January 18, 2005 A. Ceccucci, CERN 1
Rare Kaon Decays: Opportunities at CERN
Augusto Ceccucci/CERN Padova, January 18, 2005
January 18, 2005 A. Ceccucci, CERN 2
Why study Rare Kaon DecaysIn the 21st century?
• Search for explicit violation of Standard Model – Lepton Flavour Violation
• Study the strong interactions at low energy – Chiral Perturbation Theory, Form Factors
• Test fundamental symmetries– CP,CPT
• Probe the flavour sector of the Standard Model– FCNC
Unique probe of the s→d quark transitions
s d Vtd
Vts*
January 18, 2005 A. Ceccucci, CERN 3
Quark mixing and CP-Violation
'
'
'
ub
cb
td
ud us
cd cs
ts tb
V
V
V V
d d
s s
b b
V
V
V
V V
Ng=2 Nphase=0 No CP-Violation
Ng=3 Nphase=1 CP-Violation Possible
Quark mixing is described by the Cabibbo-Kobayashi-Maskawa (CKM) matrix
Predictions of standard theory (after KM ): •Direct-CP Violation exists: ’/ 0 NA48, KTeV •CP violation in the B meson sector: ACP(J/ Ks), BaBar, Belle
Paradigm shift: having established the abovelook for inconsistencies in SM using observables with small theoretical errors
Im t= Im Vts*Vtd ≠ 0
January 18, 2005 A. Ceccucci, CERN 4
Kaon Rare Decays and the SM
(holy grail)
Kaons provide quantitative tests of SM independentfrom B mesons…
…and a large windowof opportunity exists!
|Vtd|
G. Isidori
Im t = A2 5 Re t = A2 5
January 18, 2005 A. Ceccucci, CERN 5
Further Enticement: New Physics?
• These rare kaon decays are second order weak interactions mediated by Z penguins that could be sensitive to NP
• A deviation from the predicted rates of SM would be a clear indication of new physics
• Complementary programme to the high energy frontier:– When/if new physics will appear at the LHC, the rare decays may help to
understand the nature of it
January 18, 2005 A. Ceccucci, CERN 6
Kaons@CERN:NA48
1997
1998
1999
2000
2001
2002
2003
NA48: ’/
’/
’/
’/ lower inst. intensity
NA48/1 KS
NA48/1: KS
KL
no spectrometer
NA48/2: K
1996
2004NA48/2: K
Re ’/= 14.7 ± 2.2 10-4
First observation ofK0
S →0 ee and K0S →0
Ave: Re ’/= 16.7 ± 2.3 10-4
+ KL Rare Decays
Search for Direct CP-Violation in charged kaon decays
Direct CP-Violation established!
January 18, 2005 A. Ceccucci, CERN 8
NA48 Detector
1996Total: 5.3M KL00
Magnetic spectrometerLiquid krypton EM calorimeter
90 m longVacuum tank
400 GeV protonsFrom CERN SPS
January 18, 2005 A. Ceccucci, CERN 9
Recent but well established Rare Kaon Decay Tradition @CERN:
NA48/1
January 18, 2005 A. Ceccucci, CERN 10
0++, 2++
Direct CPV
Indirect CPV
CPC
NA48/1: K0s→0ee and K0
s→0
Principal aim of NA48/1: Measure the IndirectCP-Violating Contributionto K0
L→0ee and K0L→0
January 18, 2005 A. Ceccucci, CERN 11
NA48/1: Backgrounds
KS →0 ee
Source Control Region
Signal region
KS→0D0
D 0.03 0.007
KL,S → ee 0.11 0.075
e+20(0) 0.19 0.069
Total 0.33+0.18-0.11 0.15+0.05
-0.04
KS →0 Source
KL →
KL,S → Accidentals
Total
0. +0.02 -0.00
0.04+0.04-0.03
0.18+0.18-0.11
0.22+0.18-0.11
• Many other sources investigated and found to be negligible
(e,g neutral cascade decays)
• Blind analysis: Control and signal region remained masked until the study of the background was finished
January 18, 2005 A. Ceccucci, CERN 12
K0S →0 ee and K0
S →0
KS →0 eeKS →0
BR(KS→0ee) 10-9 = 5.8 +2.8
-2.3(stat) ± 0.8(syst)
|as|=1.06+0.26-0.21 (stat) ± 0.07 (syst)
PLB 576 (2003)
7 events, expected back. 0.15
BR(KS→0) 10-9 = 2.9 +1.4
-1.2(stat) ± 0.2(syst)
|as|=1.55+0.38-0.32 (stat) ± 0.05 (syst)
PLB 599 (2004)
6 events, expected back. 0.22
NA48/1 NA48/1
M. Patel PhD thesisM. Slater PhD thesis
