# University of Southampton by alicejenny

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```									                               Southampton
July 1999

Future of Heavy Flavour Physics:
Experimental Perspective
Sheldon Stone
Syracuse University

1
Future Physics Goals:
Introduction
 Our goals are to make an exhaustive search for physics
beyond the Standard Model and to precisely measure
SM parameters.
 Here we ask what studies need to be done, not just
what studies can be done.
 Measurements are necessary on CP violation in Bo and
Bs mesons, Bs mixing, rare b decay rates, and mixing
CP violation and rare decays in the charm sector.
 These quarks were present in the early Universe. There
is a connection between our studies and Cosmology.
2
The CKM Matrix
We need to connect the weak eigenstates of
quarks with the mass eigenstates

                     
weak eigenstates   VCKM    mass eigenstates

 If   n’s have mass there will be analogous matrix
3
Proper Formulation of CKM
Matrix
d                 s                    b
       1                                       1 2 
u  1  l2                 l           Al  r  ih1  l   
3
                
       2                                       2 
                                                          
V   c       l
1 2
1  l  ihA 2 l4
2
2

Al 1  ihl  2
     
 2                                                        
t  Al 1  r  ih       Al2                    1          
                                                          
                                                          
 Good l3 in real part & l5 in imaginary part
 We know l=0.22, A~0.8; constraints on r & h
 Due unitarity there are 6 CKM triangles
4
The 6 CKM triangles

 “ds” - indicates
rows or
columns used
 There are 4
independent
phases, which
can be used to
construct entire
CKM matrix

5
The 4 CKM Phases

 Vtb Vtd 
*
 Vub Vud 
*

 V V* 
  arg                 arg  *
 V V    
   cb cd                  cb cd 

 V Vcb 
*
 V Vus 
*
  arg 
 VV   
cs
  arg      
ud
*                 V V 
    tb 
*
ts                    cs 
cd

 &  probably large,  small ~0.02,  smaller
6
Usual Triangle (for ref.)
 Real a,  &  must sum to 180o
 Therefore, any two will do IF we
are really measuring the intrinsic
angles
 New physics can hide, only
these angle measurements not
sufficient.
 Ex: Suppose there is new
physics in Bo-Bo mixing (q) &
Two   sides |Vub/Vcb| &
we measure CP in yKs and pp,
|Vtd/Vts| important.
then 22q, 2a2aq, &
BTeV can measure the
22a22a, new physics
latter from Bs mixing
but a 180o                                               7
Ambiguities

Suppose we measure
sin(2) using yKs,
what does that tell us
Ans: 4 fold ambiguity-
, p/2, p, 3p/2
 Only reason h>0, is Bk>0
from theory, and related
theoretical interpretation
of e                                8
Problems with measuring a
using Bopp
 Using Bopp would be nice, but
large Penguin term, CLEO:
B(Bo p+p-) < 0.84 x 10-5, while
B(Bo K+p-) =(1.4±0.3±0.2)x10-5
 The effect of the Penguin must be
measured in order to determine a.
Can be done using Isopsin, but      for s get K-

requires a rate measurements of
ppo and popo (Gronau & London).
However, this is daunting.
9
Measuring a using
Borp  pppo
A Dalitz Plot analysis
gives both sin(2a) and
cos(2a) ( Snyder & Quinn)
CLEO has measured
the branching ratios
B(Brop =
(1.5±0.5±0.2)x10-5
B (Borp + rp          Snyder & Quinn showed that 1000-
2000 tagged events are sufficient
= (3.5±1.0±0.5)x10-5                                          10
Comparison of rp modes

