First physics from LHCb and prospect for coming years on CP - - PowerPoint PPT Presentation

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First physics from LHCb and prospect for coming years on CP - - PowerPoint PPT Presentation

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First physics from LHCb and prospect for coming years on CP violation measurements CPV from B factories to Tevatron and LHCb 1 Sept-2 Sept 2010, Sendai, Japan Tatsuya NAKADA Laboratory for High Energy Physics (LPHE) Swiss Federal

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SLIDE 1

First physics from LHCb and prospect for coming years on CP violation measurements

CPV from B factories to Tevatron and LHCb 1 Sept-2 Sept 2010, Sendai, Japan

Tatsuya NAKADA

Laboratory for High Energy Physics (LPHE) Swiss Federal Institute of Technology Lausanne (EPFL) Lausanne, Switzerland

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SLIDE 2

LHC at CERN

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

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Circumference of 27 km

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SLIDE 3

LHC at CERN

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

3

Two general purpose experiments (ATLAS and CMS), one dedicated b-experiment (LHCb), and one dedicated heavy ion experiment (ALICS) from the beginning.

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SLIDE 4

LHC running, LHCb collecting data

  • November 2009, √s = 900 GeV collisions took place
  • Since March 2010, running at √s = 7 TeV

– np-bunch≈1011

  • already nominal value

– β = 3.5 m

  • nominal 0.55 m for 1034 cm2s1

– nbunch = 46

  • nominal = 2808

– L = 1×1031 cm2s1 nominal = 1034 cm2s1 – Experiments >90% DAQ efficiencies – Current plan for this year nbunch = 46 steadily increased to 384 L ≈ 1031 cm2s1

⇒ 1032 cm2s1 (∼0.2 pb1/10h fill)

  • 2011: ∫ L dt = 1 fb1 goal to be achieved by running

with a slight improvement (~2 in the luminosity) by further decreasing β and/or increasing the number

  • f bunches.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

4

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SLIDE 5

23rd November 2009

  • First collisions took place at LHC
  • 2009 run: ∫ L dt ≈ 7 μb1, at √s = 900 GeV

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

5

One of the first event KS

0 cross sections

to be published in PLB

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SLIDE 6

LHC running, LHCb collecting data

  • November 2009, √s = 900 GeV collisions took place
  • Since March 2010, running at √s = 7 TeV

– np-bunch≈1011

  • already nominal value

– β = 3.5 m

  • nominal 0.55 m for 1034 cm2s1

– nbunch = 46

  • nominal = 2808

– L = 1×1031 cm2s1 nominal = 1034 cm2s1 – Experiments >90% DAQ efficiencies – Current plan for this year nbunch = 46 steadily increased to 384 L ≈ 1031 cm2s1

⇒ 1032 cm2s1 (∼0.2 pb1/10h fill)

  • 2011: ∫ L dt = 1 fb1 goal to be achieved by running

with a slight improvement (~2 in the luminosity) by further decreasing β and/or increasing the number

  • f bunches.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

6

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SLIDE 7

Impressive progress in L

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

7

Peak luminosity already ~1031cm2s1 Integrated luminosity already ~3 pb1

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SLIDE 8

LHC running, LHCb collecting data

  • November 2009, √s = 900 GeV collisions took place
  • Since March 2010, running at √s = 7 TeV

– np-bunch≈1011

  • already nominal value

– β = 3.5 m

  • nominal 0.55 m for 1034 cm2s1

– nbunch = 46

  • nominal = 2808

– L = 1×1031 cm2s1 nominal = 1034 cm2s1 – Experiments >90% DAQ efficiencies – Current plan for this year nbunch = 46 steadily increased to 384 L ≈ 1031 cm2s1

⇒ 1032 cm2s1 (∼0.2 pb1/10h fill)

  • 2011: ∫ L dt = 1 fb1 goal to be achieved by running

with a slight improvement (~2 in the luminosity) by further decreasing β and/or increasing the number

