Belle/Belle2

1.Jul.2011

/

F

x

x

:

(1967) – –

( )

CP

τ R , τ R (CP )

N R − N R ∼ ε ε

A. Sakharov (1921-1989)

Belle/KEKB

(1973)

Mixing Matrix

CP

3 6

4 quark (charm) 1974

Cabbibo-Kobayashi-Maskawa

d′

s′

b′

=

Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb

d

s

b

e j n Q N i

b cVcb

W

Unitarity Triangle ( )

ρ

η

β/φ1

α/φ2

γ/φ3

1

VtdVtb

VcdVcbVcdVcb

VudVub

φ1(β) , 0 CP

Belle/KEKB

(–2001 )

B CP violation B→J/ΨK0S sin 2φ1 φ1 , 0

(–2010)

Overconstrain CKM triangle (the SM)

NEW physics Fully Leptonic decay B0→τν Lepton Flavour Violation τ→µγ b→s penguin ....

The KEKB Collider

( ∼50 km)

TRISTAN

Ee−/Ee+ = 8/3.5GeV (Asymmetric)

Ecm = 10.58 GeV ∼ mΥ(4S)

βγ = 0.425

Collider

∼ 3 km

Luminosity

N = L(luminosity) × σ( ) × t( )

Lpeak = 2.11 × 1034cm−2sec−1= 21.1/nb·sec

∫

Ldt ∼ 1020 fb−1 (711M Υ(4S), )

σ(Υ(4S)) ∼ 1 nb⇒ 20 Hz

Electron Gun

Positron Target

Injection Linac

Beam Transport Line

Positron Kicker

Arc

SC

ARES

Crab

The Belle Detector

The Belle Detector

The Belle Detector

Time-Dependent CP Violation

fCPfCP

B0

B0

B0

B0

=Mixing

Mixing

ACP(∆t) ≡Γ(B0(∆t) → fCP) − Γ(B0(∆t) → fCP)

Γ(B0(∆t) → fCP) + Γ(B0(∆t) → fCP)= S sin (∆m∆t) +A cos (∆m∆t)

Indirect CPV (S,A) = (0.65, 0)

∆t (ps)0

0.1

0.2

0.3

-8 -6 -4 -2 0 2 4 6 8

Direct CPV (S,A) = (0.8, 0.6)

∆t (ps)0

0.2

0.4

-8 -6 -4 -2 0 2 4 6 8

φ1 by B0→J/ΨK0

ρ

η

β/φ1

α/φ2

γ/φ3

1

VtdVtb

VcdVcbVcdVcb

VudVub

ACP(∆t) ≡Γ(B0(∆t) → J/ΨK0

S) − Γ(B0(∆t) → J/ΨK0

S)

Γ(B0(∆t) → J/ΨK0

S) + Γ(B0(∆t) → J/ΨK0

S)= sin (2φ1) · sin (∆m∆t)

Experimental Technique

B(B0→J/ΨK0)=8.5×10−4

µµ

ν

π

π

µ−

+

−

K0

+

K+

−D0

J/ΨCP side

Tag side

electron(8 GeV)

Positron

(3.5 GeV)

Y(4S) B

B’B0

B0

∆z ~ 200 µm

- Vertexing

- Flavour

(1)

(2)

(3)

(1) fCP J/ΨK0

(2) Flavor (B0 or B0)

(3) , Propertime ( ∆z = cβγ∆t )

Belle/KEKB

(–2001 )

B CP violation B→J/ΨK0S sin 2φ1 φ1 , 0

PRL87, 091802 (2001)q.ξf = +1

q.ξf = −11/

N. d

N/d

(∆t)

-8 -4 0 4 80.00

0.10

0.20

∆t (ps)

sin 2φ1 = 0 excluded by more than 6σ

Belle/KEKB

(–2010)

Overconstrain CKM triangle (the SM)

3φ

2φ

2φ

dm∆

Kε

Kε

sm∆ & dm∆

SLubV

ν τubV

1φsin 2

(excl. at CL > 0.95)

< 01

φsol. w/ cos 2

2φ

1φ

3φ

ρ-0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0

η

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

excl

uded

are

a ha

s C

L >

0.9

5

ICHEP 10

CKMf i t t e r

( )

Belle/KEKB

(–2010)

Overconstrain CKM triangle (the SM)

NEW physics Fully Leptonic decay B0→τν Lepton Flavour Violation τ→µγ b→s penguin ....

B→τν

(GeV)ECLE0 0.5 1

Eve

nts

/ 0.

1 G

eV

0

10

20

30

40

50

B(B→τν) = (1.64±0.39)×10−4

Belle/KEKB

KEKB/Belle

2010 6 30

Belle

http://belle.kek.jp/˜isamun/kaitai/

New Physics O(1) TeV

Loop B/D/τ O(%)

New Physics Flavor structure

CP Violation phase?

