risultati recenti di babar [una selezione dalle conferenze estive] csn1 napoli 19/09/2005 giuseppe...
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Risultati recenti di BaBar[Una selezione dalle conferenze estive]
CSN1 Napoli 19/09/2005
Giuseppe FinocchiaroLaboratori Nazionali di Frascati
*ubudVV
*cbcdVV
*tbtdVV
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 2
The gold rush
(Where `gold’ is no longer J/Ks)
Most analyses in this talk used the Run1-4 dataset (~240fb-1)
KEKB delivered ~470fb-1 so far
Run1
Run2
Run3
Run4
Run5
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 3
(The usual) disclaimer
Hard selection required in this talk (75 BABAR abstracts @LP05, 57 @EPS05) In spite of ‘sub-optimal’ PEP-II
performance this year so far, still competitive wrt Belle
“Di necessità virtù”: BABAR‘s analysis power generally (still) compensates for smaller integrated statistics
More physics channels Better detector (PID, vtx) More efficient analyses
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 4
Indice Angoli (I): , Lati (I): |Vub| da b→u ℓ sin2: (persistenti) indizi di NP Lati (II): |Vtd/Vts| da b→d/s Ancora nuovi stati: la Y(4260) Non parlerò di:
SM:
B→@CLSM:± B→Ks[hep-ex/0507038] SM:L.H. sin~
Conclusioni, prospettive
]%90@10[ )041802)2005(95(PRL)0508012/(
88.611 exhepe CL
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 5
UT angles: From direct CPV in the decay of charged B’s
Interfering tree amplitudes w/ CP-violating relative weak phase and CP-conserving relative strong phase
Interference if D0/D0 decay into identical final state CP-eigenstate decay: Gronau-London-Wyler (GLW) Doubly-Cabibbo-suppressed (DCS) decay: Atwood-Dunietz-
Soni (ADS) Dalitz plot analysis of 3-body decay, e.g., : Giri-
Grossman-Soffer-Zupan (GGSZ)
*cbcdVV
*ubudVV
00~SKD
b→ucsb→cus
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 6
It all depends on rB…
Sizable interference only if large enough amplitude ratio
Unfortunately, BABAR finds small rB
Error on vs. rB
rB≈ 30o error on w/ current BABAR data need to add more channels/data
2.01.0~)(
)(
cbA
ubArB
From CKM factors & color suppression
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 7
New GLW and ADS signals in][
~ 0*0 SKKDB
B+
B-
B-
B+
NCP+=37.6±7.4 NCP-=14.8±5.9
Right Sign Wrong Sign
WS B+ WS B-
mES (GeV/c²)
~90 events ~4 events
hep-ex/0508001CP-eigenstate decay DCS decay
D0→flavour non-CP
D0 CP+→K+K,
D0 CP-→KS0, KS, KS B
B
B
B
hep-ex/0507002, submitted to PRL
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 8
The idea in pictures:
CP-conjugate B and B decay amplitudes
is the same, r(*) and (*) depend on the mode
A(B)=|A(B→D0K)|×
m2
D0
+rBei(-+B)
D0
m2
m2
m2
GGSZ DP analysis of *)(][
~ 0(*)~
00(*)
KSDS KKKDB
),(),()( 2222
mmAeermmA||ABA Dii
BDBB
),(),()( 2222
mmAeermmA||ABA Dii
BDBB
(*)*(*)22(*)22 2|||||)(| BiiDDBDBD eeAArArABA
)( 022 SKmm
Assume D decays conserve CP…
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 9
DP analysis of D0/D0 decays
Extract D(bar) decay amplitudes from DP analysis of independent cc sample with flavor-tagged decays from
