BTeV:%20%20What

1
BTeV Whats New and Whats Next
BTeV-doc 1599

• Rob Kutschke
• Fermilab

Illinois Institute of Technology CAPP Seminar,
February 27, 2003
2
What is BTeV?

• At the Tevatron p-pbar collider, at Fermilab
• Forward spectrometer.
• Beauty and charm physics
• Precision measurements.
• Exhaustive search for new physics.
• BTeV is a part of broad program to address
  fundamental questions in flavor physics.
• http//www-btev.fnal.gov
• Click on BTeV for Physicists.
• Checkout the Document Database.

3
Fundamental Questions in Flavor Physics

• Why families? Why 3?
• Quark mixing angles Are they explained by
  Standard Model (SM)? Arise from new physics?
• Mass heirarchy Why? Related to mixing angles?
• Is CPT violated? If so, what physics is behind
  it?
• Matter/anti-matter asymmetry of the universe
  What interactions were involved?
• Quarks vs leptons What are the similarities and
  differences in mass heirarchies and mixing angles?

4
Fundamental Questions in Flavor Physics

• These are interesting, compelling, questions
  which we must answer.
• The program to answer these questions involves
  present and future experiments in K, D, B, and
  neutrino physics and in astrophysics.
• BTeV is a crucial part of this program.

5
Physics Goals

• Measure CP violation in B(uds) , Bs mixing, rare
  b decay rates, CP violation and rare decays in
  the charm sector.
• Look for rare/forbidden decays discover new
  physics.
• Make an exhaustive search for physics beyond SM
  and to precisely measure SM parameters.
• Test for inconsistencies in the Standard Model
  If found go beyond the SM and elucidate the new
  physics.

6
A Brief History of BTeV

• January 1999 RD program approved by lab.
• June 2000 Stage I approval from lab.
• Two arm spectrometer.
• Fall 2001 funding situation deteriorated.
• Lab asked for a proposal for a descoped detector.
• IR to reuse components from completed CDF/D0.
• May 2002 Stage I approval for descoped detector.
• Instrument only one arm, at least initially.
• PAC recommended lab explore other IR solutions.
• Offline computed to be supplied via universities
  (grid).
• Cost reduced about 70M to about 110M.
• In FY2002 dollars, including contingency of
  33.5.

7
A Brief History of BTeV

• October 2002 Temple Review
• Fermilab internal review in the Lehman style.
• Addressed cost, schedule, management and
  technical risk.
• BTeV passed with flying colors.
• Their cost estimate about 5-10 above ours.
• ( Their report also adds overheads ).
• No new significant risks identified.

8
Nominal Tevatron Parameters
Parameter Value
Center of Mass Energy 2 TeV
Peak Instantaneous Luminosity 2?1032 cm-2 s-1
Yearly Integrated Luminosity 2 fb-1/year
Bunch spacing 132 ns
Luminous region (sx,sy,sz) (0.003, 0.003, 30.) cm
Interactions/Beam Crossing 2
sbb/stot ?1/1000
scc /stot ?1/100
_
_
Will address 396 ns later in this talk.
9
Why a Hadron Machine?

• Large samples of b quarks are available
• 4x1011 b hadrons per 107 sec at nominal Tevatron
  parameters.
• ee- machines at the Y(4S) at L 1034 cm-2 s-1
• Only 2x108 Bs per 107 s.
• Bs , Bc b-baryons are produced at hadron
  machines but not at Y(4S) ee- machines.
• Lots of charm also produced.

10
Why a Forward Detector?

• The higher momenta bs are produced at large
  pseudo-rapidity (h).
• Higher momentum
• Longer decay lengths.
• Less multiple scattering.
• b and c hadrons have lifetimes of ? 0.1 to 1.5
  fs ( ct of 30 to 450 mm).

bg
?

• Background interactions have decay lengths of
  zero.

