Overview of the LHCb experiment Status and Results Federico
Alessio, CERN on behalf of the LHCb Collaboration Epiphany
Conference, Krakow 09-01-2012 Slide 2 Epiphany Conference, Krakow.
09/01/12 F. Alessio, CERN 2 Outline 1.Introduction to LHCb The
detector Physics scope 2.Detector operation Luminosity Leveling
Trigger Detector performance 3.Selected physics results Direct CPV
and CPV in charm physics CPV in B systems Rare decays Heavy flavour
spectroscopy b and c cross sections Lifetime measurements
ElectroWeak 4. The LHCb Upgrade Slide 3 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN 3 The LHCb experiment at the LHC
LHCb is a collaboration of ~700 authors from 15 countries and 54
institutes Slide 4 Epiphany Conference, Krakow. 09/01/12 F.
Alessio, CERN 4 The LHCb experiment 4 Dedicated flavour physics
experiment forward precision spectrometer optimised for beauty and
charm decays Tracking Particle Identification Vertexing 10 -
300mrad Slide 5 Epiphany Conference, Krakow. 09/01/12 F. Alessio,
CERN High B hadron production at the LHC 10 11 B decays in LHCb
acceptance 10 12 D decays in LHCb acceptance 2x10 8 inclusive J/
triggers on tape Most B hadrons produced along beam axis
acceptance: 2 < < 5 + planar detectors vertex detector (VELO)
close to beam (~8mm) with excellent resolution An optimised forward
spectrometer 5 Slide 6 Epiphany Conference, Krakow. 09/01/12 F.
Alessio, CERN A typical LHCb event 6 Slide 7 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN LHCb physics scope 7 Slide 8
Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN All
measurements are coherent with CKM of SM BUT SM fails to explain
matter-antimatter asymmetries Present knowledge of CKM mostly
thanks to B factories LHCb will help reducing uncertainty on angle
NP is still expected in CP violation LHCb physics scope CP
Violation and rare decays of beauty and charm are the main focus of
LHCb CKM Fitter picture 8 Slide 9 Epiphany Conference, Krakow.
09/01/12 F. Alessio, CERN Data taking at LHCb 1.1 fb -1 of data
recorded out of 1.2 fb -1 of data delivered efficiency > 90%,
with > 98% of detector active channels 99% of recorded data is
good for physics analyses used about 30% or 50% of lumi for most
analyses shown here 9 Thanks to LHC and its increasingly good
performance! # of bunches Beam characteristics Peak luminosities
Slide 10 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN
Almost a nominal LHCb year Luminosity design value 2*10 32 cm -2 s
-1 3*10 32 cm -2 s -1 3.5*10 32 cm -2 s -1 4*10 32 cm -2 s -1 : 2x
designed value! Design values: L = @ 7 TeV Pileup = 1 ( ) = 0.4 (
of visible pp interactions/ crossing) 10 L = Running at higher
(higher lumi but same beam characteristics) means increasing number
of interactions/crossing Not good for B physics ! keep this value
low in a controlled way: luminosity leveling Slide 11 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN Luminosity leveling
LHCb ATLAS/CMS Luminosity leveling as real breakthrough: luminosity
kept constant throughout entire fill Fantastic operational
stability Constant occupancies and trigger rates throughout fill
Possibility of choosing the operational point: luminosity value is
selected according to running conditions Automatic procedure
between LHCb and LHC Value of requested luminosity obtained by
separating vertically the beams at the LHCb IP 11 = : ~3x designed
value Majority of data sample with similar Similar occupancies,
similar time to process events Operational stability: identical
dataset for particular period of running Optimization of online
trigger cuts! per bunch distribution RMS ~ 0.3 Slide 12 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN 12 The LHCb trigger
system Dedicated output trigger lines 3 kHz 630 TB of physics data,
peak output of 920 MB/s, 11,157,775,209 physics events gathered
Slide 13 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN
Detector performance I 13 Primary vertex resolution ~16 m Vertex
resolution Accurate field map and alignment Momentum resolution:
0.2% - 0.4% Mass resolution: J/ = 13 MeV Y(1S) Y(2S) Y(3S) Momentum
resolution Slide 14 Epiphany Conference, Krakow. 09/01/12 F.
Alessio, CERN 14 Detector performance II Resolution from prompt J/:
t = 50 fs [LHCb-CONF-2011-049] prompt J/ Lifetime resolution
Particle ID with RICH: ~ 96% Kaon ID efficiency ~ 7% misID K
Particle IDentification Slide 15 Epiphany Conference, Krakow.
09/01/12 F. Alessio, CERN 15 Offline processing and production
Re-processed entire dataset (1.1fb -1 ) by end-November already!
Thanks to availability of computing groups Thanks of usage of
Tier-2 sites for re- processing Allowed LHCb to write 3 kHz on tape
15 Slide 16 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN
16 Selected LHCb physics results See A. Ukleja, Results on charm
physics in LHCb 17:35 on 9 January See A. Martens, CPV violation in
B systems in LHCb 12:10 on 9 January See F. Soomro, Search for rare
decays in LHCb 10:15 on 10 January See A.A. Alves Jr, Heavy flavour
spectroscopy in LHCb 17:00 on 9 January See A. Dziurda, The
measurement of branching ratio of Bs->DsK and Bs->Dspi in the
LHCb experiment 10:50 on 11 January See P. Morawski, The
measurement of fs/fd from hadronic modes in LHCb experiment 11:10
on 11 January Slide 17 Epiphany Conference, Krakow. 09/01/12 F.
