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Hadronic B Decays To Double-Charm Final States. SERGIO GRANCAGNOLO L.Lanceri – J.P.Lees BINP Novosibirsk Particle Physics Seminar. Outline. Introduction The BaBar Detector at PEP-II The D sJ observations Theoretical Interpretations of D sJ Analysis of B D (*) D sJ decays

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hadronic b decays to double charm final states

Hadronic B DecaysTo Double-Charm Final States

SERGIO GRANCAGNOLO

L.Lanceri – J.P.Lees

BINP Novosibirsk

Particle Physics Seminar

outline
Outline
  • Introduction
  • The BaBar Detector at PEP-II
  • The DsJ observations
  • Theoretical Interpretations of DsJ
  • Analysis of BD(*)DsJ decays
  • Results: branching fractions and angular distributions
  • Comparison with models and conclusions

Sergio Grancagnolo

the standard model
The Standard Model
  • Fundamental particles:
    • 6 quark , 6 leptons
    • 4 interactions
  • The model works well but there are several issues to be understood, for instance:
    • Higgs boson
    • Supersymmetry
    • Strong interactions

W,Zbosons

Sergio Grancagnolo

quantum numbers of the quarks
Quantum Numbers Of The Quarks

Quark

Property

Sergio Grancagnolo

ckm matrix and unitary triangle
CKM Matrix and Unitary Triangle

qi=u,c,t

Unitary relationship

CKM

W+

Vij

qj=d,s,b

A complex phase in the V matrix can be a source of CP violation in B decays

VV†=I

VudVub*+VcdVcb*+VtdVtb*=0

a

VtdVtb*

VudVub*

Unitary triangle

g

b

VcdVcb*

Sergio Grancagnolo

mesons in the quark model
_

_

_

_

_

Mesons in the Quark Model
  • Quarks exist only in baryons and mesons
  • Mesons are made of a quark-antiquark pair
  • As an example:
  • Mesons are not stable
    • Mass, charge and lifetime are main characteristics
    • Meson width~ 1/lifetime

depends on the allowed decay modes

Sergio Grancagnolo

heavy quark approximation
sQ

sq

q

_

Q

Heavy Quark Approximation

In the heavy quark approximation

mq<

sQ, j conserved

However J, P good quantum numbers

Sergio Grancagnolo

charmed mesons spectroscopy
Charmed Mesons Spectroscopy

_

_

  • States with ℓ=1 can decay strongly with emission of a pseudoscalar meson
    • j=1/2 emission in s-wave
    • j=3/2 emission in d-wave
  • D*0,D´1observed by CLEO, Focus and Belle
    • Broad resonances as expected

ℓ=0

ℓ=1

broad ~100 MeV

narrow ~10 MeV

Sergio Grancagnolo

the expected cs meson spectra
_The expected cs Meson Spectra

M.Di Pierro, E.Eichten

Phys. Rev. D64, 114004 (2001)

2.51 GeV

2.36 GeV

States expected but not observed

  • Masses over threshold DK(*)
  • Broad states (large widths)

*

Sergio Grancagnolo

b meson decay
B Meson Decay
  • Spectator quark model

the other u,d quark enters the final state without participating to the interaction

  • In hadronic decays, could be tested the factorization hypothesis:

the final hadrons are produced independently

Since

mb >>mu,d

the B meson decay dominantly through

the disintegration of the b quark. The main transition

W* ℓn

semileptonic

is the weak decay

bcW*

where

_

hadronic

W* qiqj

W* virtual boson

Sergio Grancagnolo

exclusive hadronic b decays
_

-

_

_

_

_

Exclusive Hadronic B decays
  • In exclusive decays all particles in final state are reconstructed
  • Double charm decays contains two mesons with charm quarks
  • Examples:

Ds-

BDsD

_

D(*)0,D(*)+

B-,B0

D(*)0

K(*)-

B DDK

B-,B0

D(*)0,D(*)+

Sergio Grancagnolo

the pep ii b factory at slac
The PEP-II B-factory at SLAC

PEP-II is a high luminosity, asymmetric, e+e- collider

Integrated luminosity

Lint=254 fb-1

113fb-1

Ldesign = 3 x 1033 cm-2s-1

Lpeak = 9.21 x 1033 cm-2s-1

Sergio Grancagnolo

year

b factory cross sections
B-factory Cross Sections

E(e+) = 3.1 GeV E(e-) = 9.0 GeV

The boost allows a separation of the two B vertices.