11
Why a Forward Detector?

• bs are produced in b b-bar pairs.
• The b and b-bar are closely correlated in h.
• Important for flavor tagging

12
Flavor Tagging

• Bd and Bs undergo flavor oscillations
• A particle born as a Bd can decay as an Bdbar,
  vice versa.
• To observe mixing we need to determine the flavor
  at birth ( b or b-bar )
• Determined by looking at other properties of the
  event, often the properties of the recoil b(bar).
• Also need flavor tagging to observe CP violation
  in final states which are CP eigenstates.
• e ? efficiency
• D ? Dilution ? (Nright-Nwrong)/(NrightNwrong)
• Effective tagging efficiency ? eD2

13
The Trigger Concept

• Many forward produced b and c hadrons have lab
  frame decay lengths in the range of a few hundred
  mm to a few cm.
• Most of the background processes have decay
  lengths of zero or gtgt a few cm.
• Trigger on detached vertices at the lowest level.
• Previous experiments have used detachment
  triggers but not at the lowest level.
• Trigger is wide open, just like ARGUS, CLEO,
  BaBar, Belle will be efficient for many decay
  modes whose signficance is not yet appreciated!

14
p
15
The One Arm Configuration

• The full vertex detector
• Covers the full length of IR.
• Level 1 trigger finds tracks in both z
  hemispheres to ensure the best primary vertex.
• 1 each fwd tracking, RICH, EMCal, m systems.
• The steel for the muon toroid on the
  un-instrumented side
• Shielding support the compensating dipole keep
  floor loading constant in case we instrument the
  other arm.
• We retain the full trigger and DA bandwidth.
• Original estimate was conservative.
• See discussion of offline computing

16
Toroids

• Production bb pairs.

• Both b hadrons go into one arm.

p

• Retain 100 of trigger/DAQ bandwidth

17

Key Design Features of BTeV

• Magnet on the IR
• Allows momentum measurement in the trigger.
• Precision vertex detector
• Planar pixel arrays.
• Vertex trigger at Level 1.
• Can trigger on final states with only hadrons.
• PbWO4 Calorimeter
• g and p0 reconstruction.

• Strong Particle ID
• Ring Imaging Cerenkov (RICH) detector.
• Hadron and lepton ID!
• Background rejection.
• Flavor tagging.
• Excellent muon ID system
• Redundant triggering of final states with muons.
• Fast, high capacity DAQ.
• Can record a significant fraction of all B
  decays.

18
Pixel Vertex Detector

• Superior signal to noise.
• Excellent spatial resolution.
• 5 to 10 microns depending on angle of
  incidence.
• Very low occupancy.
• Very fast.
• Radiation hard.
• 3 bit FADC on every channel
• Used directly in Level 1 Trigger.

Elevation View 10 of 31 Doublet Stations
19
Pixel Substrates (Mechanical and Thermal)

• Existing baseline fuzzy carbon with embedded
  glassy Carbon tubes carrying water/glycol as
  coolant.
• Sole source proprietary process.
• Pin hole and mechanical stability issues.
• Backups Be, pocofoam, CFRP, and TPG
• Be CTE mismatch with Si, material budget, joint
  reliability
• Pocofoam joint reliability, tube insertion,
  still needs a lot of RD effort
• All but TPG have have coolant joint reliability
  concerns.
• Thermal Pyrolytic Graphite TPG cold-finger
• No cooling joints. Needs design and test to prove
  the concept.
• By far the simplest solution but a small hit to
  the materials budget.