  • f bunches.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

8

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SLIDE 9

LHCb Detector

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

9

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SLIDE 10

Quick reminder for LHCb

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

10

LHCb is a forward spectrometer dedicated for flavour physics

b b b b

pp-c.m. system

Both b and b are in the spectrometer. θ

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SLIDE 11

Quick reminder for LHCb

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

11

Forward: pT threshold can be set low: → high b efficiency Fe For triggering…. p > pmin p < pmin p > pmin muon: identification hadron: energy resolution σE/E ≈ √70%/√E

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SLIDE 12

Quick reminder for LHCb

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

12

p p p ≈ pT > pmin p p p ≈ pL > pmin

Forward: pT threshold can be set low: → high b efficiency central detector forward detector Fe For triggering…. p > pmin p < pmin p > pmin muon: identification hadron: energy resolution σE/E ≈ √70%/√E

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SLIDE 13

Quick reminder for LHCb

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

13

Can exploit low pT particles to trigger more b-hadron events

1 10 10 2

  • 2

2 4 6

eta of B-hadron pT of B-hadron

ATLAS/CMS LHCb

100 μb 230 μb

σbb expected in pp collisions at √s = 14 TeV: 500μb 5×1011 bb pairs in 107 s with L = 1032 cm2s1

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SLIDE 14

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

14

b detection from bD0(Kπ+)μX

Inclusive D: Clean D signal with hadron PID

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SLIDE 15

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

15

Inclusive D: dominated by the prompt production IP(D from bD) > IP (prompt D)

b detection from bD0(Kπ+)μX

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SLIDE 16

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

16

Adding μ with a right sign enhances D from b:

e.g. BD0(Kπ+)μX [BD0(K+π)μX only through DCSD]

u u b c μ ν u s u d

K π+

u d u s

π Κ+ × 0.222 B D0 b detection from bD0(Kπ+)μX

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SLIDE 17

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

17

with right sign muons with wrong sign muons

Adding μ with a right sign enhances D from b:

e.g. BD0(Kπ+)μX [BD0(K+π)μX only through DCSD]

b detection from bD0(Kπ+)μX

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SLIDE 18

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

18

Theory uncertainty

∫ L dt = 25 nb1 data b detection from bD0(Kπ+)μX

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SLIDE 19

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

19

Clean μ+μ mass distribution with ∫ L dt = 14 nb1 data

b detection from bJ/ψX

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SLIDE 20

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

20

prompt J/ψ J/ψ from b

proper time distribution of J/ψ

b detection from bJ/ψX

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SLIDE 21

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

21

prompt J/ψ J/ψ from b with detector resolution

proper time distribution of J/ψ

b detection from bJ/ψX

negative proper time important for studying resolution

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SLIDE 22

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

22

prompt J/ψ J/ψ from b with detector resolution combinatorial background with prompt tracks and b tracks

proper time distribution of J/ψ negative proper time important for studying resolution

b detection from bJ/ψX

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SLIDE 23

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

23

side band

J/ψ with a long proper time due to b-hadron decays Proper time distribution with ∫ L dt = 14 nb1 data

b detection from bJ/ψX

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SLIDE 24

LHCb σbb measurements

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

24

LHCb σbb from bD0μX and J/ψX

σbb in 4π = 292 ± 15 ± 43 μb (with LEP Bu/Bd/Bs/Λb) agree with the Pythia used for the performance studies 2<η<6

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SLIDE 25

LHC running, LHCb collecting data

  • November 2009, √s = 900 GeV collisions took place
  • Since March 2010, running at √s = 7 TeV

– np-bunch≈1011

  • already nominal value

– β = 3.5 m

  • nominal 0.55 m for 1034 cm2s1

– nbunch = 46

  • nominal = 2808

– L = 1×1031 cm2s1 nominal = 1034 cm2s1 – Experiments >90% DAQ efficiencies – Current plan for this year nbunch = 46 steadily increased to 384 L ≈ 1031 cm2s1

⇒ 1032 cm2s1 (∼0.2 pb1/10h fill)

