Future B Physics Program
(KEKB upgrade strategy)
- KEK’s Roadmap -
BNM 2008 (24-Jan, Atami)
based on slides by
Masa Yamauchi, KEK
Introduction: KEKB and Belle
Next program of quark flavour physics
KEK’s five year roadmap
KEKB upgrade plan → Onishi’s talk
Organization of new experimental group
KEKB and Belle
Central drift chamber
m / KL detector
Si vertex detector
The Belle Collaboration
Nagoya U. Seoul National U.
BINP IHEP, Vienna
Nara Women’s U. Shinshu U.
Chiba U. ITEP
National Central U. Sungkyunkwan U.
U. of Cincinnati Kanagawa U.
National Taiwan U. U. of Sydney
Ewha Womans U. KEK
National United U. Tata Institute
Fu-Jen Catholic U. Korea U.
Nihon Dental College Toho U.
U. of Giessen Krakow Inst. of Nucl. Phys.
Niigata U. Tohoku U.
Gyeongsang Nat’l U. Kyoto U.
Nova Gorica Tohuku Gakuin U.
Hanyang U. Kyungpook Nat’l U.
Osaka U. U. of Tokyo
U. of Hawaii EPF Lausanne
Osaka City U. Tokyo Inst. of Tech.
Hiroshima Tech. Jozef Stefan Inst. / U. of
Ljubljana / U. of Maribor Panjab U. Tokyo Metropolitan U.
U. of Melbourne Peking U. Tokyo U. of Agri. and Tech.
Princeton U. INFN Torino
Riken Toyama Nat’l College
Saga U. VPI
USTC Yonsei U.
14 countries, 55 institutes, ~400 collaborators
Scientific Achievements of B Factories (1)
Observation of CPV in the B meson system
G(BfCP;t) - G(BfCP;t)
ACP(t) = = Af cosDmt + Sf sinDmt
G(BfCP;t) + G(BfCP;t)
Belle, July 05
Belle, July 05
Af ~ 0
Sf = 0.652±0.039±0.020
Consistent with BaBar’s meas.
Achievements of the B Factories
Quantitative confirmation of the KM model
Belle, July 05
Discovery of CP violation in BB system
Af ~ 0
Sf = 0.652±0.039±0.020
Belle, July 05
Violation of CP symmetry !
Many new resonances
Evidence for Bgtn
AFB in BgK*l+l-
D0-D0 mixing Bgdg transition BgD*tn
and more… 8
Another important achievement
Asymmetric e+e- collider with L > 1034
Success of KEKB and PEP-II enabled us to design a new
e+e- B factory with much higher Lpeak.
What is next with flavour physics?
If new physics at O(1)TeV…
– It is natural to assume that the effects are seen in B/D/t
– Flavour structure of new physics?
– CP violation in new physics?
– These studies will be useful to identify mechanism of
SUSY breaking, if NP=SUSY.
– Search for deviations from SM in flavor physics will be
one of the best ways to find new physics.
Asymmetric energy e+e- collider at ECM=m((4S)) to be
realized by upgrading the existing KEKB collider.
Super-high luminosity 21035/cm2/sec 210 9 BB per yr.
(1st stage: >x10) 210 9 t+t- per yr.
Belle with improved rate immunity
Higher beam current,
more RF, smaller by* and
L = 21035/cm2/sec
final target ~81035/cm2/sec
(smooth transition: 50 ab-1) http://belle.kek.jp/superb/loi
Physics at upgraded KEKB
New source of New source of
CP violation flavor mixing
LFV t decays
of KM scheme
New resonances, Super-high statistics
D0D0 mixing… measurements:
aS, sin2qW, etc.
SUSY flavour physics: mass matrix of squark and slepton will be determined
by their direct production at the energy frontier and flavour physics measurements.