20
Material Properties of TPG

• Thermal Pyrolytic Graphite (TPG)
• http//www.advceramics.com/acc/products/tc1050/
• Excellent in-plane thermal conductivity (1700W/mK
  at RT), increasing to gt 4000 at cryogenic temp.
• Density 2.26 g/cm2
• CTE -1.0ppm/C (in-plane) and 25ppm/C (out of
  plane)
• Tensile strength 1000 Ksi (in-plane) and lt1 Ksi
  (out of plane)
• X0 198.5 mm
• Electrically conducting
• Used in HERA-B Silicon, will be used by ATLAS,
  LHCb
• Pyrolytic Graphite Sheet (PGS)
• http//maco.panasonic.co.jp/ad/fd/a1e.html
• Thermal conductivity 600-800 W/mK
• Flexible and withstand repeated bending
• Light weight specific density of 1

21
Schematic of a Straw Station

• 7 Stations
• 3 views per station.
• 3 planes per view.
• Forward tracking system, strawssilicon
• Key to excellent momentum resolution.
• Precision measurements of impact points on RICH
  and ECAL.

22
Straw Station 1 Layout for UV ViewSilicon
Strip detectors cover the deadened
area.(Station 2 has similar geometry)
23
Baseline Silicon Tracker Design

• 7 stations
• Coverage from beam pipe to ?13.5cm from the beam
• Each station has 3 planes of 300 mm thick SMD
  with 100 mm pitch
• Each detector is 7x7 cm2

24
Particle ID

• Two critical roles
• To reduce combinatoric background signal
  channels.
• Eg distinguish B0 ???- from the more copious B0
  ?K?.
• Flavor tagging.
• Charged particle ID ( e,m,p,K,p)
• RICH, EMCal, and Muon systems.
• EMCal used to identify gs, p0s and electrons.

25
Ring Imaging Cherenkov Counter (RICH)

• Two radiators to cover desired momentum range.
• Original design gas C4F10, aerogel.
• One array of Hybrid PhotoDiodes (HPDs) for both.
• Aerogel has proven inadequate
• Large, diffuse rings with too few photons, lost
  in gas rings.
• Thicker aerogel limited by scattering in bubbles.
• New solution
• Liquid C5F12 very large angle rings.
• Rings do not overlap with gas rings. Separate
  readouts.
• Readout by PMTs on the sides of the gas box.

26
Before and After K/p Separation
Aerogel
C5F12
c2(K) - c2(p)
c2(K) - c2(p)
27
New Layout of the BTeV RICH

• PMTs do not need quartz windows. Borosilicate
  glass OK.

Tracks from IR

• PMT costs partly offset by reduced size HPD
  arrays.

28
HPD Photos
Photocathode
Readout
Pins for Multianode Pixel readout

• 61 channel HPD shown (we have in and will use
  163 channel HPD).
• Pins through the glass envelope connect pixels
  to the electronics.
• Backup solution Hamamatsu R7600 M16 Multianode
  PMT.

29
Cherenkov Angles in the BTeV RICH

• If only the gas radiator, then for p lt 9 GeV/c
• No K/p separation
• Hurts kaon tagging.
• K/p sep. is threshold only
• Every badly reconstructed track is a kaon!
• Hurts kaon tagging.
• For 9 lt p lt 18 GeV/c, K/p separation is threshold
  only.

Liquid
Gas
30
Geant 3 Simulation of RICH Response
K/p Separation in Liquid
K/p Separation in Gas
p lt 9 GeV/c
MisID (B0 ?K?)
Efficiency(B ???-)
31
Using the RICH for Lepton ID

• Many leptons which miss the Ecal and Muon systems
  are accepted by the RICH.
• These leptons are at low momentum where RICH has
  lepton ID power.
• Perfect match!

Leptons from B decay
32
RICH has e-p and m-p Discrimination!
C4F10

• Wide angle particles are mostly low p. Perfect
  Match!
• Efficiency 2.4 (3.9) for single (double)
  lepton ID.

33
Electromagnetic Calorimeter

• Projective geometry crystal calorimeter.
• PbWO4 for s(E) and for radiation hardness (like
  CMS).

Block from Shanghai Institute of Ceramics
5X5 stack of blocks from Bogoroditsk.

• Also evaluating crystals from Beijing and
  Apatity(Russia).

