BEAUTY 2005 10th International Conference on B-Physics at Hadron Machines
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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 ,
description
BEAUTY 2005 10th International Conference on B-Physics at Hadron Machines Assisi (Perugia), Italy. June 20-24, 2005. B-Meson Mixing and Lifetimes:. Mixing Parameters: Width Differences: CP-Violation Parameters: Lifetime Ratios:. Cecilia Tarantino - PowerPoint PPT Presentation
Transcript of BEAUTY 2005 10th International Conference on B-Physics at Hadron Machines
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
)(/)(),(/)(),(/)( dbdsd BBBBB
sd BB ,
B-Meson Mixing and Lifetimes:
sdBpq
,|/|
sd mm ,
Basic FormalismBasic Formalism
Physical Physical ObservablesObservables
1.1. Mixing Mixing mmdd, , mmss
• Phenomenological importance (UTA)Phenomenological importance (UTA)• Theoretical inputsTheoretical inputs
Unitarity Triangle Analysis 1)7(502.0 psmd
.).%95(4.14 1 LCpsms
[HFAG 2005]
Extracting |VExtracting |Vtdtd|:|:
20
2
2
22
2
2
0
2
2
22
ˆ)(6
ˆ)(
6
BsBtBtsBWF
s
BsBtBtdB
WFd
fBxSVmmG
m
fBxSVm
mGm
ss
s
d
•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
systematics (NP-ren., FV effects, diff. actions …) not completely investigated 230 30 MeV
sBf
50ss Bs B i fb p
With the present accuracy:
NRQCD
FNAL
RELAT.
FNAL NRQCD
ICHEP 2004:ICHEP 2004:
NRQCD
Bs-Meson Decay Constant from Lattice QCD
•High level of accuracy;•Good agreement among different approaches;•Continnum extrapolation;[De Divitiis et al.(2003), ALPHA(2003)]
Quenched SimulationsQuenched Simulations
•Nf=2 studies [JLQCD(2003): high statistics and O(a)-improved action];•Nf=2+1 preliminary values [Wingate at al. (2003): staggered action];
Unquenched SimulationsUnquenched Simulations
s s
d d
B B
B B
f m
f m
0.050.061.22sB
B
f
f
50dd BB ip fb d
ICHEP 2004:ICHEP 2004:
• Chiral Log Effects roughly estimated [JLQCDJLQCD (Nf=2, mq/ms>0.5) +HPQCDHPQCD (Nf=2+1, mq/ms>0.2)]
With the present accuracy:With the present accuracy:
more statistics and lighter quark masses
still needed
more statistics and lighter quark masses
still needed Final Chiral Loop Effects: O(5%)
Bd-Meson Decay Constant from Lattice QCD
•Pion Loops could be significant [Kronfeld-Ryan(2002), O(15%)]
Delicate Issue: Chiral ExtrapolationDelicate Issue: Chiral Extrapolation
8.1)31(
log)4(4
)31(31
2
2
2
2
22
g
m
f
mg
mf
mf
dd
ss
BB
BB
[JLQCD(2003), N[JLQCD(2003), Nff=2]=2]
• Negligible sea quark effects!!Negligible sea quark effects!!• Consistent with diagnosis deduced Consistent with diagnosis deduced
from QChPT versus ChPTfrom QChPT versus ChPT: : [[Booth95,Sharpe,Zhang96]
With the present accuracy:With the present accuracy:
JLQCD(2003): NJLQCD(2003): Nff=2 & NRQCD=2 & NRQCD
B-B Mixing on the Lattice
qqq BBBqLLq BfmBqbqbB ˆ
3
8 22
5617
8695 )16(017.1
ˆ
ˆ ,)42(287.1ˆ
d
s
d
B
BB
B
BB
Lattice data are consistent with a constant.