Final State: rp rp rpo rop         r op o
CLEO(10-5):    3.5±1.2 <7.7 1.5±0.5±0.2 <1.8
Ciuchini et al.: 1.0-7.5 0.2-1.9 0.3-2.6 0.5-1.1   0.00-0.02
Ali et al.:   2.1-3.4 0.6-0.9 1.1-1.6 0.1-0.7      0.00-0.02
B(B+  roK+) = < 2.2x10-5 @ 90% c.l. (CLEO)
{To measure the three neutral rp modes, requires
triggering on hadronic decays with high efficiency,
RICH particle ID and high quality photon
detection}                                        11
More on a

Using rp Dalitz Plot analysis, sin(2a) and
cos(2a) are measured, only one ambiguity
remains a & pa
To remove this use Bopp.This works because
of large Penguin rate (Grossman & Quinn)
a(pp)-a(rp)=-2(AP/AT)cos(dP-dT)[cos(2a)sin(a)]
 Usefactorization to get sign of AP/AT (-)
 Theory says cos(dP-dT) is small

12
Ways of measuring 

 May be easier to measure than a
 There are 4 ways of determining 
 Time dependent flavor tagged analysis of BsDsK
 Measure rate difference between B-DoK- and B+DoK+
 Rate measurements in Kop and Kp (Fleisher-Mannel) or rates
in Kop & asymmetry in Kpo (Neubert-Rosner) . Has theoretical
uncertainties but can be useful.
 Use U spin symmetry ds: measure time dependent
asymmetries in both Bopp& BsKK (Fleischer).
 Ambiguities here as well but they are different in each
method, and using several methods can resolve them.
13
BsDsK Decay processes
±

Diagrams for the two decay modes, B ~ 10-4 for each

14
B-[K+p-]K- Decay processes

B ~ 10-6

B ~ 2x10-7

15
What do we need to measure
involving ?
 Phase of Bo-Bo mixing,  using yKs          (done soon? precision?)

 Measure  using other modes: fKs,hKs, ypo
 Remove ambiguities if possible
 Measure interference in yK*. However, either must make
theoretical assumption (factorization) to guarantee that fsi don’t
change sign of strong phase-shift or measure Bs yf & use
SU(3)
 Kayser: Measure time dependence using yKs,

Kspln, has a cos(2) term (loss of rate)

16
Decay Widths for Bo  yKs,
Kspln
 t B , t K  
e B t B {e   s t K [1  sin(2) sin(m B t B )]                              cos(2)>0
 e   s t K [1  sin(2) sin(m B t B )]                                       cos(2)<0

1
  s   L t K
 ( )2e       2
[cos(m B t B ) cos(m K t K )
 cos(2) sin(m B t B ) sin(m K t K )]}

 top sign for Bo, bottom for Bo
 3rd line 1st pair for p-l+n (K),
2nd pair for p+l-n (K)
t K integrated over t B
 CPT tests?
17
A Critical Check using 

 Silva & Wolfenstein, (Aleksan, Kayser & London), propose a
test of the SM, that can reveal new physics; it relies on
measuring the angle . (This is the sine qua non Unitarity check)
 BTeV can use CP eigenstates to measure , for example
Bsyh, hr
 Can also use yf, but need complicated angular analysis
 The critical check is
sin  sin 
sin   l 2

sin(   )
 Very sensitive since l 0.2205±0.0018
 Since  ~ 0.02, need lots of data
18
More checks using 

 Other   checks using |Vtd/Vts|, |Vub/Vcb| possible

2
Vub sin  sin(   )
sin  
Vcb      sin()
2
Vtd sin  sin(   )
sin  
Vts      sin( )
might provide best measurements of
 Ultimately,
these CKM ratios!
19
Other critical CKM
measurements
Bs mixing
  Use Bs Ds p to determine xs
 Find  by comparing lifetime for yh or K+K-
with Ds p
 If  is large enough ~10%, then other interesting
measurements are possible
|Vub|, how do we do this with minimal
theoretical error?