Quark flavor changing
SUSY mass spectrum
Lepton flavor violation
Y.Okada, Nov. 2007
Searches for new sources of
quark mixing and CP violation
CP asymmetries of penguin dominated B decays
Present upper Deviation from SM
Deviation from SM
New source of CP
at upgraded KEKB Relevant to
（ ab-1 ）
Reach of present Reach of upgraded
B factories KEKB 14
A possible hint for NP: b→sqq
Smaller than bgccs
in 7 of 9 modes
Precise measurements of t decays
LFV violating t decay?
New Physics predictions
Integ. Lum.（ ab-1 ） T.Goto et al., 2007
Reach of B factories 16
B decays with more than one n
Interactions of H± B
mb tan b + mu cot b
mt tan b n e- Υ e+
Bgtn decays B
u H+/W+ p
Belle, 2006 t+
0.2~0.3% for B+
Provides a unique method to
measure b-H±-u and
b-H±-c coupling strength.
Search region with
B decays into invisible particles?
Light dark matter?
B K(*)nn [or cc]
Heavy darm matter is being
searched for in direct detection
Model prediction experiments.
Light dark matter can be
Searched for in the upgraded
Search for right handed interaction
Left-right summetry in new physics?
CP violation in B KSp 0g
Precision of the measurement
Sizable CP asymmetry is expected
Present exp. precision
in B0Xg decay, if right-handed
interaction exists in new physics.
T.Goto et al., 2007
New resonances found at Belle/BaBar
Y(4660) Z(4430) More than 10 new resonances
Y(4008) have been found at B factories
DsJ(2700) Among them X（3872） and
Z（4430） are considered to be
D0*0 & D1*0 DsJ(2317/2460) More and more exotic states will be
hc’ & e+e-cccc Observed by the upgraded KEKB.
Identification of SUSY breaking scenario
Pattern of deviations from the Standard Model Y.Okada
Observ- Bd- e D m(Bs) B->fKs B->Msg b->sg
SUSY unitarity indirect CP direct CP
- - - - - +
GUT + nR - + + - + -
GUT + nR - - + ++ ++ +
+ + + ++ ++ ++
++: Large, +: sizable, -: small
Comparison with LHCb
e+e- is advantageous in… LHCb is advantageous in…
CPV in B→fKS, h’KS,… CPV in B→J/yKS
CPV in B→KSp0g Most of B decays not
B→Knn, tn, D(*)tn including n or g
Inclusive b→smm, see Time dependent
measurements of BS
t→mg and other LFV
Bc and bottomed baryons
These are complementary to each other !!
ILC R&D Construction Experiment
Flavor Physics at Luminosity/Intensity Frontier
n, K, m,... at J-PARC
b, c, t,... with upgraded- KEKB/Belle
• According to the JAHEP community’s master plan,
– Highest priority is given to ILC
– Before ILC, promote flavor physics at KEKB and J-PARC
• Action before the ILC approval
– ILC R&D
– Completion/commissioning of J-PARC
• Considering the world competition,
it is urgent to improve neutrino intensity
– Continuation of KEKB/Belle with upgrade 24
KEK Web page
(5 Year Plan)
KEK Roadmap : KEKB
First 3 years: shutdown
• Replace beam pipe (with ante-chamber)
• Upgrade interaction region fundamental
• Upgrade ground level RF facility part
• Improve crab cavities
Last 2 years: operation & improvements
• Installation of Damping Ring
• Installation of additional RF
• Reinforcement of cooling facility Onishi’s talk
1st goal: 2 x 1035cm-2sec-1
smooth transition feasible to 8 x 1035cm-2sec-1(50ab-1)
KEK Roadmap: Belle Upgrade
in 3 years shutdown
4 Higher background ( 20)
- radiation damage and occupancy
- fake hits and pile-up noise in the EM
4 Higher event rate ( 10)
- higher rate trigger, DAQ and computing
4 Require special features
- low p m identification f smm recon. eff.
- hermeticity f n “reconstruction”
4Replace inner layers of the vertex detector
with a silicon striplet detector.
4Replace inner part of the central tracker
with a silicon strip detector.
