april 12, 2006fpcp -- vancouver1 review –kloe (frascati) absolute branching ratios kaon lifetime...
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April 12, 2006 FPCP -- Vancouver 1
• Review– KLOE (Frascati)
• Absolute Branching Ratios• Kaon Lifetime• Form-Factors
– NA48/2 (CERN)• Search Direct CP-Violation
in K±
• Measurement of scattering length
• RK=(K e ) /(K – E391a (KEK)
• K0→ – KTeV (Fermilab)
• Radiative decays
• Outlook – DANAE– JPARC
• K0L→
– CERN-P-326 (NA48/3)• K→
Review & Outlook, KaonsAugusto Ceccucci/CERN
'
'
'
ub
cb
td
ud us
cd cs
ts tb
V
V
V V
d d
s s
b b
V
V
V
V V
Vus
April 12, 2006 FPCP -- Vancouver 2
KLOE@DANE Frascati
e e- K K(K0S K0
L)
• Advantages:– K0
S and K0L tagging
• Measure of absolute BR
– Kaons have definite momentum
• Study of K0S and K0
L semileptonic decays without ambiguities
– Low K momentum• K0
L and K+ lifetimes measurements can be done precisely
April 12, 2006 FPCP -- Vancouver 3
KLOE K0L Measurements
BR(K0L) =1 K
L)= (50.72 0.140.33ns
BR(KLe) = 0.4007 0.0006stat 0.0014syst
BR(KL) = 0.2698 0.0006stat 0.0014syst
BR(KL 3) = 0.1997 0.0005stat 0.0019syst
BR(KL) = 0.1263 0.0005stat 0.0011syst
L/c (ns)
6 - 24.8 ns40-165 cm
0.37 L
× 102Events/0.3 nsPK = 110
MeV
Quadratic fit: 1 t/m t/m2
= (25.5 1.5 1.0) 103
= ( 1.4 0.7 0.4) 103
Correlation: (, ) = 0.95Pole model fit: MV = 870(7) MeV
hep
-ex/
0601
038
L = 50.92 0.17 0.25 ns
PLB626 (2005) 15
KL
PLB608(2005) 199
K0L(e3)
Vosburgh et al. ’72:
L = 51.54 ± 0.44 ns
April 12, 2006 FPCP -- Vancouver 4
|Vus|f+(0)
0 3
2 5( ) 192
| | (0)(1 )
Lus e
L F K EW K
BR K eV f
G M S IK
Blucher & MarcianoPDG 05 f+(0)=0.961+/-0.008
Leutwyler & Roos
Only KLOE providesBR,L & f.f. (for Ie
K)
April 12, 2006 FPCP -- Vancouver 5
NA48/2 (CERN-SPS)
Beam pipe
20032003 run: ~ 50 daysrun: ~ 50 days
20042004 run: ~ 60 daysrun: ~ 60 days
Total statistics in 2 years:Total statistics in 2 years:
• KK + + : ~4: ~4·10·1099
• KK 00 0 0 : ~2: ~2·10·1088
~ ~ 200 TB of data recorded200 TB of data recorded
•400 GeV/c SPS protons•60 GeV/c secondary hadron beams•Simultaneous collection of K+ and K- decays
April 12, 2006 FPCP -- Vancouver 6
Direct CP-violation in KK
|M(u,v)|2 ~ 1 + gu + hu2 + kv2
Centre of mass frame
u = 2mK∙(mK/3-Eodd)/m2;
v = 2mK∙(E1-E2)/m2.
• Measured quantity sensitive to direct CP violation:
Slope asymmetry:
Ag = (g+-g-)/(g++g-)≠0
Lorentz-invariantsu = (s3-s0)/m
2;
v = (s2-s1)/m2;
si = (PK-Pi)2, i=1,2,3 (3=odd );
s0 = (s1+s2+s3)/3.