boost: bg=0.56

Ecm=10.58 GeV

_

_

U(4S)BB

_

_

_

s[e+e- hadrons](nb)

_

√s(GeV)

_

_

e+e- bb on-resonance BB

_

“coontinuum”e+e- cchigh momentum charmed particles

Sergio Grancagnolo

babar detector
BABAR Detector

1.5 T solenoid

Electromagnetic Calorimeter

e+ (3.1 GeV)

Cerenkov Detector (DIRC)

e-(9 GeV)

Drift Chamber

Silicon Vertex Tracker

Instrumented Flux Return

Sergio Grancagnolo

d sj 2317 discovery
DsJ(2317) Discovery

*

+

  • BaBar discovered a new particle decaying into Dsp0
    • c and s quarks
    • Mass < DK threshold
    • Width < 10 MeV
  • Seen by Belle and CLEO
  • Is this the expected Ds0?

BaBar collaboration

Phys.Rev.Lett.

90, 242001 (2003)

+

_

Dsp0Invariant mass

+

*+

m=2.317GeV

GeV

Inclusive selection of high momentum charmed meson from coontinuume+e- cc

_

Sergio Grancagnolo

d sj 2460 discovery
DsJ(2460) Discovery

+

  • CLEO observed another state decaying to Ds p0!
    • c and s quarks
    • Mass < (DK)* threshold
    • Width < 10 MeV
  • Observed also decay modes:
    • Dsg, Dsp+p-
  • Is this the expected Ds1?

CLEO collaboration

Phys. Rev. D68, 032002 (2003)

*+

_

Ds p0Invariant mass

*+

80

60

m=2.460 GeV

Events/7 MeV/c2

40

20

0

+

+

2.25 2.5 2.75

GeV

+

Seen by BaBar and Belle

Sergio Grancagnolo

the observed cs meson spectra
_The Observed cs Meson Spectra

2.51 GeV

2.36 GeV

New states observed

  • Masses below threshold DK(*)
  • Narrow states

*

Sergio Grancagnolo

isospin violation in these decays
Isospin Violation in These Decays
  • Isospin symmetry is not exact
  • Violation already observed in Ds* Dsp0 decay

_

_

_

_

_

_

_

DsJ Dsp0

Invoked hp oscillation

P.L.Cho, M.B.Wise Phys.Rev.D49: 6228-6231,1994

Sergio Grancagnolo

theoretical interpretations of d sj

Theoretical Interpretations of DsJ

Standard interpretations

Exotic interpretations

standard interpretations
Standard interpretations

Entia non sunt multiplicanda praeter necessitatem (G.Occam)

  • Quark models
    • Potential: coulombian
  • (0-,1-),(0+,1+) chiral partners
    • doublets mass splitting via chiral symmetry breaking
    • transitions via scalar meson

+ linear

Cahn, Jackson

+ spherical not linear

Lucha, Schoberl

need to adjust a posteriori input parameters, predict mass higher than observed or not reproduce non-strange charmed mesons spectra

Bardeen, Eichten, Hill

hyperfine splitting for charmed mesons (D, D*, etc.) marginally compatible with experiments

Sergio Grancagnolo

standard interpretations1
Standard interpretations
  • Unitarized chiral models
    • generalization replacing a light quark with an heavy quark
  • Non-perturbative methods
    • lattice QCD
    • QCD sum rules

Beveren, Rupp

several new mesons predicted not observed

Bali

initial difficulties to reproduces masses, reproduces mass splitting

Dai, Huang, Liu, Zhu

low accuracy

Sergio Grancagnolo

exotic interpretations
D

K

Ds

p

Exotic Interpretations

Barnes, Close, Lipkin

Dsp molecule

cs  DK  4-q

mixing

DK molecule

Szczepaniak

Browder, Pakvasa, Petrov

D

_

_

_

_

qq

qqqq

K

di-quark pairs

_

qq

Maiani, Piccinini, Polosa, Riquer

_

qq

Sergio Grancagnolo

analysis of b d d sj decays

Analysis of BD(*)DsJ decays

Branching ratios: Method

Event selection

Signal and Backgrounds

Efficiency and “cross-feed”

b d d sj decays
BD(*)DsJ Decays
  • ExclusiveDsJ production: expected to be dominant
  • Allow to measure DsJquantum numbers
  • In principle, allow to discriminate between conventional and multi-quark scenarios compared with other B decays such as BD(*)Dsand BD(*)D(*)K
  • If the DsJ is the conventional cs state should be produced in the following graph:

_

_

Weak external W emission

DsJ-

-

_

_

_

_

_

D(*)0,D(*)+

B-,B0

Same graph as BD(*)Ds

similar branching ratios could be expected

Sergio Grancagnolo

b d d sj decays ii
BD(*)DsJ Decays (II)
  • We search for DsJ particles looking at the 12 combinations:
  • With DsJ decays:
  • We measure branching ratios, quantum numbers JP

Sergio Grancagnolo

subdecay modes
Subdecay Modes

Intermediate particles are reconstructed in the following modes:

Green::clean modes

Total: 60 different submodes combined to give the 12 combinations

Sergio Grancagnolo

analysis goal and method
Analysis Goal and Method
  • We aim to measure branching ratiosBri (i=1…12) of the exclusive double charm two body production of DsJ(2317)+and DsJ(2460)+in B0and B+
  • nisignumber of signal candidates for mode i
    • after combinatorial background subtraction
  • nixfdnumber of crossfeed events for mode i
    • contains background from other signal modes
  • eireconstruction efficiency from simulation
  • NBB= [122.0 ± 0.6(stat) ± 1.3(syst)]  106 (113 fb-1)

*

_

Sergio Grancagnolo

a specific example b 0 d d sj 2460
_

D0

Ds

+

DsJ(2460)+

*

A specific example: B0D*-DsJ(2460)+

*

  • Reconstruct the chain:
  • Reconstruct tracks (K,p) and photons (g)
  • Select D0, Ds , f, p0computing invariant masses
  • Use beam energykinematicconstraint
  • Fit nisig in Dsg invariant mass distribution

K+

K+

p-

f

D*-

p-

K-

p+

B0

g

Sergio Grancagnolo

event selection invariant masses
Event Selection: Invariant Masses

Invariant mass:

D0 Kp

Dsfp

D* D0p

fKK

40000

20000

0

0.99 1.02 1.04

m(f)(GeV/c2)

Particles masses are set to their nominal values (mass constraint)

Sergio Grancagnolo

event selection b candidates
Event Selection: B candidates
  • Compute p*B and E*Bfrom selected D*, Ds, g
  • Use the B-factory constraint E*beam to compute:

5.272

mES

“Signal box”:

|DE|<32MeV

Use of beam kinematic variables

better resolution

ΔE

uncorrelation

Sidebandsto estimate background outside signal box

Sergio Grancagnolo

d e resolution
DE resolution
  • Same resolution for all the submodes
  • A systematic error will take in account differences between data and simulation

Simulation of signal events

Data candidates in mES signal region

s(DE)=16.1

s(DE)=18.9

Cross-hatched background from sidebands

Missing energy effect

Sergio Grancagnolo

d e resolution ii
DE resolution (II)

Final values used in selection (MeV)

Better resolution for modes with a p0 (mass constraint)

Sergio Grancagnolo

background rejection
Background Rejection
  • Reduction of the combinatorial background
  • Simulated signal events selected in signal region
  • Background from data events selected in DsJ mass sideband region
  • Curves represent

fraction of events cut by

m(D0g)> mcut(D0g)

  • Optimal cut set at the

maximum separation

between two samples

m(D*g) cut

Events rejected:

25% signal

75% backgrd

m(D*g)>2.4GeV/c2

Gev/c2

Sergio Grancagnolo

optimization
Optimization
  • Maximized the significance ratio:

S = simulated signal events in signal region

B = background from data in m(DsJ) sidebands

Tried different cut levels for D and Dsusing PID, vertexing and helicity cut

f cos(qhel)

f mass

5000

40000

2500

20000

Tried different numbers of s cut for variables: DE, m(Ds), m(D)

-1

1

1.94

2.0

cos(qhel)

m(f)

Cleaner modes require less stringent cuts

Sergio Grancagnolo

fit n i sig in d sj 2460 d s g
Fit nisig in DsJ(2460)+Ds+g

m(Dsg)

  • Finally, in selected candidates: m(Dsg)
  • Fit the background shape with a polynomial
  • Fit the signal peak with a Gaussianof fixed width
    • s=12 MeV
    • estimated in data
  • Events in the signal peak:

Entries/10 Mev/c2

GeV/c2

significance=11.7

nisig = 53.0±7.7

Sergio Grancagnolo

efficiency and cross feed
Efficiency and Cross-feed
  • From gi=60k simulated signal events for each mode i
    • Efficiency:

nisim= number of B0D*-DsJ(2460)+ events reconstructed in the corresponding simulated sample

    • Total cross-feed:

nijsim= number of B0D*-DsJ(2460)+ events reconstructed in the simulated sample (mode j)

fij= cross-feed from the mode j to the mode i

Typical efficiency range: 1-10%

depending on the presence of photons, soft tracks, stringent cuts, etc.