New K-matrix model: 9 BW resonances + K-matrix formalism for s-wave Deals with broad,
overlapping, multi-channel scalar resonances
00SKD 0* DD s
91fb-1 82k D0s
hep-ex/0507101
)( 022 SKmm
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 10
Signals in all modes (*)0(*)~KDB
D0K- D*0[D00]K- D*0[D0]K-~ ~ ~ ~ ~Mode
Signal events
B-D0K− 282 ± 20
90 ± 11
B-D*0[D0]K− 44 ± 8
B-D0K*−[K0S-] 42 ± 8
B-D*0[D00] K−
227×106 BB
~
~~
~~~
(mES>5.27 GeV/c²)
NEW B-D0K*−[KS]~
hep-ex/0507101
hep-ex/0
504039,
accepte
d by P
RL
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 11
GGSZ DP results: vs. r(*)B
Mode rB/r*B /rs
DK
D*K
DK*
statsystDP)o
all D()K() modes combined:
hep-ex/0507101
2 fold ambiguities for both and B
D0K- D*0K- D0K*-
rB
(d
eg
)
r*B .rs (<0.75@2 CL)
~ ~~
2 CL
1 CL
(stat.+syst. uncertainties)
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 12
Putting it all together…
… we can measure !!!! 3 theoretically clean (= w/o
penguins) methods to measure did not mention TD D(*)… (no new
measurement) Small r()
B very hard measurement, but no longer “mission impossible”
No single channel dominates To improve precision, need more
data/channels )(57 7
13-CKM )(63 1512-WA
BABAR only:: 231851
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 13
UT angles from TD asymmetries
d
d
0B
*tbV
tdV
b
b
0Bt
t
*tdV
tbV** // tdtbtdtb VVVVpq
B0B0 mixing
du
dd0B
/ubV
*udV
b /u
Tree decay
ubudVVA *
du
dd
0B
/g
b
/utcu ,,
Penguin decay
tbtdVVA *
Specific example is for , but valid in general Single CKM phase in decay ↔ Cf=0 (no direct CPV)
b→uud
Preamble: CPV from interference of decay and mixing
22
2
||1
Im2
||1
||1
SC
14
Difficult to reliably estimate how much penguins contribute
B(B0K+) (~ pure penguin) indicates they cannot be neglected
Gronau/London analysis Assuming isospin symmetry, these triangular relations between the Bhh amplitudes hold:
The B and B triangles do not match, and 2eff = 2+κ Need to measure 5 BFs, including B(B00) from tagged
samples still a 8-fold ambiguity
Grossman/Quinn bound:
and the penguins: more triangles are needed
effi
i
i
i eeT
P
eTP
eA
A
p
q
22 ||1
1
κ
000 22 AAAdecaysB
000 22 AAAdecaysB
)BF(B
)BF(Beff 0
00
2 )(sin
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 15
Measuring in B→ decays Tough analysis [VV state, , ’s are wide] However:
(~6 times x B→)
(isospin triangle collapses to a line) Small penguin contribution:
eff@CL
(almost pure CP-even state)
60 10)5430()( BB
CL %90 @ 101.1)( 6000 BB
021.0029.0014.0978.0
Lf
232M BB
PRL 95 041805 (2005)
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 16
from B→ decays
All three modes give consistent and complementary measurements of
constraint rather weak due to large penguin contamination
yields single most precise constraint
TD analysis of Dalitz plot in Weak constraint at 90% CL, but disfavors mirror solution near 170o
)99][ 129-hh (
)(95 1013-CKM
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 17
UT sides: |Vub|Tree-level process (charmless semileptonic) NP free ‘complementary’ (opposite in the UT) to sin
BF(b→u l ) measured from inclusive and exclusive s.l. branching fractions From inclusive (partial) s.l. BFs using O.P.E.