  • 2011: ∫ L dt = 1 fb1 goal to be achieved by running

with a slight improvement (~2 in the luminosity) by further decreasing β and/or increasing the number

  • f bunches.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

25

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SLIDE 26

LHCb how about BsJ/ψφ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

26

Nice φ with kaon identification

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SLIDE 27

LHCb how about BsJ/ψφ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

27

Nice φ with kaon identification

φ is also used to calibrate PID with one kaon identified NB: flavour-tag with kaons loose cut tight cut

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SLIDE 28

LHCb how about BsJ/ψφ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

28

BsJ/ψφ candidates with ∫ L dt = 140 nb1 data

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SLIDE 29

LHCb how about BsJ/ψφ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

29

BsJ/ψφ candidates with ∫ L dt = 140 nb1 data

Yield agrees with the MC performance expectation of ~7

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SLIDE 30

LHCb how about BsJ/ψφ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

30

1σ error for CPV in BsJ/ψφ 1 fb1 of data expected by the end of 2011

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SLIDE 31

LHCb how about Bsμ+μ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

31

Of course we see currently no serious background, but can validate analysis method with data by comparing with MC; They agree well!

Muon miss ID Selection variable

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SLIDE 32

LHCb how about Bsμ+μ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

32

1 fb1 of data expected by the end of 2011

Exclusion limit @90% C.L.

Of course we see currently no serious background, but can validate analysis method with data by comparing with MC; They agree well!

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SLIDE 33

LHCb how about BdK0μ+μ?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

33

If the current BABAR and Belle results are correct, LHCb could exclude SM prediction with 4σ significance

With 1 fb1 LHCb expects 1200 events

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SLIDE 34

LHCb how about Bhh?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

34

BdK±π candidates with ∫ L dt = 122 nb1 data

PID, IP, vertex, pT cuts Agrees with the MC performance expectation of ~16 With 1 fb-1 data, >100k events! similar improvements for all the other Bhh modes

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SLIDE 35

LHCb how about charm physics?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

35

Huge number of charms can be detected with LHCb

Initial flavour tagged D0 decays: D+D0π+, D0K+K with 124 nb1 data

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SLIDE 36

LHCb how about charm physics?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

36

Huge number of charms can be detected with LHCb Huge statistics to study CPV from the decay time distribution between D0 and D0K+K, well before reaching 1 fb1 (~15×106 events)

Initial flavour tagged D0 decays: D+D0π+, D0K+K with 124 nb1 data

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SLIDE 37

LHCb how about charm physics?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

37

Huge number of charms can be detected with LHCb Huge statistics to study CPV: comparing the decay time distribution between D0π+K and D0K+K, comparing the D0 and D0K+K, well before reaching 1 fb1 (~15×106 events)

Initial flavour tagged D0 decays: D+D0π+, D0K+K with 124 nb1 data

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SLIDE 38

LHCb how about charm physics?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

38

Huge number of charms can be detected with LHCb CPV study with ~5×106 events (1 fb1)

Other interesting D0 decays: with 124 nb1 data Initial flavour tagged Dπ+π

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SLIDE 39

LHCb how about charm physics?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

39

Huge number of charms can be detected with LHCb CPV study with ~5×106 events (1 fb1)

Other interesting D0 decays: with 124 nb1 data Initial flavour tagged Dπ+π Initial flavour tagged DKSπ+π

Bench mark for γCKM with BDK Dalitz method

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SLIDE 40

Current situation with as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

40

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SLIDE 41

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

41

How to deal with

  • possible Bs

0 / Bs 0 production asymmetry in pp 2<η<6

  • controlling detection and background asymmetries to < 103
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SLIDE 42

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

42

How to deal with

  • possible Bs

0 / Bs 0 production asymmetry in pp 2<η<6

  • controlling detection and background asymmetries to < 103

Inclusive muon pairs difficult to control systematic errors…

slide-43
SLIDE 43

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

43

How to deal with

  • possible Bs

0 / Bs 0 production asymmetry in pp 2<η<6

  • controlling detection and background asymmetries to < 103

Inclusive muon pairs difficult to control systematic errors… Time dependent Bs decay asymmetry Ds

