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S. StoneSyracuse Univ.May 2003

Heavy Quark Physics

Far too much interestingMaterial to include in 40 min.Apologies in advance.

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Physics Goals

Discover, or help interpret, New Physics found elsewhere using b & c decays - There is New Physics out there: Standard Model is violated by the Baryon Asymmetry of Universe & by Dark Matter

Measure Standard Model parameters, the “fundamental constants” revealed to us by studying Weak interactions

Understand QCD; necessary to interpret CKM measurements

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The Basics: Quark Mixing & the CKM Matrix

A, , and are in the Standard Model fundamental constants of nature like G, or EM

multiplies i and is responsible for CP violationWe know =0.22 (Vus), A~0.8; constraints on &

2 3 2

2 2 4 2 2

3 2

1 11- λ λ Aλ -i 1- λ

2 2

1V= -λ 1- λ -i A λ Aλ 1+i λ

2Aλ 1- -i -Aλ 1

η

η

ρ

η

ηρ

d s bu

c

t

mass

mass

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The 6 CKM Triangles

From Unitarity“ds” - indicates

rows or columns used

There are 4 independent phases: ( can be substituted for or )

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All of The CKM Phases

*cdcb

*tdtb

VV

VVarg

cd*cb

ud*ub

VV

VVarg

tb*ts

cb*cs

VV

VVarg

cs*cd

us*ud

VV

VVarg

The CKM matrix can be expressed in terms of 4 phases, rather than, for example , A, ,

not independent& probably large, small ~1o, smaller

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Required Measurements

|Vub/Vcb|2 = (2+ 2)/2 use semileptonic B decaysmd and ms are measured directly in Bd and Bs mixing.

There is a limit on the ratio which is a function of Vtd/Vts and depends on (1-)2+2

K is a measure of CP violation in KL decays, a function of , and A

Asymmetries in decay rates into CP eigenstates f (or other states) measure the angles & , sometimes with little or no theoretical model errors

Bo Bo

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|Vub | a case study

Use semileptonic decaysc >> u, so difficult expAlso difficult theoretically

Three approachesEndpoint leptons: Clear signal seen first this way; new

theory enables predictionsMake mass cuts on the hadronic system; plot the lepton

spectrum. Problems are the systematic errors on the experiment and the theory.

Exclusive B or decays. Data are still poor as is theory. Eventually Lattice Gauge calculations should be able to remove this problem

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Vub from lepton endpoint

Vub both overall rate & fraction of leptons in signal region depends on model. Use CLEO b sspectrum to predict shape

CLEO: Vub=(4.08±0.34 ±0.44±0.16 ±0.24)x10-3

BABAR: Vub=(4.43±0.29 ±0.25±0.50 ±0.35)x10-3 theory errs : Vub formula, using s

Luke: additional error >0.6x10-3 due to:

CLEO

Y(4S) data bccontinuum

Shape fromb s

bu

subleading twist, annihilation

CLEO

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Vub Using Inclusive Leptons

ALEPH & DELPHI, OPAL select samples of charm-poor semileptonic decays with a large number of selection criteria

Mass < MD b uCan they understand b c

feedthrough < 1% ? |Vub|=(4.090.370.44

0.34)x10-3

DELPHI

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Problem According to Luke

PROBLEM: QCDmB and mD

2 aren’t so different!kinematic cut and singularity are perilously close …SOLUTION: Also require q2>~7 GeV2

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Vub using reconstructed tags - BABAR

Use fully reconstructed B tags

|Vub|=(4.520.31(stat)0.27(sys)

0.40(thy)0.09(pert)

0.27(1/mb3)) x10-3

Preliminary

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Vub from Belle

Two techniques (Both Preliminary)

|Vub| = 5.00 0.60 0.23 0.05 0.39 0.36 103stat. syst.

|Vub| = 3.96 0.17 0.44 0.34 0.26 0.29 103

bc bu

stat. syst. bc bu

“D(*) tag”

“ reconstruction and Annealing uses Mx < 1.5, q2 > 7”theor.

theor.