reliable prediction of total B→Xuℓ decay rate experiment measures partial BFs (hard cuts against B→Xcℓ) biggest uncertainty in extrapolation of BF(b→u l ) to full phase space from
motion of b quark in B meson Parameters measured e.g. from E* in b→s
VcdVcb*
VudVub* VtdVtb
*
γ
α
β
PRD72 052004 (2005)
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 18
Inclusive |Vub| measurements
Electron endpoint spectrum
Electron and momentum
Lepton and hadronic system recoiling against fully-reconstructed B mesons
signalregion sideban
dregion
signal
88M BB
hep-ex/0408075, being submitted to PRD
3th
42.0
38.0exp 10)22.025.044.4(||
SFubV
lEq 2
89M BB
hep-ex/0506036 submitted to PRL
3th
58.0
42.0exp 10)25.026.095.3(||
HQubV
232M BB
hep-ex/0507017
3th
46.0
38.0exp 10)23.034.065.4(||
SFubV
Xmq 2
19
|Vub| from exclusive measurements: untagged Bℓ
Exclusive s.l. BFs |Vub| using form factors (FFs) in bins of q2
several approaches LCSRs, LQCD, quark models … FF uncertainties affect measurement twice
1. FF shape acceptance try and measure on data2. FF normalisation in extraction of |Vub| from pBF (~10-15%)
|Vub|=(3.82±0.14stat±0.22syst±0.11FF– 0.52FFnorm)x10-3+0.88
83M BB, hep-ex/0507003, subm. to PRD
LCSR LQCD
)/(|| 0 Bub BV
for GeV
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 20
Incl. vs. Excl. : which wins?Inclusive
Improved expt. error: 4% Very much improved theory
error ( OPE parameters): 6%
Exclusive Improved expt. error: 4% Theory error still dominant: ≥15%
Experimental input, i.e., FF shape, will reduce theory error in the future
Measurements now compatible within errors
325.022.0 10)56.3(
CKM
ubV
Indirect |Vub| determination
]HFAG[10)16.076.3(|| 387.0
51.0exp
LQCDubV
]HFAG[10)27.019.038.4(|| 3th,exp
bmubV
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 21
Why this is relevant
• constraints from TREE process only
• Gauge the UT in any extension of the SM
• Firm starting point for NP searches
UTfit JHEP 0507:028,2005
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 22
sin2 from charmonium [to find NP, must know OP]
Reference point for NP C=0 (only 1 phase) S=-fsin
Precise! Validation of SM predictions
sin[UTFit]=0.793±0.033 (sides) [0.734±0.024 (all)] In fact, a big success…
J/
KS
BO
032.0687.02sin EPS'05 New Belle meas. (357M BB):sin0.652±0.044
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 23
Why b→s penguins are good for NP
Small effects (e.g. from propagators of heavy particles circulating in the loop) more easily detectable since Tree is missing
CKM factors same as J/Ks
If single phase, SM predicts: Speng=Scharmonium=sin Cpeng=Ccharmonium
Naïve [HFAG] average of penguin modes 2.7 below charmonium
note: BABAR and Bellehave ~same precision
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 24
To find NP, must know OP (II)
In fact, we know that > 1 amplitude/phase is (usually) involved
e.g., b→uus CS tree () in channels involving non-strange neutral mesons
Even J/Ks could have penguins S± [hep-ph/0507290]
Is there a dominant one? Intense theoretical work lately
sin always >0 (contrary to experiment)
some predictions quite precise theory parameters constrained to
measured BF (will further improve) Averaging still not meaningful
QC
D f
act
oriz
atio
n:
[Ch
en
g,C
hu
a,S
on
i, h
ep
-ph
/05
06
26
8]
[Be
ne
ke,
he
p-p
h/0
50
50
75
]
sin
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 25
New signals (~230M BB) in [KK]KL0
hep-e
x/0
50
70
87
KS0
has smallest stat. error on sin KL
0 adds 50% more events ( total)
SK0 ±±, CK0 ±±
K0 and KKK0 have largest BF
among b→s modes
SK+KK0L ±±, CK+KK0
L ±±Using fCP-even ±±
sinK+KK0 ±±±
hep-ex/0507016
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 26
CPV in b→s penguins Intriguing difference from b→c remains
This could be one of the greatest discoveries of the century, depending, of course, on how far down it goes…
2.7
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 27
b→d Large background Only accessible through exclusive modes B Simultaneous fit to B+→, B0→, B+→ assuming
BBM 211
hep-ex/0408034
2.1/
0.1
4.0
8.1
)BF(10Channel
0
-6
Belle claim observation
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 28
UT sides: |Vtd/Vts| Constraint used to come entirely from md/ms
(smaller theoretical uncertainty on ) Now radiative penguins sufficiently precise to start providing
meaningful UT constraints, using:
Low B→ BF favors small |Vtd|
VcdVcb*
VudVub* VtdVtb
*
γ
α
β
ssdd BfBf 22 /
s
dd m
mm
and
)(
)(*
KBB
BB
R=0 in this plot
Ali et al.,Eur.Phys.J.C23:89-112,2002
FF ratio ±
difference in dynamics R
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 29
New States: X→J/ Discovered by Belle in 2003 in
3872 is just above open-charm threshold Confirmed by D0, CDF, BABAR
isovector charged partner(s) must exist ruled out @10CL by BABAR in B0(+)→XK
searched in B0(+)→X0(J/)K decays
Need more data to discriminate among different models Does not fit in standard charmonium spectroscopy
why does not decay onto DD? J/ isospin violating (but is a ?)
