# Presentation: 524080

## E2 Snowmass Report

- Convenors:

- Gustavo Burdman, Joel Butler,
- Ian Shipsey & Hitoshi Yamamoto

- Charge: consider the future of low-energy electron-positron
- colliders and evaluate developments needed to make
- incisive instruments practical.

- 3⁄4 of the E2 convenors can hear.
- I am completely deaf, please write down your questions.
- Pass them up to me
- I will read out your question before answering it.

## Low Energy e+e – Colliders: The Physics case

- Radiative corrections. Testing the consistency of the SM requires a variety of measurements for which radiative corrections play a crucial Role. Examples: (I) g-2/2 ,
- (II) electroweak natural relations (Higgs mass bound)

- Flavor physics, B, D, K, & . Does the standard model account for quark mixing & CPV? Measuring the magnitudes and phases of all CKM matrix elements (most remain poorly determined) is a sensitive probe for New Physics. In addition rare (loop) decays probe physics at high mass scales.

- Non-perturbative QCD  is a great challenge to theoretical physics. LHC may uncover strongly coupled sectors in beyond the SM physics.  Critical need: reliable theoretical techniques & detailed data to calibrate them:  ,  spectroscopy, decay constants,form factors provide the data to calibrate QCD now

## Advantages of e+e- colliders

- The quantum #’s of the initial state are known, quantum
- coherence is a powerful tool.

- e+e- annihilation produces clean final states,
- with low backgrounds i.e.favorable S/N.

- Low energy e+e- colliders can reach high luminosity:
- witness the stunning success of PEP-II KEK-B.

##           Scope of the E2 Report 

-           Scope of the E2 Report

- A snapshot of the low-energy e+e- colliders landscape:

- PEP-N

- CLEO-c /CESR-c
-  BEPCII

- Super B factories

- KLOE at
- DAFNE

- 

- -charm

**B**

- CP in K system
- Rare K decays
- new physics

- Flavor Physics: D, 
- New physics
- Precision tests  non-perturbative QCD

- Status: running

- Status: proposed

- Precision R

- Status: proposed

- CP in B system
- New physics

- Status: proposed

**10****9 ****Z**

## Report Methodology:Evaluation of the physics case

- Determine what special detector capabilities are required to achieve
- the scientific goals, What detector R&D issues arise?

- Develop & evaluate the physics case jointly with P2

*For each type of factory**:*

- Identify the outstanding questions that heavy-flavor factories address

- Evaluate the contributions from existing and potential experiments
- using other instruments.

- Critically assess the competitive advantages and disadvantages
- of e+e- colliders

- Outline a comprehensive experimental program and estimate the
- integrated luminosity required to carry it out.

##  Factory Physics

- Measurement to test CP and CPT violation with K ( Double Ratio, Interferometry)
-  requires 1010 KLKS
- Rare K decays
- Measurement of interest for ChPT:
- (K Semileptonic Decays &
- Kl4, /’ mixing , K  3... )
-  Measurement of )  at low energy :
-  important  for g-2
-   radiative decays   (f0, a0, , ’ )

-  Factory Physics

- Focus
- on
- these

- DANE:  symmetric e+e- Ebeam= 510 MeV
- Target Luminosity 5 x 1032 cm –2s  -1
- Current Luminosty 2.5 x 1031 cm –2s  -1  (x 20 low)

- Luminosity arrow(pb-1)

- 5000
- 1000
-   100
-     20

- today

- 12/01

**Notes:**
Kloe makes  1e^ KLKs per pb^-1  so for 2000 pb^-1 expect 2e9 KlKs

## DANE 

- DANE

- Two independent machines
- intersection at  25 mrad

- Bunch length       3  cm
- Horizontal size    2  mm
- Vertical size    0.02 mm

-  Working condition now :
-           800 mA stored into  50 e+/e-  bunches
-   Delivered Luminosity :  1.3 pb-1 per day (sustained)

- 2000: 30 pb-1
- 2001: 55 pb-1 18/7
-           200pb-1 by end of year

**Notes:**
16 — 29 Apr  L dt  = 11.3 pb-1  ~900 nb-1/day
Resumed in June 1.3 pb-1 /day From Bloise talk.

## The KLOE Detector

- d=4m

- DC He gas, minimize MS &
- KL regeneration
- EMC: Pb/SciFi

**Notes:**
Here is the KLOE detector it consists of a large drift chamber with helium to minimize Multiple Scattering 
and Klong regeneration and an lead scintialtiing fibre calorimeter with excellent energy resolution
Down to 20 MeV.  