Alessio, CERN 17 Direct CP Violation [LHCb-CONF-2011-042] Slide 18
Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 18 Direct CP
Violation See more in A. Martens, CPV violation in B systems in
LHCb 12:10 on 9 January [LHCb-CONF-2011-042] Slide 19 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN 19
[LHCb-CONF-2011-049] [LHCb-CONF-2011-051] Slide 20 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN 20 Slide 21 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN 21
[LHCb-CONF-2011-049] Slide 22 Epiphany Conference, Krakow. 09/01/12
F. Alessio, CERN 22 [LHCb-CONF-2011-049] Events yield in 340 pb -1
Most precise measurement Slide 23 Epiphany Conference, Krakow.
09/01/12 F. Alessio, CERN 23 CPV in charm [LHCb-CONF-2011-023]
signficance of 3.5 First evidence of CP violation in charm sector!
[LHCb-CONF-2011-061] See more in A. Ukleja, Results on charm
physics in LHCb 17:35 on 9 January Slide 24 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN 24 SM expectations [A.J.Buras,
arXiv:1012.1447] See more in F. Soomro, Search for rare decays in
LHCb 10:15 on 10 January Slide 25 Epiphany Conference, Krakow.
09/01/12 F. Alessio, CERN 25 Small excess in most sensitive bin,
compatible with SM (event shown earlier) [LHCb-CONF-2011-037] Slide
26 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 26
[arXiv:1108.3018] End of 2012?Now Slide 27 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN 27 Exotics, X(3872) and (non
observation) of X(4140) [LHCb-CONF-2011-021] (2S) See more in A.A.
Alves Jr, Heavy flavour spectroscopy in LHCb 17:00 on 9 January
X(3872) Slide 28 Epiphany Conference, Krakow. 09/01/12 F. Alessio,
CERN 28 Beauty and Charm cross-sections [Eur. Phys. J. C71 (2011)
1645] [PLB 694 (2010) 209-216] [LHCb-CONF-2010-013] Analyses
performed already in 2010 [Eur. Phys. J. C71 (2011) 1645]
Differential LHCb J/ from b wrt to theorethical predictions Slide
29 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 29
Lifetime measurements [arXiv:1111.0521v2] [CDF note 06-01-26] [Eur.
Phys. J. C71:1532,2011] Analyses performed already in 2010 with 37
pb -1 Slide 30 Epiphany Conference, Krakow. 09/01/12 F. Alessio,
CERN 30 EW measurements [LHCb-CONF-2010-039] [LHCb-CONF-2010-041]
Slide 31 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN
LHCb is foreseeing to upgrade its detector in first LHC long
shutdown (~2018?) To run at 10x design luminosity: L = To collect
10x more integrated luminosity: ~50fb -1 To improve trigger
efficiencies Removing hardware trigger and having all events
available in the software trigger 31 LHCb Upgrade See C. Parkes,
Upgrade of the LHCb experiment 15:20 on 10 January Slide 32
Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 32 LHCb
Upgrade This can be achieved with a trigger-less readout
architecture: record all LHC events! require modification of
readout system many Front-End electronics + detectors will be
replaced readout electronics will be replace To write to tape
~20kHz of triggered events! Letter of Intent already submitted and
approved by LHCC [LHCC-I-018] Work is already progressing
intensively with the aim of complete the upgrade in 2018! 3 kHz ~20
kHz Slide 33 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN
33 Conclusions Thanks to: -the outstanding performance of the LHC
accelerator Provided the LHC experiments with L > expectations
-the outstanding work of the LHCb operation team Reached the
milestone of 1 fb -1 data recorded Online efficiency above 90% and
offline efficiency > 99% -the outstanding work of the LHCb
analysis working groups > 60 analysis have been published as
conference proceedings > 20 papers have been submitted to
international journals LHCb set itself as the world leading
experiment in flavor physics providing world class measurement for
CP violation, charm physics, B hadrons physics, loop and penguin
processes, exotics. The dataset will be doubled, reaching a total
of ~2.5 fb -1 by end of 2012 Many results will be finalized and an
upgrade is envisaged for 2018 Stay tuned for the winter conference
with the full 1.1 fb -1 dataset! Slide 34 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN 34 Backup Slide 35 Epiphany
Conference, Krakow. 09/01/12 F. Alessio, CERN 35 Another rare decay
from related b s diagram Analysis of angular distribution allow
extracting information about NP LHCb has largest sample in world,
as clean as the B factories A FB consistent with SM: data
consistent with SM predictions A FB changing sign as predicted by
SM 303 signal events [LHCb-CONF-2011-038] [arXiv:1006.5013] Slide
36 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 36 Study
of quarkonia production provides important tests for
Non-Relativistic QCD [LHCb-CONF-2011-026] [CMS-BPH-2011-026] Slide
37 Epiphany Conference, Krakow. 09/01/12 F. Alessio, CERN 37 Heavy
b barions [LHCb-CONF-2011-036] Slide 38 Epiphany Conference,
Krakow. 09/01/12 F. Alessio, CERN 38 Heavy b barions
[LHCb-CONF-2011-060] 72.2 9.4 events