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Vub from exclusives:BBUse detector

hermeticity to reconstruct

CLEO finds rough q2 distribution

BABAR finds

(GeV)

CLEO

exp thytheor -3

stat ρlν FFsys

+0.16 +0.533.17±0.17 ±0.03 ×10

-0.17 -0.39ubV

thy

-3

stat syst

+0.393.64±0.22 ±0.03 ×10

-0.56ubV

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|Vub | Summary

All measurements nicely clustered. RMS ~0.3x10-3

However, there are theoretical errors that might all have not been included (see Luke)

Also previous values may have influenced new values

Safe to say |Vub|=(4.0±1.0)x10-3

Future: More and better tagged data

from B-factories Lattice calculations

(unquenched) for exclusives in high q2 region

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Bd Mixing in the Standard Model

Relation between B mixing & CKM elements:

F is a known function, QCD~0.8BB and fB are currently determined only

theoreticallyin principle, fB can be measured, but its very

difficult, need to measure Bo Current best hope is Lattice QCD

td

222 m*2 2F t

B B tb t QCD2 2mWB B

m Gx B m V m F

6f V

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Bs Mixing in the Standard Model

When Bs mixing is measured then we will learn the ratio of Vtd/Vts which gives the same essential information as Bd mixing alone:|Vtd|2=A24[(1-)2+2] 1/fBBB

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|Vtd|2/ |Vts|2=[(1-)2+2] fBsBBs2/fBBB

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Circle in () plane centered at (1,0)

Lattice best value for

S S S S

222 m* 2s F t

s B B tb t QCD2 2m

2B B ts

Ws

m Gx m V m F

6B Vf

S S

d d

B B

B B

f B1.24 0.04 0.06

f B

Partiallyunquenched

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Upper limits on ms

P(BSBS)=0.5X

Se-St[1+cos(mSt)]

To add exp. it is useful to analyze the data as a function of a test frequency

g(t)=0.5 S

e-St[1+cos(t)]

4 discovery limit

LEP + SLD

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Status of sin(2)

B0 fCPB0 fCP

sin2 = 0.7410.0670.034 BABAR sin2 = 0.7190.0740.035 Belle sin2 = 0.73 0.06 Average

sin2 = 0.7410.0670.034 BABAR sin2 = 0.7190.0740.035 Belle sin2 = 0.73 0.06 Average

78 fb-1

fCP=J/Ks, Ks, etc..

( )

sin(2 )sin( )

BBCP

BB

d

N NA t

N N

m t

No theoretical uncertainties atthis level of error

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Current Status Constraints on & from Nir using Hocker

et al. Theory parameters exist except in

Asymmetry measurements, because we measure hadrons but are trying to extract quark couplings. They are allowed to have equal probability within a restricted but arbitrary range

Therefore large model dependence for Vub/Vcb, K and md, smaller but significant for ms and virtually none for sin(2). The level of theoretical uncertainties is arguable

sin(2)

sin(2) may be consistent with other measurements

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for s get K-

Bo+-

In principle, the CP asymmetry in Bo measures the phase . However there is a large Penguin term (a “pollution”) (CLEO+ BABAR+BELLE): (Bo +-) = (4.8 ±0.5)x10-6 (Bo K±) =(18.6±1.0)x10-6

ACP(t)=Ssin(mdt)-Ccos(mdt),

where SC

To measure , use Bo see Snyder & Quinn PRD 48, 2139 (1993))

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Results

Inconsistent Results!

S C S2+C2

Belle -1.23±0.42 0.77±0.28 2.1±2.2

BABAR 0.02±0.34 -0.30±0.34 0.1±0.3

-5 0 5 t (ps)

BABAREach exp~80 fb-1

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Progress on Best way to measure is

2nd best is

Another suggestion is DoK*±K (Grossman, Ligeti &

Soffer hep-ph/0210433)

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Currently available data

Belle signals (also B+)

Where is a strong phase &

These data do not constrain BABAR has similar results

0fD K

1 ,D K K

02 , , ,

,S S S

S S

D K K K

K K

signal

1,2 1,2

1,2 11

,2,2

( ) ( )

( ) ( )

B B D K B B D K

B B D K B BA

D K

2

2 sin( )sin( )

1 2 cos( )cos( )

r

r r

0

0

( ) ( )

( ) ( )

A B D K A b u

A B D K A b cr

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New Physics Tests

We can use CP violating or CP related variables to perform tests for New Physics, or to figure out what is the source of the new physics.

There are also important methods using Rare Decays, described later

These tests can be either generic, where we test for inconsistencies in SM predictions independent of specific non-standard model, or model specific

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Generic test: Separate Checks

Use different sets of measurements to define apex of triangle

(from Peskin)

Also have K

(CP in KL system)

Magnitudes

Bd mixing phase

Bs mixing phase

Can also measure via

B-DoK-

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Generic Test: Critical Check using

Silva & Wolfenstein (hep-ph/9610208), (Aleksan, Kayser & London), propose a test of the SM, that can reveal new physics; it relies on measuring the angle .Can use CP eigenstates to measure BsJ/ Can also use J/but a complicated angular analysis is

requiredThe critical check is:

Very sensitive since 0.2205±0.0018Since ~ 1o, need lots of data

2 sin sinsin

sin( + )

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Rare b Decays

New fermion like objects in addition to t, c or u, or new Gauge-like objectsInclusive Rare Decays such as inclusive bs, bd, bs+Exclusive Rare Decays such as BBK*+: Dalitz plot & polarization

+-

A good place to find new physics

Ali et. al, hep-ph/9910221

SUSYexamples

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Inclusive bs

CLEO B(b s)=

(2.85±0.35±0.23)x10-4

+ALEPH, Belle & Babar

Average

(3.28±0.38)x10-4

Theory

(3.57±0.30)x10-4

CLEO

7 b 7 8 b 8

μν μν7 b L μν R 8 b

2 522 *F b

7 tb ts4

L μν R2

*Feff tb ts c (m )O c (m )O

e 1O = m s σ b F , O = m s σ b G

1

G αmΓ(b sγ)= c V

4

6

GH

V in lowest order32π

V V2

π 4π

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Implications of B(b s ) measurement

Measurement is consistent with SM

Limits on many non-Standard

Models: minimal supergravity,

supersymmetry, etc… Define ala’ Ali et al.

Ri=(ciSM+ci

NP)/ciSM ; i=7, 8

Black points indicate various New Physics models (MSSM with MFV)

SM

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BK(*)+-

Belle Discovery of K+-

They see K+-

BABAR confirms in Ke+e-

Only u.l. on K*+-

0.25 60.21

(B K )

0.75 0.09 x10

B

0.24 0.11 60.20 0.18

(B K )

0.78 x10

B

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BXs+-

Belle finds B(b s+- )=

(6.1±1.4 )x10-6

Must avoid J/, ´Important for NP

+1.4

-1.1

Heff = f(O7, O9, O10)

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Tests in Specific Models:First Supersymmetry

Supersymmetry: In general 80 constants & 43 phasesMSSM: 2 phases (Nir, hep-ph/9911321)

NP in Bo mixing: D , Bo decay: A, Do mixing: K

Process Quantity SM New Physics

BoJ/Ks CP asym sin(2) sin2(D)

BoKs CP asym sin(2) sin2(DA)

DoK-+ CP asym 0 ~sin(K)

NP

Difference NP

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CP Asymmetry in BoKs

Non-SM contributions would interfere with suppressed SM loop diagramNew Physics could show if there is a difference between sin(2) measured here and

in J/ KsMeasurements: BABAR: -0.18±0.51±0.07

Belle: -0.73±0.64±0.22 Average: -0.38±0.41

2.7 away from 0.73 - bears watching, as well other modes

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relies onfinite strongphase shift

MSSM Predictions from Hinchcliff & Kersting

(hep-ph/0003090)

Contributions to Bs mixing

CP asymmetry 0.1sincossin(mst), ~10 x SM

BsJ

B-K-

Contributions to direct the CP violating decay

Asym=(MW/msquark)2sin(), ~0 in SM BABAR u.l Asy=(3.9±8.6±1.1)%

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Extra Dimensions – only one

Extra spatial dimension is compactified at scale 1/R = 250 GeV on up

Contributions from Kaluza-Klein modes- Buras, Sprnger & Weiler (hep-ph/0212143) using model of Appelquist, Cheng and Dobrescu (ACD)

No effect on |Vub/Vcb|, Md/Ms, sin(2)

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One Extra Dimension

Precision measurements needed for large 1/R

–8% –100

+72%

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SO(10)ala’ Chang, Masiero & Murayama hep-ph/0205111

Large mixing between and (from atmospheric oscillations) can lead to large mixing between bR and sR.

This does not violate any known measurements

Leads to large CPV in Bs mixing, deviations from sin(2) in Bo Ks and changes in the phase

~ ~

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Possible Size of New Physics Effects

From Hiller hep-ph/0207121

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Revelations about QCD

BABAR discovery of new narrow Ds+o state

and CLEO discovery of narrow Ds*+o state

Double Charm BaryonsThe C(2S) and implications for Potential

Models (no time)The Upsilon D States (no time)

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The Dso state

“Narrow” state, mass 2316.8±0.4±3.0 MeV width consistent with mass resolution ~9 MeV found by BABARLighter than most potential modelsWhat can this be?