January 18, 2005 A. Ceccucci, CERN 13
Isidori, Unterdorfer,Smith:
Fleischer et al*:
Ratios of Bd → modes could be explained by enhanced electroweak penguins which, in turn, would enhance the KL BR’s:
•A. J. Buras, R. Fleischer, S. Recksiegel,
F. Schwab, hep-ph/0402112, NP B697 (2004)
1.6 111.6
0.7 110.7
9.0 10
4.3 10
NP
e e
NP
B
B
0 12L(K ) 10Br
0 12L( ) 10Br e e
K0L→0ee (): Sensitivity to NP
January 18, 2005 A. Ceccucci, CERN 14
NA48/1: Semileptonic decays
+
semileptonic decay is the only source of in the neutral beam because→ is kinematically forbidden
January 18, 2005 A. Ceccucci, CERN 15
Preliminary Result
• Based on 6238 -decays:BR(→e)=(2.51 ± 0.03sta ±0.11sys)10-4
Compare KTeV: (2.71 ± 0.38) 10-4
Systematics: Trigger Efficiency 2.6 % Acceptance 3.0 % ff (g1 and f2) 1.0 % Polarisation 1.0 % Lifetime 0.5 % Tot systematics 4.2 % Stat Uncertainty 1.2 %
January 18, 2005 A. Ceccucci, CERN 16
NA48/2 : K+/K-
Simultaneous K+ and K- beams
January 18, 2005 A. Ceccucci, CERN
17
Direct CP violation
in K± ± ± , K± ± 0 0 M(u) 1 + gu, u= f( )
(Ag ) < 210 – 4
NA48/2: AimNA48/2: Aim
g + - g -
Ag = ———— g+ + g -
In addition:• Study of scattering using Ke4 (and ± events
• Study of medium-rare charged kaon decays• Study of semi-leptonic decays
*
oddE
January 18, 2005 A. Ceccucci, CERN 18
cos(e)
K±+-e±ν (Ke4) selection (preliminary)
Cabibbo-Maksymowicz
variables [backgr. in red]
Background
Ke4 hypothesisK- mass
0 0.1 0.2m(e), GeV/c2
0.3 0.4 m(), GeV/c2
2003 data: > 500k (background ~0.6%)
January 18, 2005 A. Ceccucci, CERN
19
First Observation of the + - - rescatteringin K 0 0 decays
M2(00), (GeV/c2)2 M2(00), (GeV/c2)2
4m2()= 0.0779(GeV/c2)2
29M decaysNA48/2 Preview!
January 18, 2005 A. Ceccucci, CERN
20
M2(00), (MeV/c2)2
Determination of a0-a2
from K 0 0 decays
a0-a2 = 0.265
= 0.N. Cabibbo hep-ph 0405001, PRL93 (2004)
January 18, 2005 A. Ceccucci, CERN 21
Z=(M(ee)/MK)2
Form-factorK± ± e+e-
> 2600ev.
M(± e+e-), GeV/c2
• low background (1-2%)
• expected data sample in 2003-2004 comparable to the World best sample
Kee & K±±+- selection(preliminary)
K± ± +-
> 1000ev. (PDG:
~ 800)
NA48/2(2003)
January 18, 2005 A. Ceccucci, CERN 22
“CERN Director General Outlines Seven-point Strategy for European Laboratory”
18.6.2004 Official CERN Press Release Geneva 18 June 2004. “At the 128th session of CERN Council, held today under the chairmanship of Professor Enzo Iarocci, CERN Director General, Robert Aymar, outlined a seven-point scientific strategy for the Organization. Top of the list was completion of the Large Hadron Collider (LHC) project with start-up on schedule in 2007. This was followed by consolidation of existing infrastructure at CERN to guarantee reliable operation of the LHC, with the third priority being an examination of a possible future experimental programme apart from the LHC.”………
……… The possible Future Programme was reviewed by the SPSC in
Villars (September 22-27, 2004)
January 18, 2005 A. Ceccucci, CERN 23
Message from the CERN Director General to the staff (Jan 05)
• The top priority is to maintain the goal of starting up the Large Hadron Collider (LHC) in 2007
• “…Meanwhile, the natural break we have in the fixed-target programme in 2005 is already allowing the community to develop a well-focused programme for the future”
January 18, 2005 A. Ceccucci, CERN 24
The Next Step: NA48/3 K → at the CERN-SPS
SPSC-2004-029SPSC-I229
Cambridge, CERN, Dubna, Ferrara,
Firenze, Mainz, UC Merced, Perugia,
Pisa, Saclay, Sofia, Torino, + ??