Chiral Loops not a problem for
They are expected small from ChPT
Chiral Loops not a problem for
They are expected small from ChPT
B-B Mixing on the Lattice
qqq BBBqLLq BfmBqbqbB ˆ
3
8 22
dBB̂
ICHEP 2002 (Lellouch)BEAUTY 2005
(ICHEP 2004, Hashimoto)
203(27)(+0-20) 189(27)
238(31) 230(30)
276(38) 262(35)
1.18(4)(+12-0) 1.22(+5-6)
1.18(4)(+12-0) 1.23(6)
ˆ (MeV)s sB Bf B
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
SPECTATOR EFFECTS
Scale separation
• : short-distance (perturbative)• : long-distance (non-perturbative)
)(qkc
020 )( q
Bqkq BOB
•Lifetime Ratios (1996) [M. Neubert and C.T. Sachrajda]
(2002)•[E. Franco, V. Lubicz, F. Mescia and C.T.]•[M. Beneke, G. Buchalla, C. Greub, A. Lenz and U. Nierste]
(2004)•[F. Gabbiani, A. I. Onishchenko and A. A. Petrov]
•Width Differences and CP (2003)•[M. Ciuchini, E. Franco, V. Lubicz, F. Mescia and C.T.]•[M. Beneke, G. Buchalla, A. Lenz and U. Nierste]
(1996) •[M. Beneke, G. Buchalla and I. Dunietz]
)( sO
)/1( bmO
)/1( bmO
)( sO
)1(O
kk
b
kkk
bb
s
B
bcbF Om
cOc
mbGb
m
gcbbc
M
mVG )7()7(
)6()6(3
2
2)5()3(
3
522 96
)2(192
b
s
mSScscbB
bFs QGQGVVM
mG/1
2*22
21 )()2(12
Wilson Coefficients from P.T.
Matrix Elements: Operators2B
)/1( 3bmOLeading contribution
21 , qq BB From the lattice (with different methods) or QCD -sum rules [J.G. Korner et al., 2003]
Subleading contribution )/1( 4bmO
4 operators :),,,( 4321qqqq RRRR
qq RR 41 ,
qq RR 32 ,
• : related, through Fierz and eq. of motion, to operators computed on the lattice
• : from the VSA
21 , qq BB on the lattice•HQET
•NRQCD
•unquenched NRQCD
•QCD
•QCD +HQET
[V. Gimenez and J. Reyes, 2000]
[Hi-KEK (S. Hashimoto et al.), 2000]
[JLQCD (S. Aoki et al.), 2001-2003]
[APE (D. Becirevic et al.), 2000]
[APE (D. Becirevic et al.), 2001]
• So far, the approach has been only applied in the quenched case
Matrix Elements: Operators0BLeading spectator effect contribution )/1( 3
bmO
(not computed)
(not computed)
B-parameters:b• :computed in lattice-HQET, evolved at the LO
BBB sd B-parameters
•Lattice-HQET
•Lattice-QCD
•Sum Rules, in HQET
Subleading spectator effect contribution )/1( 4bmO
8 operators, from the VSA (B-mesons) or the quark-diquark model (baryon)
[M. Di Pierro and C.T. Sachrajda, 1998]
[APE (D. Becirevic et al.), 2001]
[M.S. Baek et al., 1998]
Width Differences
Experimental measurements:
Theoretical predictions at the NLO + contribution of :)/1( 4bmO
LO 26%
LO+ 16%
NLO 18%
NLO+ 7%)/1( 4bmO
2 01.065.0 25.033.0
s
s
[CDF, 2004] 21.0 27.0
40.0
s
s
[D0, CKM2005]
(preliminary)
097.0)064.0240.0()014.0018.0(
)()(* /12)1(
2)0(
21)1(
1)0(
1
bm
ss
s
s OccOccFact )/1( 4bmO
21 cc
%27)0(
2
)1(2 c
c
%5522
/1 s
m
Ocb
(large cancellations at the NLO)
(large cancellations at ))/1( 4bmO
[THEORY]
CP-Violation Parameters
Theoretical predictions at the NLO:
Experimental measurement:
•Importance of more accurate measurements UTA
0034.00013.01(q/p)d [HFAG, 2005]
Lifetime Ratios
LO NLO
)(
)(
dB
B
)(
)(
d
s
B
B
)(
)(
d
b
B
Theoretical predictions at the NLO + contribution of : )/1( 4bmO
Experimental measurements:
•Good agreement at the NLO and )1at )(/)(( db B)/1( 4bmO
LO 1.01(3) 1.00(1) 0.93(4)
NLO 1.06(3) 1.00(1) 0.90(5)
NLO+ 1.06(2) 1.00(1) 0.88(5)
)(
)(
dB
B
)(
)(
d
s
B
B
)(
)(
d
b
B
)/1( 4bmO
Conclusions
DECAY: Importance of NLO corrections in QCD and in the HQE
Lifetime Ratios 1at )(/)( db B
Width Differences
)/1( 4bmO
[CDF, 2004]
01.065.0 25.033.0
s
s
Importance of more accurate measurements UTA
CP-Violation Parameters
21.0 27.040.0
s
s
[D0, Lattice2005]
(preliminary)
03.007.0
s
s
[THEORY]
MIXING: Phenomenological importance of in the UTA Theoretical inputs at 5-15% from Lattice QCD
sd mm ,
