The LHCb Experimentpresented at

Digital Divide and HEPGRID WorkshopRio de Janeiro, Feb 2004

Tatsuya Nakada

CERN and Swiss Federal Institute of Technology Lausanne (EPFL),

Switzerland

CP Violation

We know two examples which showsmatter world anti-matter world.

CP symmetry is violated !!

Evolution of Universe

matter

anti-matter

amount of matter = amount of anti-matter

our universeonly with matter

big bang

We see no anti nucleus in the cosmic ray.We se no rays from pp annihilation in space.

ConclusionNo evidence of anti matter in our domain of universe.

(~20 Mps 108 light-years)

Can our universe be “inverse” Emmental Cheese?Difficult!!

Most likely, no anti matter in our universe.(~3000 Mps 1010 light-years)

Void

matter

anti matter

What do we know?

Two key numbers

Number of baryons (NB)

Number of photons (N)~

cosmic microwave background radiation

stars, gas etc.

Number of baryons now but

NBNB

NBNB

_

_ ~

1 baryon out of did not annihilate and survived.

How can we generate

from NB NB initial condition for Big Bang at t?

NBNB

NBNB

_

_ ~

Necessary conditions:1) Baryon number violations:

initial and final baryon numbers are different.2) C and CP violation:

partial decay widths are different.3) Out of equilibrium:

no reversing reaction installing the initial state.(A.Sakharov, 1967)

_

Discovery of CP violation in particle physics: J.H. Christenson et al., PRL 1964

KL X

KL

p = p + p

= angle between pKL and p

If X = 0, p = pKL: cos = 1If X 0, p pKL: cos 1

cos

KL

m () < mK

m () = mK

m () > mK

Why KL is CP?

neutral kaondecay time distribution

anti-neutral kaondecay time distribution

CP violation

CPLEAR Experiment (1999)

CP violation in a more intuitive way!

Initial K0 CP transformation Initial K0

BABAR and Belle Experiments (2002)

t = 0

J/ KSB0

J/ KSB0

CP

t

similarly...

CP violation

How to generate CP violation?

1) Since CPT is respected, CP is like T2) T transformation is like making complex conjugation:

eiEt T eiEt 3) T transformation to the Hamiltonian operator H

H T H

if H H, eiH t eiH*t eiH t

T i.e. CP

Standard Model and CP violation

U =uct

D =dsb

Up type quarkspinor field

Q =

Down type quarkspinor field

Q =

Weak interaction neutral currentcharged current:

W

dL

cL

W

Vcd coupling

example

there are = 9 V’s

Strong interaction gluonsElectromagnetic interaction photons

Electroweak theory with 3 families cannaturally accommodate CP violation

in the charged current induced interactionsthrough the complex

Cabibbo-Kobayashi-Maskawa quarkmixing matrix V, with

4 parameters.

One family (u, d): V realTwo families (u, d), (c, s): V realThree families (u, d), (c, s), (t, b): V can be complex

Problem!!

CP violation inthe K and B meson decays

canbe explained by

the Standard Model.

New source for CP violation beyond the Standard Model in the particle world?

CP violation inthe universe

cannot be explained by

the Standard Model.

NBNB

NBNB

_

_ ~ Universe:

NBNB

NBNB

_

_ ~Standard Model:

New source of CP violation

X

q

q

complex coupling constant

X: Super Symmetric Particles, Multi-Higgs doublets, etc.

CP transformation containscomplex conjugation:

eiH t eiH*t

i.e. H* H CP violation

Search for unexpected effects in CP violation and rare decaysin Bu, Bd, Bs, Bc and b-baryons.