20
Rare b Decays

 Exclusive Rare Decays
such as Br,
BK*l+l
 Inclusive Rare Decays
 Possibilities for New Physics     such as inclusive bs,
 W- in loop is replaced by      bd, bsl+l. Can
other charged object such
as H-, X -
this? Probably using
 new fermion like objects
replace t
same technique as
CLEO.
21
Charm decays

Predictions of the Standard Model contribution
to mixing and CP violation in charm decay are
small. Thus, this provides a good place to
search for New Physics.
 Currentexperimental limit on mixing, rD<5x10-3,
SM expection rD~10-8
 CP current limit is ~10%, SM expectation is 10-3

22
Summary of required
measurements for b’s
Physics             Decay Mode         Vertex    K/p    det Decay
Quantity                               Trigger   sep         time 
sin(2a)         Borppppo                           
sin(2a)         Bopp & BsKK                            
cos(2a)         Borppppo                           
sign(sin(2a))   Borp & Bopp                        
sin()          BsDs K                                     
sin()          BoDo K                         
sin()          BK p                                 
sin(2)         BsJ/yh, J/yh                             
sin(2)         BoJ/yKs
cos(2)         BoJ/yK* & BsJ/yf
xs              BsDsp                                     
 for Bs       BsJ/yh, KK, Dsp                              23
Summary of Standard Model
Tests
 Check that a     = 180o, after removal of
ambiguities; necessary if we have properly measured
these quantities
 Check that the Silva-Wolfenstein test has been met:
2 sin  sin 
sin   l
sin(   )
 Check that magnitude ratios |Vtd|/|Vts| and |Vub| / |Vcb|
are consistent with determined a, , , 
 Search rare decays for anomalous rates, or dilepton
polarizations
24
Current Status: Brief Summary

We know xd and have limit on xs
We know |Vcb| & |Vub|, but how accurately?
 What   is the meaning of a theoretical error?
 Is it Gaussian distributed?
 Does statistics work in combining undefined errors?

 Whatis the error on Vcb?
 What is the error on Vub?

25
(still some mysteries)
total = 1/t
2

1.9
1.8

1.7

1.6

1.5   B+
Bo
1.4
Bs              “Low”
1.3

1.2
1.1
Lb
1

26
Heavy Quark Effective Theory

HQET tells us that in first order when a b quark
transforms to a c quark with the c going at the
same velocity as the b, the form factor is 1 in
first order AND the corrections to 1 can be
calculated
The form-factor therefore known to be 1-
correction, at maximum q2, called w=1, where
M2  M2 *  q 2
w B        D
2M BM D*
27
|Vcb| from BD*l n

Use BD*l n because the decay rate is largest
for and the corrections are better determined.
In HQET there is one “universal” form-factor
function, so we don’t have to deal with 3 form-
factors
To find Vcb measure value at w=1, here D* is at
rest in B rest frame                        m  m                                    2  
          1  2wD*
 D* 
d(B  D*ln)   G2                                                               mB m 2
 F 3 Vcb F2 (w)(m B  m D* ) 2 m 3 *   w2  1  4w(w  1)
2                                                                B
dw       48p
D                                       2 
               m D*     
1     
                                    




mB    

28
CLEO Measurement

background

background

29
Vcb results, an example

 To get results fit using shape proposed by Caprini et
al, or Boyd & Grinstein, or in CLEO case by Stone
 Use F(1)=0.91±0.03, from Caprini, Uraltsev…..
 Results
 DELPHI: (41.2±1.5±1.8±1.4)x10-3
 ALEPH: (34.4±1.6±2.3±1.4)x10-3
 OPAL: (36.0±2.1±2.1±1.2)x10-3
 CLEO: (39.4±2.1±2.2±1.3)x10-3
 World Average 0.0381±0.0021 by adding
theoretical error in quadrature with exp error.     30
Theoretical Value of F(1)
 Lim F(1) = 1 as mb  ,
 F(1)=1+O(as/p)+d1/m2+d1/m3 (no d1/m , Lukes thrm)
 F(1)=0.91±0.03,    from Caprini, Uraltsev…..
 F(1)=0.89±0.06, from Bigi
 Can we get an accurate non-quenched value from the Lattice?
 The errors are not consistent. What do the errors mean?
 Bigi: “In stating a theoretical error, I mean that the real value can
lie almost anywhere in this range with basically equal probabilty
rather than follow a Gaussian distribution. Furthermore, my
message is that I would be quite surprised if the real value would
fall outside this range. Maybe one could call that a 90% confidence
level, but I do not see any way to be more quantitative.”
31
QCD Sum Rules for |Vcb|

