The b-Quark a Vertex of New Physicsevans/talks/iu.pdf · 0.09 (to 0.20) 0.01 LHC (Atlas,CMS,LHCb) 500 25K1.5 Tevatron (DØ,CDF) 100 600 0.5 HERA (H1,Zeus) ~0.010 δ>0.1 Z-Fact (LEP,

H.Evans UCI Colloquium: 24-Mar-05 1

The b-Quarka Vertex of New Physics

The b-Quarka Vertex of New Physics

Hal Evans Columbia U.


What You’re In For…What You’re In For…

1. Overthrowing the Standard Model

2. The Revolutionary b-Quark and Its Role

3. Bs Mixing at DØ – The Next Campaign

4. What’s Coming in the Grand Flavor Plan


Standing on Solid GroundStanding on Solid Ground

LEP EW-WG: Winter 2005H

Higgs


If it ain’t Broke – Fix It !If it ain’t Broke – Fix It !Why Look Beyond the SM ?

• Has (at least) 19 arbitrary parameters

• Does not include Gravity∗ Why Mpl >> MEW?

• Higgs Mass not stable to radiative corrections⎯

⎯ Λ ~ Mplanck for no new phys⎯ Mh < 800 GeV

⇒ tuning to 10-16

• No Motivation for EW Symmetry Breaking

222

20

2

4 hhh MM~M δ+Λπλ

+


Where Should We Look ?Where Should We Look ?

Start with the BIG Questions1. Why is there Mass ? EW Symmetry Breaking2. Antimatter ? Weak vs Mass States & CPV3. What about Matter ? understanding QCD

Ask Them in the Right Way• Look in New Places higher E, sparse meas• More Precision new techniques

Two Particularly Promising Areasa. The Neutrino Sectorb. EW Symmetry Breaking (related to 2. as well)


News Flash 2008 !News Flash 2008 !

But…

What Now ?

all the news that’s yet to print

Elusive Higgs Boson DiscoveredBy THE FREE ASSOCIATION PRESS

The scientific community was rocked yesterday when the ATLAS collaboration announced the discovery of the long-sought Higgs boson in a press conference at CERN. “This is an historic occasion.”, said Peter Higgs, the physicist after whom the particle is named…

ATLAS: H → γγM(H) = 120 GeV

L = 100 fb-1


Lots of IdeasLots of IdeasThere are lots of Ideas…• Dynamical Symmetry Breaking

⎯ Technicolor: ∗ running, walking, limping…

• Supersymmetry (SUSY)⎯ GMSSM, SUGRA, R-Parity

Violating• Large Extra Dimensions

⎯ testable string theory!

f−1(k2)

f1(k1)

KK f−2(q2)

f2(q1)

(a)

f−1(k2)

f1(k1)

KK V2(q2)

V1(q1)

(b)⎯ pp →⎯ff ⎯ pp → VV

• monojets

• single VB

• f,VB-pairs

SuperpartnersStandard Model

½1

½0

½1

0½

0½

0½

SSparticleSParticle

RL q,q

RL ,ll

Lν

γ± ,Z,W 0

±H,A,H,h 000

g

RL q~,q~

RL~,~ll

L~ν

±± χχ 21~,~

04

03

02

01

~,~,~,~ χχχχ

g~

MSSM: M(h) < 135 GeV !!!

• Most predict something very similar to the Higgs

• Distinguish using input from many sources• etc., etc., etc….


The Symmetry–Flavor ConnectionThe Symmetry–Flavor Connection

The SM has a Lovely Plan for EW Sym Break & Mass⎯

SM Symmetries & Yukawa Couplings ⇒ Quark Mixing⎯

⎯

Mixing (CKM) Matrix: Vij⎯

EW Sym Breaking ⇒ Observed Flavor Structure

.]c.hUQyDQyELy[L jR

iL

uij

jR

iL

dij

jR

iL

familyj,i

eijY +φ+φ+φ∑−=

=

diagonal-non s,comp' imag.

diagonal real, )convention (by

=

=dij

uij

eij

y

y,y

∑ ∑ +φ−+φ−=i j,i

jRij

iL

dj

iR

iL

uiY .]c.hDVQy[]c.hU~Qy[L

b u

W-

2ubgVFamily Changing

Decays Mixing

s

t

t

s

b

b

WW0sB 0

sB


Mixed Up QuarksMixed Up QuarksQuark Weak ≠ Mass Eigenstates

⇒ CKM Mixing Matrix⎯ 3 angles⎯ 1 complex phase ⇒ CP-violation⎯ Obs. CPV requires m(qi) ≠ m(qj)