New Physics

New Physics

O(%)

10−8

B/D/τ

upgrade Luminosity

SuperKEKB Accelerator

SuperKEKB Target

KEKB

Luminosity × 40

Luminosity × 50

The SuperKEKB Accelerator

Luminosity

Luminosity

L =N+N− f

4πσ∗xσ∗yRL

∝I±ξy±

β∗y

Luminosity ,

(I),

beam beam (ξy),

beam (σ∗y =√

β∗y · ε∗y)

SuperKEKB

KEKB SuperKEKBLER HER LER HER

E 3.5 GeV 8 GeV 4 GeV 7 GeVφ 11 mrad 41.5 mradI 1.6 A 1.2 A 3.6 A 2.6 A

1584 2500ξ 0.13 0.09 0.09 0.08β∗y 1200 mm 5.9 mm 0.27 mm 0.3 mmσ∗y 0.94 µm 0.94 µm 48 nm 62 nmσz 6 mm 6mm 6mm 5mmLpeak 2 × 1034 8 × 1035

AC Power 20 MW 30–40 MW

Luminosity 40

×2

× 1/20

Luminosity

εx ∝Cqγ

2

2πρ20

∮

BendHds

Lattice/Optics LER HER H Wiggler Dump

SR SR (ρ ) (η )

Wiggler

HER arc

LER arc

Wiggler

Luminosity

IP β

Beam

IP

Belle IP chamber

Synchrotron Radiation

Beampipe Beampipe

QCS Magnet Bellows Chember

Belle2 Detector Upgrade

The Belle II Collaboration

13 countries/regions, 57 institutes, ∼400 Collaborators, increasing (Jan. 2011)

4 ns 1 (2 )

Event

Lumi ∼ 800 /nb/sec

100 kHz

Trigger L1 30 kHz / HL 6 kHz

Background

Touschek

Beam-Gas

Radiative Bhabha

Ionizing (1–10 kGy/ )

Non Ionizing (1011–1012 neutrons//cm2)

Event Rate

Process σ(nb) Rate (kHz)Υ(4S) 1.2 1qq 2.8 2.2µ+µ− 0.8 0.6τ+τ− 0.8 0.6e+e− 44 35γ-Pair 2.4 2Two-γ 80 64Total 132 ∼100

Background 10–20

L1 Trigger Rate O(10) kHz 30kHz

10

The Belle II Detector

The Belle II Detector

Vertex Detector

Belle2 Beller Beampipe 1 cm 1.5 cmPixel 2

X L

Strip 4

X

4

Xrmin

G b X

14 mm 20 mmrmax

G X

140 mm 88 mm

17–150 coverage

rmin resolution

rmax K0S→π+π− eff.

Beampipe

(2 ) +

83 mrad (was 22 mrad)

∼1 m ∼20 cm

∼100 W (wall current)

PXD

DEPFET for ILC adopted to Belle2

Thinning 50 µm (0.2%X0 total)

768

Readout 20µs = 768×100(ns)/4

∼360(20) W⇒ CO2 cooling

Data Rate , O(10) GB/s

occupancy 1–3%

4 Byte/pix × 30 kHz L1 trig rate

Data reduction

online track–hit association

reduction factor 10

r pix size # pix lad. size # lad.1 14 50×55 768×250 70×15 82 22 50×75 768×250 85×15 12

SVD

4 ( 0.6%X0 total)

6” wafer

3 shapes (2 , 1 )

APV25 ASIC (CMS)

128ch/chip, ∼160 deep analog pipe

32MHzoperation⇒ 5µspipe (L1Latency)

chip on sensor

“Origami”

6.7% occupancy ( )

90 kB/evt⇒ 2.6 GB/s

# strip pitch size # APV # senser

768/768 50/160 38.4×122.8 6+6 16g

768/512 75/240 57.6×122.8 6+4 130

768/512 —/240 —×122.8 6+4 41

CDC (1)

Belle CDC worked well

keep concept

same structure, same gas, same wire

Increase inner radius

increase Silicon lever arm (K0S→π+π−)

reduce hit rate

Increase Outer Radius

Smaller outer detector (BPID)

more lever arm⇒ better p reso

Adjust cell size for occupancy

AUAVAUAVA configuration

dE/dx readout for PID

∼100µm resolution

55–75 mrad stereo angle

Cell Structure

Belle Belle2inner radius 88mm 168mmouter radius 863mm 1111mm# Layers 50 56# sense wire 8400 14336Gas He:C2H6 = 50:50

Wire (S/F) W(30µmφ) / Al (120µmφ)Cell size 6mm/18mm 10/20 mm

Max. Drift Time 80–300 ns 100–350 ns

CDC (2)

48ch board

ASD ASIC 8ch/chip

Analog out 10 bit/32 MHz FADC for dE/dx

Logic out (1 ns) TDC in FPGA (250 MHz×4 φ)

Buffer for 5µs

RocketIO for Trigger (62.5 MHz)

RocketIO Bell2Link

20 Layer Test Chamber

Full length chamber

Development on going with Cosmic

Particle ID

4 GeV K/π 4σ

Threshold Ring-Image Cerenkov

Barrel TOF + ACC forcusing TOP counter

Foward ACC Aerogel RICH

BPID TOP (1)

Time of Propagation Counter with Focusing

Cherenkov Light from particles

propagate γc with total reflection

Focusing with spherical mirror

record (t, x, y) of each γc, 15–30 γc/event

compare with expectation from tracking

∆t(TOF+TOP) ∼ 30–50 ps (4 GeV), 130–200 ps (2 GeV)

Quartz (Radiator +Mirror +Expansion Volume)

2.6m× 45cm× 2cm × 16

5Å!!

