The b-Quark a Vertex of New Physicsevans/talks/columbia_colloq.pdf · 0.09-0.20 0.01 LHC 500 250001.5 Tevatron 100 600 0.5 HERA ~0.010 δ> 0.1 LEP, SLC 0.007 0.07 3 B-Fact 0.001 10

H.Evans Columbia Colloquium: 18-Oct-04 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

H?H?


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 Breaking

2. Antimatter ? Weak vs Mass States & CPV

3. What about Matter ? understanding QCD

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

EW Symmetry Breaking !• turns out to be related to question 2) as well


News Flash 2008 !News Flash 2008 !

Science all the news that’s yet to print

The Nu York Times

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, and it’s all because of the work of the Columbia University group”, said Peter Higgs, the physicist after whom the particle is named…

ATLASttH productionM(H) = 100 GeV

but What Now ?but What Now ?


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⎯ A = 0.801 ± 0.025⎯ λ = 0.2265 ± 0.0024⎯ ρ = 0.189 ± 0.079⎯ η = 0.358 ± 0.044

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


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.

⎯ ∆md ~ 0.5 ps-1 ; ∆ms > 15 ps-1

∗ c.f. ∆mK ~ 0.005 ps-1

⎯ ∆Γs/Γs < 0.3∗ c.f. ∆ΓK/ΓK ~ 1

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


The Beautiful TriangleThe Beautiful TriangleUnitarity of VCKM ⇒ 6 triangles: Angles

⎯ one has all sides ~ equal ⎯ 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

0.39 ± 0.10α (100 ± 10)o

γ Acp(B→D(*)K) (77 ± 25)o

|Vcb| x 103 B→D(*)/Xc lv 41.4 ± 2.1|Vub| x 103 B→Xu lv 4.66 ± 0.43|εK| x 103 KL, KS 2.282 ± 0.017∆md (ps-1) Bd mixing 0.502 ± 0.007∆ms (ps-1) Bs mixing > 14.5

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 allall

all

all

Bd, B+

1.96

0.32

0.09-0.200.01

LHC 500 25000 1.5Tevatron 100 600 0.5

HERA ~0.010 δ > 0.1

LEP, SLC

0.007 0.07 3

B-Fact 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

Main Injector(new)

Tevatron

DØCDF

Chicago↓

⎯p source

BoosterIb92-96

IIa(now)

IIb(goal)

E-CM [GeV] 1800 1960 1960

p/bch (x1010) 23 22 27

Bunches 6x6 36x36 36x36

Anti-p/bch (x1010) 5.5 2.2 13

396

10

80.59~1

Spacing [ns] 3500 396

Peak Lumi. (x1031)

[cm-2s-1] 0.16 28

Lumi/week pb-1 3.2 55Tot Lumi fb-1 0.125 9Int’s/X’ing 2.5 >6


DØ CollaborationDØ Collaboration650 people84 institutions19 countries

DØ

Collaboration M

eeting: June 2003, Beaune, France


Data Collected & AnticipatedData Collected & AnticipatedRun II Data so Far

⎯ Apr 2001 start of Run II⎯ Apr 2002 DØ fully commiss.⎯ 470 pb-1 collected to now⎯ 200 – 250 pb-1 analyzed

• 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


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


B MixingB Mixing

sd,

t

t

s,d

b

b

WW0sd,B 0

sd,B

*tbV

tbVstd,V

*std,VWeak ≠ Mass Eigenstates

⇒ Neutral B’s can mix

Time Evolution

The B is a Notorious Flip-Flopper !

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−


Mixing Now !Mixing Now !∆md = 0.502 ± 0.007 ps-1

30 separate measurements !

∆ms > 14.5 ps-1 (95% CL)

Heavy Flavour Averaging GroupWinter 2004 update


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%


Some Hints ?Some Hints ?