[qq][qq] [Maiani et al. PRD71, 014028 (2005)]: R=1, m±MeV/c2
D*0D0 molecule [PRD71, 074005 (2005)]: R<0.1 Search in ISR events
J)3872( ,)3872( XKXB 6.1σ
2.5 σ
R=BF(B0→XKS)/BF(B→XK)=
m= MeV/c2
JPC= 1(2S),
(3770), …
...no sign of X(3872) in ISR, but...
Discover Y(4260)→J/!!
S
hep-ex/0506081
232fb-1
Just above DSDS threshold Could be two states
Very robust signal. Among other tests: Use (2S) for optimisation/validation fit for null signal with
different bkgd shapes bin sizes
check for reflections
Split by run, J/ decay mode search in J/sidebands require ISR (25% of events) change/reverse selection feed-down e.g. from undetected 0
Peak cross section ~50pb
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 31
Where else?
No trace in R-scan hadnb Y~pb accuracy of R~4%
no surprise it‘s not seen in R
• But why a dip?• And why does not decay to DD?
Y(4260)
√s (GeV)
Feeble signal (so far) inB→J/K
• 3.1 assuming mISR, wISR • need more data
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 32
Summary & outlook
CPV in mixing↔decay (and decay) well established Precision in measurements of CKM parameters steadily improving The Standard Model resists (surprisingly well…)
New states keep popping up in unexpected places renewed interest in spectroscopy, new models proposed and being scrutinized
Finding NP is the name of the game now Deviations from sin in b→s penguin getting smaller (~1 for most modes) In general, processes with clear SM predictions are good candidates
B→around the corner?
20052005 2008 (?)2008 (?)