Wolfenstein Parameterization

Strength of CPV⎯ J = A2 λ6 η ~ (7×10-5) η

⎟⎟⎟⎟⎟⎟

⎠

⎞

⎜⎜⎜⎜⎜⎜

⎝

⎛

λ−η−ρ−λ

λλ−λ−

η−ρλλλ−

11211

211

23

22

32

A)i(A

A

)i(A

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛=

⎟⎟⎟

⎠

⎞

⎜⎜⎜

⎝

⎛

bsd

VVVVVVVVV

'b's'd

tbtstd

cbcscd

ubusud

Wea

k

Mas

s

CKMFitter Group: hep-ph/0406184

very different hierarchy than Lepton Mixing Matrix

04600420

08800700

0025000230

02900200

35801890226508010

.

.

.

.

.

.

.

.

.

.

..A

+−

+−

+−

+−

=η

=ρ

=λ

=


Why is Flavor Promising (1)Why is Flavor Promising (1)

The SM has a very Specific Flavor Sector:Only one Higgs Doublet

1. FCNC’s suppressed

2. Universal Charged Current

3. VCKM is Unitary

4. 1 Parameter describes strength of all CP Violation


Getting to Know the BGetting to Know the BWeakly Decaying B Hadrons

Large Mass ⇒ Many Decays⎯ >100 observed for Bd⎯ small QCD corr’s to pred’s

Long Lifetime⎯ τ(B) ~ 4 τ(D) ~ 5 τ(τ)⎯ flight lengths O(1mm) at

colliders exp’s

Neutral B-Mesons Mix⎯ 1987: obs by ARGUS & UA1

⇒ predict heavy top 8 years before direct obs.

B-Hadrons exhibit large CPV⎯ structure of CKM matrix

Hadron Mass [MeV] Life [ps]5279 1.675279 1.545370 1.466400 0.55624 1.23

u)b( B+

d)b( B0d

s)b( B0s

c)b( Bc

(bdu) 0bΛ s

t

t

s

b

b

WW0sB 0

sB

Meson ∆m [ps-1] ∆Γ/ΓBd 0.5 < 0.01Bs > 15 < 0.3K0 0.005 ~1


The Beautiful TriangleThe Beautiful TriangleUnitarity of VCKM ⇒ 6 triangles:

⎯ one has all sides ~ equalAngles

⎯ α CPV in B0 → ππ,ρρ,ρπ⎯ β CPV in B0 → J/ψ K0,η,η’

CPV in B0 → φ,η,η’ K0

⎯ γ CPV in B± → D0 K±

CPV in B0 → D(*)+ π-

Sides⎯ Ru B.R.(B → Xc,u lv)⎯ Rt Bd Mixing

Other⎯ ρ,η CPV in K0 system

K+ → π+ v v⎯ η K0 → π0 v v⎯ N.P. Bd,s → µ+µ- , µ+µ- Xd,s

0=++ *tdtb

*cdcb

*udub VVVVVV

(0,1)

γ β

α

(0,0)

(ρ,η) ⎥⎦

⎤⎢⎣

⎡− *

ubud

*tbtd

VVVVarg

t*cbcd

*tbtd R

VVVV

≡

⎥⎦

⎤⎢⎣

⎡− *

tbtd

*cbcd

VVVVarg⎥

⎦

⎤⎢⎣

⎡− *

cbcd

*ubud

VVVVarg

*cbcd

*ubud

u VVVVR ≡

UnitarityTriangle


Putting Things TogetherPutting Things Together

CKMFitter – ICHEP 04

Param Mode Meassin 2β 0.726 ± 0.037

0.43 ± 0.07α (113 ± 27)o

γ Acp(B→D(*)K) (69 ± 20)o

|Vcb| x 103 B→D(*)/Xc lv 41.4 ± 2.1|Vub| x 103 B→Xu lv 4.70 ± 0.44|εK| x 103 KL, KS 2.282 ± 0.017∆md (ps-1) Bd mixing 0.502 ± 0.006∆ms (ps-1) Bs mixing > 14.4

s)cc(b →cpAs)qq(b →cpAd)uu(b →cpA

HFAG summer 2004

CKMFittersummer 01

SM Fit Probability ~ 70%

CKM Phase probably the dominant source of CPV in FC processes

(damn !)