At LHC

p7 TeV= cal

1g of those p’s = 20 daysof US energy consumption

p7 TeV

LHCb detector

14 TeV mini bang

~100 times more B mesons then before

(Pre)History

-high luminosity e+e- B factoriesproposed at Cornell, DESY, KEK, Novosibirsk, PSI and SLAC

(since 1985…)realised at SLAC and KEK in 2000

-Idea to use high energy hadron machines as a source of B mesonsCERN pp collider, FNAL pp collider and LHC

Study of CP violation in B meson decays with high statistics

At LHCthree proto-experiments

GAJET (internal gas target), COBEX (collider mode) andLHB (extracted fix target beam)Expressions of Interest in Letters of Intent in

Joint experiment, LHCb: a forward spectrometer in collider mode

Letter of Intent in August 1995: encouragement from LHCCUFRJ group joined the LHCb Collaboration in 1997

S. Amato, J.R.T. de Mello, L. de Paula, M. Gandelman, J.H. Lopes and M. MarechalThe group has worked in the DELPHI experiment:

-data analysis, participating in detector construction by sending people at CERN (mainly PhD students)

Technical Proposal in February 1998 (S. Amato et al.)

recommended for an approval by LHCC in July 1998

b-b correlation

b

b

b

b

bb

Both b and b are in the spectrometer.

Draft Interim Memorandum of Understanding preparedTotal cost 86 MCHF (inclu. common fund 24.5 MCHF)

examined by the “CORE” committeeFunding discussion with the funding agencies by the

participating institutes.

Brazilian contribution in IMoU = 1.8 M CHF to the detector cost the detector (Muon system) + common fundwith an aim to construct a part of the muon chambers and contribute to the front-end electronics.

Total request to the funding agency (more than 1.8MCHF) includedparticipation to the R&Dpreparing the infrastructure for the construction and testtravel expense necessary for the installation, commissioning, data

taking, analysis meeting at CERN.

The idea was to ask for a global “project” money and manage locally. flexibility is important!

LHCb Resource Review Board (RRB) at CERN in September 1998Most of the funding agencies expressed positively theirfinancial contribution to the LHCb experimentBrazil: C. Aragao (UFRJ, head of the Physics Institute)

Extract from the Minutes;“C. Aragao reported the result of a visit to Brasilia with B. Marechal, the Brazilian representative on the Collaboration Board. The project was presented to the President of the Research Council (CNPq) who assured them that Brazil would contribute to the Common Fund should the experiment be approved and appear to consider the 0.824 MUSD request for detector construction to be reasonable. A more detailedrequest was subsequently submitted for seven annual contribution of 200 kUSD giving a total of 1.4 MUSD. No final comment has been received but, at the suggestion of the President, a workshop will be held in November in Rio, at which details of the experiment and the Brazilian part of the project will be presented to members of the CNPq. It is hoped to have a clearer indication of likely participationby then. C. Aragao said that, at the present time, he was authorised to say that Brazilwill participate in the Common Fund and will be studying participation in detectorconstruction at the level indicated in IMoU.”

Recommendation by LHCC and positive outcome from RRBCERN management approved the experiment in September 1998

Rio workshop on the LHCb experiment in January 1999organized by B. Marechal sponsored by CNPqpresentation by

T. Nakada: physics and organizationH.J. Hilke (Technical Coordinator): detectorJ. Christiansen (Electronics Coordinator) electronicsB. Schmidt (Muon system convener)

with participation by people from funding agencies (Rio and Brasilia)UFRJ management etc.

-very positively received.-understanding on how high energy physics manages itself increased.-a visit by the CNPq president to CERN in the occasion of the LHCb

RRB in April 1999 discussed.

LHCb magnet Technical Design Report: December 1999Superconductive coil Normal conductive coil16.5 MCHF (TP) 6MCF

LHCb MoU for the construction of the LHCb detector:finalised in November 2000

Detector Cost Funding expected from BrazilTP 86 MCHF ~70 MCHF 1.8 MCHFMoU 75 MCHF 73 MCHF 1.8 MCHF

February 2001 CBPF joined in the LHCb collaboration

September 2001LHCb Collaboration meeting was held in Ilha de Itacuruca, Brazil

October 2000, Visit to CNPq Brasilia by C. Aragao, B. Marechal and T. Nakada

July 2002Visit to CERN by the minister of State for Science and TechnologyJoint letter signed by the minister and DG for an extended cooperation.

