Precision measurements Probes for New...

2006-6-11 Gang RONG, IHEP, BES collaboration

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Prospects of Charm Physics at BES-III-- Based on Monte Carlo Study of D decays

Gang RONGInstitute of High Energy Physics, Beijing, China

e- e+

Ψ(3770)

D

D

Precision measurementsIntroduction

D0D0-bar MixingProbes for New Physics

Search for CP violationSearch for some rare decays

Other topics Note: I borrow some slides from some wonderful talks on studies of Charm transitions. For a working group I make the presentation. I would like to thank Prof. D.S. Du for some useful discussion about charm decays.

SummaryPRC--US Workshop on e+e- Collision Physics, Beijing, June , 2006


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The people who involved in the Monte Carlo study of the Charm decay properties, (reported in this talk) with BES-III/BEPC-II. During the last three weeks, the 4 graduate students worked on full Monte Carlo simulation to study the charm decays to be observed with the BES-III/BEPC-II.


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IntroductionCharm plays an important role in understanding the SM (standard model) dynamics in two respects:

Precision measurements of decay constants fD, fDs, form-factors of semileptonic decays of Charm mesons provide the calibration of Lattice QCD calculation. In turn, the very precise calculation of the ratio of the decay constants fD/fB, fDs/fBs and form-factors from LQCD support measurements for B physics.

Precision measurements

The parameters of Standard Model are:mixings and mass fermion,,sin, 2

, HwF MG θα

udV usV ubV

cdV csV cbV

tdV tsV tbV

='d

's'b

dsb

Mass eigenstates

2

211 λ− λ )(3 ηρλ iA −

2

211 λ−λ− 2λA

)1(3 ηρλ iA −− 2λA− 1

)( 4λΘ+

The 4 quark mixing parameters ( ) reside in CKM matrixηρλ ,,, A

CKMWeak eigenstates

CKM

To understand the quark mixing and CP violation in SM, and detect New Physics in flavor change sector, one must determine the CKM elements as precisely as possible !


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Now With Charm data one can calibrate the QCD calculations. If the QCD pass the test with the charm data, the theory errors of a few % on B system decay constants & semileptonic form factor are achieved, and the CKM elements achieved to

+

η

ρ

Then the uncertainties will be reduced to

The constraints in ( ) plane arising from some measurements …

ηρ , The width of band is mainly dominated by theoretical (LQCD) errors on fB, fBs and B semileptonic form factors .

500 fb-1 @ BABAR/Belle


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Measurements of some transition rates of Charm provide probes for New Physics.

Probes for New Physics

In the SM, the D0D0 mixing, CP violation and rare decays of charm are all small. However, some New Physics effects beyond the SM can enhance the mixing, the CP violation and the rare decays. So search for the mixing, the CP violation and the rare decays provide the unique opportunities to search for New Physics beyond the SM indirectly.

200 10mixing −≤DD310asymmetry −≤CP610decays Rare −≤


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For the precision measurements, one need a large data sample, high quality data and to do absolute measurements.

Threshold data

Using the data collected near threshold, one can precisely measure the absolute branching fractions, decay constants, form factors and/or |Vcd| and |Vcs|, …

e- e+

Ψ(3770)

D

D

),( 00 −+−+ → DDDD DDee

Near the DD-bar threshold, Only DD-bar production. Event is very clean.Beam energy constraint mass

22DbeamEC pEM −=

Or kinematic fitted massto reconstruct the D decay

fitM


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Charm Physics at BES-III

BES-III will be the successor of the previous successful

BES-I and BES-II

Luminosity reach to 1033 at Ecm = 3.78 GeV (compare to 1031 for BEPC).

BEPC

Large angle coverage, good charged PID & momentum resolution, good photon energy resolution.