4Better particle identification device
4Replace endcap calorimeter by pure CsI.
4Faster readout electronics and computing
Belle detector upgrade
Faster calorimeter with
Wave sampling and pure
Super particle identifier with
precise Cherenkov device
and new generation
super small cell
New Dead time free tracking detector
Si vertex detector with
high speed high background New ideas are
computing systems tolerance
New experimental group
It will be practical to build new detector by upgrading
However, the experimental group will be a new group, not
an extension of the present Belle collaboration.
New participants are all welcomed and have equal
opportunities to work on detector construction and physics.
It is welcomed to join the new group, but not Belle.
Interim Steering Committee is being formed. First meeting
is scheduled March 2008, inviting potential new
2007 2008 2009 2010 2011 2012
10 1 4 7 10 1 4 7 10 1 4 7 10 1 4 7 10 1 4
Experiment at KEKB KEKB/Belle upgrade
Detector Final detector
Study Report design
(March 08) (April 09)
2007 2008 2009
10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4
Detector proposals Internal review
BNM Pre kick-off Kick-off
(January 08) meeting meeting
(19,20 March 08) (3,4 July 08)
Actions to invite new collaborators One-day general meeting and
an IB meeting at every BGM
KEKB/Belle and PEP-II/BaBar have been running very
successfully, and brought important scientific and technical
Next generation e+e- B factory with L~1036 will be very
useful to study the new sources of flavor mixing and CP
– Search for new CPV in bgs transition
– Very precise test of CKM scheme
– Search for lepton flavor violating t decays
– Studies of H± interactions with fermions
– Very precise measurements of aS(@10GeV), sin2qW(@10GeV)…
KEK Roadmap includes KEKB upgrade.
KEKB machine upgrade plan Onishi’s talk
Detector upgrade necessary to improve BKG/rate immunity.
New collaboration to be formed soon.
Our final goal of the integrated luminosity is 50/ab in the new
experiment at the upgraded KEKB.
However, we did not include the full upgrade of the machine
in the KEK's roadmap, due to the financial constraint in the
lab. We will upgrade the fundamental part of the accelerator
in the first three years, followed by incremental installation of
the RF systems over several years to increase the beam
current and the luminosity. The initial goal, 10/ab, will be
achieved in the five years of operation after resuming the
experiment. It should be noted that the plan up to this point is
included in the KEK's roadmap. Then, considering the results
of this experiment and LHC as well as progress of ILC and
others carefully, we will decide if we propose further
installation of the RF system to achieve the final goal, 50/ab,
in the next five years.
Precision test of KM scheme
Search for new flavor mixing
l- : Probe the flavor changing
g, Z0 process with the “EW probe”.
b quark s quark This measurement is especially sensitive to new
? physics such as SUSY, heavy Higgs and extra dim.
Theoretical predictions for l +l - forward-backward
charge asymmetry for SM and SUSY model with
Possible observables: various parameter sets.
4Ratio of branching fractions
4q 2 distribution
4Triple product correlation
4Forward backward asymmetry
4Forward backward CP asymmetry
The F/B asymmetry is a consequence
of g-Z0 interference.
Search for new CP phases
In general, new physics contains new sources of flavor
mixing and CP violation.
4In SUSY models, for example, SUSY particles contribute to the bs
transition, and their CP phases change CPV observed in BfK, h’K etc.
SM SUSY contribution
In general, if SUSY is present, the s-quark
mixing matrix contains complex phases just
as in the Kobayashi-Maskawa matrix.
T.Goto et al., 37
Background & TRG rate in future
HER curr. (A) 1.2 4.1
LER curr. (A) 1.6 9.4
vacuum (10-7Pa) ~1.5 5
KEKB Bkg increase - x 20
Bkg TRG rate (kHz) 0.4 14
phys. origin 0.2 10
SVD CDC PID / ECL KLM
Bkg origin 0.2 4
Beam-gas scattering (inc. intra-beam scattering)