Work inspired by:•High Quality NA48/2 charged Kaon beams and Beam Spectrometers•Outstanding Progress by BNL E787/E949 •In flight technique with separated beam proposed by FNAL CKM
• not ratified by HEPAP P5
January 18, 2005 A. Ceccucci, CERN 25
Prediction (CKM Workshop): BR(K+ → ) = 8.0 ± 1.1 × 10-11
Expect improvements NNLO calculation + reduction parametric uncertainty 4 % error (Buras)
K+→+ : Theory
220
411
2242
32
)(109.8
||||sin2
)()(
A
XXV
KBKB
lcctt
usW
eSD
•The hadronic matrix element can be extracted from the well measured K+→ 0 e+ •No long distance contributions
QCD NLOBuchalla,Buras 1999
January 18, 2005 A. Ceccucci, CERN 26
Main K+ decay modes competing with K+→+
Decay
e
BR
63 %
21 %
6 %
2 %
3 % (called K+3)
5 % (called K+e3)
Suppression:
PID, kinematics
veto, kinematics
CHV, kinematics veto, kinematics veto, PID veto, E/P
BR(K+→+ )~10-10 !!
January 18, 2005 A. Ceccucci, CERN 27
K+→+ : State of the art
BR(K+ → + ) = 1.47+1.30-0.89 × 10-10
•Twice the SM, but only based on 3 events…
hep-ex/0403036 PRL93 (2004)
Stopped K~0.1 % acceptance
AGS
January 18, 2005 A. Ceccucci, CERN 28
NA48/3 (I229): Decay In Flight
• Collect 80 K+→+ events in about two years of data taking for:
– 4 1012 Kaon decays/SPS year– BR( K+→+ ~10-10
– Acceptance ~ 10%
– Absolute advantage:
High energy kaon beam: >35 GeV of EM energy deposited in the vetoes Vey Difficult to miss 0 !!
– Disadvantage:
Unseparated Kaon beam
Region II
Region I
P(K)=75 GeV/c
January 18, 2005 A. Ceccucci, CERN 29
NA48/3 Detector Layout
800 MHz(/K/p)
Only the upstream detectors see the 800 MHz beam
10 MHz Kaon decays
K++
undetected
January 18, 2005 A. Ceccucci, CERN 30
Acceptance
75 / 40 /
Assume Acceptance (Region I+II) ~ %KP GeV c P GeV c
( / )KP GeV c ( / )KP GeV c
Acceptance
Acceptance
Region I Region II
2 2 20 0.01 ( / )missm GeV c 2 2 20.026 0.068 ( / )missm GeV c
14 ( / ) 40P GeV c 14 ( / )P GeV c
14 ( / ) 30P GeV c
75 GeV/c
January 18, 2005 A. Ceccucci, CERN 31
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 Total : 1.35
Mom. band RMS: (p/p in %)
4 1 ~0.25
Area at Gigatracker (cm2) 7.0 20 2.8
Total beam per pulse (x 107)per Effective spill length MHz MHz/cm2 (gigatracker)
5.5182.5
25080040
~45 (~27)~45 (~27)~16 (~10)
Eff. running time / yr (pulses)
3* x 105 3.1 * 105 1.0
K+ decays per year 1.0x1011 4.0x1012 40
New high-intensity K+ beam for NA48/3 AlreadyAvailable
January 18, 2005 A. Ceccucci, CERN 32
GIGATRACKER
• Specifications: – Momentum resolution to ~ 0.5 % – Angular resolution ~ 10 rad– Time resolution ~ 100 ps– Minimal material budget– Perform all of the above in
• 800 MHz hadron beam, 40 MHz / cm^2• Hybrid Detector:
– SPIBES (Fast Si micro-pixels)• Momentum measurement • Facilitate pattern recognition in subsequent FTPC• Time coincidence with CHOD
– FTPC (NA48/2 KABES technology with FADC r/o)• Track direction
January 18, 2005 A. Ceccucci, CERN 34
Main Tracker w/o beam pipe?
?
We are considering a full straw tracker operated in vacuum
January 18, 2005 A. Ceccucci, CERN 35
TRT ATLAS
Straw diameter – 4 mm, length – 40 and 150 cm
17 end-cap wheels are built in JINR (105 kpc of straws)
COMPASS TRACKER
Straw diameter – 6 and 10 mm, length up to 3.8 m
15 chambers were built in JINRStraw tracker operated in vacuum:
COSY-TOF, Juelich,IKP
Straw tracker, 3100 straws, evacuated –
10-3 mbar (P.Wintz)
MECO, BNL (W.Molzon)
Etc.