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Two rings, 93 bunches:• Luminosity

1033 cm−2 s−1 @ 3.78 GeV 6× 1032 cm−2 s−1 @ 3.10 GeV 6× 1032 cm−2 s−1 @ 4.20 GeV

BESIII Detector

MDC: small cell & He gasσxy=130 µmsp/p = 0.5% @1GeVdE/dx=6%

TOF:σT = 100 ps Barrel

110 ps Endcap

Muon ID: 9 layer RPC

Data Acquisition:Event rate = 3 kHzThruput ~ 50 MB/s

Magnet: 1 T Super conducting

EMCAL: CsI crystal∆E/E = 2.5% @1 GeVσz = 0.6 cm/√E

Trigger: Tracks & ShowersPipelined; Latency = 6.4 µs

The detector is hermetic for neutral and charged particle with excellent resolution ,PID, and large coverage.


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Precision Measurements at BES-III (con’t)Absolute BFs BES III Full MCBES III Full MC simulation

Charm absolute branching fractions are very important. Most branching fractions of charm decays are normalized to them. The branching fractions are also used to normalize the B & Z decay branching fractions (Rb & Rc) … They also entry the CKM element measurements.

)()()( 0

obs00

0+−

+−+−

→×→

=→πε

ππKDN

KDNKDBtagD

)%24 ,58( 00 −+−+ → D DD% D DDee

DD decay to all possible final states according to PDG04

)()()(

tag

obs

++−+

++−+++−+

→×→

=→− ππε

ππππKDN

KDNKDBD

e+ e-

D0 K+

tag

D0

D0 π+

+π

π+

π-

−K

Singly tagged D0With double tag method we can measure the absolute BFs

Real simulation of data


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Precision Measurements at BES-III (con’t)

)3770(ψ→−+ ee

58.0 42.000 DD −+ DD

+−πK

−++− πππK−+ππ0K

0ππ +−K

llK ν+−

ll νπ +−

llK νπ +−0

00 πππ −+K

Charge conjugation

Charge conjugation

…

++− ππK

+π0K0πππ ++−K

llK ν+0

llK ν+0*llK νπ ++−

−++ πππ0K

00 ππ +K

µνµ +

…

Physics Release Boss 6.0.2

We would like to thank Prof. W.D. Li, Prof. H.M. Liu, Miss S.P. Wen, Mrs. Z.Y. Deng, G.W. Yu for kind help with BES-III software, we thank Dr. G.X. Sun, Mrs. J. Su, Mrs. Y. Yang and Mrs G.H. Du for help with computers.

Generated Monte Carlo eventsGenerated 800 pb-1 @ 3.773 GeV

BES-III software


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Precision Measurements at BES-III (con’t)Current statusAbsolute BFs

B(D+→Κ-π+π+)B(Do →K-π+)

PDG042.43.80 ±0.09

CLEO-c3.13.91±0.08 ±0.09

ALEPH3.83.90±0.09±0.12CLEO3.63.82±0.07±0.12ExperimentError(%)B (%)

B(Do →K-π+) 56pb-1

PDG047.79.1±0.7CLEO-c3.99.52 ±0.25±0.27

MKIII14.99.1±1.3±0.4CLEO10.89.3±0.6±0.8SourceError(%)B (%)

B(D+→Κ-π+π+) 56pb-1

2.2% projected error with 281 pb-1

1.8% projected error with 281 pb-1

CLEO-c

Three best measurements:

BES-II and CLEO-c(not in PDG average)


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)%04.083.3()( 0 ±=→ +−πKDB

7504330000tag

±=D

N12512350)( 0 ±=→ +−πKDN

%4.74=ε

INPUT) (MC 80.3)( 0 %KDB =→ +−π

−+πK 0ππ −+K

+−−+ πππK +−ππ0K

H.L. Ma did the nice analysis.

bcMbcM

bcM bcM

bcM

+−πK

B(Do →K-π+)Absolute BFs Double tag analysis, Independent of Double tag analysis, Independent of

Luminosity and cross section in the Luminosity and cross section in the double tag measurementsdouble tag measurements

BES III MCBES III MC 1fb 02/%3.0/ −=BBδ


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Precision Measurements at BES-III (con’t)Absolute BFs

H.L. Ma did the nice analysis.