34
Electromagnetic Calorimeter

• BTeV can use PMTs for readout.
• CMS uses avalanche photodiodes(barrel) and
  triodes (endcap) because their readout is inside
  B field.
• Mock up the mechanical design exists
• To help estimate cost and schedule.
• Basic design Al lattice
• Cooling design also underway.

35
EMCal IHEP Test Beam Program

• IHEP Protvino Dec/00, Mar-Apr/01, Nov-Dec/01,
  Mar-Apr/02, Nov-Dec/02.
• Electron and pion beams (momentum measured).
• Study s(E) vs incident energy, position and
  angle
• Time, temperature and rate stability.
• Radiation hardness and recovery.
• Realistic dose rates and artificially high dose
  rates.
• Used 10 stage tubes in tests, will use 6 stage
  in BTeV.
• 6 stage QIE chip almost identical to KTeV.

36
s(E) Measured in IHEP Test Beam
s(E)/E ()

• Stochastic term 1.8 is good enough.
• Original estimate of 1.6 was for different size
  crystals.

37
Geant 3 Simulations of B?yh, B?yh/
h?gg
h?pp-g
h??(pp-)gg
s 5 MeV/c2
s 5 MeV/c2

• 6 MeV/c2

M(gg)
M(pp-g)
M(pp-gg)
(GeV/c2)
38
G3 Simulation of B0?K0g, K0? Kp-

CLEO barrel e89
Radius (cm)

• minbias events Possion distributed mean
  2/beam crossing.
• Plots are for events in which the charged tracks
  pass all cuts.
• CLEO/BaBar/Belle-like performance in a hadronic
  environment.

39
The BTeV Muon System

• Two main functions
• Muon ID both for signal selection and for
  tagging.
• Triggering
• Redundant trigger to test the detached vertex
  trigger.
• More efficient for some states of particular
  interest such as B?J/y h, B?J/y h/, B? Kmm-
  
• Toroidal B field for momentum measurement in
  trigger.
• 3/8 inch dia. stainless steel proportional tubes.
• 36864 channels per arm.

40
Muon Vocabulary Review

• Three (3) stations of detectors

Toroids
IP
Compensating Dipole

• Each station is made up of overlapping octants.
• 4 views/octant r,u,v, r.

41
Muon Vocabulary Review

• Two octants form a quad
• Quads will be built at institutions and delivered
  to FNAL

• Each quad will individually supported it will
  be possible to install/remove a quad during run.
• Scale mock up built at Univ. of Illinois.

42
Level 1 Trigger

• Uses only information from the pixel detector.
• Inspects every beam crossing.
• Heavily pipelined.
• Finds tracks, and looks for a primary vertex with
  evidence for a nearby secondary vertex.
• Momentum measurement in trigger allows
  identification of low momentum tracks which can
  scatter a lot and fake tracks from a secondary
  vertex.

43
Level 1 Trigger Performance

• Nominal requirement at least 2 tracks detached
  from primary vertex by more than 4s.
• Rejects 99 of background beam crossings
• Achieves the following efficiencies

• Efficiency is quoted relative to a events which
  pass all analysis cuts.

44
Simulation of Level 1 Di-Muon Trigger

• Geant 3 simulation with 2 interactions per
  crossing.
• Signal events J/y ???- from generic B decays.
• Find tracks standalone within each octant.
• Require two oppositely charged tracks in
  different octants indicated cuts.
• J/y efficiency denominator has good
  reconstructable tracks, with pgt5 GeV.

J/y efficiency
Minimum bias rejection
45
Simulation of DiMuon Trigger

• In order to meet the DAQ bandwidth restrictions,
  we need a rejection of minimum bias events of
  around 1 to a few hundred.
• There is a wide range of possible operating
  points.