 Using Operator Product Expansion & Heavy Quark
Expansion, in terms of as(mb), L, and the matrix
elements l1 and l2, we can accurately determine Vcb.
 These quantities arises from the differences
l1  3l 2                       l  l2
mB  mb  L                , m B*  m b  L  1      ,
2m b                           2m b
 From B*-B mass difference, l2 = 0.12 GeV2

        a         L          a 
1  1.54 s  1.65    1  0.87 s 
p                     p 
2
2       5
G F Vcb m B                         mB 
   sl              0.369
192p 3
        L2        l1         l2 
 0.95 2  3.18 2  0.02 2 
        mB        mB         mB 
32
Measurement of sl & moment
analysis
Use total Branching
Ratio Measurement
 CLEO   using lepton tags
(10.490.170.43)%
sl= 65.03.0 ns-1
 (note   LEP 68.61.6 ns-1 )
“Moment Analysis” of
BXln, Mx and El
33
Result for |Vcb| Using Moment
Analysis
 Discrepancy between
El moments
 Theoretical estimates favor
Mx moments
 Taking Mx estimates only:
L    = 0.330.020.08 GeV
 l1=-0.130.010.06 GeV2
 Ligeti claims:
|Vcb| = 0.04150.0012, but      Is this an experimental problem
or an inherent problem in OPE?
it would be foolish to use it                                 34
Vub from lepton endpoint

B & value of
Vub depends
on model,                   Y(4S) data
 bcln 
since fraction               continuum
of leptons in
signal region
depends on
model!

35
Vub from pln and rln

pln  p0ln

bu backrounds
& cross-feeds

rln  r0ln                   bc backrounds
woln
bu backrounds
& cross-feeds

36
New CLEO form-factor
Analysis
Find rln  r0ln woln as function of El using
likelihood method to fit M(pp) & E distributions,
where E = Er+El+|pmiss|-Ebeam
El >2.3 GeV/c
r modes with E cut        r modes with M(pp cut   r modes with both cuts

buln
bkgrd
bcln

M(pp)                            E                     El              37
Form-factor Results

 In general 3 form-factors for
0-  1- transitions, but we do
not have enough precision to
disentangle them
 Data shows the need for more
data
 Combining with older result:

|Vub|=(3.250.14 0.29 0.55)x10-3
+0.21

38
Summary of |Vub| Results
 LEP measurements use 8% theoretical
error as given by Uraltsev. However
Jin’s similar calculation claims a 10%
error but differs by 14%. I use a 14%
theory error here
 Since the LEP Monte-Carlo
calculations are highly correlated, I
take a common 14% systematic
uncertainty
 The exclusive channels rule out the
Korner & Schuler (KS) model (gets
the wrong V/P ratio), but have large
errors
 The CLEO endpoint results have the
best statistical error. Hard to estimate
the theoretical error. I take 14%.
39
CKM Plot

68% c.l.

95% c.l.

From Parodi, Roudeau & Stocchi

 Several authors have done these
 Dominant error in e band is
Vcb                              fits: Mele, (long ago Rosner).
Question: If we find a region well
 1 errors, not to be believed
outside of contour after measuring
 good art?                        angles is SM ruled out?            40
Short Term Perspective

e+e- B factories at Y(4S) will turn on: CLEO III,
BaBar, Belle
Since CLEO III didn’t have an upgrade talk, I
will show you some pictures. Detector
installation is occurring now.