)%12.048.9()( ±=→ ++−+ ππKDB

440158800tag

±=−DN1008130)( ±=→ ++−+ ππKDN

%0.54=εbcM bcM

bcM

B(D+→Κ-π+π+)

3.1/ %BB =δ

++− ππK

−−+ ππK

0πππ −−+K

−−+ πKK

−π0

K +−− πππ0

K

00ππ −K

Independent of Luminosity and cross Independent of Luminosity and cross section in the double tag measurementssection in the double tag measurements

BES III MCBES III MC 120/%3.0/ −= fbBBδ


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Precision Measurements at BES-III (con’t)Absolute BF(D+

S φπ+) Current status

)( %5.12/ BABARBB =δ

)c (CLEO %0.4/ −=BBδ

CLEO-c hope to achieve the accuracy level up to 4% with 750 pb-1 @4.17 GeV.


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εϕπ

ϕπ×

→=→

−

++++

tag

obs)()(SD

SS N

DNDB

~2.3 fb-1

Absolute BF(D+S φπ+)

He made the full Monte Carlo simulation.

−−−− πϕπ 0

00* ,,, fKKKK

tag mode

bcM

%23=ε20380)( ±=→ ++ ϕπSDN

21546161tag

±=−SD

N

)%18.059.3()( ±=→ ++ ϕπSDBr

+ϕπM

%5/ =BBδ)fb (20 %7.1/ 1−=BBδ

BES III Full MCBES III Full MC simulation


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22233

2

2 |)(|||24

)( qfVpGdq

PlDdcqP

F+=

→Γπ

ν

The parameters of Standard Model are:mixings and mass fermion,,sin, 2

, HwF MG θα

The 4 quark mixing parameters ( ) reside in CKM matrix

udV usV ubV

cdV csV ubV

tdV tsV tbV

='d's'b

dsbMass eigenstates

ηρλ ,,, A

νPlD →D Semi-leptonic Decays

Form Factor

CKMWeak eigenstates

Absolute branching fractions give direct measurements of the CKM matrix elements Vcd& Vcs and form factors

Questions: Does the CKM fully explain quark mixing? CP Violation?

To detect New Physics in flavor change sector, one must know the CKM well


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Current status


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missmissmiss PEU −=Neutrino carries energy and momentum away

Should be around zero

Fully reconstruct one D

e+ e-

D0 K-

tag

D0

D0 π+

−eν

π+

Require two additional charged track and no additional photons

π-

)( ++ πK

−+→ πKD0

+−−+→ πππKD0

BCM

BCM

BES III Full MCBES III Full MC simulation

22233

2

2 |)(|||24

)( qfVpGdq

PlDdcqP

F+=

→Γπ

ν

00ππ −+→ KD

−+→ ππ00KD

)pb 800( 1−≈L

She did the nice analysis.

Precision Measurements at BES-III (con’t)D Semi-leptonic Decays


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%45=ε805528)( 0 ±=→ +− νeKDN

600359884 ±=tagN

)%05.041.3()( 0 ±=→ +− νeKDBr

DDe e →× −+6109.4)pb 800( 1−≈L

%48=ε29707)( 0 ±=→ +− νπ eDN

)%02.041.0()( 0 ±=→ +− νπ eDBr

%5.1/ =BBδ

%1.4/ =BBδ

νπ +−→ eD 0

missmissmiss PEU −=


ν+−→ eKD0

ν+−→ eKD0


She made the nice full Monte Carlo simulation.


