Flavor Physics

18
Flavor Physics CKM Matrix B Physics Production New States Lifetimes B s Mixing CP Violation Other Measurements Top Physics Production Spin Correlation W Polarization V tb

description

Flavor Physics. CKM Matrix B Physics Production New States Lifetimes B s Mixing CP Violation Other Measurements Top Physics Production Spin Correlation W Polarization V tb. Quarks: Flavor. CKM Matrix of Flavors: u,d,c,s,t,b. ). (. Wolfenstein Representation. ). (. - PowerPoint PPT Presentation

Transcript of Flavor Physics

Page 1: Flavor Physics

Flavor Physics• CKM Matrix

• B Physics– Production– New States– Lifetimes

– Bs Mixing

– CP Violation– Other Measurements

• Top Physics– Production– Spin Correlation– W Polarization

– Vtb

Page 2: Flavor Physics

Quarks: Flavor

Vud Vus Vub

Vcd Vcs Vcb

Vtd Vts Vtb( )CKM Matrix of Flavors: u,d,c,s,t,b

1-2/2 A3(-i)

1-2/2-i A24 A2

A3(1--i) -A2 1( )Wolfenstein Representation

Different Processes give different elements

Page 3: Flavor Physics

FNAL CKM Measurements“KTeV”,“KAMI”

“CKM”

B Physics Colliders?

Page 4: Flavor Physics

CP violation in B decays

(1,0)

Vtd

Vts

(0,0)

()

Vub*

Vcb

Measured by CLEO+LEP at level

Ratio md/ms or

radiative B decays

ACP in B0J/ Kos

ACP in B0

ACP in Bs0Ds

Page 5: Flavor Physics

B Physics: Production• Central Rapidities

Title:DISK2:[DARIA.RUN1B]BCROSS_CDF_D0.EPS;1Creator:HIGZ Version 1.22/09Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

• Rapidity DependenceTitle:bmu_dxdy_color.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Title:bmu_dxdpt_color.epsCreator:HIGZ Version 1.23/07Preview:This EPS picture was not savedwith a preview included in it.Comment:This EPS picture will print to aPostScript printer, but not toother types of printers.

Page 6: Flavor Physics

B Physics at the Tevatron

bbbbbp

Bd0 , B , Bs

0 , Bc , b all

produced

Two main trigger samples: J

high pt leptons

To improve S/N:• good mass resolution• displaced vertex cuts

SELECTED CDF RESULTS

– M(B ) = 5279.1 ± 1.7 ± 1.4 Mev/c2

M(Bd0) = 5281.3 ± 2.2 ± 1.4 Mev/c2

(Bs0 ) = 1.36 ± 0.09 ± 0.06 ps

(Bs0 )/ (Bd

0 ) = 0.899 ± 0.072

– Bc discovery

Prompt J/

J/from B’s

Side-band background

J decay length

Page 7: Flavor Physics

B Physics: Heavier States

• Bc Observation

Page 8: Flavor Physics

B_c Lifetime

Page 9: Flavor Physics

B_c

Page 10: Flavor Physics

B Physics: Lifetimes

• Neutral and Charged very close

• Note higher mass states Bs, b

Page 11: Flavor Physics

A(t) = = cos ( mqt)

reconstruct B-decay measure displaced vertex tag B-flavor at production:

• Soft Lepton Tagging (SLT)• Jet Charge Tagging (QJT) • Same Side Tagging (SST)

CDF has five independent Bd0 mixing measurements:

md = 0.481 ± 0.028 ± 0.027 ps-1

CDF has also limits for Bs0 mixing:

ms > 5.8 ps-1 @ 95% CL from Bs0lX

ms < 96 ps-1 @ 95% CL from Bs0Dsl anal.

Bd0 and Bs

0 mixing

b W d, s

BodBo

d

Wd

uct b

uct

tt

tt

Vtb1

VtdOpposite side tagging

Like-sign asymmetry vs decay-length

Xq= mq/q Vtq

Page 12: Flavor Physics

sin (2) measurement

• ACP(t) = = sin (2) sin (mdt) f is J/ Ks0

Measured asymmetry: Amea(t) = DACP(t)

Use multiple B flavor tagging algorithms: SST SLT JCTD2 (%) 1.80.5 0.910.15 0.780.14

sin @ 93% CL (Feldman-Cousin statistics)

Important Demo at least!!!

tf tf

tf tf

B

BS

ND

1)2(sin

2

16.039.079.0)2sin(

Page 13: Flavor Physics

RUNII : sin 2

SIN(2) FLAVOUR TAGGING D2 CDF I CDF II CDFII +TOF

SST() 1.8% 2.0% 2.0% JCT 0.8% 3.0% 3.0% SLT 0.9% 1.7% 1.7% KAON - - 2.4%

SIN(2) SENSITIVITY

– statistics of fully reconstructed B-decays is expected to increase by:

Run II luminosity bb(s) increase

Efficiency x Acceptance e+e- channel

For 2fb-1 :

CDF II(sin 2) = 0.078

CDF II+TOF (sin 2) = 0.067D0 (sin 2) =

0.10

1801.1 2 4 20

Page 14: Flavor Physics

B Physics Measurements

• Bs Mixing

– use states…...

– 20,000 Bs with SVT trigger– tagging using ….

xs Reach 40 - 60

Page 15: Flavor Physics

B Physics: Other Measurements

• CP Violation in Bs

– Bs J/

• sin 2 , sin 2 – ( tough, need rate, id, space resolution)

• Rare Decays

A Rich and Extensive Program in good part beyond the B Factory reach

Asymmetry error vs. xs

Page 16: Flavor Physics

Assuming BR(t Wb) = 100, the measured top quark pair-production cross section agrees well with the SM prediction.

Top Quark Production Cross Section

(DØ) tt= 5.9 1.7 pb

(CDF) tt= 7.6 1.8 pb

Page 17: Flavor Physics

New CDF top production cross section:

6.4 pb.1.51.3

(NEW!)

Page 18: Flavor Physics

W Polarization in Top DecaySM predicts fraction of longitudinally polarized W’s

from top decay: F0 = M2top/(Mtop

2 + 2MW2) =

0.70

Extract W helicity fractions from the shape of thecharged lepton pT spectrum in t bW b

• better measured than angular correlations• unaffected by reconstruction or combinatorics

• assume a mixtureof longitudinally

polarized andnegative helicity

W’s producedin top decay

• use a maximumlikelihood method

to estimate F0(assume positivehelicity fraction

F+ = 0)

F0 = 0.97 0.37 0.12

(assume F0 = 0.75) F+ = 0.11 0.15 0.06