All the subsystem TDR’s have been approved.Computing TDR to be submitted in 2005.Detector construction advancing…

Beam Pipe

Al window

Done by the LHC vacuum group

Magnet YokeAssembly of the lower half Plates are fixed by tie-rods

Lower half completed Assembly of the sides in progress

VELO

PrototypeTest

Constructionof VELO tanksupport stand

Si sensor test beam set-up Wake-field suppressor and RF foil

design constructed

RICH2

RICH2 exit window being made

Calorimeter

Ecal modules: 100% constructed Hcal modules: 30% constructed

SPD/Preshower production started

Muon system

First series production chambersFrascati CERN

Frascati Clean Room

panel on wiring machine

soldering table

assembly tables

At the time of LHCb RRB October 2003

MoU all signed except: Brazil ???Germany funding was guaranteed at the meetingPoland institute are receiving funding

Detector Cost Funding expected From BrazilTP (1998) 86 MCHF ~70 MCHF 1.8 MCHFMoU (2000) 75 MCHF 73 MCHF 1.8 MCHFOct. 2003 73 MCHF 71 MCHF since no clear

informationavailablewe had to assume0

Brazilian contribution to theconstruction of the experiment up to now

People visiting CERN, Marseille and Rome participating in the R&D, construction and testing of the experiment:

PhD students Muon chamberssupported by Muon Front-end electronics (VLSI)Brazil (~1 year) Muon trigger system

Postdocs and Muon chamberssenior scientists Muon electronics (test system)supported by Muon Experimental Control SystemBrazil (few weeks Core software development forto several months) and on- and offlinecollaboration(few weeks several months)

Work done at their home institute

CBPF Muon chamber test systemMuon electronics test systemCore software development

UFRJ Core software developmentLarge volume

MC data production

local expertise indetector physicists

Infrastructure i.e.equipped workshop andlaboratories

Small local funding forcomponents

local expertisephysicists with IT know-how

Infrastructuresmall CPU cluster

Small local funding forCPU

data production in 2003

Using LHCbhome made software toolsfor distributedproduction management.

Only you need isa reasonable-goodlink!No special middleware required.

Brazilian contribution to physicsPhysics performance study using MC data at home institute

UFRJ by PhD students and senior physicistsreconstruction of various decay modes

J/KS, J/ K*. DK* etc…reconstruction efficiency, signal over background, propertime resolution, etc…

Extraction of CP violation parameters and

Work is done in the framework of Physics Performance Task Force:short visitsweekly meeting with VRVS and/or phoneregular e-mail discussion

many LHCb notes, LHCb reoptimization TDR, conference talk

How do we plan to continue? Muon system

test of the front-end VLSI chips in Riotest of the front-end cards in Italy/CERNtest of wire chambers at CERNECS development in Rio/ItalyInstallation and commissioning at CERN

TriggerDevelopment of High Level Trigger algorithm in RioDevelopment of online system software framework in Rio

ComputingAnalysis framework software development in Rio/CERNData production in Rio

Physics study in Rio

Impressive list of contribution but there are serious problems…

No long term funding approved:Cannot fulfil “minimal” duty to the collaboration, i.e.

annual contribution to the Maintenance and Operation cost till theend of data analysis.

Difficult to under take a long term commitment.

No flexible funding was available:Travel cannot be arranged with a short notice (< 3 months)

Missing chances to give a talk in several conferencesCannot participate in many important meetings:

However, some progress is being made here…

Conclusions1) LHCb experiment will search for new physics beyond the Standard

Model in a complimentary way to ATLAS and CMS2) LHCb is consciously adjusting the project to the funding situation

without loosing physics performance3) Brazil has been in the collaboration since 1997. Originally

anticipated level of contribution to the detector construction (1.8 MCHF) does not seem to be realised. (MoU not signed)

4) Despite of this difficult situation, CPBF and UFRJ groups are making well appreciated contribution in developing test systems,on and offline software, data production and physics studies.

5) GRID is a great help but not a solution for the real problem.They still need a long term funding to cover the maintenance andoperation and trip to CERN to fully participate in the preparation,data taking, and physics analysis, i.e. exploiting their contribution(a few 100k CHF/year).