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LHCb Upgrade:Flavour Physics

at High LuminosityChris Parkes

EPS HEP Conference, Manchester, Detector Session, July 21st 2007

•LHCb - Aims for first phase (~2013)•SuperLHCb physics – Probing New Physics•Technology - Vertex Trigger, Radiation Level•Conclusion- Forward Plan

Thanks to LHCb collaborators, notably:Hans Dijkstra, Jim Libby, Franz Muheim, Guy Wilkinson,

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p p

250 mrad

10 mrad

Dedicated B System CP Violation & Rare Decay Experiment

•Full spectrum of B hadrons:

• Bs system, All angles, sides of both CKM s

•Lots of events !

baryons ,B,B 0sd,cu,

yearper pairsbb )(10 μb, 500σ 12bb

O

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LHCb Construction on Schedule

Muon Calorimeters RICH2Trackers

Magnet

RICH1VELO

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LHCb Goals - First Phase 10 fb-1

• First observation of very rare decay

• Bs mixing phase

• Unitarity Triangle

• Spectacular progress in heavy flavour physics:– Baseline measurement ACP (J/KS) – Bs Oscillations Measurement, Charm results

• Impressive range of additional measurements

Flavour Physics Progress

sB

s at 0.01 rad

BDKBsDsK B(s)h+h− exploiting U-spin

γ at few degrees

TodayToday

10 fb10 fb-1 -1

LHCbLHCb+ lattice + lattice

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LHCb Physics Programme

But NOT Limited by LHCLimited by Detector

• Upgrade to extend Physics reach – Exploit advances in detector technology

–Radiation Hard Vertex Detector–Displaced Vertex Trigger

– Better utilise LHC capabilities

• Timescale, 2015

• Collect ~100 fb-1 data

• Modest cost compared with existing accelerator infrastructure

Independent ofLHC upgrade

•SLHC not needed•But compatible

with SLHC phase

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Upgrade Physics Programme Examples

• CP Violation– Angle to better than 10

– Tree Diagram Dominated Decays, <<10 theory

– Gluonic Penguins

BdK0

KDB 0 KDB ss

Complementary to ATLAS / CMS direct searches•New particles are discovered

•LHCb measure flavour couplings through loop diagrams• No new particles are found

•LHCb probe NP at multi-TeV energy scale

KBd Angular Correlations

- Not just Afb

•Rare Decays

• Charm Physics• Mixing studies in D0→hh• CPV searches

• Rare decays, eg. D(0)(s)→l+l- [(Xu,s)]

LHCb 2 fb-1 superimposed

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Bs mixing phase s

/JBs

Upgrade can achieve 10% measurement of SM

Also measure from loops - penguin dominated

sB

= New Physics !

Standard LHCb 1 Year

SMq

iqq mehm q 21

CDF ms

Little Higgs Model

s

Blanke & Buras[hep-ph/0703117]

SM

Ligeti et al.

[hep-ph/0604112]

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Initial Phase of LHCb Operations• Data taking starts 2008

Defocus LHC beams•LHCb L= 2x1032 cm-2s-1

•Factor 50 below ATLAS/CMS design L•Most events have single interaction

•Displaced Vertex trigger•2nd level of triggering

•Multiple Interactions •Limit Triggering

rate of pp interactions

•LHCb Upgrade L= 2x1033 cm-2s-1

•Cope with 4 int./x-ing

•SLHC peak L= 8×1034 cm-2s-1

•Baseline - 40MHz, alternate High, Low I

H LLHCb

GPDs H H

Effective 20MHz Crossing rate

Select Low I for desired luminosity

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LHCb Trigger System• Cope with 4 interactions / beam crossing

Existing 1st Level Trigger 1MHz readout•Veto on multiple interactions

•Existing Trigger based on:

•High pT Muons•Calorimeter Clusters

Events with muons – trigger efficient

Events with hadrons – need improved trigger

Require Displaced Vertex TriggerAt 1st level

Current 1st Level Trigger Performance

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Trigger Gains – 40 MHz readout• Improve efficiency for hadrons and photons

– εTrig(B→hadronic) ~ 25-35%– εTrig(B→γX) ~ 30-40%– εTrig(B→μμX) ~ 60-70%

• Higher Level Trigger– Only limitations

• CPU • Algorithmic Ingenuity

– (Former) improves with Moore’s Law

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Radiation Hard Vertex Locator