41
CLEO III (not yet shown here)

 Yes Virginia CLEO will continue with symmetric
beams and higher L
 Illustrative lesson: Best CESR Performance
“These are the highest values measured during normal
High Energy Physics running with a beam energy of
5.3 GeV. They did not necessarily occur
simultaneously:
 Peak  luminosity 8.0 x 1032 cm-2/sec
 Best integrated luminosity 40 pb-1 per day, 750 pb-1 per
month, 4.4 fb-1 per year”
42
CLEO II  CLEO III
 Replace everything inside the magnet coil to allow for interaction
region quads to move closer (higher L) and allow for new
particle identification system (RICH)

43
Some CLEO Pictures

44
More CLEO III RICH photos

The Photon Detectors   Mating the Two Cylinders

45
Expected Results from e+e- B
factories
Babar & Belle can & should measure sin(2)
For everything other than CP violation via
mixing CLEO III will be directly competitive
 Rare  decays
 CP violation in rare decays
 Better understanding of Vcb, especially using D*oln
at maximum q2
 Better understanding of Vub using moments and
higher statistics data on exclusive decays
 Lattice calculations may help
46
Short Term Competition

 HERA-b  has the potential to also measure sin(2)
measuring sin(2). Next run will start ~Aug. 2000.
 CDF could also measure xs.

47
Why do b & c decay physics at
 Large  samples of b quarks are available, with the
Fermilab Main Injector, the collider will produce
~4x1011 b hadrons per 107 sec at L = 2x1032 cm-2s-1.
Rates are potentially 5 x larger at LHC.
 e+e- machines operating at the Y(4S) at L of 3x1033
produce 6x107 B’s per 107 s.
 Bs & Lb and other b-flavored hadrons are accessible
for study.
 Charm rates are ~10x larger than the b rate

48
Main detector challenges
 Problems:
 b/tot~ 1/500 at Fermilab, 1/100 at LHC
 Background from b’s can overwhelm “rare” processes
 Large data rate just from b’s - 1 kHz into detector
 Large rates cause Radiation damage to EM calorimeter; photon
multiplicities may obscure signals
 Solutions   for BTeV:
 Use  detached vertices for trigger and background rejection
 Have excellent charged particle identification & lepton id
 Dead-timeless trigger and DAQ system capable of writing kHz
of events to tape
 Use PbWO4 crystal calorimeter                                  49
Fundamental Detector
Principles
Necessary to trigger efficiently on purely
hadronic final states - detached vertex trigger
Necessary to reconstruct final states with
excellent decay time resolution, good efficiency
and mass resolution
Necessary to detect final states with  or po
efficiently with good energy resolution
Necessary to able to identify p/K/p

50
production
The higher momentum     b production peaks at large
b’s are at larger h’s   angles with large bb correlation



h                                        51
Long Term View

 All measurements I have discussed, must be done
 Hadron machines produce enough b’s, & Bs
 We will have LHCb, Atlas, CMS & possibly BTeV
 Atlas & CMS work in central region, they lack the
ability to trigger on purely hadronic final states and the
lack particle id. Atlas also lacks an excellent EM cal
 Although LHCb & BTeV can do all the measurements
that Atlas & CMS can do, there is a class of
measurements involving J/y decays, for which they
can compete
52
The BTeV Detector

Inside the beam pipe

-PbWO4 crystals

53
The C0 Interaction Region

 Construction finished    BTeV is designed to be
compatible

54
The LHCb Detector

55
The BTeV Pixel Detector

 Pixels necessary to
eliminate ambiguity
problems with high track
density; Essential to our
detached vertex trigger
 Crucial for accurate decay
length measurement
 Low noise