HFAG: summer 2004

SM Preferred Region:

16.5 – 25.3 ps-1 (“1 σ”)

SM Preferred Region:

16.5 – 25.3 ps-1 (“1 σ”)

CKMFitter: ICHEP 2004


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. 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

Sensitivity

⎯ N = no. of Bs candidates⎯ ε = frac. of Bs in N⎯ D = 1 – 2xProb(mistag)⎯ S/B = signal/ bgrd in N⎯ σt = ave. proper time res.

22

2

2Signif /)m( tse

BSSDN σ∆−×+

ε=


Finding the Elusive BsFinding the Elusive Bs

+π

−µ−π

+π

ν-B

−K0D

0sB

-sD

−K

+K

Experimental Challenges⎯ 20–40% of Bs out of accept

when trigger on opp. lepton⎯ 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⎯ L1 is the bottleneck⎯ Di-µ (Pt>3, |η|<2.2) no presc.⎯ Di-µ (Pt>1.5, |η|<2.2) prescale⎯ 1- µ (Pt>3-5, |η|<2.2) prescale

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 !

Bd → J/ψ Ks0

B± → J/ψ K±

ψ’ → J/ψ π+ π-

X(3872) → J/ψ π+ π-

B → µ D* X


Unique to the Tevatron !Unique to the Tevatron !Bs → J/ψ φ

⎯ Lifetime⎯ ∆Γs

Bc → J/ψ µ X⎯ Signal: 135 ± 18 (>5σ)⎯ M: 6.11 ± 0.17 ± 0.44 GeV

210 pb-1

Λb → J/ψ Λ

250 pb-1


Mixing SamplesMixing Samples

B → µ D* X~100 pb-1

200 pb-1

200 pb-1

Bs → µ Ds X~25 / pb-1

B → µ K*K X

B → µ D0 X

200 pb-1

Bd

Mix

ing

B → µ φ π X

Bs → µ Ds X~40 / pb-1

250 pb-1

Bs

Mix

ing


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∗ average vs. evt-by-evt

⎯ 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

(t))N(B)N(B0

±

Bs → J/ψ φ

Λs → J/ψ Λ Bc → J/ψ µ X

220 pb-1

210 pb-1250 pb-1


...the Results...the Results

Mode DØ Measurement [ps] HFAG Ave. [ps] ct Res. [µm]B0 / B+ (D(*) µ) 1.093 ± 0.021 ± 0.022 1.086 ± 0.017 35B+ → J/ψ K+ 1.65 ± 0.08 +0.08/-0.12 1.671 ± 0.018 29Bd → J/ψ K*0 1.473 ± 0.051 ± 0.023 25Bd → J/ψ K0

s 1.56 +0.32/-0.25 ± 0.13 1.536 ± 0.014

Λb → J/ψ Λ 1.22 +0.22/-0.18 ± 0.04 1.229 ± 0.080Bs → J/ψ φ 1.444 +0.098/-0.090 ± 0.020 1.461 ± 0.057 25

Bc → J/ψ µ X 0.45 +0.12/-0.10 ± 0.12 0.46 ± 0.17


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 using Opposite Side⎯ Soft Lepton (muon) Tag

∗ µ-charge ⇒ b-charge⎯ Jet Charge Tag

∗

2. Tag Flavor at Production using Same Sidea. Charge of leading non-Bs

hadron∗ B** → B h or fragmentation

3. Tag Flavor at Decay⎯ D-charge ⇒ b-charge

ν+µ

∑∑

=i,t

ii,t

PqP

Q Jet

ε (%)Method 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+


Putting it All TogetherPutting it All Together50K 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

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


Nostradamus PredictsNostradamus Predicts• Add Dsπ & e modes

• Combine Results

⇒ Sensitivity to SMFit Region

Sensitivity for1 fb-1

τ∆σ

Signif21~ m)(

Mode Yield / pb-1 εD2 (%) S/B σt (fs)Ds(φπ) µ X 40 2.5 0.66 120

Ds(K*K) µ X 25 2.5 0.27 120Ds

(*) π 1.4 2.5 1 70

Competitive Limits

Spring 2005

Competitive Limits

Spring 2005


DØ’s Road AheadDØ’s Road Ahead• Establish Bs Mixing Measurement

⎯ systematic studies: tagging, resolution⎯ produce ∆ms limit with current data

• And Make Improvements⎯ include electron modes⎯ better resolution & momentum estimates

• But the Measurement is within Our Grasp !

