BR = (14 +6 -5 (stat) ± 2(syst) ± 5 (BR)) 10 -5 From PDG * From MC * BR( needs to be rescaled...
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Transcript of BR = (14 +6 -5 (stat) ± 2(syst) ± 5 (BR)) 10 -5 From PDG * From MC * BR( needs to be rescaled...
BR = (14 +6 -5 (stat) ± 2(syst) ± 5 (BR)) 10-5
From PDG * From MC
* BR(needs to be rescaled for fs/fd
//
0
0
0
0
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)(J
Js
s
s
s
KKBR
JBR
JBN
BN
JBBR
BBR
From Data
b->sss pure penguin amplitude Bs B± K ±
New Physics has a chance to compete! B K*: polarization discrepancy Bs is the Bs counterpart of Bd K*
Unexpected result (3s effect) from sin(2) measure from penguin dominated modes)
Measuring angular distribution of decay products determine polarization amplitudes and their relative phases through interference effects:
CP violation ΔΓs…
Blind Analysis:Normalize rate using another BsVV decay: BsJ/ :
•NO production ratio of Bs vs Bd (fs/fd) •one K+K- in the final state •some systematic on efficiency cancel•sizeable rate
B s
First o
bserva
tion
Charmless B decays at CDFMauro Donegà
Université de GenèveOn behalf of the CDF collaboration
LAYER 00: 1 layer of radiation-hard silicon at very small radius (1.5 cm) (expected 50 fs proper time resolution in Bs Ds )
COT: large radius (1.4 m) Drift Chamber
• 96 layers, 200ns drift time • Precise PT above 400 MeV/c
• Precise 3D tracking in ||<1
(1/PT) ~ 0.1%GeV –1;
(hit)~150m
SVX-II + ISL: 5 + 1 (2) layers of double-side silicon (3cm < R < 30cm)• Standalone 3D tracking up to ||= 2• Very good I.P. resolution: ~30m (~20 m with Layer00)
TIME OF FLIGHT
B =1.4 TTOF: ~100ps resolution, 2sigmaK/ separation for tracks below 1.6 GeV/c (significant improvement of Bs flavor tag effectiveness)
35 m 33 m = 47 m(resolution beam)
Primary Vertex
Secondary Vertex
BDecay Length
Lxy
d = impact parameter
Trigge on 2 displaced tracks :
Silicon Vertex TriggerALL b-
hadrons
Bd, Bs, b
• K/ separation:
>1.4 @PT>2 GeV/c
…no ev/ev PID separation
• This PID performance implies statistical separation of K-pi with resolution 60% of a “perfect” PID
e
p
k
893±47 Bhh’ events
Bd Bs
Bd kBs kk
Bd Bs k
Invariant mass hp (GeV/c2)
BKG fraction (float)
BKG Likelihood
Sum over the 4 channels
Likelihood variables:
•ΔΓs/Γs = 0.12 (Standard Model) •Bs KK = 100% short eigenstate•(HFAG2005) BR(Bd K ) = 18.2 x 10-6
•(PDG 2004) fs = 0.107 fd = 0.397
Bhh’ the future: •Higher precision BR(BsKK)•Bs KK lifetime: ΔΓs
•Precision Acp(Bd Kπ) (eventually1%)
•Bs Kπ BR and direct Acp
•Tagged time-dependent measurements further ahead:
Acp parameters for Bd and Bs
180 pb-1
360 pb-1
B hh’
180 pb-1
Luminosity usedin the analysesof this poster
180
massExtended unbinned maximum likelihood fit to :
•MKKK
•M
•helicity angle
•dE/dx
Helicity angle
Measure at the same time:
• N(B± K±)
• ACP(B± K±)
kaons
pio
ns
Bu,dX
B± K*0
B±f0K±
comb
ID
.)(.)(17.007.0)()(
)()()(
10.)(7.0.)(3.16.7)(
03.002.0
6
syststatKBNKBN
KBNKBNKBA
syststatKBBR
CP
+ PDG =
BR(B± J/ K±)
47.0 ± 8.4439 ± 22NB
B± K±B± J/ K±
With dataset now on tape new Bs modes should be visible (BsK*0K*0 , Bsρ):And other charmless decays are currently under study:
• Bd(s)K*+p-(K-)
• fV0 (as LbfL0 )
Next round with :~360 pb-1
Better trackingImproved PID
Bs
B± K±