;

Sergio Grancagnolo

narrow cross feed
Narrow Cross-feed

Efficiency

Reconstructed mode: B0D*0Ds1- [Ds-g]

m(DsJ)

Generated mode: B0D*0Ds1- [Ds-g]

nisim= 2778 gi=60000

ei=(4.63±0.08)%

Cross-feed

Generated mode: B0D*+Ds1- [Ds+g]

nijsim= 24 gj=60000

fij=(0.82±0.04)%

Narrow: sxfdssig

Sergio Grancagnolo

GeV/c2

wide cross feed
Wide Cross-feed

Efficiency

Reconstructed mode: B0D0Ds1- [Ds-g]

m(DsJ)

Generated mode: B0D0Ds1- [Ds*-p0]

nisim= 1350 gi=60000

Cross-feed

ei=(2.25±0.07)%

Generated mode: B0D*+Ds0- [Ds-p0]

nisim= 144 gi=60000

fij=(0.24±0.02)%

Cross-feed

nisim= 162 gi=60000

Generated mode: B0D*0Ds0- [Ds-p0]

fij=(0.27±0.02)%

Wide: sxfd 2.5 ssig

Sergio Grancagnolo

GeV/c2

branching ratios and cross feed
Branching Ratios and Cross-feed

An iterative procedure is needed:

  • Compute for each mode i without considering cross-feed
  • Estimate nixfdusing Brj and the cross-feed fij from all the modes
  • Subtract the number of cross-feed events
  • Compute the corrected branching ratio
  • Recompute the cross-feed iterating point 2-4 until convergence.

__

Sergio Grancagnolo

fit results and significance
Fit Results And Significance

s=5.5

s=4.2

s=5.0

s=5.2

s=7.4

s=11.7

s=3.1

s=5.1

s=4.3

s=6.0

s=7.7

s=2.5

Sergio Grancagnolo

main systematic errors
Main Systematic Errors

Depends on the tracks or photons number

  • Tracking efficiency 9%
  • g/p0 efficiency 5%
  • Background fitting model5%
    • Tried exponential instead of polynomial to fit background
  • DE width 5%
    • Changed the width of the DE signal region by ±3 MeV
  • DsJ width 3%
    • Varied by ±1 MeV the s of the Gaussian (12 MeV) that fit the signal

Modes with D*0 more affected

Sergio Grancagnolo

branching ratios results
Branching Ratios Results

Phys.Rev.Lett.93:181801,2004

NEW!

NEW!

NEW!

NEW!

NEW!

NEW!

Sergio Grancagnolo

Measurements with significance>5

d sj 2460 angular analysis i
DsJ(2460)+ Angular Analysis (I)

_

  • Use B0DsJ+D-and B+DsJ+D0 with DsJ+Dsg
  • B DDsJ+is a transition 0- 0- JP so DsJis polarized
  • Compute the helicity angleqh of DsJ+Dsgand compare with the predictions for JP=1+ and JP=2+(0+forbidden)

Sergio Grancagnolo

d sj 2460 angular analysis ii
DsJ(2460)+ Angular Analysis (II)

DsJ events are fitted separately in 5cos(qh) bins

not used cut m(Dg)>2.3

Sergio Grancagnolo

Simulation is used to correct for detector acceptance

d sj 2460 angular analysis iii
DsJ(2460)+ Angular Analysis (III)
  • Expected distribution for JP=1+ is:

1-cos2(qh)

  • Distribution compatible with this case
    • c2/d.o.f.=3.9/4
    • Supporting the Ds1+ hypothesis for this state
  • Comparison with JP=2+ hypothesis is also provided
    • c2/d.o.f.=34.5/4

Sergio Grancagnolo

some comparisons with models
Some Comparisons With Models
  • Branching ratios smaller than the corresponding BD(*)Ds(*)
    • Factorization effects could be important and could not cancel in the ratios RD0,1
    • support a multiquark hypothesis
  • Observation of electromagnetic DsJ(2460)+ decay
    • supports a conventional cs picture
  • In agreement with prediction from chiral multiplets we measure:

Colangelo, De Fazio, Ferrandes: Mod.Phys.Lett. A19:2083,2004

Godfrey Phys.Lett. B568:254,2003

_

Bardeen, Eichten, Hill: Phys.Rev. D68:054024,2003

Sergio Grancagnolo

conclusions
Conclusions
  • We combine 60 different final states to obtain 12 branching ratios BD(*)DsJ measurement with
    • The modes BD*DsJ with a D* or a D*0 are first observations
    • Extraction of JP=1+ quantum numbers of DsJ(2460)+

Sergio Grancagnolo

babar run 5
BaBar run 5

Sergio Grancagnolo

inner tracking and vertexing svt
Inner Tracking and Vertexing: SVT

Low pT track

Double side silicon microstrips

High pT track

  • Extrapolation of secondary vertex
  • Standalone tracking capability for low pt tracks

Sergio Grancagnolo

the detector of internal reflected cherenkov light
The Detector of Internal Reflected Cherenkov light

A charged particle traversing the DIRC produces Cherenkov light if bn>1

Sergio Grancagnolo

particle identification de dx dirc
Particle IDentification:dE/dx, DIRC

For tracks with p<700MeV: dE/dx from DCH and SVT

For tracks with p>700MeV: Cerenkov angle from DIRC

Sergio Grancagnolo

photons emc
Photons: EMC
  • Projective geometry
  • Discriminate between hadron and electromagnetic showers
  • Contribute to trigger

mp=134.5MeV

sp =6.4MeV

Sergio Grancagnolo

mgg (MeV)

theoretical d sj interpretation references
Theoretical DsJ Interpretation References
  • Cahn, Jackson: Phys.Rev.D68, 037502 (2003)
  • Lucha, Schoberl: Mod.Phys.Lett. A18, 2837 (2003)
  • Bardeen, Eichten, Hill: Phys.Rev.D68,054024 (2003)
  • Beveren, Rupp: Phys.Rev.Lett.91, 012003 (2003)
  • Bali: Phys.Rev.D68, 071501 (2003)
  • Dai, Huang, Liu, Zhu: Phys.Rev.D68,114011 (2003)
  • Szczepaniak: Phys.Lett.B567, 23(2003)
  • Browder, Pakvasa, Petrov: Phys.Lett.B578, 365 (2004)
  • Barnes, Close, Lipkin: Phys.Rev.D68,054006(2003)
  • Maiani, Piccinini, Polosa, Riquer:Phys.Rev.D71.014028 (2005)

Sergio Grancagnolo

reconstruction of soft pions
Reconstruction of Soft Pions
  • Fundamental to understand our capability of reconstructD*
  • Estimate tracking efficiencyfrom data itself

dm = m(D*+)-m(D0)=140.6 MeV

m(p)=139.6 MeV

We reconstruct: D*+D0 p+

Kp

JP

 Energy available for the p is very low

1- 0- 0-

Angular analysis

Expected symmetric angular distribution of the events in the D* frame

Helicity angle

D* direction of flight

Sergio Grancagnolo

soft pion studies
Soft Pion studies

Separation of pion sample based on D* momentum

p(D*) bins

p(D*) GeV/c

Critical regions

For a given D* momentum:

Slower D*

 linear relationship

Sergio Grancagnolo

background subtraction
Background subtraction
  • Use of two kinematic variables: m(D0), dm
  • Four categories of events:
  • Signal
  • Real-D0+bad-ps
  • Bad-D0+real-ps
  • Combinatoric background
  • Use of kaon and pion PID to distinguish between different contributions

m(D0)

dm

Background removal within each p(D*) bin, that cover the same soft pion kinematic range of the signal

Sergio Grancagnolo

efficiency of soft pion
Efficiency of Soft Pion

cos(q*)

Efficiency estimate from asymmetries in the helicity angle distributions

Expected distribution (symmetric)

High p(D*)

Asymmetric distribution

Low p(D*)

Low cos(q*)

-1.0

0

1.0

Convolute the helicity distributions with an efficiency function parameterized as:

Sergio Grancagnolo

soft pion efficiency results
Soft Pion Efficiency Results
  • Convoluting function parameters obtained minimizing a c2
  • Relative efficiency raise over 90% already at 100Mev/c
  • From the differences between data and simulation: a systematic uncertainty of 1.4% per track in the efficiency