SM estimates vary within an order of magnitude (few 10few 10-6-6…8x10…8x10-5-5). Models beyond SM predict substantial enhancement
April 12, 2006 FPCP -- Vancouver 7
Selected Statistics 2003
U
|V|
even pionin beam pipe
Data-taking 2003: 1.61x101.61x1099 events selected
KK+ + : 1.03x10: 1.03x109 9 eventsevents
KK : 0.58x10: 0.58x109 9 eventsevents
odd pionin beam pipe
MM=1.7 MeV/c=1.7 MeV/c22
Events
April 12, 2006 FPCP -- Vancouver 8
Stability and Systematics Systematic uncertainties
Effect on Δx104
Acceptance and beam geometry
0.3
Spectrometer alignment 0.1
Analyzing magnet field 0.1
π± decay 0.4
U calculation and fitting 0.2
Pile-up 0.2
Total systematics 0.6
Trigger efficiency: L2 0.5
Trigger efficiency: L1 0.4
Control of Detectorasymmetry
Control of Beamlineasymmetry
Jura Jura (Left)(Left)
A+A+
A- A- SalèveSalève(Right)(Right)
ZZ
XXYY
Achromats: KAchromats: K+ + UpUp
Achromats: KAchromats: K++ DownDown
B+B+
B-B-
April 12, 2006 FPCP -- Vancouver 9
NA48/2 (2003 data)K Slope difference:Δg = (-0.7±0.9stat.±0.6stat.(trig.)±0.6syst.)x10-4 = (-0.7±1.0)x10-4
Charge asymmetry:Ag = (1.7±2.1stat.±1.4stat.(trig.)±1.4syst.)x10-4 = (1.7±2.9)x10-4
KSlope difference:Δg = (2.3 ± 2.8stat. ± 1.3trig.(stat.) ± 1.0syst. ± 0.3ext.)x10-4 = (2.2 ± 3.1)x10-4
Charge asymmetry: Charge asymmetry: [using g0=0.638 ]
A0g = (1.8 ± 2.2stat. ± 1.0trig.(stat.) ± 0.8syst. ± 0.2ext.)x10-4 =
(1.8 ± 2.6)x10-4
hep-ex/0602014; PLB 634 (2006)
Order of magnitude improvement
April 12, 2006 FPCP -- Vancouver 10
Observation of scattering effect in K→3 decays
1 bin = 0.00015 GeV2
K±±00
4mπ+2
30M events
4mπ+2
NA48/2 has made the first observation the of the charge exchange process +00 in the K00 decay.
M2(00) (GeV/c 2)2
NA48/2PLB 633 (2006) hep-ex/0511056
N. Cabibbo, hep-ph/0405001 PRL 93121801 (2004)
N. Cabibbo and G. Isidori, hep-ph/0502130 JHEP 503 (2005)
~|M0+M1|2
April 12, 2006 FPCP -- Vancouver 11
Difference between scattering length in I=0 and I=2 states
(a0 – a2)m+ = 0.268 ± 0.010(stat) ± 0.004(syst) ± 0.013(theor)
In agreement with theory (a0 – a2)m+ = 0.265 ± 0.004 (Colangelo 2001)
NA48/2PLB 633 (2006)
hep-ex/0511056
April 12, 2006 FPCP -- Vancouver 12
hep-ph/0511289
NA48/2EPS05
RK=(K e ) /(K
April 12, 2006 FPCP -- Vancouver 13
CKM Unitarity and Rare Kaon Decays The unitarity of the CKM matrix can be expressed by triangles in a complex plane. There are six triangles but one is more “triangular”:
VudVub*+VcdVcb*+VtdVtb*=0
Wolfenstein parameterization: Vus ~ Vcb ~ Vub ~ iVtd ~ i
Sensitive to |Vtd|
Im t = 2 5 Re t = 2 5
SM: BR(KSM: BR(K++++) ) (1.6×10(1.6×10-5-5)|V)|Vcbcb||44[[22+(+(cc--))22] ] (8.0 ± 1.1)×10 (8.0 ± 1.1)×10-11-11
BR(KBR(KLL00) ) (7.6×10 (7.6×10-5-5)|V)|Vcbcb||442 2 ± 0.6± 0.6×10×10-11-11
