40-layer small-cell chamber - 7104 drift cell formed from hexagonal wire pattern
- 80&120m Al wires and 20m Tungsten sense wires
Layer organized into superlayers 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). Inclusive B→XℓMeasurements: 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 spectrum in the recoil of a Breco (almost no background for E>2.2 GeV) CP asymmetry (<1% in SM, up to 15% in some NP models). Xs from sum of 16 exclusive modes - ACP=(-0.0120.030) Observation of the b→dtransition with B→ - Br(B→)=(1.10-0.330.37 0.09)x10-6
- Br(B→)=(0.790.200.22 0.06)x10-6
- Br(B→)=<0.78x10-6@90%CL
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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 D0K+-
- Decay modes under analysis: KS,KSKK,KK,,K3,K0
- Limits on CP violation in KK, at O(0.1%) level
- KS, KSKK, 0 are also important tools for analysis
Spectroscopy: - DsJ* new resonances
- New charm baryons
- Measurements of spin
- new states discovered; new interpretations
- improved measurements of resonance parameters
ee ISR ee ISR ISR X ee ISR ee ISR ISR X X is any allowed final state ( JPC = 1) Radiator function W(s,s) known to <1% (ee X) measured as a function of mX = s ee interactions accessible from threshold up to ~5 GeV
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