Efficiency

Simulation

Data

p(p) GeV/c

Sergio Grancagnolo

event selection i tracks
Event Selection (I): tracks

Tracks:

Kaon PID:

Photons and p0:

f:

Invariant mass:

Sergio Grancagnolo

event selection ii d 0 d s
Event Selection (II): D0, Ds

Measure invariant mass m, and resolution s in data:

Apply the request:

- nss < m-m0 < nss

Sergio Grancagnolo

another example
Another example
  • B0->D*-DsJ(2460)+, DsJ->Ds*pi0
    • We have D*->D0pi (soft p+)
    • Ds*->Dsgamma
    • D0,Ds as before
  • Pi0 veto on gamma

Sergio Grancagnolo

background from b d d s
Background from BD(*)Ds(*)
  • IdenticalD(*),Ds(*) selection
  • B candidates selected in mES, DE signal region

m(Dsg)

Reject events with at least a candidate compatible with BD(*)Ds(*)

350

Events rejected

200

Events/10 MeV/c2

easily combine with lowenergyg or p0 to give a DsJ

0

Gev/c2

2.7

2.0

2.35

Background events that enter marginally in the DsJsignal region

Sergio Grancagnolo

background events
Simulated ~220 fb-1 of generic events

No peaking background observed

Background Events

m(Dsp0)

  • Simulated ~60k events for each mode BD(*)Ds(*)
    • No peaking background observed

400

Entries/10 Mev/c2

200

2.4

2.2

Gev/c2

2.6

m(Dsp0)

100

Entries/10 Mev/c2

50

2.4

2.2

Gev/c2

2.6

Sergio Grancagnolo

reconstruct b candidates
Reconstruct B candidates

60k signal events for each submode

Determine selection criteria using a simulation

DE

10000

Events/5 MeV/c2

5000

Resolution:

s=16 MeV

GeV

B candidates must enter in the signal box: mES, DE

If more than one B candidate is found, the one with the smaller difference DE-DE0 is retained

Sergio Grancagnolo

slide71
nisig = 34.8±7.9

s=5.5

nisig = 23.6±6.1

s=5.2

nisig = 32.7±10.8

s=3.1

nisig = 15.3±6.8

s=2.5

Sergio Grancagnolo

slide72
nisig = 17.4±5.1

s=4.2

nisig = 26.5±5.6

s=7.4

nisig = 28.0±5.8

s=5.1

nisig = 30.5±6.4

s=7.7

Sergio Grancagnolo

slide73
nisig = 24.8±6.5

s=5.0

nisig = 53.0±7.7

s=11.7

nisig = 32.0±8.2

s=4.3

nisig = 34.6±7.5

s=6.0

Sergio Grancagnolo

other efficiency and cross feed
Other Efficiency and Cross-feed
  • In B+D0DsJ(2317)+ cross-feed is dominated by DKppD0Kpp0

10

m(DsJ)

m(DsJ)

DKpp reconstructed as D0 Kpp0

250

D0 Kpp0

Cross-feed

Efficiency

GeV/c2

GeV/c2

fij=(0.04±0.01)%

ei=(1.93±0.06)%

nisim= 1160 , gi=60000

Sergio Grancagnolo

nijsim= 24 , gj=60000

isospin averaged branching ratios
Isospin averaged branching ratios
  • CombineD+ and D0 and D*+ and D*0 measurements
  • Average with statistical weightw=1/si2
  • To compare two measurementsx1 and x2 with variance s1 and s2 we use the variable z:

Sergio Grancagnolo

ratios of branching ratios
Ratios of Branching Ratios
  • Compare BD(*)Ds and BD(*)DsJ measurements is possible through ratios:
  • Neglecting phase space we expect:
  • We know BD(*)Ds from PDG (1-5%)
  • Final results to be revised

Datta, O’donnell Phys.Lett. B568:254,2003

and similarly for RD*0 and RD*1

Sergio Grancagnolo

comparison with belle
Comparison with Belle

Phys.Rev.Lett.93, 181801 (2004)

J.Phys.Conf.Ser.9:115-118,2005

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comparison with old belle results
Comparison with old Belle results

Phys.Rev.Lett.91:262002,2003

Experimental results compatible within errors

Sergio Grancagnolo

conclusions1
Conclusions

“no compelling evidence that a non-standard scenario is required … neverthless unanswered questions remain …” (Review by P.Colangelo, F.De Fazio, R.Ferrandes, hep-ph/0407137)

Sergio Grancagnolo

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