Why is Flavor Promising (2)Why is Flavor Promising (2)CKM Phase as only Quark-Sector CPV is ODD

⎯ most Models beyond SM ⇒ lots of new CPV phases∗ 43 in generic SUSY models !

⎯ FCNCs are also generally large Beyond the SM

Flavor Physics is Already a Major Constraint on Physics Beyond SM⎯ Note that the 3rd Family is the least well constrained

What’s Left Then? (some examples)⎯ Minimal Flavor Violation GMSB, univ.E.D.

∗ only source of FV is in Yukawa couplings⎯ New Sources of CPV R.-S. w/ bulk q’s

∗ FV parts have to be suppressed by e.g. heavy mass scales

⎯ Both can ⇒ Modified Coupling Strengths enhanced rare decays

General Scheme⎯ different models predict different relationships b/w observables

∗ c.f. sin 2β in B → J/ψ Ks vs. B → φ Ks


Natural Habitats of the b-QuarkNatural Habitats of the b-QuarkIncoming Particles

HardInteract

OutgoingParticles Machine √s

(TeV)σ(bb) (µb)

Rate (Hz)

<L>(mm)

B’s

14 all

all

all

all

Bd, B+

1.96

0.32

0.09(to 0.20)

0.01

LHC(Atlas,CMS,LHCb)

500 25K 1.5

Tevatron(DØ,CDF)

100 600 0.5

HERA(H1,Zeus)

~0.010 δ>0.1

Z-Fact(LEP, SLC)

0.007 0.07 3

B-Fact(BaBar,Belle,CLEO)

0.001 10 0.3

Q

Q

p

p

p –

p(ba

r)

ijσ

p

e

ijσ

e –

pe+

–e- e+

ijσe-


Fermilab & Flavor PhysicsFermilab & Flavor PhysicsHistory

⎯ Commissioned 1967⎯ Tevatron (p-pbar) 1983⎯ Main Injector 1999⎯ Run II Start 2001

Some Highlights⎯ b-quark discovery: 1977

∗ Lederman, et al⎯ t-quark discovery: 1994

∗ CDF & DØ⎯ υτ discovery: 2000

∗ DONUT


The Tevatron ColliderThe Tevatron ColliderWorld’s Highest E Accelerator

⎯ proton – antiproton collisions⎯ ~4 miles circumference⎯ >1000 supercond. magnets

Ib92-96

IIa(now)

IIb(goal)

E-CM [GeV] 1800 1960 1960396

10

0.9

Collisions [ns] 3500 396

Peak Lumi. (x1031)

[cm-2s-1] 0.16 28

Tot Lumi fb-1 0.125 4-9

Main Injector(new)

Tevatron

DØCDF

Chicago↓

⎯p source

Booster


DØ CollaborationDØ Collaboration

650 people84 institutions19 countries


DØ Detector (the cartoon)DØ Detector (the cartoon)Central Scintillator

Forward Mini-drift chamb’s

Forward Scint

Shielding

Tracking: Solenoid(2T), Silicon,FiberTracker,Preshowers

New Electronics,Trigger,DAQ

Calorimeter

Central PDTs


The Real McCoy !The Real McCoy !

~1M Channels

2.5M Event/s

250 KB/Event


DØ à la carteDØ à la carte

DØ is a General Purpose DetectorDesigned to Study a Huge Range of Physics Topics

QCD • Understand the strong force where it is predictive• Background for all other physics

B Physics • QCD at perturb/non-perturb interface• Probe quark mixing• Indirect evidence for new physics

W/Z • QCD Tests• Precision measurement of EW parameters

Top • Precision measurement of EW parameters• Most massive particle ⇒ new physics

Higgs • The heart of EW symmetry breakingSearches • Directly look for new particles/effects predicted by

specific beyond the SM models


Data Collected & AnticipatedData Collected & AnticipatedRun II Data so Far

⎯ Apr 2001 start of Run II⎯ Apr 2002 DØ fully commiss.⎯ ~700 pb-1 collected to now⎯ 450 pb-1 analyzed

Run II Projections (June 04)⎯ inst. lumi. → 2.8x1032 cm-2s-1

⎯ total data → 4 – 9 fb-1

⎯ DØ upgrade: October 2005

0

50

100

150

200

250

300

9/29/03 9/29/04 9/30/05 10/1/06 10/2/07 10/2/08 10/3/09Date

Peak

Lum

inos

ity (x

1030cm

-2se

c-1)

0

2

4

6

8

10

12

Tota

l Int

egra

ted

Lum

inos

ity (f

b-1 )