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1.0%τ∆τ

0.6%τ∆τ

s

s

D

D

D

D ≈≈

Well measured

11122 10|)0(||53.1)( −+ ×=→Γ sfVKeD K

cseν11122 10|)0(||01.3)( −

+ ×=→Γ sfVeD cdeπνπ

2pole

22

/1)0()(

mqfqf

−= +

+

To extract Vcs & Vcd need form factor from theory at one fixed q2 point.CKM Matrix at BESIII

22233

2

2 |)(|||24

)( qfVpGdq

PlDdcqP

F+=

→Γπ

ν

22

D

D2

cq

cq

2f∆f

2τ∆τ

2B∆B

V

V∆

+

+

=

Form factor from theory (Lattice QCD). Assuming Δf/f ~3% , BESIII will approach

BESIII: L=20 fb−1

ψ(3770) MC simulation

lνD π

lνD

Κ

δVcd/Vcd 11% δVcs/Vcs 4%

BESIII

δVcd/Vcd ~1.7% δVcs/Vcs ~1.6%l

νD π

lνD Κ

Quark models, HQET, Lattice & other methods have all been invoked to calculate form factor absolute normalizations. These calculations have been done

mostly at q2 =0 or q2 =q2max. (i..e w=1, just like F in Vcb in B →D* lν)

Great contribution to CKM Unitarity


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ν++ → eKD )892(0*

eeKD ν++ → 0*

eeKD ν+−→ *0

BES-II

BES-III MC simulation

Umiss(GeV)

Eve

nts

( )

( )

( )

( ) { }δθ θ

θ θ

θ θ

χ θ θ

+

−

−

+

+ − = +

+

+

∫

2 22 2

2 22 2

22 222 20

2 2 20

2

(1 cos )sin ( )

(1 cos )sin ( )1A 2sin cos ( )

8 sin cos ( ) ( ) e8

R

( )

l V

l V

l V

V

o

l

iH q h q

H q BW

H q BW

d q H q B

O

W

A

Ae BW

H0(q2), H+(q2), H-(q2) are helicity-basis form factors which are computable by LQCD A new factor h0 (q2)is needed to describe s-wave interference piece.

S-wave interfere asymmetry

cosV

Focus FPCP 2006


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Precision Measurements at BES-III (con’t)XeDDD S

+++ →,, rates Inclusive 0


23

Dif06 I.Shipsey

Measurements of fD and fDs are very important for improving our knowledge on CKM matrix, and to calibrate the LQCD.

Precision Measurements at BES-III (con’t)Status of measurements of fD


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Dif06 I.Shipsey

Previous measurements of fD

MARK-III set an upper limit

BES first observed 1 & 3 signal events and measured fD


25

Precision Measurements at BES-III (con’t)Previous measurements of fD

c)(CLEO %8 −=∆

D

D

ff

CLEO-c observed 50 signal events and made a nice measurement


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Precision Measurements at BES-III (con’t)fD at BESIII J. Liu made the

nice full Monte Carlo simulation.−−−+− → πππ 0, KKD

bcM


++ → π0KD

%53=ε0.56.20)( ±=→ ++ νµDN

33559720tag

±=−DN

DDe e →× −+6109.1)pb 306( 1−≈L

)%016.0065.0()( ±=→ ++ νµDBr

),( 0 −−−+ πππ KK

+−−−−−+−−+ πππππππππ 000 ,,, SS KKKK−−+− πππ KKK S ,00

modes tag 6For

%9/ ,18/ == DD ff %BB δδ

%2.1/ ≈DD ffδ

)3770(@ fb 20 1 ψ−

analyzed


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e+ e-

D+S

D-S

+µ

K-

K+

ν

π-

%52=ε80.63)( ±=→ ++ νµSDN

)fb 10( 51626894 1

tag S

−≈±=− LN D

−+−+ →× SS DDe e6109.1

)%057.0453.0()( ±=→ ++ νµSDBr

−−−+−−− ππππϕπ 0000* ,,,, fKKKKK SS

modes tag 5For

%2.6/%,5.12/ == ++SS DD ffBB δδ

%1.3/%2.6/ == ++SS DD f, δ BBδ

fDs at BESIII D-s tag

bcM

−ϕπSingle tag mode


)fb 02(L %2/ 1−=≈++SS DD fδf


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fD(s) at BESIII2

cd(s)

cd(s)22

D

D

D

D

|V||V|

BB

21

21

(s)

