CP violation with the LHCb detector

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CP Violation in 2007 the LHCb Experiment
Lluís Garrido Jornades CER, 8/5/2002
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Asymmetry matter antimatter

• Energy -gt matter antimatter in equal amounts
  , .

• Expect equal amount of primordial He and anti-He
  from the Big Bang nucleosynthesis.
• Search for
• anti-He in cosmic rays
• AMS experiment

2004
1998

• Result
• No anti-Helium seen

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Sakharovs argument

• How to get rid of anti-matter (simplified
  version)
• Proton decay
• CP violation (Cparticle-antiparticle exchange,
  PParity r -gt -r)
• Thermal non-equilibrium (Big Bang)

CP violation is one of the keys
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CP violation in the SM
Can be accommodated within the Standard Model
CKM matrix
???????? ?
???????????i??? ??? ?
????????? ? ??? ???????????i???? ????
?
VCKM

( Wolfenstein parameterization, with l sinqC
0.22, and A, r, h of order 1 )

• In the SM, CP violation is due to ??¹ 0
• Unitarity triangles obtained through products of
  rows and columns

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CP violation in the interference of
t measured in units of B lifetime, and
is one the angles of the unitary triangle
Need to tag the other B
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The LHC accelerator (I)
Atlas
LHCb
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The LHC accelerator (II)

• Parameters (protons)
• Energy at collision 7 TeV (1700 TeV for ions)
• Dipole field at 7 TeV 8.3 T
• Bunch spacing 7.5 m
• Bunch separation 24.95 ns
• Particles per bunch 1011
• Current 0.56 A
• Luminosity 1034 cm2 s
• Lot of energy ..
• energy per beam up to 0.35 GJ
• Stored magnetic energy up to 1.29 GJ per sector
• TOTAL STORED ENERGY 11 GJ

at 40 kph
In case of a quench this energy must be extracted
in a controlled manner to prevent damage .
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The LHCb detector

• Spectrometer
• A single-arm spectrometer covering ?min 15 mrad
  (beam pipe and radiation) to ?max 300 mrad
  (cost optimisation)
• has an equal bb acceptance
• as a large central detector.
• ?bb500?b
• Modest luminosity
• O(1012)bbpairs/year
• ?bb/ ?inelastic510-3

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The LHCb trigger
Channels 1000k
The multi-level trigger chain
Logging rate 200 Hz (20 MB/s) ? 200 TB/year
All LHC experiments 5-8 PB/year
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The Challenge of LHC Computing
Storage Raw recording rate 0.1 1
GBytes/sec Accumulating at 5-8
PetaBytes/year 10 PetaBytes of disk 40
PetaBytes of tape Processing 200,000 of
todays fastest PCs
The solution

• What does the GRID do for you?
• you submit your work, and the GRID
• Finds convenient places for it to be run
• Organises efficient access to your data (Caching,
  migration, replication)
• Deals with authentication to the different sites
  that you will be using
• Interfaces to local site resource allocation
  mechanisms, policies
• Runs your jobs, monitors progress and recovers
  from problems
• .. and .. tells you when your work is complete

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The UB contribution SPD (I)
6000 units
100 units

• Main
• SPD electronics
• SPD simulation
• PMT test
• Physics simulation
• Computing the GRID

People ECM Electrònica URL R. Graciani S.
Bota X. Vilasis D. Gascon A. Dieguez M.
Rosello E. Aguilo A. Herms S.Luengo M. Calvo X.
Cano R. Ballabriga S. Gomez (URV) J.Riera Ll.
G.
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The UB contribution SPD (II)
Electronics of SPD ASIC (800) VFE (100) FE
(25)
PMT Pad test and MC studies The photon time
arrival agrees very well with simulations
The GRID

• El GRID en ECM durante 2002
• Establecer infraestructura inicial 10 PCs
  para cálculo 1 TB de disco.
• Participar en producción de sucesos simulados
  para LHCb.
• Integrarnos con las actividades del resto de los
  grupos españoles.

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Physics
2005
2009