• Upgrade Requires high radiation tolerance device

>1015 1 MeV neutroneq /cm2

• Strixels / Pixels– n-on-p, MCz, 3D

Z Beam

8cm

VELO Module

Active Silicon only 8mm from LHC beam

Pixel layout

x

z

390

mra

d

60 mrad

15 mrad

1 m

x

y

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LHCb Upgrade Baseline & Issues• Trigger in CPU Farm

– Event building at 40 MHZ, CPU power OK – Hadron efficiency ~ factor two improvement

• Read-out all detector 40MHz– Replace all FE Electronics

• Vertex locator, Silicon Tracker, RICH HPD, • Outer Tracker FE, Calorimeter FE boards

• Radiation Damage– Need to replace Velo anyway– Inner part of Shashlik Calorimeter– Inner part of silicon tracker– Remove muon chamber before Calorimeter

• Occupancy– Inner part of outer tracker, 6%25%

• Increase silicon coverage (faster gas, scintillating fibres)

– Tracking algorithms for higher occupancy

Inner / Outer Tracker

PWO crystals

ECAL

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• Major Physics Programme at modest cost

– Flavour Sector of New Physics s measurement

– Precision • Critical Technology

– Radiation Hard Vertex Detector

– With Displaced Vertex Trigger

• Compatible with but independent of SLHC

Upgrade Summary

W

W

b 0

sB

s

b

s 0sB

t

t? ?

?

?

LHCb preparation in good shape Looking forward to first data

And an even brighter far future

Lowry Upgrade

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University of Glasgow, Scotland1st - 5th September 2008

The conference explores the scientific and technical developments of detector systems used in: Astronomy and space

science; Astrophysics; Condensed matter studies; Industrial applications;

Life sciences; Medical physics; Nuclear Physics, Particle physics and Synchrotron based science.

National Organising

Committee(subject to change)

P.P. Allport, LiverpoolR.L. Bates, GlasgowA.J. Bird, SouthamptonC.R. Cunningham, UK

ATC, EdinburghG.E. Derbyshire, STFC,

RALP. Evans, ICR, London R. Farrow, STFC,

DaresburyW. Faruqi, MRC,

CambridgeM. Grande, AberystwythP.R. Hobson, BrunelD.P. Langstaff,

AberystwythP.J. Nolan, LiverpoolD.J. Parker, BirminghamP.J. Sellin, SurreyA. Smith, MSSL, LondonR. Speller, UCL, LondonT.J. Sumner, IC, LondonS. Watts, Manchester

psd8@physics.gla.ac.ukhttp://www.psd8.physics.gla.ac.uk

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Backup

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• Extrapolating to 100 fb-1

• Only consider strategies which are theoretically clean• Critically reliant on Trigger Upgrade

Bs →DsK: statistical scaling leads to 1° uncertainty for 100 fb-1

B D(Ksππ)K: statistical scaling leads to 1.2 ° for 100 fb-1

Other modes B D(KsKπ)K, B D(KsKK)K and 4-body to be exploited

B D(hh)K: ADS/GLW methods statistics huge but will need global fit including additional information to overconstrain

Toward a sub-degree error on

LHCb

(10 fb-1)

Super-LHCb

(100 fb-1)

Super Flavour Factory

(75 ab-1)

DsK 27 k 540k -

D(Ksππ)K ≤25k 0.5M 80k

D(Kπ)fav K 280k 5.6M 131k

Extrapolationsfrom publishedB-factory analyses

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BK*μμ• AFB 0 point is not enough:

– SLHCb σs0/s0=2.1%

– Exclusive NLO theory today σs0/s0=9%

– improve by 2020• Transversity angle asymmetry

analysis extremely promising– Probes chiral structure (c.f.

TDCPV BK*γ)

– Theoretically clean– Will benefit greatly from

SLHCb statisticsLHCb 2 fb-1 superposed

Kruger and Matias, Phys.Rev.D71:094009, 2005

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Charm physicsIf charm mixing has indeed been observed, what next ?

• Precise measurements of x(‘) and y(‘)

• Search for (and detailed study) of CPV in charm – v. promising for NP

Recent detailed simulation studies at LHCb show great promise inD0→hh decays.

• After all selection cuts yield from B decays alone is expected to be 10-20 times (10 fb-1) that of total from B-factories (2 ab-1).