PeakPhasesTotal

DRAFT June04

current peak L

install upgrades


Flip-Flopping B’sFlip-Flopping B’sWeak ≠ Mass Eigenstates

⇒ Neutral B’s can mix

Time Evolution

matrices 2x2 Hermitian 2

=Γ

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎠⎞

⎜⎝⎛ Γ

−=⎟⎟⎠

⎞⎜⎜⎝

⎛

,M)t(B)t(B

iM)t(B)t(B

dtdi

]1[

]1[00

00

)tmcos(e)t)(BB(P

)tmcos(e)t)(BB(P

qt

qq

qt

qq

q

q

∆−∝→

∆+∝→Γ−

Γ−

sd,

t

t

s,d

b

b

WW0sd,B 0

sd,B

*tbV

tbVstd,V

*std,V

t (lifetimes)

Prob

abili

ty

( ) 2222

2

6*

tbtqqBqBqBtWF

q VVBfmxSmGm ηπ

=∆


Mixing Now !Mixing Now !∆md = 0.502 ± 0.006 ps-1 ∆ms > 14.4 ps-1 (95% CL)

30 separate measurements !Heavy Flavour Averaging Group

Winter 2005 update


Some Hints ?Some Hints ?Results presented as

“Probability” that data is consistent with oscillations at various values of ∆ms

ObservationStatistically significant Amp(∆ms) = 1

95% C.L. LimitAmp + 1.645 = 1

SM Preferred Region

16.2 – 24.5 ps-1 (“1 σ”)

SM Preferred Region

16.2 – 24.5 ps-1 (“1 σ”)HFAG: winter 2005

CKMFitter: ICHEP 2004


The Importance of B’ing StrangeThe Importance of B’ing Strange

• Bd Mixing ⇒ |Vtd| (side of triang.)

• So Why should we bother with Bs ?

s

d

Bd

Bs

BdBd

BsBs

ts

td

mm

mm

BFBF

VV

∆∆

=

Ratio reduces error: 14% → 5%


Anatomy of a Bs Mixing AnalysisAnatomy of a Bs Mixing Analysis1. Identify Bs Candidates

⎯ produce them⎯ get them to tape⎯ reconstruct them

2. Determine Proper Time⎯ decay length⎯ ct = L / γβ

3. Tag Mixed or Unmixed⎯ flavor at production⎯ flavor at decay

4. Fit for ∆ms⎯ or ampl at ∆ms

−µ−π

+π

ν-B

−K0D

0sB

-sD

−K

+K

ν+µ

Significance of Observation

⎯ S = no. of Bs signal cand’s⎯ ε = frac. of cand’s w/ tag⎯ D = 2xProb(tag) – 1⎯ S/B = signal/ bgrd⎯ σt = ave. proper time res.

22

2

2Signif /)m( tse

BSSDS σ∆−×+

ε=


Finding the Elusive BsFinding the Elusive Bs

+π

−µ−π

+π

ν-B

−K0D

0sB

-sD

−K

+K

Experimental Challenges⎯ determining backgrounds⎯ Low Pt trigger lepton⎯ Low Pt tracks

−µ−π

+π

ν-B

−K0D

0sB

-sD

−K

+K

ν+µ1. Produce a Bs

⎯ fs ~ 0.1 vs. fd = fu ~ 0.4

2. Trigger on the Event⎯ Collision Rate 2.5 MHz⎯ Rate to Tape 50 Hz⎯ Trigger on 1 or 2 µ’s

3. Reconstruct Bs⎯ Ds

(*) l v BR ~ 10%∗ more stat’s poorer σt

∗ (can trigger on lepton)⎯ Ds

(*) nπ BR ~ 0.5%∗ less stat’s better σt

⎯ Ds → φπ, K*0K ∗ φ →KK, K*→Kπ


We Reconstruct B’s !We Reconstruct B’s !Mode evts / 100pb-1

J/ψ → µ+ µ- 1.14 MB+ → J/ψ K+ 1700Bd → J/ψ K*0 740Bd → J/ψ K0

S 40Bs → J/ψ φ 100Λb → J/ψ Λ 25Bc → J/ψ µ X 65

B → D** µ v 210B** → B π 150Bs → Ds1 µ X 5B+ → D0 µ+ X 46.2 KBd → D*- µ+ X 10 KBs → Ds(φπ) µ X 2900Bs → Ds(K*K) µ X 2500