April 12, 2006 FPCP -- Vancouver 14
Reminder: K+→+
BR(K+ → + ) = 1.47+1.30-0.89 × 10-10
hep-ex/0403036 PRL93 (2004)
Stopped K+
~0.1 % acceptance
AGS
April 12, 2006 FPCP -- Vancouver 15
K0L E391a Upper Limit
BR(K0L )<2.8610-7 90%CL
Preliminary (KAON2005)6 improvement over KTeV one day special run2 improvement over published limit (KTeV Dalitz technique)
10% of RUN I
•Pencil beam •Expected background from K0
L decays: 0.02
•Acceptance: 0.73%
M=M
Require missingPt
April 12, 2006 FPCP -- Vancouver 16
Kaon Radiative Decays (KTeV, preliminary)
• K0L
– gM1 = 1.198 +/- 0.035 (stat) +/- 0.086 (syst)
– a1/a2 = -0.738 +/- 0.007 (stat) +/- 0.018 (syst)
– gE1 < 0.21 (90% CL)
• BR(K0L ) < 2.52 10-7 90%CL
• BR(K0L eee,Mee>5 MeV/c2) =
1.606 +/- 0.012(stat)+0.026-0.016(syst)+/-0.045(ext.) 10-5
• BR( ee,X>0.95)=6.56+/-0.26(stat) +/- 0.23(syst) 10-8
• K0L ee
– BR(K0L ee) = 9.25 +/- 0.03(stat) +/- 0.07(syst) +/- 0.26 (ext) 10-6
– CK* = -0.517 +/- 0.030 (fit) +/- 0.022 (syst)
– DIP= -1.729 +/- 0.043(fit) +/- 0.028(syst)
• BR(K0L ) = 1.70 +/- 0.03(stat)+/- 0.04(syst)) +/- 0.03(norm) 10-4
• BR(K0L ee,Eee>20 MeV/c2) = 1.60 +/- 0.18(stat) 10-7
April 12, 2006 FPCP -- Vancouver 17
OUTLOOK
April 12, 2006 FPCP -- Vancouver 18
DANE Luminosity and plans
• Last KLOE run: 2006• DANE runs until 2008
for other experiments: FINUDA +SIDDHARTA
• Plans for Luminosity and Energy upgrades (DANAE)
CM Energy
(GeV)
1.02 2.4
Peak Luminosity
(cm-2s-1)
1033 1032
DANAE Motivation:•Kaon interferometry•Nuclear Physics•N N form factor•Synchrotron rad.•R&D
April 12, 2006 FPCP -- Vancouver 19
Outlook: K0L
• KOPIO @ BNL stopped• In Japan a step by step approach is followed:• KEK:
– E391a has completed data taking (three runs)– They aim to reach the Grossman-Nir bound from the
accumulated data• J-PARC
– A proposal is being prepared for the new J-PARC hadron facility
– Step I: move the E391a detector at J-PARC– Step II: build a new detector and a dedicated beamline to be
able reach ~ 100 SM events
April 12, 2006 FPCP -- Vancouver 20
1.0E- 09
1.0E- 08
1.0E- 07
1.0E- 06
E391a Expected sensitivity
1-day 1-week Run-I Run-II Run-III
Sin
gle
Eve
nt S
ensi
tivi
ty
G-N Limit
KTeV Limit (Current Exp. Limit)
From: T. Inagaki
April 12, 2006 FPCP -- Vancouver 21
From Taku YamanakaOutlook: K0
L→0From Taku Yamanaka
April 12, 2006 FPCP -- Vancouver 22
Proposal to Measure the Rare Decay K at the CERN SPS
CERN, Dubna, Ferrara,Florence, Frascati, Mainz,Merced, Moscow, Naples,Perugia, Protvino, Pisa,Rome, Saclay, San Luis Potosi, Sofia, Turin
CERN-SPSC-2005-013 SPSC-P-326
April 12, 2006 FPCP -- Vancouver 23
Setting the bar for the next generation of K+→+ experiments
100 eventsMean=SM
100 eventsMean=E787/949
Current constraint on plane
?