46
L2/L3 Trigger Plans

• L2 and L3 triggers are implemented in the same
  hardware, a PC Farm
• L2 Uses tracking information to look for
  detached vertices and detached tracks
• Prototype code is working.
• L3 does the full reconstruction and writes DSTs
  (similar to traditional offline)

47
Flavor Tagging

• Methods in order of decreasing dilution
• Away side Kaon (Reasonably high efficiency).
• Away side muon (Low efficiency).
• Same side tag K (for Bs) and p ( for B0).
• Jet charge (Large overlap with ASK and ASM).
• Still to come away side electron.
• To remove overlaps, use the simplest method
• Poll methods in order of decreasing dilution.
• Stop when a method gives an answer.

48
Summary of Flavor Tagging
Tag Type Bs Bs Bd Bd
eD2 Independent eD2 Correlated eD2 Independent eD2 Correlated
Away Side K 5.8 5.8 6.0 6.0
Away Side m 1.3 1.3 1.2 0.8
Same Side K(p) 5.7 4.5 4.8 1.4
Jet Charge 5.4 0.4 1.8 1.0
Total 12.1 9.2
Nominal 13 10

• Include electrons
• Allow for optimized use of all info.

Extra 1
49
CP Violation, CKM Physics andall That

• Physics reach estimates are quoted for one
  Snowmass year (107 s) of running at these
  parameters.
• Exception a using B0? rp ? pp-p0 is 1.4 years.

50
Formulation of CKM Matrix
d s
b
u
c
t

• Good l3 in real part l5 in imaginary part.
• We know l0.22, A0.8 constraints on r h.

51
The 6 CKM Unitarity Triangles

• p-(bg)

?, b g probably large, c0.03, c? smaller
52
Measuring b

• sin(2b) has already been shown to be non-zero.
• First hints CDF. Best measurements BaBar/Belle.
• We presume that sin(2b) will be well measured
  before BTeV starts running.
• BTeV should still be able to improve the
  measurement.
• Sensitivity sin(2b) using Bo?J/y Ks only in one
  year of running 0.017.
• Determined using Geant 3 based simulation.

53
Removing Ambiguities from b

• Bo ? yKo, Ko?pl-n
• Exploits K0S/K0L interference.
• Equal amplitudes to pl-n.
• Low yield
• ?1/100 of Ks?pp-.
• ?1700/year (untagged)
• Can determine sign of b with O(100) low
  background, tagged events.
• Sensitivity improves for smalle sin(2b).

For sin(2b)0.7
Decay Rate
tK integrated over tB
54
Measuring a

• B0? pp-
• Sensitivity to ACP in one year 0.030
• But penguin pollution!
• Need p-p0 and p0p0 to unpollute. Tough to do!
• B0? rp ? pp-p0
• Dalitz plot analysis (Snyder and Quinn ).
• (next page)

• Sensitive to both sin(2a) and cos(2a).

55
Mini MC Study of B0? rp ? pp-p0

• Dalitz plot density
• Synder Quinn matrix element.
• Incoherent BG SBG 41.
• Non-resonant (flat).
• Resonant in r.
• Acceptance and smearing parameterized from Geant
  based study.
• Results for trials of 1000 signal events BG.
• Sensitivity (1.4 years) lt 4o.

a (gen) Rres Rnon a (recon) da
77.3o 0.2 0.2 77.2o 1.6o
77.3o 0.4 0 77.1o 1.8o
93.0o 0.2 0.2 93.3o 1.9o
93.0o 0.4 0 93.3o 2.1o
111.0o 0.2 0.2 111.7o 3.9o
111.0o 0.4 0.2 110.4o 4.3o
56
Four Ways of Measuring g
Model independent

• Time dependent flavor tagged analysis of Bs?DsK-.
• Sensitivity in one year 8o
• Rate difference between B-?DoK- B?DoK.
• Sensitivity in one year 13o
• Rate measurements in Kop? and K?p?
  (Fleisher-Mannel) or rates in Kop? asymmetry in
  K?po (Neubert et al) .
• Sensitivity in one year 4o Theory
  uncertainties.
• Use U spin symmetry d?s measure time dependent
  asymmetries in both Bo?pp- Bs?KK- (Fleischer)

57
Measuring c

• Bs?J/y h and Bs?J/y h?.
• y ? ll-
• We now use both electrons and muons.
• This measurement is possible because of the
  excellent photon and p0 detection provided by the
  PbWO4 calorimeter.
• Excellent S/B 151 for h and 301 for h/.
• Sensitivity for one years running 0.024.
• Will take several years to resolve expected
  c?0.03.