X(3872) → J/ψ π+ π- 230

Bs → J/ψ φ

450 pb-1

N = 483 ± 32

210 pb-1

N = 135±18M = 6.1±0.2±0.4 GeV

Bc → J/ψ µ X


Mixing SamplesMixing SamplesPr

elim

inar

y

BM

ixin

gd

Prel

imin

ary

BM

ixin

gs

250 pb-1

B → µ D0 X~83% B+

200 pb-1

B → µ D* X~85% Bd

200 pb-1

B → µ K*K X

Bs → µ Ds X4930 ± 380200 pb-1

B → µ φ π X

Bs → µ Ds X13340 ± 280

450 pb-1


How Long Does It Live ?How Long Does It Live ?

−µ−π

+π

ν-B

−K0D

0sB

-sD−K

+K

1. Estimate Decay Length (Lxy)⎯ Beam Spot

∗ size ~35 µm in x-y⎯ Bs Decay Point

∗ vertexing⎯ Decay Length Error (σL)

2. Estimate B Momentum⎯ ct = L / γβ⎯ Bs → Ds

(*) π very precise⎯ Bs → Ds

(*) l v missing v∗ must use MC to est. corr.

ν+µ

3. Proper Time & Error

Experimental Challenge⎯ understand resolution

KPMLct meast

Bxy ⎟⎟

⎠

⎞⎜⎜⎝

⎛=

22

0

2

⎟⎠

⎞⎜⎝

⎛ στ

+⎟⎠

⎞⎜⎝

⎛ σ=⎟

⎠

⎞⎜⎝

⎛τσ

Kt

LK

BB

L

B

t


Study Resolution w/ LifetimesStudy Resolution w/ Lifetimes

Λs → J/ψ Λ

250 pb-1

(t))N(B)N(B0

±

440 pb-1

Bs → Ds µ X

400 pb-1 Bc → J/ψ µ X

210 pb-1


Lifetime ResultsLifetime ResultsLifetime Measurements at DØ

⎯ compared with World Ave’s(from HFAG)

Bs Lifetime Difference

3

SM

104 −×⎟⎟⎠

⎞⎜⎜⎝

⎛∆∆Γ ~ms

s

Bs → J/ψ φ450 pb-1


To Mix or Not To MixTo Mix or Not To Mix

−µ−π

+π

ν-B

−K0D

0sB

-sD

−K

+K

+h

1. Tag Flavor at Production⎯ Opposite Side

∗ Soft Lepton (muon) Tag– µ-charge ⇒ b-charge

∗ Jet Charge Tag–

⎯ Same Side∗ Charge of leading non-Bs

hadron– B** → B h or fragm

2. Tag Flavor at Decay⎯ µ-charge ⇒ b-charge

ν+µ

∑∑

=i,t

ii,t

PqP

Q Jet

Method ε (%) D (%) ε D2 (%)Soft Muon 5 45 1.0 ± 0.2Jet-Q / Same Side 68 15 1.5 ± 0.3BaBar/Belle ~20

Experimental Challenge⎯ Measure mis-tag rate in Data⎯ Control Samples: B± decays

∗ B+ → D0 µ+, B+ → J/ψ K+


Contributions to Mixing UncertaintyContributions to Mixing Uncertainty50K Simulated Bs → Ds µv Events: ∆ms = 15 ps-1

cτs

reduces ampl of osc big effect at large t

big effect at small t


Testing the Waters with Bd MixingTesting the Waters with Bd Mixing∆m & D from Unmix – Mix Asymmetry

Agrees with Previous Measurements

( ) ( ) ( )( ) ( ) ( )mxcosD~

xNxNxNxNxA mixunm

mixunm

∆+−

=

ctvis (µm)

Unm

ix-M

ix A

sym

(t)

“B+” → D0 µ+ X(JetQ+SST)

“B0” → D*- µ+ X(JetQ+SST)

“B0” → D*- µ+ X(SLT)

cτd

DØ

Prel

imin

ary:

200

pb-

1


First Try at ∆msFirst Try at ∆ms

Bs → Ds(φπ) µ X460 pb-1

No Oscillations Evident

⇒ Set Limits

Bd

B+

Dilution44.8 ± 4.2 %

Dilution46.8 ± 3.0 %

Fermilab Result of the Week: March 10, 2005


Still Only a Limit…Still Only a Limit…

∆ms > 5.1 ps-1 (95% CL)∆ms > 5.1 ps-1 (95% CL) Expected Limit ComparisonExpected Limit Comparison

comb. sens18.1 ps-1

CDF prelim (Moriond): ∆ms > 7.9 ps-1


…but Nostradamus Predicts…but Nostradamus PredictsMode Yield / pb-1 εD2 (%) S/S+B σt (fs)

curr. (φπ) 29 1.2 0.4 150125

Ds(φπ) e X 30 1.25 0.4 125Ds(K*K) µ X 25 2.5 0.2 125

Ds(*) π 0.5 25 0.5 110

Ds(φπ) µ X 30 2.5 0.4

Significance for1 fb-1

τ∆σ

Signif21~ m)(

Extra Improvement from:

• more powerful statisticaltechniques


The Road Ahead for DØThe Road Ahead for DØ

⎯ 1st obs ⇒ good accuracy

Other B-Physics Meas’s benefit greatly from increased statistics

Big Challenges: Triggering⎯ Level-1 Bandwidth

Limitations⎯ Data to Tape

& Reconstruction

Run II Projections (June 04)⎯ inst. lumi. → 2.8x1032 cm-2s-1

⎯ total data → 4 – 9 fb-1

⎯ DØ upgrade: summer 05

0

50

100

150

200

250

300

9/29/03 9/29/04 9/30/05 10/1/06 10/2/07 10/2/08 10/3/09Date

Peak

Lum

inos

ity (x

1030cm

-2se

c-1)

0

2

4

6

8

10

12

Tota

l Int

egra

ted

Lum

inos

ity (f

b-1 )

PeakPhasesTotal

DRAFT June04

current peak L

install upgrades

τ∆σ

Signif21~ m)(


The Current DØ Trigger SystemThe Current DØ Trigger SystemProblem as Rates Increase

Readout not Deadtimeless

⎯ L1 Accept → Deadtimewhile data is digitized & stored to buffers

⎯ 2.5 kHz L1A → 5% Dead

CAL

c/f PS

CFT

SMT

MU

FPD

L1Cal

L1PS

L1CTT

L1Mu

L1FPD

L2Cal

L2PS

L2CTT

L2STT

L2Mu

Global L2Framework

Detector

Lumi

Level 1 Level 22.5 Mhz 3 khz 1 khz

Level 3


The Scope of the ProblemThe Scope of the Problem

Term Proc effvvbb 85%

1-EM W → ev 86% 440 HzHi Pt Trk (iso) Pt>10 98% 17 kHz1-µ + Track W→ µv ~90% 6 kHz

Run IIa2-Jet + MEt 2.1 kHz

2.5 kHzLimit

2.5 kHzLimit

Trigger Problems SolutionsJet(L1Cal)

1) Trig on ∆η×∆φ=0.2×0.2 TTs⇒ slow turn-on curve, high rates

• Clustering

EM(L1Cal + Cal-track)

1) ~Linear rate increase w/ lumi⇒ affected by noise

• Clustering & Isolation• Cal-Track Match

Track(L1CTT + Cal-Track)

1) Rates sensitive to occupancy⇒ ×100 increase now→2×1032

• Narrower Track Roads• Improve Cal-Track Match

Muon(L1Muon + L1CTT)

1) Mainly from tracking • Requires Track Trig


The New SystemThe New System

CAL

c/f PS

CFT

SMT

MU

FPD

L1Cal

L1PS

L1CTT

L1Mu

L1FPD

L2Cal

L2PS

L2CTT

L2STT

L2Mu

Global L2Framework

Detector

Lumi

Level 1 Level 22.5 Mhz 3 khz 1 khz

Level 3

CalTrk

Installation

Oct. – Dec. 2005

Installation

Oct. – Dec. 2005


An Example: L1CalAn Example: L1CalNew Algorithms: search for Local Maxima & Cluster

LM Finding Jet Algorithm Tau Algorithm EM Algorithm

Novel Implementation⎯ Challenge LM Finding ⇒ Data Distribution Nightmare !⎯ Solution All Data Transmission & Arithmetic done Bit Serially

Serial Adder(like 50’s-era computers)


With Trigger ImprovementsWith Trigger Improvements

Term Proc effvvbb 85%

1-EM W → ev 86% 440 Hz 260 HzHi Pt Trk (iso) Pt>10 98% 17 kHz 1 kHz1-µ + Track W→ µv ~90% 6 kHz 1.1 kHz