E787/E949: BR(K+ → + ) = 1.47+1.30-0.89 × 10-10
April 12, 2006 FPCP -- Vancouver 24
P-326 Detector Layout
75 GeV/c800 MHz beam/K/p
K+
+
~11 MHz
Gigatracker
(KABES)
K
April 12, 2006 FPCP -- Vancouver 25
Background rejection
1) Kinematical Rejection
2) Photon vetoes and PID ()
Basic idea to reject K++0 :P(K) = 75 GeV/c
Require P() < 35 GeV/c
P() > 40GeV/c It can be
hardly missed in the calorimeters
2222 ||||||
||1
||
||1 KK
K
KKmiss PP
P
Pm
P
Pmm
Region I: 0 < m2miss < 0.01 GeV2/c
Region II: 0.026 < m2miss < 0.068 GeV2/c4
April 12, 2006 FPCP -- Vancouver 26
Gigatracker
26
X/X0 << 1%
Pixel size ~ 300 x 300 m(p)/p ~ 0.4% excellent time resolution
to select the right kaon track
Provide very good time resolution Minimise mass (multiple scattering and beam interactions)Sustain high, non-uniform rate ( 800 MHz total)
PP
K
•Two Silicon micro-pixel detectors (SPIBES)
•Timing•Pattern Recognition
•Improved KABES (micromegas TPC)•To minimise scattering in the last station
SPIBES:
Dependence of the signal to background (from K+ ) ratioas a function of the gigatracker time resolution
April 12, 2006 FPCP -- Vancouver 27
LKr inefficiency measured with data
Cluster not reconstruct
edE = 22
GeV
Pion P=42 GeV/c
Photon E=11 GeV
Expected
position
K+ collected by NA48 in 2004 track and lower energy are use topredict the position of the other
+00
LKr ineff. per photon (E > 10 GeV):
= (2.8 ± 1.1= (2.8 ± 1.1statstat ± 2.3 ± 2.3systsyst) × 10) × 10-5 -5
(prel.)(prel.)
April 12, 2006 FPCP -- Vancouver 28
Signal & backgrounds from K decays / year*Total Region I Region II
Signal (SM) 65 16 49
K++0 2.7±0.2 1.7±0.2 1.0±0.1
K2 1.2±0.3 1.1±0.3 <0.1
Ke4 2±2 negligible 2±2
K++ and other 3-tracks
bckg.
1±1 negligible 1±1
2 1.3±0.4 negligible 1.3±0.4
K2 0.4±0.1 0.2±0.1 0.2±0.1
Ke3, K3 ,others negligible
Total bkg 9±3 3.0±0.2 6±3•SPS used as LHC injector (so it will run in the future)•No flagrant time overlap with CNGS•P-326 fully compatible with the rest of CERN fixed target because P-326 needs only ~1/20 of the SPS protons•Beam time estimates based on decennial NA48 experience at SPS
*Before taxes. Proposal quotes 40 evt/year @BR=10-10
April 12, 2006 FPCP -- Vancouver 29
Status of P-326 (a.k.a. NA48/3)
• Presented at the CERN SPSC in September 2005
• R&D endorsed by CERN Research Board on December 2005
• Beam Test foreseen in August 2006• Seeking more groups to join• Aims to receive full approval by end of
2006….• …to be able to start data taking some time
in 2009-2010
April 12, 2006 FPCP -- Vancouver 30
Action is needed to keep KAONS at the heart of Flavour Physics & CP-Violation
Conclusions• The last two years have been MIXED for kaon physics. On the one side
there have been excellent results:
– Vus Renaissence
– Precise bounds on Direct CP-Violation in charged kaon decays
– Progress on K0L
– Some surprises
• BUT on the other side:
– All US-based future programmes have been stopped !!