58
xs Reach

• If xs is less than about 70, BTeV will be able to
  measure it in about 1 year.
• If it is less than about 80, BTeV will be able to
  measure it in about 3.2 years.

59
Physics Beyond the Standard Model

• New Physics (NP) effects can be subtle
• More than just a b g ? 180o.
• Suppose there is NP in B0 mixing
• If we measure b and a via mixing mediated modes,
  J/yK0S and pp-, we may measure
• 2b? 2b q
• 2a? 2a - q
• And measure g via a non mixing method.
• a? b? g a b g 180o
• The triangle closure test misses this sort of NP.
• We need to be careful when we do this!

60
Generic Tests for New Physics

• Specific decays, non-specific models
• B?K??- B?K??- can observe NP in
  distribution of M(??-) and Dalitz plot is
  sensitive to subtle interference effects. See
  hep-ph/9408382.
• Check for inconsistencies in SM without reference
  to a particular model.

Reaction B(10-6) Yield/year S/B
B?Kmm- 1.5 2530 11
B?Kmm- 0.4 1470 3.2
b?s mm- 5.7 4140 0.13
61
Critical Checks using c

• Silva Wolfenstein (hep-ph/9610208), (Aleksan,
  Kayser London)
• Measure c using Bs?J/yh(?) , h?gg, h??rg.
• Can also use J/yf, but need a complicated angular
  analysis.
• The critical check is
• Very sensitive since l 0.22050.0018
• Since c 0.03, need lots of data.
• Sensitivity to sin(2c) for one year of running
  0.024.

62
Survey of New Physics Sensitivities

• See the BTeV Proposal Update for a discussion
  of how many NP ideas can be tested in B decay.
• MSSM and othe SUSY variants
• Left-Right Symmetric models
• 2 Higgs doublet models
• Extra d type single quarks.
• FCNC couplings of the Z.
• Non-commutative geometries
• Mixing with a 4th generation.
• Extra dimensions

63
Tests for New Physics (Nir, hep-ph/9911321)

• Suppose NP in Bo mixing, qD , Bo decay, qA, Do
  mixing, fKp.

Model dN/10-25 qD qA asyD?Kp
SM ?10-6 0 0 0
Approximate Universality ?10-2 ?(0.2) ?(1) 0
Alignment ?10-3 ?(0.2) ?(1) ?(1)
Heavy squarks 10-1 ?(1) ?(1) ?(10-2)
Approx. CP 10-1 -b 0 ?(10-3)

• Specific pattern in each model ?ways of
  distinguishing models.

64
Summary of New Physics

• Using b and c decays mediated by loop diagrams
  BTeV is sensitive to mass scales of up to few
  TeV.
• The New Physics effects in these loops may be the
  only way to distinguish among models.
• Masiero Vives the relevance of SUSY searches
  in rare processes is not confined to the usually
  quoted possibility that indirect searches can
  arrive first in signaling the presence of SUSY.
  Even after the possible direct observation of
  SUSY particles, the importance of FCNC CPV in
  testing SUSY remains of utmost relevance. They
  are will be complementary to the Tevatron LHC
  establishing low energy supersymmetry as the
  response to the electroweak breaking puzzle
  (hep-ph/0104027)
• We agree, except we would replace SUSY with
  New Physics

65
Comparison with LHC-b

• Advantages of LHCb
• 5? higher b cross-section 1.6? higher sb/stot.
• Advantages of BTeV
• Detached vertex trigger at level 1.
• Enabling technologies
• Magnet on the IR we can reject low p tracks at
  level 1.
• Pixels very low occupancy, only 6mm from beam (
  cf 1 cm ).
• Allows us to trigger on very general properties
  of bs.
• PbWO4 Ecal with CLEO/BaBar/Belle-like
  performance.
• Trigger/DA design lets us read out 5? as many
  bs/second.

