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

)(

)/(

)/(

)(

)/(

)(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±