January 18, 2005 A. Ceccucci, CERN 36
Straw Tacker w/o beampipe
Four views (X,Y,U,V)One Station (Exploded view)
January 18, 2005 A. Ceccucci, CERN 37
New NA48/3 simulation
Uncorrelated non gaussian tails
Gaussian MSC (old)
Non-Gaussian MSC
P (Spectrometer 1) GeV/c P (Spectrometer 1) GeV/c
P (Spectrometer 2) GeV/c
P (Spectrometer 2)GeV/c
M(miss)2 (GeV/c2)2
New MSC
REGION I
REGION II
January 18, 2005 A. Ceccucci, CERN 38
ANTI
• Set of ring-shaped photon vetoes surrounding the decay tank• Specification: inefficiency to detect photons above 100 MeV < 10-4
• The NA48 ANTI’s (AKL) need to be replaced• Extensive R&D Performed by American and Japanese groups • Claims that inefficiency as low as 10-5 can be achieved• Baseline solution: Lead/ Plastic scintillator sandwich (1-2 mm
lead / 5 mm plastic scintillator)• Cost driver of NA48/3
January 18, 2005 A. Ceccucci, CERN 39
LKR
• The NA48 Liquid Krypton Calorimeter • Must achieve inefficiency < 10-5 to
detect photons above 1 GeV • Advantages:
– It exists – Homogeneous (not sampling)
ionization calorimeter– Very good granularity (~2 2 cm2)– Fast read-out (Initial current,
FWHM~70 ns)– Very good energy (~1%, time ~
300ps and position (~1 mm) resolution
• Disadvantages– 0.5 % X0 of passive material in
front of active LKR– The cryogenic control system
needs to be updated
January 18, 2005 A. Ceccucci, CERN 40
MAMUD
Pole gap is 11 cm V x 30 cm H
Coils cross section 15cm x 25cm
•To provide pion/muon separation and beam sweeping.
–Iron is subdivided in 150 2 cm thick plates (260 260 cm2 )
•Four coils magnetise the iron plates to provide a 1.3 T dipole field in the beam region•Active detector:
–Strips of extruded polystyrene scintillator (1 x 4 x130 cm3) –Light is collected by WLS fibres 1.2 mm diameter
January 18, 2005 A. Ceccucci, CERN 41
Where are we?
• August 2004 test run– WC: raise intensity to about 30 times NA48/2– GIGATRACKER
• Tested a state-of the-art ALICE SPD assembly in our beam• Use a thinner 25 micron MICROMEGAS amplification gap• Read out KABES with 480 MHz FADC (former NA48 tagger FADC)• Read KABES at ~14 times the NA48/2 rate
– LKR: Complement the photon coverage with Small Angle Calorimeter SAC (CMS ECAL prototype)
– CHOD test of prototypes• September 26-27, 2004
– Our presentations at Villars were well received• October 7, 2004
– John Dainton, SPSC Chairman reported the conclusions from Villars at CERN in a seminar at CERN
– Verbally: ”The SPSC looks forward to receive a proposal”• October 18, 2004
– Letter of Intent officially submitted. SPSC-2004-029 SPSC-I229– We have establishing working groups aiming to submit a proposal by mid 2005:
John DaintonVillars 2004
October 7th 2004CERN seminar
SPSCSPSC
● new rare decay frontier in K physics at CERN
● new experiments planned for Kπνν important
● support R&D now for K+π +νν results ≤ 2010- no competition … yet!
● longer term opportunity for K0π 0νν - direct competition (decay at rest)
● synergy with energy frontier @ LHC … @ CERN - B-physics - LF violation
● rare charm decay: feasibility of operating experiment (NA60) ?
January 18, 2005 A. Ceccucci, CERN 43
Time Schedule
• 2005– Launch GIGATRACKER R&D– Vacuum tests– Evaluate straw tracker– Start realistic cost estimation– Complete analysis of beam-test data– Submit proposal to SPSC
• 2006-2008– Costruction, Installation and beam-tests
• 2009-2010– Data Taking
January 18, 2005 A. Ceccucci, CERN 44
Conclusions
• We have found a fortunate combination where a compelling physics case can be addressed with an existing accelerator, employing the infrastructure (i.e. civil engineering, hardware, some sub-systems) of an existing experiment
• We stress that this initiative in not a mere continuation of NA48
• We are seeking new Collaborators!
January 18, 2005 A. Ceccucci, CERN 45
Kaons: Longer term (i.e. More Protons Needed!)
