or
Theory may need somemechanism to explain suppressed or
Right-handed current in bs ■ In SM, s is left-handed → is left-handed. In the CP conjugate mode, is right-handed. Flavor-specific →no tCPV. (suppression factor ~ms/mb) ■ In BSM, s may be right handed. → tCPV
LRSM, SUSY, Randall-Sundrum, etc. * LRSM: SU(2)LSU(2)RU(1)
S~0.5 is allowed
sb
XX
tCPV in B→ KsBelle (386M BB pairs) : use Ks vertex for t
S = 0.08±0.41±0.10 (MX<1.8 GeV) consistent with zero
SM : S = -2 ms/mb sin2
CPV in b s and SUSY models (Super B)
■ Correlations are useful to differentiate new physics models■ Correlations are useful to differentiate new physics models
Expected precision at 5ab
T.Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanaka (2002, 2004) + SuperKEKB LoI
S[(Ks error = 0.5(now) → 0.14(5ab-1)
AFB(ll) in b→sll
?b quark s quark
l l
sensitive to new physics : SUSY, heavy Higgs and extra dim.
Polarization of ll system(or whatever is creating it)+L/R couplings to l → AFB(ll)
S(ll) = q2
AFB
SM and SUSY models
SM also has large Asymmetry : Z- interference
AFB(ll) in b→sll : Sensitivities
MC, 50 ab-1
Experimental results with 0.35 ab-1
Belle, 2005
Standard model
Sensitivity at Super KEKB
Zero-crossing q2 for AFB will be determined with 5% error.
Control sample B→KllHelicity(ll system) = 0 → No FB asymmetry.
Belle, 2005
These (radical) models are already excluded by recent data from Belle.
AFB(ll) in b→sll : now
Γq2,cos function of A7, A9, A10
Search for LFV in decays
■ SUSY + Seesaw, or GUTLarge LFV possible
Br()=O(10-7~9)BR() ~10-6 tan2(mL
2)32
mL2
~
~( ) 41 TeVmSUSY
mSUGRA
Search for LFV in decays
0tanâ=30,A=0,ì>0
Gaugino mass = 200GeV
Present limit Super-B limit
l
l’
3l
l Ks
B
Well within range!SUSY →
More tests of SUSY breaking scenarios
S(K*)
S(Ks)
Br(b s)
A(b s)
AFB(b sll)
Br( )S(Ks)
50ab-1 A(b s)Br(b s)
AFB(b sll)
T.Goto, Y.Okada, Y.Shimizu,T.Shindou, M.Tanaka (2002, 2004) + SuperKEKB LoI
Sensitivity for Charged Higgs
(Fo
rm-f
acto
r) ~
5%
(For
m-facto
r) ~15
%
BD
B (present)
Constraint from BXs
LHC100fb-1
Unitarity triangle at 50ab-1
Triangle closes, or...
It may not close.Something new in loops!
DNA Identification of BSMby Flavor Physics
Bd- unitarity
m(Bs) B->Ks B->Ms indirect CP
b->s direct CP
mSUGRA - - - - - +SU(5)SUSY GUT + R
(degenerate)- + + - + -
SU(5)SUSY GUT + R
(non-degenerate)- - + ++ ++
+
U(2) Flavor symmetry + + + ++ ++ ++
++: Large, +: sizable, -: small
Unitarity triangle Rare decays
Okada et al (2004).
Comparison with LHCb
SuperKEKB 5ab-1 50ab-1 LHCb 2fb-1
CK
Mw
/ F
CN
CC
PV
(b s
)
Advantages of Super B Factory
■ B decays with neutrinosB D, , ul etc.
■ B decays with , 0
B Xs, 00 etc.
■ B vertex reconstruction with Ks only ! B Ks0, Ks0 etc.
Ks trajectory IP profileB vertex
Υ(4S)e (8GeV)
e+(3.5GeV)
B
B
full (0.1~0.3%)reconstructionBD etc.
full (0.1~0.3%)reconstructionBD etc.
D etc.D etc.B meson beam !B meson beam !
Charged HiggsCharged Higgs VubVub
direct CPVdirect CPV 2(α) isospin analysis2(α) isospin analysis
Summary
■ B-factories have been successful, and now beginning to probe new physics.
■ Many new physics are well within reach of Super B factory.
■ Super B factory can distinguish various BSM models.
■ New particles that would be discovered at LHC/ILC will be tested/measured in their flavor sector.
■ Super B factory is sensitive to mass scale beyond the reach of LHC/ILC.
Back Ups
Hint of Problems?fL (B→VV) ~ 1 in SM
treepenguin
Limited by statistics at the moment.Limited by statistics at the moment.
ACP(B→Kπ) is equalbetween B± and B0.
B0
B±
Direct CP Violation
Projection of integrated luminosity
■ Crab cavity installation in 2006
■ ~2109 BB pairs by 2008 (4now)
■ Long shutdown (14months) in 2009-2010
■ Constant improvement from 2010◆ realistic and reliable plan
based on experiences at KEKB
◆ Crab cavities well tested before 2010: a big advantage !
We are here.We are here.
5
4
3
2
1N
BB
(10
10)
NBB ~100 now !in the LHC era
NBB ~100 now !in the LHC era
Bkg & TRG rate in future
KEKB SuperB
Luminosity(1034cm-2sec-1)
~1 40
HER curr. (A)
LER curr. (A)
vacuum (10-7Pa)
1.2
1.6
~1.5
4.1
9.4
5
Bkg increase - x 20
TRG rate (kHz)phys. origin
Bkg origin
0.40.2
0.2
1410
4
Synchrotron radiationBeam-gas scattering (inc. intra-beam scattering)Radiative Bhabha
SVD CDC PID / ECL KLM
KEKBBkg
x10 Bkg
x20 Bkg