Target charm analyses at LHCb and SLHCb (diverse programme!):

• Mixing studies in D0→hh

• CPV search in partial width differences in D0→KK, ππ (SCS)

• CPV search in D+→K-ππ Dalitz (SCS)• Mixing and CPV in D0→Ksππ Dalitz

• Mixing and CPV in D0→K+πππ (DCS)• CPV search in T-odd moment & amplitude analysis of D0→KKππ (SCS)

• Rare decays, eg. D(0)(s)→l+l- [(Xu,s)]

Will benefit from change of trigger strategy at SLHCB

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CPV in gluonic penguin• One of the poster children of a SFF

– For good reason given the tantalising hints of a discrepancy with sin2 from bccs

• Concentrate on the cleanest modes BdK0,ηK0 and K0 K0 K0

– Average discrepancy 0.10±0.06• No attempt to add theory

– 5σ with current central value an important goal

• BdK0 most promising at current LHCb– Precision at end of LHCb 0.14

– End of SLHCb 0.03• assuming 2×εtrigger

• same as SFF but they have the other important modes…..

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Bs→ • Bs analogue of BdK0,η K0 etc

• Dependence on Vts in both the decay and Bs mixing amplitudes leads to the SM CPV being < 1% – for example M. Raidal, PRL 89,

231803 (2002) • PVV decay requires full angular

analysis to extract CP info• Simulation studies with background

and detector effects– 2000 (4000) events/fb-1 @

(S)LHCb

– NP phase sensitivity of 0.042 at current LHCb

– SLHCb sensitivity 0.009 (0.5°)

s

b

Bs0

s

s

s

s

W

t

g

1

decay

*

*

mixing

*

*

tstb

tstb

tstb

tstb

SM

VV

VV

VV

VV

A

A

p

q

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Mixing phases-the systematic frontier

• sin2 improvement can be made with control channel measurements of penguin pollution and tagging

– Bs J/ψK0S

• R. Fleischer, Eur. Phys. J. C. 10., 299 (1999)

– Push toward 1%/0.2° uncertainty

• 8% relative uncertainty on SM-like Bs mixing phase from BsJ/ψ possible at SLHCb– Matches current indirect determination– Direct proportionality to η leads to

interesting constraint on UT • // to that from KL π0νν

– Penguin control possible from BsJ/ψρ

(Super-)LHCb

2 fb-1 10 fb-1 100 fb-1

σ (stat) 0.021

0.009 0.003Superposed on LHCb 10 fb-1 + lattice

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Bs(d)μμ• 5σ observation expected at current LHCb

even if value of BF is SM• Theory prediction already at ~10% • More precise determination at SLHCb would be

constraining of NP models with large tan– c.f. BK*μμ transversity analysis constrains

small tan

• Bs μμ/Bdμμ = 32.4 ± 1.9 tightly constrained in SM and MFV– one of the magic numbers of CMFV (Buras)

• Matching theory precision is impossible with 100 fb-1

– But observation possible at SLHCb as long PID can cope with double punch-through background from Bdππ

– Maybe SLHC GPDs???? Or UltraLHCb!

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• LHCb high luminosity running L= 2x1033 cm-2s-1

• e+e- Super B-Factory– Linear Super-B (Frascati)– Super-Belle

Super B Factories

100 fb-1, 2020

50 ab-1, 2020

Complementarity•Bs – LHCb Upgrade•Neutrals – e+e-

•Bd - overlap

LHCb upgrade•Bs

•Lower cost•No new accelerator

Bs

Com

mon

No

IPN

eu

trals,

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Detector Upgrade• Critical component to achieve this physics

Radiation Hard Vertex Detector with

Displaced Vertex Trigger

VElo Superior Performance Apparatus

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•Maximum Fluence •NIEL 1 MeV neq/cm2/year•Strongly non-uniform • dependence on 1/r2 and station (z)

Middle station

Far station

Extreme Radiation Environment• LHCb VELO will

be HOT!

VESPA needs > 1015 neq/cm2 charged particle tolerance

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Radiation Hard Technologies• Active UK Technology R&D for LHC upgrades• Applicable to strixels & pixels

Extreme rad. hard

3D

Czochralski n-on-p

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Schedule & Costing• Schedule

– R&D underway• Velo/Vespa Testbeam in Autumn ’08• Exploit commonality with GPDs on Electronics

– 2010 decision on upgrade instrumentation – 2013-2015 upgrade detector during planned SLHC

upgrade – 2015-2020 gather 100 fb-1

• Cost– Front-end electronics replacement estimate 12 M€– Detailed costing not available till after R&D phase– Anticipated hardware cost ~ 45 M€