Run IIa Run IIb2-Jet + Met 2.1 kHz 0.8 kHz

Triggering and B-Physics

• without Trigger Upgrade⎯ all DØ Physics is Compromised

• with Trigger Upgrade⎯ high PT abilities retained or enhanced⎯ new Flexibility creates room for low PT (B-Physics) Triggers


Further Down the PathFurther Down the Path

DØ,CDF BaBar,Belle LHCb Atlas,CMSBeams e+e- pp ppECM [TeV] 1.96 0.0106 14 14Timeframe now → 2009 now → 2008 2007 2007Inst Lumi(×1032 cm-2s-1)

1.0 → 2.8 100 2.0 100

Data Set [fb-1] 0.5 → 9 150 → 500 1012 bb/yr 100/yr

pp


The Next StepsThe Next Steps

Quantity Mode Curr. W.A. Next Step Improvement|Vcb| B→Xclv (41.4 ± 2.1)×10-3 theory|Vub| B→Xulv (4.70 ± 0.44)×10-3 theory

CDF,DØ ? ± 0.03 (2 fb-1)0.43 ± 0.07 BaBar,Belle ± 0.03 (1.5 ab-1)

BR(K→π0vv) < 5.9×10-7 KOPIO/E391 O(100) evts – 2009

γ B→D0CPK,Kπ (69 ± 20)o BaBar,Belle ±14o (1.0 ab-1)

Rare K’s BR(K→π+vv) NA48/3 ~50 evts (2 years)Rare BR(Bs→µ+µ-) < 3.7 × 10-7 Atlas,CMS (3.5±0.8)×10-9 (100fb-1)

∆ms Bs→DslvX,Dsπ > 14.4 ps-1 DØ,CDF ~20-25 (5σ w/ 2 fb-1)LHCb ~50 (1 year)

α B→ππ,ρπ,ρρ (113 ± 27)o LHCb ±4o (1000 tag ρπ)

sin 2β 0.726 ± 0.037 BaBar,Belle ± 0.03 (0.5 ab-1)sccb →

sqqb →

103010.89- 101.47 −+ ×.


ConclusionsConclusions

• B-Hadrons provide a Sensitive Probe of EW Symmetry Breaking & Physics Beyond the SM⎯ allow classes of models to be favored/ruled out⎯ complementary to direct searches for new particles

• The DØ Experiment is Poised to make Major Contributions in the next few years⎯ CKM: Bs Mixing, ∆Γs, sin 2β, sin 2βs…⎯ QCD: lifetimes, spectroscopy, production…⎯ Rare: Bs→µ+µ-, B →K*µ+µ-

• Future Experiments will keep b’s at the Vertex of New Physics for many years to come !


Backup SlidesBackup Slides


Bs Event SelectionsBs Event SelectionsSelection Ds

+ → φ(K+K-) π+ Ds+ → K*0(K+π-) K+ (differences)

Muons • penetrate toroid• matched track: SMT+CFT• Pt > 1.5, P > 3 GeV• |η| < 2

• same

Ds Candidate • 3 tracks in same jet as µw/ hits in SMT+CFT & correct Q

• |η| < 2• Pt(trk) > 0.7 GeV• φ-mass (1.006<MKK<1.030 GeV)• 3-track vertex: χ2 < 16• (εT/σ)2+(εL/σ)2 > 2(π), 4(one K)• dT

D/σ > 4 & cos(αTD) > 0.9

• Pt(trk) > 1.0 GeV• K*-mass (0.84 < MKπ < 0.96)• χ2(Ds) < 20 & χ2(K*) < 20• (εT/σ)2+(εL/σ)2 > 2(π), 5(one tk)• dT

D/σ > 4 & cos(αTD) > 0.95

• dTD · P(D) > 0

• cos(helicity-angle) > 0.60Bs Candidate

• µ - Ds vertex: χ2 < 9• 1.5 < M(µDs) < 5.5 GeV• dT

B < dTD + 3σ

• P(µDs) > 8 & PTrel > 1 GeV

• µ - Ds vertex: χ2 < 20• 2.2 < M(µDs) < 5.5 GeV

In Ds M Peak 29 ± 0.6 events per pb-1 25 ± 2 events per pb-1


Selection Bias vs VPDLSelection Bias vs VPDL

Bs → µ+ v Ds X MC


Proper Time ResolutionProper Time ResolutionPrimary Vertex

⎯ evt-by-evt determination using ave PV as seed

VPDL Resolution⎯ parameterized from MC for

each sample w/ 3 Gaussians⎯ IP errors (main contrib)

tuned using data tracks from PV depending on SMT hits

True Proper Time⎯ convolute over K-factor

distributions in Asym. prediction

⎯ K = PT(Dsµ) / PT(Bs)