April 12, 2006 FPCP -- Vancouver 31
SPARE SLIDES
April 12, 2006 FPCP -- Vancouver 32
Gigatracker (Hybrid Pixel)
• 200 m Silicon sensor (>11 000 e/h mip)
– Following Alice SPD
– Bump-bonding• Read-out chip
– Pixel 300 m x 300 m
– Thinned down to ~100 m (Alice SPD 150 m)
• Beam surface ~ 14 cm2
– Adapted to the size of the SPIBES
r-o chips • ~125 m Cfibre for cooling & support
y
x2mm/bin
2mm
/bin
Station 1(pixels) 2(pixels) 3(FTPC)
G. Anelli, M. Scarpa, S. Tiuraniemi
Front End and R/O considerations based on the experience of the CERN-PH/MIC and PH/ED Groups with the ALICE SPD
MeV
April 12, 2006 FPCP -- Vancouver 33
Example: “hadronic” cluster of a photon
Expected position
Maximum energy ~300 MeVExpected energy: ~29 GeVDeposited energy: ~9 GeV
Measured LKr inefficiency per photon (Eg > 10 GeV): = (2.8 ± 1.1= (2.8 ± 1.1statstat ± 2.3 ± 2.3systsyst) × 10) × 10-5 -5 (preliminary)(preliminary)
April 12, 2006 FPCP -- Vancouver 34
Acceptance equalisation for K+ and K-
Detector Left-Right asymmetry cancellation in the 4 K+/K ratios:
SD
N ( , ,u)R (u)
N ( , ,u)
A
B
B
A
+
-
+-- -
=
DJ
N ( , ,u)R (u)
N ( , ,
A
u)
B
BA
+
-
- -+-
=
♦
♦
♦
♦
US
N ( , ,u)R (u)
N ( , ,
A
u)
B
BA
+
-
+ +-+
=
JU
N ( , ,u)R (u)
N ( , ,u)
A
B
B
A
+
-
-++ +
=
R(u) = RUS(u)RUJ(u)RDS(u)RDJ(u) = (1 + 4 Δg u)
Fit of R(u) is sensitive only to the time variation of asymmetries in experimental conditionswith characteristic time smaller than corresponding field alternation periods (beam week,detector day) 2003 data taken in 4 SUPER-SAMPLES of 2 weeks each
Quadruple ratio:
Cancellation of systematic biases: - Detector L-R asymmetries ( K+ Salève / K- Salève and K+ Jura / K- Jura ) - Beam line biases ( K+ beam Up / K- beam Up and K+ beam Down / K- beam Down) - Global time-variable biases (K+ and K- simultaneously recorded)
Jura Jura (Left)(Left)
A+A+
A- A- SalèveSalève(Right)(Right)
ZZ
XXYY
Achromats: KAchromats: K+ + UpUp
Achromats: KAchromats: K++ DownDown
B+B+
B-B-
April 12, 2006 FPCP -- Vancouver 35
RICH Layout
April 12, 2006 FPCP -- Vancouver 36
Downstream straw tracker 6 chambers with 4 double layers of straw tubes each (
9.6 mm) Rate: ~45 KHz per tube (max 0.5 MHz) (+)Low X/X0
Operate in high vacuum
X/X0 ~ 0.1% per view
Good space resolution
130 m / hit
(P)/P = 0.23% 0.005%P() ~ 50 20 rad
Redundant momentummeasurement
2 magnets:270 and 360 MeV Ptkick
8.8
m
7.2
m
7.2
m
5.4
m
Veto for chargednegative particlesup to 60 GeV/c
5 cm radius beam holes displaced in the bending plane according to the 75 GeV/c beam path
z
x
y
2.3
m
April 12, 2006 FPCP -- Vancouver 37
P-326 Detector Layout
75 GeV/c800 MHz beam/K/p
K+
+
~11 MHz
Gigatracker
(KABES)
K
April 12, 2006 FPCP -- Vancouver 38
NA48 LKr as Photon VetoEnergy of photonsfrom K hitting LKr: > 1 GeV
GeVConsolidation of thesafety/control system and read-out under way
April 12, 2006 FPCP -- Vancouver 39
Backgrounds not kinematically constrained
Decay BRK+0e+
(K(Ke3e3))
0.049
KK33 0.033
KK22 5.5×10-3
K+++00
1.5×1
0-3
KKe4e4 4×10-5
KK44 1×10-58% of K+ decays
They span accross the signal regionsMust rely on Particle ID and veto
April 12, 2006 FPCP -- Vancouver 40
Beam:
Present K12
(NA48/2)
New HI K+
> 2006
Factor
wrt 2004
SPS protons per pulse on T10 1 x 1012 3 x 1012 3.0
Duty cycle (s./s.) 4.8 / 16.8 1.0
Solid angle (sterad) 0.40 16 40
Av. K+momentum <pK> (GeV/c) 60 75 K+ ~ 1.5
Mom. band RMS: (p/p in %) 4 1 ~0.25
Area at Gigatracker (cm2) 7.0 14 2.0
Total beam per pulse (x 107)
per Effective spill length MHz
MHz/cm2 (gigatracker)
5.5
18
2.5
250
800
60
~45 (~27)
~45 (~27)
~24(~15)
Eff. running time / yr (pulses)
3 x 105 3 x 105 1.0
K+ decays per year 1.0x1011 4.8x1012 48
New high-intensity K+ beam for P-326 AlreadyAvailable