66
Comments on the ee- Super B-Factories

• At the Y(4S), it would take a 1036/cm2/s ee-
  collider to match the performance of BTeV for Bo
  B.
• There would be no competition on Bs, Lb,
• KEK is only proposing 1035/cm2/s.
• For Super-BaBar there are serious technical
  problems for both the machine the detector.
• We believe the cost will far exceed that of BTeV.
  Recent HEPAP subpanel mentions 500M.

67
A New Wild Card 396 ns

• Original plan for Run II bunch spacing
• 396 ns, for the first few years ( Run IIa ).
• 132 ns, afterwards ( Run IIb ), to increase lumi.
• Recent change stay at 396 ns.
• BTeV originally designed to operate at 132 ns and
  a peak luminosity of 2?1032 cm-2 s-1 ( 2
  fb-1/year ).
• 2/interactions/beam crossing at peak lumi.
• For the same luminosity and 396 ns
• 6 interactions/beam crossing at peak lumi.

68
A Partial Solution Luminosity Leveling

• Squeeze the beams more tightly as a Tevatron
  store progresses
• Luminosity drops more slowly.
• Can achieve 2 fb-1/year with a peak luminosity of
  1.3?1032 cm-2 s-1.
• Only 4 interactions/beam crossing at peak
  luminosity and 396 ns bunch spacing.

69
Impact of 396 ns on BTeV

• Issues Radiation damage, occupancy, false
  triggers.
• Pixels, Forward Silicon, Muon
• Probably OK may need to revisit shielding.
• Straws, ECAL
• Need to carefully study occupancy. Work
  underway.
• Trigger
• Two nearby background collisions can look like a
  b.
• Need to retune cuts and algorithms. Work
  underway.

70
Peering into the Future

• Particle Physics Project Prioritization Panel
  (P5)
• A HEPAP subpanel created at request of DOE/NSF.
• Charge to prioritize experiments in light of the
  wider and long term US HEP program.
• First charge is to review
• BTeV
• CKM
• CDF and D0 Run IIb detector upgrades.
• Will meet at Fermilab, March 26-27, 2003.
• We will understand the implications of 396 ns by
  this time.
• Response due by June 2003.

71
Peering into the Future

• Summer 2003, test beam at Fermilab for most
  components.
• Presuming success in P5, there will be a Lehman
  review (Fall 2003?).
• FY 2004-2008 Construction funding.
• Lab has had BTeV in long range plan for several
  years.
• Only small amounts of money presumed for FY2004
• For a few items with long lead times.
• Staged installation to get some components in
  early and to allow early commissioning.
• 2008 Start of physics running.

72
Summary and Conclusions

• The Fermilab director has given Stage I approval
  to a revised proposal to run BTeV with only one
  arm fully instrumented.
• Full DAQ and Trigger bandwidth retained.
• Aerogel RICH radiator replaced with liquid C5F12.
• We have learned use the RICH for lepton ID
• Single(double) lepton ID efficiency up 2.4
  (3.9).
• The reduced scope BTeV remains an excellent
  detector and will be a leader in b and c physics
  in the last half of this decade.

73
Backup Slides
74
HPD Schematic
HPD Pinout
HPD Tube
HPD Pixel array
PC
ped
1 pe
Pulse Height from 163 pixel prototype HPD, using
old CLEO electronics. Note pedestal, 1, 2, 3 pe
peaks.
2 pe
3 pe
20 kV
Si pixel array
75
Miscellaneous RICH Issues

• PMTs and HPDs will be in a region of low but
  non-zero B field.
• Now testing shielding options.
• Mirror options
• Glass
• Glass composite
• Composite Replica
• Test pieces for first two are in hand.
• Mechanical, cooling, electronics underway.