Initial State Tagging ProcedureInitial State Tagging Procedure

Use “other” B→µ in the evt to tag prod flavor of Bs⎯ allow use of Bd mixing sample to measure eff and dilution

∗ “tagging” B essentially independent of “signal” B⎯ cannot do this for “same side” tagging

Define a Tagging Variable using an optimal combination of variables sensitive to initial flavor

Variables Used⎯ All Events Events w/ Secondary Vertex

( )( )∏=

+−

== svari ii

ii

xbxby

yyd

11

∑ ∑==trksi i

iT

iT

iJet p/pqQ

µ⋅qprelT

( ) ( )∑ ∑==trksi i

.iT

.iT

iSV p/pqQ 6060


Binned AsymmetryBinned AsymmetryNunm/mix in each VPDL bin

⎯ fit Ds mass distrib for unm/mix events in that bin

∗ single Gauss for Ds→φπ & D+→φπ, exp for bgrd

⎯ param’s fixed from untagged sample mass fit

Sample Composition (Peak)

Process BR x Eff (%)Bs → µ v Ds

- 20.6Bs → µ v Ds

-* 57.2Bs → µ v Ds0

*- 1.4Bs → µ v Ds1

’- 2.9Bs → Ds

+Ds-X, Ds → µ v X 11.3

B+ → D Ds X, D → µ v X 3.2B0 → D Ds X, D → µ v X 3.4cc → µ Ds X 3.5

Ds → φ πTagged Events-0.01 < VPDL < 0.06 cm


Reconstructed B’sReconstructed B’s

Bd → J/ψ Ks0

B± → J/ψ K±

ψ’ → J/ψ π+ π-

X(3872) → J/ψ π+ π-

B → µ D* X


The J/ψThe J/ψ


ResonancesResonances

σ = 7 MeV

σ = 3 MeV


Rare Decays and FCNCsRare Decays and FCNCsTheoretically Clean• FCNC B0 decays forbidden

at tree level in SM

• Can be large beyond SM⎯ Γ2HDM ∝ tan4 β⎯ ΓMSSM ∝ tan4 β

Plays to DØ’s Strengths⎯ Muon Triggers to large η⎯ Low Backgrounds⎯ also Bs → µ+ µ- φ

Mode BR(Bd) BR(Bs)µ+µ- 1x10-10 4x10-9

1x10-6

K*γ 4.4x10-5

µ+µ-K* (φ) 1.5x10-6

µ+µ-Xs 6x10-6

BR(Bs → µ+ µ-) < 3.7×10-7 (95% CL)BR(Bs → µ+ µ-) < 3.7×10-7 (95% CL)

µ+ µ- Mass [GeV]

300 pb-1


Measuring βMeasuring β

d

b

0dB W

*cbV

csV s

cc

d0K

ψJ/

b

d

Wt

t b

0dB 0

dB s

cc

d0K

ψJ/

tbV *tdV

tdV *tbV *

cbV

csV

s

c

cW

b

d

0dB

sd

0K

cc ψJ/

cbV

*csV 0K

*cdV

*cdV

csV

*csV

s)cc(b KJ/B 0s →ψ→

b

dW

tt b

0dB 0

dB 0K

tbV *tdV

tdV *tbV

*cbV

csVc

d

qq

s',ηφ

b

d

0dB

c cc

csV *cdV

s0K s

qq

',ηφ

0Kd

cdV *csV

cbV

*csV

b

0dB 0K*

cbV csVc

d

qq

s',ηφ

d

s)qq(b KB 0s →ηφ→ ',

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛=λ

fCP

fCPfCP A

Apq

B-Mixing Decay

β−−=⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛=ψλ i

cd*

cs

*cdcs

cs*

cb

*cscb

td*

tb

*tdtb e

VVVV

VVVV

VVVV)K( 20

β−−=⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛=φλ i

cd*

cs

*cdcs

cs*

cb

*cscb

td*

tb

*tdtb e

VVVV

VVVV

VVVV)K( 20

Documents

The b-Quark a Vertex of New Physicsevans/talks/iu.pdf · 0.09 (to 0.20) 0.01 LHC (Atlas,CMS,LHCb) 500 25K1.5 Tevatron (DØ,CDF) 100 600 0.5 HERA (H1,Zeus) ~0.010 δ>0.1 Z-Fact (LEP,