Post on 17-Jan-2016
NA48the CERN Kaon facility
Fixed target experiment with 400-450 GeV protons from SPS
NA48: CP violation
4εRe (14.7 2.2) 10
ε
KL→ee decay A
L(14.2 ± 3.0stat ± 1.9sys)%
Ke3 Charge Asymmetry
L stat systδ (e) = (0.3317±0.0070 ±0.0072 )%
NA48: rare decays
KL→ee
1997 data (7000 events): BR(KL→ee) = (1.06±0.02stat±0.02syst±0.04norm)×10
K* = 0.207 ± 0.019 ± 0.017
In the BMS model: K* measure the relative strenght of intermediate pseudoscalar and vector meson contribution 1998-1999-2001 (600000 events)
BR(KL→eeee3.30±0.24stat±0.14syst±0.10norm)×10
KL→eeee
BR(KL→BR(KL→32.81±0.01stat±0.02syst)×10
BR(KL→) = (1.36 ±0.03stat±0.03syst±0.03norm) x 10-6
Mee
X= Mee2 / MK
2
NA48: Vus
0 2.8 9S 2.3BR(K π e e ) 5.8 (stat) 0.3(syst) 0.8(theor) 10
6 events found in the signal region with a background of 0.22+0.19-0.12
0 1.5 9S 1.2BR(K π μ μ ) 2.9 (stat) 0.2(syst) 10
NA48/1
NA48/2: cusp effect
NA48/2: “Neutral Asymmetry”
NA48/2: “Charged Asymmetry”
NA48/2: Vus
)%03.005.002.014.5()( )0
(0
BrsysstateKBr
)%07.001.002.046.3()( 865)0
(0
EeBrsysstatKBr
0015.02204.0|)0(|
0015.02192.0|)0(|
3
3
fVK
fVK
us
use
Vus x f
+(0
)
NA48/2: Ke2/K2