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 33
The next few years
Statistical uncertainties have scaled so far faster than (adding new channels) Even for J/Ks systematics not an issue, for several ab yet Theory often feeded by exptl. measurements
also improves with more data Expected precision on UT angles vs. time:
L/1
from
sin in penguins
from B→DK
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 34
Our analysis commitments
BaBar in Italia
Torino: decadimenti senzacharm a due corpi (, K,KK), Vub (recoil)
Milano: analisi dipendenti dal tempo in decadimenti senza charm e misure di BF (KKS/LaK/Ks)
Genova: charmonio(B cc adroni,B cc[Cg]K),
Pisa: sin/CP/CPT, vita media del , →Ks, DK Dalitz per l'estrazione di b→s inclusivo, B→D*l , B→D0
CPK(), B→D*
Roma I: sin(), BDS/K, DKS, b→s sul rinculo, mixing del B, X(3872), Vub, DK Dalitz per l'estrazione di , decadimenti senza charm e analisi dipendenti dal tempo per l'estrazione di (K, KK), →, sin dai pinguini (KS, KL, KSKSKS ,K+KKL,KS, K*), B→K+
Trieste: B→D*D*, Vcb B→D*l BD(*)DsJ
Padova: Vcb B→D*l Vub, vitamedia e mixing del B, →CPV nel mixing
Ferrara: Vub, Vcb e charmonio sul rinculo
Perugia: BD*DS*, DS,
, CPV dal lato di tag,CPV nel mixing
LN Frascati: BD*D*, BD*DS*,
DS, ISRK*+K, ISRCPV nel mixing
Napoli: Vcb B→D*l B→J/KB→ decadimenti semileptonici
Bari: decadimenti a 3 corpi della D,DsJ*(2317)+, DsJ*(2460)+ (analisi di Dalitz)
°o
° ° °
°
°°
°°
°°
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 35
Backup slides
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 36
L-scaling of channels for angles measurements
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 37
How NP would be constrained
NP (assuming only in loops) parameterised as di
ddeCSM
NPSM
From tree measurements
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 38
Event yields in 229M BBbar
soon to come: forward-backward asymmetry
RK = 1.06 0.48 0.05 [SM:~1]RK*= 0.93 0.46 0.12 [SM:~0.75]
ACP(K) [SM:~0]ACP(K*) [SM:~0]
ll(*)KB
hep-ex/0507005, preliminary
N=57±14
ll*KB
N=45±10
llKB smallest BF fromB’s measured to date!
• sensitive to relative contribution of -, Z-penguin and box diagram• new physics can show up in any of these
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 39
B→Ks Phase in B→K*0 between mixed and
unmixed decay is 2 W couples only to left-handed quark: b→sL
interference suppressed in SM: Smix -2ms/mb sin sin
possibly large enhancement from NP can use Ks0 even if not from resonance (Atwood
et al (2004))
2.00.19.0)(05.040.021.0)(
00
0*
SKSKSK
non-K
Compatible w/ SMErrors still large
hep-ex/0507038, submitted to PRL232M BB
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 40
B→ CKM fit predicts
Direct measurement of fB (currently only from LQCD)
B→/md constraints |Vub/Vtd|
> 2 in the event. Analysis:o Use hadronic or semileptonic tago 1 or 3 prong topology
o Can constrain SUSY parameters
510)5.21.8()Β( B
C.L.%[email protected] 4)Β( B
BBM 232 We’re almost there!
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 41
(NP in) b→d/s
• FCNC• sensitive to NP @ EW scale• solid SM predictions:
• BFB→Xs
• ACP~0• Huge backgrounds
• cuts on or Xs spectra ↔ model dependence
• Fully inclusive (no requirement on Xs/d)• lepton tag [/1200 on Bkg (/20 on Sig)]• topology cuts, vetoes
• Exclusive (semi-inclusive) b→s• reconstruct Xs→K+n+m (n,m<5)
• 38 states,55% of all possible 1504 85sigN
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 42
b→d/s spectra, BF, ACP
Inclusive Semi-inclusive
ACP(b s b d ) = ( 0.010 0.115 0.017 )
hep-ex/0506043
BBM 88
BBM 153 hep-ex/0403004
Partial Branching Fractions (PBF)
(4s) frame B rest frame
LP Paper-100
Method, cut BF(10-4)
Inclusive, 1.9 GeV
Exclusive, 1.6 GeV
Inclusive, 1.8 GeV
29.034.029.067.3
07.064.008.041.019.038.3
11.030.007.031.032.055.3
19/09/2005 G. Finocchiaro @ CSN1 Napoli 2005 43
from B[K]K: ADS method
Equalize the interfering amplitudes (PRL 78, 3257)
Extract from decay rates measurements
KKB D][ KDKDB 00 ,
favored suppressed
KDKDB 00 ,favoredsuppressed
coscos2
)][()][(
)][()][(22
sup.
fav.
favoured
suppressed
BDBDK rrrrN
N
KKBKKB
KKBKKBR
0.93±0.04
rD=0.060±0.003, from
D*+[K± ]
rB~0.1÷0.3