(s)

(s)

(s)

∆+

∆

+

∆=

∆

τ

τ

ff

0.06%|V||V|∆1.1%

|V||V|∆

cs

cs

cd

cd ≈≈

1.0%τ∆τ

0.6%τ∆τ

s

s

D

D

D

D ≈≈

4)%~2( B∆B

≈With 20fb−1

at BESIII

3 generation unitarity global fit:hep-ph/0406184 CKMfitter group

BESIIIff %2.1∆

D

D ≈

BESIIIff

%1.2∆

s

s

D

D ≈ Ecm=4.03 GeV

Ecm=3.773 GeV

Challenge LQCD Prediction


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7.5~1.04.015.0~1002.08.0

16.61.04.1 5.00.52.06.50.41.52.30.31.2

CLEO-cMode+−→ πKD 0

)fb (1 / -1BBδ )fb (20 / -1BBδ )04(PDG / BBδ

++−+ → ππKD

ν+−→ eKD 0

νπ +−→ eD 0

νµ −+ →D

+Df

281 pb-1

Short summaryRelative error (%) on the measurements

Statistical error only


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Relative error (%) on the measurementsShort summary

142.19.4384.319 N/A7.030253.013252.09.0

Mode

ν++ → eKDS0

)fb (1 / -1BBδ )fb (20 / -1BBδ )04(PDG / BBδ

νµ ++ →SD

++ → φπSD

νφ ++ → eD S

ντ ++ →SD

+SDf

Statistical error only Assuming Ecm=4.03 GeV


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−+KK−+ππ…

New physics will enhance New physics will enhance xxDD by entering new by entering new particles in the virtual particles in the virtual state contribution. state contribution.

Search for D0D0-bar Mixing00 :mixing DD ⇒

)('produce' uc− )('decay' cu−

shifts energy of CP eigenstates

Γ∆

= DD

Mx

Change of identity due toThe box diagrams are proportional to two Cabibbo suppressed factors and are suppressed by the GIM mechanism. It involves intermediate down-quarks which are much lighter than top for K0-K0bar and B0-B0bar mixing.

Γ∆Γ

=2Dy Mixing

parameters

shifts lifetimes of CP eigenstates

2

22DD

mixyxR +

≡The standard model predicts very small D0-D0bar mixing, xD& yD 10-2.≤


32

e+ e-

D0 K-

tag

D0

D0

π+

D0

K-

π+D0

π+K-

mixing

00)3770( DD→ψ

Coherence simplifies study no DCSD

Search for D0D0-bar Mixing

e+ e-

D0 K-

tag

D0

D0 π+π+

π-

D0

K-π+

D0π+

K-

mixing

DCSDare coherentDCSD+−+−→→ ππψ KKDD

00)3770(Can not measure the time evolution of D0 meson decays, DCS decay can not be separated from the final states. The level of the DCSD background is higher than the level of the mixing.

requiring L to be even, DCSD1L )3770( =ψ

So DCSD can not happen


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Search for D0D0-bar Mixing

J. Liu made the nice full Monte Carlo simulation.

Rmix sensitivity : 1.5x10−4 with 20 fb−1

BESIII

at BESIII (based on this MC simulation)

K−π+ vs K−π+

2 background events are observed

K−π+ vs K+π−

BESIII Monte Carlo Simulation

BCM

BCM


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Search for Direct CP Violation

e- e+

Ψ(3770)