56
Pixel Trigger Description

   Triplets used to get space point & mini-vector, called a ‘station hit’
   Station hits are organized
      into f-slices
   Tracks are found in
these f-slices
 full pattern
recognition
is performed
 Minimum track p cuts are applied
   Event level processors then find primary vertices & detached tracks
57
Detached Vertex Trigger

 Level I Trigger uses information from the Pixel
Detector to find the primary vertex and then look for
tracks that are detached from it
 The simulation does the pattern recognition. It uses
hits from MCFast including multiple scattering,
interactions and decays in flight
 Detailed studies of efficiency and rejection for up to an
average of three interactions/crossing

58
BTeV Trigger Performance

 For a requirement of at least 2 tracks detached by more
than 4, BTeV triggers on only 1% of the beam
crossings and achieve the following efficiencies for
these states:

State     efficiency(%)   State    efficiency(%)
B  p+p-        55        Bo  K+p-       54
Bs  DsK        70        Bo  J/y Ks     50
B-  DoK-       60        Bs  J/yK*      69
B-  Ksp-       40        Bo  K*        40

59
Ring Imaging Cherenkov’s

 Both LHCb & BTeV have excellent p/K/p using gas
(C4F10) & possibly also aerogel radiators
 Visible photons detected use phototubes or HPD’s

60
EM calorimeters

 BTeV uses 22 cm long         LHC-b uses a Shaslik
PbWO4 crystals developed      EM cal with scintillating
 20k-40k crystals             There is also a
 Crystals are radiation hard   preshower detector
 Scintillation is fast, 99%   This is very radiation
of light emitted < 100 ns     hard
 BTeV will use phototube
is not in a magnetic field
61
Expected EM Calorimeter
Performance
BTeV                             LHCb
Energy resolution:

E 
1.6%   2
 0.55%
10%  1.5%2
2
E 
2

E                              E
E in (GeV)
Position resolution:

 x (m) 
35002  2202
E
62
Physics Simulations: Some
Lessions
BTeV simulations do have pattern recognition
(except for trigger); smears hits and refits the
tracks using “Kalman Filter,” has multiple
scattering, bremsstrahlung, pair conversions,
hadronic interactions and decays in flight
included
Parameterized shower energy deposits

63
The CP asymmetry in Bop+ p-

   The average decay
distance and the             B momentum
uncertainty in the average
decay distance are
functions of B
momentum:
<L> = 480 m x pB/mB
Decay distance error

64
Bop+ p-: L/ distribution

 L/ = Decay length/error
is very important in
rejecting background
both at trigger level and
in analysis
 Much better in Forward
(BTeV) geometry than
Central geometry
because b’s are moving
faster                        L/
65
Bop+ p- analysis: the importance
of particle identification
   Require that each p be properly identified in the RICH.
Otherwise the measurement is probably impossible.

66
A sample calculation: Bop+p -
BTeV        LHCb
Cross-section                                                  100 µb      500 µb
Luminosity                                                     2x1032      2x1032
# of Bo/Year (107 s)                                          1.4x1011     7x1011
B(Bo p+p-)                                                   0.75x10-5   0.75x10-5
Reconstruction efficiency                                        0.06       0.032
Triggering efficiency (after all other cuts)                     0.50        0.17
# (p+p-)                                                       34,000      28,560
eD2 for flavor tags (K±, l±, same + opposite side jet tags)      0.1          0.1
# of tagged p+p-                                                3,400       2,900
Signal/Background                                                0.6           1
Error in p+p- asymmetry (including bkgrd)                      ±0.023      ±0.019
67
Measuring a Using
Bo r p p+p-po
BTeV        LHCb
B (x10-5)    4           4
efficiency 1.0x10-2     1.7x10-4      BTeV
# found     28,000       2,400
# tagged     2,800         240

 Backgrounds not yet
determined
 BTeV has more than enough
for Dalitz plot analysis

68
xs Reach

Both LHCb & BTeV
have excellent xs
reach using BsDsp-
LHCb gets a 5
signal for ms < 48
ps-1 (xs < 68)