+(K+Kπ+)π vs Ds (K+Kπ+)π+

production or detection asymmetry from data

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SLIDE 44

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

44

How to deal with

  • possible Bs

0 / Bs 0 production asymmetry in pp 2<η<6

  • controlling detection and background asymmetries to < 103

Inclusive muon pairs difficult to control systematic errors… Time dependent Bs decay asymmetry Ds

+(K+Kπ+)π vs Ds (K+Kπ+)π+

production or detection asymmetry from data Bd and Bs time depended CP asymmetries from the same final ftates: i.e. BdD+(K+Kπ+)μX - c.c. and BsDs

+(K+Kπ+)μX - c.c.

difference depends only on as

SL ad SL

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SLIDE 45

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

45

D+ K+Kπ+ and Ds

+ K+Kπ+

with 124 nb1 data D+ Ds

+

slide-46
SLIDE 46

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

46

D+ K+Kπ+ and Ds

+ K+Kπ+

with 124 nb1 data Expected statistical errors on ΔSL as

SL ad SL

6.3×104 with 1 fb1 of data Systematic errors still to be investigated D+ Ds

+

slide-47
SLIDE 47

LHCb how about as

SL?

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

47

LHCb expected performance with 1 fb1 data assuming ΔSL(LHCb measured) = Ab

SL(D0 now)

B factories

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SLIDE 48

Conclusions

  • LHC has made a successful start at √s = 7 TeV
  • LHCb is taking data with >90% efficiency
  • LHCb starts to reconstruct b-hadrons and measured

σbb in pp interactions at √s = 7 TeV

  • LHCb data shows that they agree well with the MC

expectations of the detector performance

  • LHC luminosity is expected to reach ~1032, i.e. the

designed luminosity for LHCb, and collect 1 fb1 of data by the end of 2011: significant results can be expected from LHCb for BsJ/ψφ, μ+μ, BsJ/ψK0, CPV in charm, and others

  • In 2013, LHC will start at √s = 14 TeV; LHCb,

γCKM, photon polarization in bsγ, and others.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

48

slide-49
SLIDE 49

Conclusions

  • LHC has made a successful start at √s = 7 TeV
  • LHCb is taking data with >90% efficiency
  • LHCb starts to reconstruct b-hadrons and measured

σbb in pp interactions at √s = 7 TeV

  • LHCb data shows that they agree well with the MC

expectations of the detector performance

  • LHC luminosity is expected to reach ~1032, i.e. the

designed luminosity for LHCb, and collect 1 fb1 of data by the end of 2011: significant results can be expected from LHCb for BsJ/ψφ, μ+μ, BsJ/ψK0, CPV in charm, and others

  • In 2013, LHC will start at √s = 14 TeV; LHCb,

γCKM, photon polarization in bsγ, and others.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

49

slide-50
SLIDE 50

Conclusions

  • LHC has made a successful start at √s = 7 TeV
  • LHCb is taking data with >90% efficiency
  • LHCb starts to reconstruct b-hadrons and measured

σbb in pp interactions at √s = 7 TeV

  • LHCb data shows that they agree well with the MC

expectations of the detector performance

  • LHC luminosity is expected to reach ~1032, i.e. the

designed luminosity for LHCb, and collect 1 fb1 of data by the end of 2011: significant results can be expected from LHCb for BsJ/ψφ, μ+μ, BsJ/ψK0, CPV in charm, and others

  • In 2013, LHC will start at √s = 14 TeV; LHCb,

γCKM, photon polarization in bsγ, and others.

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

50

slide-51
SLIDE 51

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

51

2009 fit

Γ(buW) CPV(BDK) Now

slide-52
SLIDE 52

CPV from B factories to Tevatron and LHCb, Sendai, Japan, 1-2.9.2010

  • T. Nakada

52

Γ(buW) CPV(Β→DK) Γ(buW) CPV(BDK) LHCb with 10 fb1

2009 fit

May be a surprise!