• K0L→ 0eeand K0
L→ 0(NA48/4)
• K0L → 0 (NA48/5)
January 18, 2005 A. Ceccucci, CERN 46
K0L→ee() : Perspectives
• Detector ×2 – Very ambitious, KTeV/NA48 already state of the art
• KS-KL time dependent interference ×2– Position experiment between 9 and 16 KS lifetimes (hep-ph/0107046)
• KS-KL time independent interference ×3 – Assume constructive interference (theoretically preferred)
• Data Taking ×5 – Run in “factory mode”. After all E799-II run only for a few months to
collect ~7 × 1011 KL decays• Beam intensity ×4
– Need ~1012 protons/sec, slowly extracted, high energy (≤ 1 TeV), DC • Tot ~ ×240 → sens on BR ~ ×15 (on Im t ~×4-15)
– explore the window of opportunity between current upper limit and SM
Ideal Kaon Application for High Intensity/High Energy Machine
January 18, 2005 A. Ceccucci, CERN 47
K0L → 0
•Purely theoretical error ~2%: SM 3 10-11
•Purely CP-Violating (Littenberg, 1989) •Totally dominated from t-quark•Computed to NLO in QCD ( Buchalla, Buras, 1999)•No long distance contribution SM~3 × 10-11
• Experimentally: 2/3 invisible final state !!• Best limit from KTeV using →ee decay
BR(K0 → 0) < 5.9 × 10-7 90% CL
Still far from the model independent limit: BR(K0 → 0) < 4.4 × BR(K+ → +) ~ 1.4 × 10-9 Grossman & Nir, PL B407 (1997)
January 18, 2005 A. Ceccucci, CERN 48
E391a@PS-KEK
•First dedicated experiment to search for KL→ •SES~ 3 10-10
•Based on pencil kaon beam and photon vetoesScheduled for ~100 days KEK PS beam in 2004 This is a Stage I project for further study at J-PARC
January 18, 2005 A. Ceccucci, CERN 49
KOPIO@BNL
• Aim to collect 60 KL→ events with S/B~2 (Im t to 15%)• Measure as much as possible
– Energy, Position and Angle for each photon• Work in the Kaon Center of Mass
– Micro-bunched AGS beam– Use TOF to measure KL momentum
• Start construction in 2005?
January 18, 2005 A. Ceccucci, CERN 50
KL→0@CERN?
NA48/5?
E391A
J-PARC
CERN may become competitive if the E391A technique works
From KAMI proposal
SPS
January 18, 2005 A. Ceccucci, CERN 51
Conclusions
– A competitive programme can start pnow for charged kaons at the current SPS
– For a very competitive neutral kaon decay experiment, ~ 1013 slowly extracted, high energy protons per second would be needed
January 18, 2005 A. Ceccucci, CERN 53
CompetitionNA48/3 P940
Accelerator CERN-SPS FNAL-MI
Energy (GeV) 400 120
Duty cycle (s /s ) 4.8 / 16.8 = 0.29 1.0 / 3.0 = 0.33
1 HEP year (s) 107 107
Eff. Spill. Length (s / s) 3.0 / 4.8 = 0.63 1.0 / 1.0 (?)
Total Rate (GHz) 0.8 0.23
Fraction of Kaons (%) 6 4
Flux of Kaons (MHz) 50 10
Decay fraction (%) 9 (50 m / 100 m) 17 (60 m / 67 m)
Acceptance (%) 10 5
Events/y (BR~10-10) 82 31
January 18, 2005 A. Ceccucci, CERN 54
KL→0@CERN?
NA48/5?
E391A
J-PARC
CERN may become competitive if the E391A technique works
From KAMI proposal
SPS
January 18, 2005 A. Ceccucci, CERN 55
Intermezzo: Vus puzzle
• The Unitarity of the CKM matrix requires for the first row:
• PDG04:
• Semileptonic kaon decays are the best method to determine |Vus|: – protection from first order SU(3) symmetry
breaking
2 2 2| | | | | | 1ud us ub
V V V
2 2 2 3| | | | | | 1 3.3 1.5 10ud us ub
V V V
2.2
3
| | 0.9738 0.0005 | | 0.2200 0.0026| | (3.67 0.47) 10
ud us
ub
V VV
January 18, 2005 A. Ceccucci, CERN 56
NA48 KL→e (Ke3) analysis
• Data from minimum bias run 1999 (80 M events) • The basic measured quantity is the ratio R of
decay rates of Ke3 decays relative to all decays with two charged tracks
2 2
0 0 0 0 0
0
/
/ (2 ) 1 (3 ) ( ) (2 ) (2 ) (4 ) = 1.0048 (3 )
( 3) (2 )
e e
T T
D
N aR
N a
B T B B B B B TB
B Ke R B T
External input: BR(KL→0 00)
January 18, 2005 A. Ceccucci, CERN 57
NA48 Experimental Result
R= 0.4978 ± 0.0035
• To compute BR(K3e) we need : BR(KL→0 00)• PDG04: 0.2105 ± 0.0028• KTeV 04: 0.1945 ± 0.0018 Take average*: 0.1992 ± 0.0070
BR(2T) = 0.8056 ± 0.0070
BR(Ke3) = R * BR(2T) = 0.4010 ± 0.028 ± 0.0035
*NA48/1 Internal cross check (Y2K data, see later)
in good agreement with KTeV
5 !!