MPC-PMT (32(16×2 ) /Bar)

Waveform Digitization (4GS/s)

BPID TOP (2)

MCP-PMT

MCP-PMT SL10

MCP with 10 µmφ Pore ( B field)

Gain ∼ 106 (single photon sensitive)

Time Resolution ∼30 ps/photon

SBA Photocathode with protection

5×5 mm2/ch 4×4 readoutσT ∼ 100ps

FPID ARICH (1)

Proximity Focusing Aerogel Ring-Image Cerenkov Detector

( 25cm⇒ 20cm gap)

Aerogel Radiator

16cm×16cm×2cm×2 , n ∼ 1.05∓∆

”Focus”

(HAPD)

5mm

Single Photon Sensitive @ 1.5T

4σ 4 GeV K/π

σθc =14 mrad (by geometry)

6 p.e. 4σ ⇒∼15 p.e.

FPID ARICH (2)144ch HAPD

144ch HAPD

12×12× 4.9 mm (72mm)

Gain ∼ 105

Gain ∼1500 @ 8kV APD Gain ∼50 @ 300 V

SBA photocathode Q.E.∼25%

36ch ASIC × 4 digitalNp.e. = 15.3, σθc = 13.5mrad

ECL (1)

Calorimeter

γ π0

10(50) MeV 10(5) GeV σE mass cut

Hermeticity⇒ ν

Rate resistance

8736 CsI(Tl) Crystals

5.5×5.5×30 cm3

6624(B)+1152(FWD)+960(BWD)

12 ↔ 155

λ =560 nm/τ =1.3 µsec (Slow)

50000 p.e./MeV (stochastic term )

∼100

PIN photodiode 2

The Belle Calorimeter

ECL (2)

16 Crystal

Sum Shaper

0.5µs

to FAM(Trigger) FINNES on COPPER

FADC I/O BufferPD/Amp

16ch / Board

Sum

0.2µs

2 MHz

18 bit

FPGA

Collector

FPGA

I/O

12ch / Board

WFA

Trigger

Shaping 1µs→ 0.5µs (Scintillation )

18 bit 1.8 MHz ADC

FPGA

Collector Board 12 Shaper/ADC/DSP board

Collector⇔ Backend Belle2 Fiber I/O

Factor ∼7 Background

ECL (3)

“ ” Prototype

2011 2

FPGA

Trigger Analog sum

Collector

prototype

Collector Board

2009 12

12 ShaperDSP Data

Calibraion

Slow Control

Parameter/Firmware Loading

FiberIO

2nd Prototype

VME Shaper Prototype

Collector Prototype

KLM (1)

Return Yoke 15 super layer Resistive Plate Chamber

Ar : C4H10 : HFC134a = 30 : 8 : 62

(∼ 5 × 1012Ω ·m)

RPC Recover O( )

+WLS +MPPC

KLM (2)

T2K ND

Vladimir, 10mm×40mm×2.8m

Y11MCWLS Fiber

Hamamatsu MPPC

1.3mm, 50µm pitch, 667 pixel

15–30 p.e./mip ( )

KLM Test Module

Trigger (1)

Belle2 Trigger Flow

L1 Rate 30 kHz

HL Trigger ∼ ×0.2

Latency 5µs for SVD

Timing Reso. ∼ 10 ns

Interval 190 ns

Physics Triggers

Three-Tracks (B)

Two-tracks (τ )

Total Energy (B)

Isolated Cluster (B)

Calibration Triggers

e+e−, µ+µ−, γ-pair

Random

Vetos

Beam Injection

Cosmic

Trigger (2)

Sub Trigger FineCDC 14 64 ×6ECL 15 576×12TOP 8 128×1KLM 5 300×1

42 bit 180 Gbps

Sub Trigger

Fine Info. reserve

Uinversal Trigger Board

RocketIO for Data transfer

big FPGA for Logic

UT3β Board

DAQ (1)

FPGA, COPPER, PC, Switch, GbE

FrontEnd Backend

Belle MQT + Fastbus TDC

Belle2Link + Belle2HSLB

PXD ( data )

DAQ (2)

Timing/Trigger distribution

127 MHz system clock (1/4 RF)

5 Trigger pipe

Latency for acknowledge 26.6µs

3.4% DAQ deadtime for 30 kHz

FTSW module

Belle2link

FrontEnd Data Transfer RocketIO/Opt Trigger/Timing reciver (RJ45) JTAG interface (RJ45) FPGA (Vertex5/Spartan6)

Backend (B2HSLB)

RocketIO/Opt (3.125 Gbps)

Belle2link

SuperKEKB/Belle2 2014 First Beam