D

D

+K−K

+π−π

0

0

+CP

+CPCP violating asymmetries can be measured by searching for events with two CP odd or two CP even final states, such as,

π+π−, K+K−, π0 π0, ρ0π0 …+CPΚsπ0, Κsρ0, Κsφ , Κsω ...−CP

21ψ(3770) of decay thefor ff→−=−⋅⋅= L

2121 1)()CP()CP()CP( ffff

+=)]3770(CP[ ψ

If we observed two CP odd or two CP even final states simultaneously we need to analyze many channels to elucidate the sources of CP violation !BESIII MC simulation


35

Search for Direct CP Violation

CP+(-) eigenstate Tags

+CP π+π−, K+K-, π0 π0, ρ0π0, KS KS KSπ0 π0 …Κsπ0, Κsρ0, Κsφ , Κsη, Κsη′, Κsω ...−CP

from 20 fb-1Ψ(3770) data, we can select about 4x105 CP+ tags and about 4x105 CP- tags. With the large CP tagged samples we can probe the direct CP violation, measure the strong phase difference between the direct and DCS amplitudes, and measure other mixing parameters.


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−+−+ K vs KKK

BCM

Search for Direct CP Violation20 fb-1

ACP < 5x10-3 @ 90% C.L.

−+−+ ππ vs KK

−+−+ πππ π vs

−+−+ K vs KKK

−+−+ ππ vs KK


BCM

BCM

440 events

340 events

66 events

−+−+ K vs KKK

−+−+ ππ vs KK


sensitivity


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Measurement of Strong PhaseI. Shipsey

Dr

Flavor mode

Dδ

Using the CP tag samples (CP+ vs Kπ double tags & CP- vs Kπ ), we can measure the strong phase difference between the direct and DCS amplitudes, which appears in the time dependent mixing measurements.

Dδ

~9000 CP+ vs KπDouble tags~9000 CP- vs Kπ

cos δD < 8% at BESIII

D.H. Zhang modified


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Search for rare decaysObservation of D+

FCNC and lepton number violating decays could indicate new physics.

In the SM (Standard Model), the short distance charm FCNC (flavor changing neutral currents) are much highly suppressed by the GIM mechanism than down type quarks due to the large mass difference between up type quarks.

The dilepton decay proceeds by penguim annihilation or box diagram.

( )( )( )

0 -10

0 -6

0 -6

up to 10

up to 10

up to 10

D e e

D

D e

+ −

+ −

±

→

→ µ µ

→ µm

B

B

B

The decay is strictly forbidden in the SM.0D e ±→ µ m

New Physics (Beyond the Standard Model ) may enhance these decay processes. For example, R-parity violating SUSY:gives

(Burdman et al., Phys. Rev. D66, 014009).Best limits are from BABAR

SM 230 10~)( −−+→ eeDB130 103~)( −−+ ×→ µµDB

Search for these kind of rare decays can probe New Physics


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Search for rare decaysCurrent status Experiment sensitivity is up

to about 10-5~10-6Branching Fraction

Talk from Ian Shipsey

2310−

Expt. sensitivity 10-5-10-6

Just beginning to confrontmodels of New Physics inan interesting way.

Still plenty of roomfor New Physics.

Outlook: promisingCDF/D0, B factories,CLEO_c/BES IIIsuperflavour

G. Burdman and I. Shipsey Ann. Rev. Nucl. Part. Sci. 53 431 (2003)arXivhep-ph/0310076 (updated 12/2005).


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−+eeφ

−+eeK0

−+eeK 0*

−+ µe

−+µφe

−+µeK0

−+ µeK 0*

We studied the rare decay processes with untagged D mesons to increase sensitivity with full Monte Carlo simulation based on 500 pb-1 at .ψ(3770)

Experimental sensitivity

to access the decay

Search for rare decays

M.G. Zhao made the full Monte Carlo simulation.


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−++ eeπ ++− eeπ

−++ eeK ++− eeK

+−−+ → eeKDS5103~ −×


He made the full Monte Carlo simulation.