January 18, 2005 A. Ceccucci, CERN 58
Extraction of Vus
• Taking the latest calculation:– (Cirigliano et al., 2004) f+(0)= 0.981 ± 0.010
|Vus| = 0.2187 ± 0.0028 still 2.4 from unitarity (0.2274)• For comparison, if one takes the old Leutwyler and Ross
value: – f+(0)= 0.961 ± 0.008
|Vus| = 0.2232 ± 0.0029 one finds good agreement with unitarity
January 18, 2005 A. Ceccucci, CERN
59
ICHEP-2004
PDG
SMV
us x f
+(0
)
8 hours of 2003minimum-bias run9104
K 0e
normalizationchannel: 7105 K+ 0
Br(Ke3)= (5.14 ± 0.02stat ± 0.06syst)%
BR (K 0e ) preliminary
January 18, 2005 A. Ceccucci, CERN 60
FTPC (KABES+FADC)
• NA48/2– KABES has achieved very good performance – Position resolution ~ 70 micron– Time resolution ~ 0.6 ns– Rate per micro-strip ~ 2 MHz
• NA48/3 – Intensity ~ 10 higher per unit area– 600 ns drift – The long drift (600 ns) makes a standalone pattern
recognition very difficult or just impossible ( That’s why we plan to have SPIBES in front)
– To reduce double pulse resolution and improve the time resolution one has to reduce the pulse duration and possibly read-out every micro-strip with 1 GHz FADC
January 18, 2005 A. Ceccucci, CERNMara Martini 61
GIGATRACKERS
PIB
ES
1
SP
IBE
S2
FT
PC
6.25 12.45 m
♠ momentum: use SP1 and SP2 to measure y = 40 mm displacement. Assuming σp~50µm from pixel and 350µm thick Si (0.37% X0)
σ = (σp√2 ‡ σMS ) ⁄ 40 mm = 0.25%
♠ direction: use SP2 and FTPC. Assuming σp~100µm from pixel and similar from FTPC and no MS from FTPC (from SP2 no influence)
∆Өх= σp√2 ⁄ 12.4m = 11µrad
Tails in the beam? (Turtle simulation)
♠ time resolution: essential to obtain a low background due to accidental hits and to allow the pattern recognition (see result from test beam) . For a pixel C≈ 100 fF a risetime ~ 2 ns should be achievable for 130 nm technology and a good S/N.
January 18, 2005 A. Ceccucci, CERNMara Martini 62
Proposal for SPIBES
5 cm
300 x 100 µm pixel cell 80000 pixels in total to cover the beam
• An effort must be done to minimize the overall thickness to ≤ 350 µm of Si without loosing in yield .
• Should avoid a substrate
• The cooling should be studied
• The dimension of the pixel cell and of the chip must be optimized to fit the 2n rule and to match the design requirements (PA, Discri, multiplexed TDC, power consumption, r/o bus)
Beam square shape 5x5 cm2
January 18, 2005 A. Ceccucci, CERN 63
Test of ALICE pixel in NA48/2 beam 1 ALICE assembly
1 DAQ adapter card 30 m DAQ cables
30 m JTAG control cables LV and HV power supplies
VME crate with r.o. module (Pilot) and JTAG
controller JTAG multiplexer
MXI interface to PC ALICE PTS software
(LabView)
PC remotely controlled from NA48 control room
January 18, 2005 A. Ceccucci, CERN 64
Single Chip Alice Assembly tested
Assembly 7:•150µm thick ALICE chip•200µm thick sensor• 1.1 % X0 all together
Mounted on a thin test-PCB
Vfd=15VVop=50V
8192 pixelsProduced 2003, tested inALICE p-TB 2003
Sensor
Chip
January 18, 2005 A. Ceccucci, CERN 65
MULTIPLICITY (200 nsec gate)
I0I0/4
4xI0
14xI0
<mult> = 1.1 <mult> = 1.3
<mult> = 3.1 <mult> = 7.8
January 18, 2005 A. Ceccucci, CERN 66
MULTIPLICITY (200 nsec gate)MULTIPLICITY (200 nsec gate)
for r/o window of 10 ns:
1GHz x 10 ns x 1.1 ~ 10 hits/ trig
for σ = 100ps we expect in a ±2.5σ:0.5 accident hits/trig
January 18, 2005 A. Ceccucci, CERN 67
driftE
driftE
Tdrift1
Tdrift2
Operated @ Edrift=0.83kV/cm
Tdrift1 + Tdrift2 = 750ns
48 strips with 0.8 mm pitch
Very low discharge probability
Micromegas
Gap 50 μm
Micromegas
Gap 50 μm
KABES principle: TPC + micromegas
January 18, 2005 A. Ceccucci, CERN 68
Recent lab test with 25 m gap
50 m gap 25 m gap
improvement of occupancy observed with 25m amplification gap
Width ~30 ns Width ~18
ns
KABES 25 micron amplification gap
January 18, 2005 A. Ceccucci, CERN 69
480 MHz FADC
January 18, 2005 A. Ceccucci, CERN 70