• And That’s Not All !⎯ sin(2β) from J/ψ Ks

0 & J/ψ φ⎯ Rare Modes: Bs → µ+ µ- & Bd → µ+ µ- K*

⎯ Studies of the Bc & Λb⎯ Precise measurements of production


Further Down the PathFurther Down the Path

DØ,CDF BaBar,Belle LHCb Atlas,CMS BTeVBeams e+e- pp pp

1.9620092.0

1011 bb/yr

ECM [TeV] 1.96 0.0106 14 14Timeframe now → 2009 now → 2006 2007 2007Inst Lumi(×1032 cm-2s-1)

0.4 → 2.8 100 2.0 100

Data Set [fb-1] 0.3 → 9 150 → 500 1012 bb/yr 100/yr

pp 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 (4.66 ± 0.43)×10-3 theory

CDF,DØ ? ± 0.03 (2 fb-1)0.39 ± 0.10 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 (77 ± 25)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-) < 5 × 10-6 Atlas,CMS (3.5±0.8)×10-9 (100fb-1)

∆ms Bs→DslvX,Dsπ > 14.5 ps-1 DØ,CDF ~20-25 (5σ w/ 2 fb-1)BTeV,LHCb ~50 (1 year)

α B→ππ,ρπ,ρρ (100 ± 10)o BTeV,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⎯ QCD: lifetimes, spectroscopy, production…⎯ CKM: Bs Mixing, ∆Γs, sin 2β, sin 2βs…⎯ Rare: Bs→µ+µ-, B →K*µ+µ-

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


Backup SlidesBackup Slides


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

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

µ+ µ- Mass [GeV]

BR(Bs → µ+ µ-) < 5.0×10-7 (95% CL)BR(Bs → µ+ µ-) < 5.0×10-7 (95% CL)

240 pb-1


b Facilitiesb Facilities

TevatronRun II

LEP CLEO B-Fact LHC

Collisions e+e- e+e- e+e- ppEcm [GeV] 1960 91 10.5 10.5 14000Species Prod all all Bd,B+ Bd,B+ all

S/B [%] 0.1 0.15 ~0.3 ~0.3 0.6

Rate w/o trig [Hz] 600 0.07 0.8 10 25,000

[µb] ~100 0.007 0.001 0.001 ~500

In Accept. [%] ~6 ~100 ~100 ~100 ~5Luminosity [cm-2s-1] 1×1032 ~1031 7.5×1032 1×1034 1×1033

<Decay L> [mm] 0.45 3 0.025 0.26 1.7 (Lxy)

pp

)b(bσ


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


Beauty as a ProbeBeauty as a ProbeB-Physics is a Good Place to Probe EW Sym. Breaking

⎯ measurable unitarity triangle⎯ QCD corrections to predictions small

1. Look for Modifications to Couplings Rare Decays⎯ Different EW Sym. Breaking Struct. ⇒ Different Couplings⎯ Most Interesting Channels = Rare or Zero in SM

2. Check for NP in Consistency of CKM Picture CPV & Mixing⎯ Need meas’s of each parameter in several modes⎯ Use SM loop level processes (NP effects can compete here)⎯ Differences in param’s measured by proc’s w/ diff. flavor struct.

But Wait, There’s More – QCD !⎯ b-production, spectroscopy, lifetimes…


The J/ψThe J/ψ


ResonancesResonances

σ = 7 MeV

σ = 3 MeV

Documents

The b-Quark a Vertex of New Physicsevans/talks/columbia_colloq.pdf · 0.09-0.20 0.01 LHC 500 250001.5 Tevatron 100 600 0.5 HERA ~0.010 δ> 0.1 LEP, SLC 0.007 0.07 3 B-Fact 0.001 10