DK molecule Barnes, Close & Lipkin hep-ph/0305025“Ordinary” excited cs states: D**, narrow because isospin is violated

in the decay. Use HQET + chiral symmetry to explain. Bardeen, Eichten & Hill hep-ph/0305049

Etc…

Ds* New

BABAR

+

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Ds** States

Ds** predicted Jp: 0+, 1+, 1+ & 2+. One 1+ & 2+ seen. Others predicted to be above DK threshold and have large ~200 MeV widths, but this state is way below DK threshold

The Dso decay from an initial cs state violates isospin, this suppresses the decay width & makes it narrow. So the low mass ensures the narrow width

Decays into Ds, Ds* and Ds +- are not seen. If the 2317 were 1+ then it could decay strongly into Ds +- but it cannot if it’s 0+

+

+

+ + +

+

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CLEO Sees Two Mass Peaks

These two states can reflect into one another

DsoDs*o not to bad,

~9%, because you need to pick up a random

Ds* signal region

Ds* sideband region

Ds*o Dso

m=349.3±1.1 MeV=8.1±1.3 MeV

m= 349.8±1.3 MeV= 6.1±1.0 MeV

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Feed Down: Ds(2460) Signal, Reconstructed as Ds(2317)

All events in the Ds*0

mass spectrum are used to show the Ds(2460) signal

“feed down” to the Ds(2317) spectrum.

Feed down rate is 84%

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Unfolding the rates

We are dealing with two narrow resonances which can reflect (or feed) into one another

From the data and the MC rates can be unfolded

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Upper Limits on other Ds(2317) modes

Mode Yield Efficiency(%) 90% cl Theory

Corrected for feed acrossTheory: Bardeen, Eichten and Hill

Dso 150±49 13.1±0.7 - 1

Ds -22±13 18.4±0.9 <0.057 0

Ds* -2.0±4.1 5.3±0.4 <0.078 0.08

Ds+- 1.6±2.6 19.6±0.7 <0.020 0

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Belle Confirms Both States

M(Ds+

π0 ) M(Ds*+

π0 )

M=(2317.2±0.5) MeV

=(8.1 ±0.5) MeV

M=(2459±1.9) MeV

=(7.0 ±1.7) MeV

Also see “feed up”

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Conclusions on Ds**’s

CLEO confirms the BABAR discovered narrow cs state near 2317 MeV, measures mDs(2320)-mDs =350.4±1.2±1.0 MeV

CLEO has observed a new narrow state near 2463

mDs(2463)-mDs*=351.6±1.7±1.0 MeV Belle confirms both states The mass splittings are consistent with being equal (1.2±2.1 MeV)

as predicted by BEH if these are the 0+ & 1+ states The BEH model couples HQET with Chiral Symmetry and makes

predictions about masses, widths and decay modes. These results provide powerful evidence for this modelSeen modes and u.l. are consistent with these assignment;

except 1+ Ds+- is above threshold for decay, predicted to be 19% but is limited to <8.1% @ 90% c. l.

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Selex: Two Isodoublets of Doubly Charmed Baryons

cc

++

(J=1/2+)?

cc

++

(J=1/2-)?

cc

+

(J=1/2+)?

cc

+

(J=1/2-)?

Consider as (cc)q - BEH

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The Future

Now & near term Continuation of excellent new results from Belle

& BABARBs physics, especially mixing from CDF & D0CLEO-c will start taking data in October on

LHC eraSome b physics from ATLAS & CMSDedicated hadronic b experiments: LHCb &

BTeV (at the Tevatron) – enhanced sensitivity to new physics

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Summary of Required Model Independent Measurements for

CKM testsPhysics Quantity

Decay Mode Vertex Trigger

K/ sep

det Decay time

sin(2) Bo

cos(2) Bo

sin() BsDs K

sin() BoDo K

sin(2) Bs J/ J/

sin(2) Bo J/Ks

cos(2) Bo J/Ko, Ko

xs BsDs

for Bs Bs

J/ K

K Ds

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CDF measures BsDs-

needed for Bs mixing

For fs/fd = 0.27±0.03, B(Bs)/B(Bd)=1.6±0.3

0.060.o + -

d d

o + -S S

7S

0

( )0.42 0.11 0.11

( )f B

f π

D π

B DB

B

+o

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BTeV & LHCb

Dedicated Hadron Collider B experiments Tevatron LHC

LHCb

Could find narrow Bs** states

PbWO4

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BTeV & LHCb

Physics highlightsSensitivity to Bs mixing up to xs ~80

Large rare decay rates BoK*o+- ~2500 events in 107 s

Measurement of to ~7o using BsDs K-

Measurement of to ~4o using Bo (BTeV)Measurement of to ~1o using BoJ/ (BTeV)

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Conclusions

There have been lots of surprises in Heavy Quark Physics, including:Long b LifetimeBo – Bo mixingNarrow Ds** states

We now expect to find the effects of New Physics in b & c decays!