Beam Test 2004: WC
• With the exception of one sector in the Y view of DCH3 all other channels could be operated at nominal HV at the highest beam intensity
• Quite encouraging: plane efficiency decreases only by 1-2% • Ability to operate the WC at intensity close to NA48/3 is very
important
January 18, 2005 A. Ceccucci, CERN 71
NA48 Liquid Krypton Calorimeter
9 m
3 o
f Lk
r (132
12
ce
l ls)
1.2
5 m
dep
h (27
X0 )
(E)/E = 3.2%/E 9 % /E 0.42%(m)~1 MeV/c2 ;(t) ~ 300 ps
FAST: 70 ns FWHM (it can be reduced)EXCELLENT GRABULARITY: 2 2 cm2
January 18, 2005 A. Ceccucci, CERN 72
Small angle photon vetoPbWO4 crystals (CMS) Dimension of crystals 2x2x23 cm3 7 x 7 cm matrix ~ 25 X0
Readout with light guides and PMTInstalled for last week of data taking
January 18, 2005 A. Ceccucci, CERN 73
General definitions
2 2 2( / )missm GeV c
Region I
Region II
( / )P GeV c
K
0
0 Peak Region
January 18, 2005 A. Ceccucci, CERN 74
Detectors• CEDAR
– To tag positive kaon identification• GIGATRACKER
– To Track secondary beam before it enters the decay region
• ANTI
– Photon vetoes surrounding the decay tank • WC
– Wire chambers to track the kaon decay products• CHOD
– Fast hodoscope to make a tight K-pi time coincidence
• LKR
– Forward photon veto and e.m. calorimeter• MAMUD
– Hadron calorimeter, muon veto and sweeping magnet• SAC and CHV
– Small angle photon and charged particle vetoes
January 18, 2005 A. Ceccucci, CERN 75
Tentative Indication of costElement Cost (MCHF) Comments
BEAM LINE 0.5 Modified K12 line
CEDAR 0.2 Photon Detectors
GIGATRACKER 1.4 Assuming 0.13 m
VACUUM 0.7 Upgrade of vacuum system
ANTI 4.2 Based on CKM estimate + elec.
WC 3.0 Two more chambers + R/O
MNP33/2 2.5 Including prolongation of He tank
CHOD 1.0 2000 PMs, 500 CHF/channel
LKR 2.0 New supervion system and R/O
A state-of the art calorimeter is 15 MCHF
MAMUD 2.0 Cost of iron: ~500 KCHF
SAC & CHV 0.5
TRIGGER & DAQ
TOTAL 19.0
January 18, 2005 A. Ceccucci, CERN 76
Compatibility/Competition
• NA48/3 is fully compatible with COMPASS running– We need only 3 1012 per cycle (already available now on
T4!)
• There are two approved competitors for beam time – LHC filling and CNGS
• The extent of the project implies that there should not be in addition (at the stage of data taking)– A fixed target heavy ion programme– Any other experiment in ECN3 competing for proton
beam time
• We understand that the SPS can deliver protons for fixed target physics even when LHC is being operated with ions
January 18, 2005 A. Ceccucci, CERN 77
Simulation: GeometryStandardStandard
Upgrade2Upgrade2
Testrun 2004 (beatch file)NA48/3 (beatch file)
Upgrade1Upgrade1
January 18, 2005 A. Ceccucci, CERN 78
Kaons @ CERNPast:NA48: Direct CP Violation Established ! NA48/1: First Observations of K0
S → 0 ee () •Mixing CP-Violation in K0
L → 0 ee () measured !Present: NA48/2: K+ / K- Taken data in 2003/2004
•Search for Direct CP-Violation•Inspiration to study K+ → + in flight
Future Opportunities:•Short to medium term (≤ 2010)NA48/3 K+ → + TODAY MAIN FOCUS•Longer term
NA48/4 K0L → 0 ee ()
NA48/5 K0L → 0
January 18, 2005 A. Ceccucci, CERN 79
Direct CP
Indirect CP
Short Distance Contribution
directly from
Interference Term ?Constructive
Destructive
Interference between K0L→0ee and
K0s→0ee
Two independent theoretical analyses find that theinterference term is constructive:•Buchalla,Isidori,D’Ambrosio: hep-ph/0308008, NP B 672 (2003)•Friot, Greynat, de Rafael: hep-ph/0404136, PL B 595 (2004)
January 18, 2005 A. Ceccucci, CERN 80
NA48/1: K0s→0ee
• Experimental difficulties:• Backgrounds from K0
s→00→0ee (with one lost photon)
– Apply cut m(ee)>0.165 GeV/c2
• Backgrounds from double Dalitz and photon conversions
• Radiative backgrounds from K0L→ee
– Measured directly from large (2001) KL sample
• Accidental backgrounds from two event overlap, e.g.