69
Comparisons

Here I compare BTeV with LHCb and with
other experiments that posses the all the
necessary elements for a state of the art heavy
quark experiment:
 Ability  to trigger efficiently on purely hadronic
final states
 Ability to detect final states with  or po efficiently
with good energy resolution
 Ability to identify p/K/p

We are left with e+e- B factories                            70
Comparisons of BTeV
With e+e- B factories
 Number of flavor tagged Bop+ p - (B=0.75x10-5)
L (cm-2s-1)    #Bo/107s e eD2 #tagged
e+e-       3x1033      1nb 3.0x107 0.4 0.4     46
BTeV       2x1032 100b 1.4x1011 0.03 0.1    3400
 Number of B-Do K -
L(cm-2s-1)    #Bo/107s e      #
e+e-        3x1033     1nb 3.0x107 0.5       2
BTeV        2x1032 100b 1.4x1011 0.015    320
Bs , Bc and Lb not done at Y(4S) e+e- machines
 Number of tagged, reconstructed Bo decays to rp is a
factor of at least 10 higher for BTeV.                 71
Comparisons of BTeV
with LHCb
 b 5x larger at LHC, while t is only 1.6x larger
 The mean number of interactions per beam crossing is 3x lower at LHC,
when the FNAL bunch spacing is 132 ns
 LHCb HAS BEEN APPROVED!
   Advantages of BTeV (machine specific)
 The 25 ns bunch spacing at LHC makes 1st level detached vertex
triggering more difficult.
 The 7x larger LHC beam energy causes problems: much larger range of
track momenta that need to be analyzed and large increase in track
multiplicity, which causes triggering and tracking problems
 The long interaction region at FNAL, =30 cm compared with 5 cm at
LHC, somewhat compensates for the larger number of interactions per
crossing, since the interactions are well separated
72
Comparisons with LHCb II

 Advantages    of BTeV (detector specific)
 BTeV   is a two-arm spectrometer (gives 2x advantage)
 BTeV has vertex detector in magnetic field which allows rejection
of high multiple scattering (low p) tracks in the trigger
 BTeV is designed around a pixel vertex detector which has much
less occupancy, and allows for a detached vertex trigger in the first
trigger level.
for accumulation of large samples of rare hadronic decays and
 Important
charm physics.
 Allows BTeV to run with multiple interactions per crossing, L in excess of
2x1032 cm-2 s-1
 BTeV    will have a much better EM calorimeter
73
The Status of BTeV

 BTeV is an approved R&D project at Fermilab, E897,
whose purpose to generate a full proposal for a heavy
quark decay experiment at the Tevatron collider by
May 2000.
 BTeV has submitted a preliminary
technical design report in May of 1999.
 BTeV has been asked to submit a full
proposal in May of 2000.

74
Conclusions

 A complete program to test the Standard Model and
see beyond it requires the measurement of CP
violation and rare decays in the b & c sectors.
 A complete experiment requires:
 large   b rates to measure small B’s & asymmetries in B & Bs
 ability to trigger on purely hadronic final states
 excellent mass & decay time resolution
 ability to identify leptons p/K/p
 ability to use final states with  and po

75
Conclusions II
 Short term
 We will see a statistically significant measurement of sin(2) from e+e- B
factories and CDF, HERA-b
 Perhaps a measurement of xs from CDF
 Beware of fit confidence levels where theoretical errors dominate

 Long term precision measurements of a, , ,  & ambiguity
removals from BTeV & LHC-b with some important contributions
from Atlas & CMS
 Ultimate tests will couple magnitudes l, |Vub/Vcb|, |Vtd/Vts| with the
phase measurements where  is essential
 Moreover, BTeV & LHCb are powerful enough experiments to do
physics beyond that mentioned here which may become much more
interesting in the future, ex: CPT tests                               76

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