76
Summary of CKM Physics Reach (107 s)
Reaction B (B)(x10-6) of Events S/B Parameter Error or (Value)
Bo?pp- 4.5 14,600 3 Asymmetry 0.030
Bs? Ds K- 300 7500 7 g 8o
Bo?J/y KS , J/y ?l l - 445 168,000 10 sin(2b) 0.017
Bs? Ds p- 3000 59,000 3 xs (75)
B-?Do (Kp-) K- 0.17 170 1
B-?Do (KK-) K- 1.1 1,000 gt10 g 13o
B-?KS p- 12.1 4,600 1 lt4o
Bo?Kp- 18.8 62,100 20 g theory errors
Bo?rp- 28 5,400 4.1
Bo?ropo 5 780 0.3 a 4o
Bs?J/y h, 330 2,800 15
Bs?J/y h? 670 9,800 30 c 0.024
J/y ?ll-
77
Specific Comparisons with LHC-b
Mode BR Yield S/B Yield S/B
Bs? Ds K- 3.0x10-4 7530 7 7660 7
Bo?rp- 2.8x10-5 5400 4.1 2140 0.8
Bo?ropo 0.5x10-5 776 0.3 880 not known
BTeV
LHC-b
78
Comparisons With Current ee- B factories

• Number of flavor tagged Bop p - (B0.45x10-5)
• Number of B-Do K - (Full product B1.7x10-7)
• Bs , Bc and Lb not done at Y(4S) ee- machines

79
Reconstructed Events in New Physics Modes
Comparison of BTeV with B-factories
Mode BTeV (107s) BTeV (107s) BTeV (107s) B-fact (500 fb-1) B-fact (500 fb-1) B-fact (500 fb-1)
Yield Tagged S/B Yield Tagged S/B
Bs?J/yh(?) 12650 1645 gt15 - -
B-?fK- 11000 11000 gt10 700 700 4
Bo?fKs 2000 200 5.2 250 75 4
Bo?Kmm- 2530 2530 11 50 50 3
Bs? mm- 6 0.7 gt15 0
Bo?mm- 1 0.1 gt10 0
D?pDo, Do?Kp 108 108 large 8x105 8x105 large
80
Summary of Required Measurements for CKM Tests
81
Offline Computing Model

• Reuse Level 2/3 trigger farm.
• 2500-4000 Linux processors
• Sized to deal with peak lumi.
• About 2/3 of cycles are available for other uses
  
• Lower lumi late in run.
• Machine filling, downtime etc
• Use of large computing clusters at universities.
• Grid aware but not grid dependent.
• See talk by Joel Butler Tuesday afternoon.

82
Changes in Efficiencies wrt Proposal

• We lost one arm Factor 0.5
• We gained on leptons
• We now use RICH to improve lepton ID
• Larger solid angle larger momentum range.
• In proposal we used only mm-, now we include
  ee-
• Factor 2.4 (or 3.9), depending on whether
  analysis required one or two leptons to be IDed.
• DA bandwidth constant for one arm Factor 1.15
• For Bs only improved eD2 Factor 1.3

83
Summary of Efficiency Changes
Mode Quantity Yield in Proposal Yield Factors New Yield New eD2 Sensitivity Sensitivity
Mode Quantity Yield in Proposal Yield Factors New Yield New eD2 Proposal One Arm
Bo?J/y Ks sin(2b) 80,500 0.53.9 1.152.24 168,000 0.10 0.025 0.017
Bs?J/yh(?) sin(2c) 9,940 0.52.4 1.151.38 12,600 0.13 0.033 0.024
Bs? Ds K g 13,100 0.51.15 0.58 7,500 0.13 6o 8o

• In the proposal all eD2 were 0.10.