K0s→00 (with 2 lost photons) + K0
L→e(with pion mistaken as electron)– Measure in time-side-bands exploiting excellent time
resolution (signal region < 3 ns) , Side time band ~50 ns
January 18, 2005 A. Ceccucci, CERN 81
NA48/3: Beam Layout
Beam-line 102 m long
about 17%K+ lost
Dipoles
Dipoles
January 18, 2005 A. Ceccucci, CERN 82
Villars 2004
Report on the SPSC Villars MeetingSeptember 22-28 2004
John DaintonUniversity of Liverpool, GB
(on behalf of the SPSC)
January 18, 2005 A. Ceccucci, CERN 83
NA48: Re ’/=14.7 ± 2.2 10-4
Top “down-loaded” articles from Physics Letters B:• 1. The hierarchy problem and new dimensions at a millimeter
http://dx.doi.org/10.1016/S0370-2693(98)00466-3 Physics Letters B, Volume 429, Issues 3-4 , 18 June 1998, Pages 263-272 Nima Arkani-Hamed, Savas Dimopoulos and Gia Dvali
• 2. A precision measurement of direct CP violation in the decay of neutral kaons into two pions http://dx.doi.org/10.1016/S0370-2693(02)02476-0 Physics Letters B, Volume 544, Issues 1-2 , 19 September 2002, Pages 97-112 J. R. Batley et al. (NA48 Collaboration)
• 3. Has the GZK suppression been discovered? http://dx.doi.org/10.1016/S0370-2693(03)00105-9 Physics Letters B, Volume 556, Issues 1-2 , 13 March 2003, Pages 1-6, John N. Bahcall and Eli Waxman
• 4. Testable scenario for relativity with minimum length http://dx.doi.org/10.1016/S0370-2693(01)00506-8 Physics Letters B, Volume 510, Issues 1-4 , 21 June 2001, Pages 255-263 Giovanni Amelino-Camelia
• 5. Role of effective interaction in nuclear disintegration processes http://dx.doi.org/10.1016/S0370-2693(03)00801-3 Physics Letters B, Volume 566, Issues 1-2 , 24 July 2003, Pages 90-97 D. N. Basu
• 6. Determination of solar neutrino oscillation parameters using 1496 days of Super-Kamiokande-I data http://dx.doi.org/10.1016/S0370-2693(02)02090-7 Physics Letters B, Volume 539, Issues 3-4 , 18 July 2002, Pages 179-187 S. Fukuda et al.
• ….
January 18, 2005 A. Ceccucci, CERN 84
NA48/1: KS →0 ee
e+-e-+ (Odd Sign) DATA e+-e-+ DATA vs. MC
Blind Control& Signal regions
mee (GeV/c2)
me
e
(G
eV/c
2)
January 18, 2005 A. Ceccucci, CERN 85
NA48/1: KS →0 ee
e+-e+- (Same Sign) DATAe+-e+- DATA vs. MC
Search region
me
e
(G
eV/c
2)
mee (GeV/c2)
January 18, 2005 A. Ceccucci, CERN 86
NA48/1: KS →0 •Study of backgrounds from KL→ →
January 18, 2005 A. Ceccucci, CERN 87
0 12L(K ) 10Br
0 12L( ) 10Br e e
Constructive
now favored by two independent analyses*
(Isidori, Unterdorfer, Smith,
EPJC36 (2004))
1.1 110.9
0.3 110.3
3.7 10
1.5 10
e eB
B
Destructive0.7 110.6
0.2 110.2
1.7 10
1.0 10
e eB
B
*G. Buchalla, G. D’Ambrosio, G. Isidori, Nucl.Phys.B672,387 (2003)
*S. Friot, D. Greynat, E. de Rafael, hep-ph/0404136, PL B 595
*
K0L→0ee () in SM
Thank to the NA48/1, the KL BR can now be predicted* Interference between short- and long-distance physics*
Exp (KTeV) (90%CL):BR(K0
L→0ee)<2.8 10-10
BR(K0L→0)<3.8 10-10
January 18, 2005 A. Ceccucci, CERN 88
How to measure +0 Rejection
M2(miss) (GeV/c2)2 M2(miss) (GeV/c2)2
DATAMC
DATAMC
745862 MC212569 DATA
1486 MC678 DATA
0 peak BEFORE APPLICATION OF EXTRA CLUSTERS IN LKR
AFTER APPLICATION OF EXTRA CLUSTERS IN LKR
January 18, 2005 A. Ceccucci, CERN 89
Kinematical rejection
Events accepted
( / )P GeV c
2 2 2( / )missm GeV c0
Region I
Region I
2 2 2 2( cos )miss K K K Km EE pm m p Measured quantities
Region II