BEAUTY 2005 International Conference on B-Physics at Hadron Mac Assisi (Perugia), Italy. June 20-24, 2005 •Mixing Parameters: •Width Differences: •CP-Violation Parameters: •Lifetime Ratios: Cecilia Tarantino Università Roma Tre and INFN Sezione di Roma III ) ( / ) ( ), ( / ) ( ), ( / ) ( d b d s d B B B B B s d B B , B-Meson Mixing and Lifetimes: s d B p q , | / | s d m m ,
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BEAUTY 2005 10th International Conference on B-Physics at Hadron Machines Assisi (Perugia), Italy. June 20-24, 2005 Mixing Parameters: Width Differences:
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BEAUTY 200510th International Conference on B-Physics at Hadron Machines
Assisi (Perugia), Italy. June 20-24, 2005
•Mixing Parameters:
•Width Differences:
•CP-Violation Parameters:
•Lifetime Ratios:
Cecilia TarantinoUniversità Roma Tre and INFN Sezione di Roma III
•OPE•Dominant top contribution • : short-distance physics, from Perturbation Theory (2%) [at NLO, Buras et al.: Nucl.Phys.B347 (1990)] • : non-perturbative QCD effects, from Lattice QCD
• : lattice uncertainties cancel
)(0 tB xS
22 ,ˆ ss BB fB
2
),( Wt mm
2
22
ˆ
ˆ
dd
ss
BB
BB
fB
fB
B-Physics on the Lattice
MULTISCALE PROBLEM
(computational cost limit)
1bam HQET, NRQCD, FermiLab approach, extrapolation in the heavy quark mass
1LM Extrapolation in the light quark mass using ChPT
Accurate “quenched” studies + recent Nf=2, Nf=2+1 calculations
50/ aL
Lattice QCD Actions:•Wilson/O(a)-improved Wilson: problem at light masses (exceptional quenched configurations)•Twisted mass: no exceptional configurations, easier improving, but more expensive•Staggered: light masses, but 4 tastes (fourth root trick)•Domain-wall/Overlap: light masses, but the most expensive
• sea quark effects seem at O(10%-15%):• But continuum scaling or other
Now averages include rough ``estimates’’ of chiral logs (mq/ms>0.2) and unquenched effects (Nf=2+1)
Now averages include rough ``estimates’’ of chiral logs (mq/ms>0.2) and unquenched effects (Nf=2+1)
B Mixing from Lattice QCD
)(MeVdBf
(MeV)sBf
ds BB ff /
fB O(s2) recently calculated
BB O(s) completed but non-factorisable contributions important
B Mixing from QCD Sum Rules
1. Equating phenomenological and theoretical spectral functions;2. Determination of theoretical spectral functions by calculating two or three-point correlators in perturbative QCD, including corrections from the OPE.
Problem: many parameters, loosely constrained!
2. 2. Decay:Decay:
sd BB ,
sdBpq
,|/|
)(/)(),(/)(),(/)( dbdsd BBBBB
•Width Differences
•CP-Violation Parameters
•Lifetime Ratios
)0( 11 Bq
)2( 21 Bq
HQE )( QCDbm Large energy release contact interaction