40-layer small-cell chamber

40-layer small-cell chamber

• 40-layer small-cell chamber

• 7104 drift cell formed from hexagonal wire pattern
• 80&120m Al wires and 20m Tungsten sense wires

• Layer organized into superlayers

• wire directions in axial-u-v pattern

• 80:20 helium:isobutane gas mixture

• low-mass gas and small Lorentz angle

Tallium-doped CsI crystals

• Tallium-doped CsI crystals

• Barrel: 5760 crystals Forward endcap: 820 crystals

• 16÷17 radiation lengths

• 16o<<142o polar angle coverage (90% in CM frame)

Absorber-detector alternating layers for  and KL detection:

• Absorber-detector alternating layers for  and KL detection:

• Bwd endcap: original RPC (18 layers);
• Fwd endcap: new RPC (16 layers) in streamer or avalanche mode;
• Barrel: old degraded RPC replaced by LST in summer 2004/2006 (12 layers)

Semileptonic Cabibbo favoured B→Xcℓ decays allow to extract the magnitude of the CKM parameters Vcb: Experimental clean but good understanding of QCD corrections is crucial

• Semileptonic Cabibbo favoured B→Xcℓ decays allow to extract the magnitude of the CKM parameters Vcb: Experimental clean but good understanding of QCD corrections is crucial

• Exclusive decays: B→D*ℓ, clean but need Form Factor normalization at zero recoil, F(1): (from Lattice QCD).

• Exploiting the full kinematics of the B→D*ℓ both the form factors ratios (R1, R2) and the F(1)*|Vub| parameter have been extracted

• Inclusive B→XℓMeasurements: Operator Product Expansion allows to extract Vcb exploiting the fit to moments of many experimental quantities:

• Moments of the hadronic mass distribution, and moments of the lepton momentum distribution as function of the minimum lepton momentum

b→uℓ decays allow to extract |Vub|:

• b→uℓ decays allow to extract |Vub|:

• |Vub|/|Vcb| provides benchmark for testing New Physics in other processes

One loop process: sensitive to New Physics

• One loop process: sensitive to New Physics

•  spectrum in the recoil of a Breco (almost no background for E>2.2 GeV)

• Br=(3.650.85)x10-4

• CP asymmetry (<1% in SM, up to 15% in some NP models). Xs from sum of 16 exclusive modes

• - ACP=(-0.0120.030)

• Observation of the b→dtransition with B→

• Br(B→)=(1.10-0.330.37 0.09)x10-6
• Br(B→)=(0.790.200.22 0.06)x10-6
• Br(B→)=<0.78x10-6@90%CL

D mixing and CP violation:

• D mixing and CP violation:

• Look for signs of new physics (x>>y or CP violation)
• First evidence of D mixing in D0K+-
• Decay modes under analysis: KS,KSKK,KK,,K3,K0
• Limits on CP violation in KK, at O(0.1%) level

• Dalitz plot Analysis:

• KS, KSKK, 0 are also important tools for  analysis

• Spectroscopy:

• DsJ* new resonances
• New charm baryons
• Measurements of spin

new states discovered; new interpretations

• new states discovered; new interpretations
• improved measurements of resonance parameters

ee  ISR ee  ISR   ISR X

• ee  ISR ee  ISR   ISR X

• X is any allowed final state ( JPC = 1)‏

• Radiator function W(s,s) known to <1%

• (ee  X) measured as a function of mX = s

• ee interactions accessible from threshold up to ~5 GeV