The sensitivity will be 10-7 for D decays based on 20 fb-1 of ψ(3770) data at BESIII


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Note: the * means that the upper limit is estimated (it is not obtained from full Monte Carlo simulation)


with 20 fb-1 data at ψ(3770), the sensitivity can go down to 10-7 ~10-8.


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Other topicsSearch for hybrid charmonium, DD-bar molecular or other exotic states

BES-III will collect data at 3.773 GeV, 4.03 GeV and 4.14 (4.17) GeV, and perform finer cross section scans covering the resonances.

“Finer resonance line-shape analysis” provide an opportunity to search for heavy hybrid, DD-bar molecular, and four-quark states.

Fine cross sections scan

Analysis of the fine cross section scan data may probe new structures associated with hybrid charmonium, DD-bar molecular or other exotic states in this energy region…

If BEPC-II maximum energy can extend more than 4.2 GeV, that will be nice.


44

Measurements of the line-shapes of the cross sections for the exclusive processes:

,....cee ωη→−+

,.../,/,/,/ ' XJJJJee ψψηψηπψπ −+−+ →..., −+−+−+ → πϕπϕ KKee

..., )2,1,0()2,1,0( ωχρχ ==−+ → JcJJcJee

−+−+−+ → SS DDDDDDee ,,00

and comparing the line-shapes with these for the inclusive hadron production, one may find something new.

BES-II made finer cross section scan from 3.66 to 3.88 GeV, and studied the line-shapes of the inclusive hadron production, DD-bar production and some exclusive charmless final states production. But data sample is too small. We suggest that BES-III make the finer cross section scan covering the resonances with large samples to carefully study the structures.


45

To measure the resonance parameters of ψ(3770) or ψ(3686), one had better to simultaneously fit ψ(3686) and ψ(3770) resonances, since there are strong correlations between the fitted parameters of the two resonances.

ψ(3770)

ψ(3686)

If one do not consider the effects of vacuum polarization corrections on the observed cross sections in the data reduction, the total width of ψ(3686)would decrease by about 40 keV!

ψ(3686)

hep-ex/0605107

Mainly due to vacuum polarization corrections

After subtraction of ψ(3686) , ψ(3770)and J/ ψ from the observed cross sections, one obtains the expected cross sections of the continuum hadron production.


46

Precision measurementsSummary

BES-III can improve measurements on some important quantities: fD, fDs, form-factors or Vcs and Vcd. The accuracy level of measurements of fD and fDs can achieve ~2% with 20 fb-1 data. These quantities can be used to test or calibrate QCD technologies .

The accuracy level of measurements of non-leptonic charm Brs can achieve ~1% for D0 and D+ (~2.0% for D+

s ) with 20 fb-1 data.

New PhysicsBES-III can allow access to D0-D0bar mixing at ~2×10−4 and direct CP violations at ACP~ 5x10−3 with 20 fb-1 of data.

BES-III can allow access the rare decay at the sensitivity of 10−7.Using the data samples, we can measured the strong phase cos δD at the uncertainty level < 8%.


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SummaryMolecular charmonium & hybrid charmonium

With the data to be taken at 3.773 GeV and 4.030 GeV (or 4.160 GeV) with BES-III, we can search for molecular charmonium and hybrid charmonium, connecting with “fine” cross section scan data.

The start of data taking at BESIII promises an era of precise charm physics. BES-III will provide ~2% precision to calibrate LQCD calculations in D and Ds system.

The measurements from BaBar, Bell, CDF, D0, BTeV, CMS, ATLAS and LHC-b combining the precision LQCD calculations will produce a few per cent determinations of |Vub|, |Vcb|, |Vtd| and |Vts|, which allow us to approach the maximizing the sensitivity for probes for New Physics.


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Thank you 谢谢

Precision measurements Probes for New...

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