## CPV in the K system ’/ comparision  Factory to Fixed Target

- At a  factory  double
- ratio and interferometric
- methods are complementary
- to fixed target appraach.
- KLOE goal ’/ to ~2 x10-4
- BUT Hadronic uncertainities
- dominate measurements of ’/

- (5000 pb-1)

**Notes:**
When a phi meson decays into two neutral kaons the C-parity invariance forces the two kaons to be in a KS KL state. 

## Rare K Decays comparision of  Factory to Fixed Target

- Rare K Decays comparision of  Factory to Fixed Target

- The important measurements
- in Kaon physics are now rare
- Decays: B(K++ )~9 x 10-11
- B(KL0) ~3 x 10-11
- Measurements driven by
- high flux

- KLOE

-  factories have unique &
- desirable features but unlikely
- to provide enough flux to
- challenge hadron machines for
-  K 
- Few year window for KLOE to
- push KL0 sensitivity into a
- region where new physics may
- be observed

- Kopio
- /KAMI+

- KAMI+

- KAMI+

- +KAMI not
- approved

## PEP-N Physics

- Proposed novel extension to PEP-II e+e- at 1.2  3.1 GeV
- Broad range of physics:
- R measurement
- evolution of EM
- hadronic contribution to g-2
- Nucleon form factors
- Other baryon form factors
- Meson form factors
- Vector meson spectroscopy
- Multihadron channels
- * interactions

- Focus on
- this

- e+

- e-

- *

- h
- a
- r
- d
- o
- n
- s

- Hadron loop

- Hadronic vacuum
- polarization:

## Importance of R #1: Precision Electroweak Measurements/Fits

- Evolution of  EM

- PEP-N

- CMD2, KLOE

- CLEO-c
- BESIII

- had(5):

- R

- S

- The SM can be defined by GF Mz EM(Mz2). The latter is
- the least well known and limits accurate prediction of MHiggs

- 1 < s < 3 GeV crucial, goal: R2%
-                        reduces had(5) x2

- CLEO

**Notes:**
Equations from Mandekerns’ talk, statement that 1-3 GeV region is crucial  page 134 CLEO-c book 
The reduction in had unceratinty by x2  this claim is fromrCLEO using rad returns 1-3 at 5% 
Plus s 3-7 at 2 % not consistent with Mandelkern number where a significant portion of error
is above the Upsilon which is inconsistent with Figure from Burkhard and Petrzyk 
which uses experiment only.  

## Importance of R #1: Precision Electroweak Measurements/Fits

- had limits precision
- on extraction of
- sin2w & hence
- constraint on MH MH ~30 GeV
- PEP-N  R2% improves
- Constraint MH ~10 GeV
- Giga-Z goal x10 (sin2w)
- requires had~ 5 x 10-5
- R1% MH ~4 GeV

- Pre (& post Higgs discovery)
- constant improvement in R is
- a goal of low energy
- e+e- colliders

**Notes:**
The error in delta_alpha_had limits the precision with which we can extract sin^2theta_W from experiment, therefore limiting our ability 
to constrain the Higgs mass (and/or new physics).
For instance, to achieve the GigaZ goal of a factor of ten improvement in sin^2theta_W, we 
need delta_alpha_had known with an error of about 5x10^-5. This, in turn, requires 
an error in R of the order of 1% all the way up to the upsilon, but especially in the low energy region. 
Note the estimate of 30 GeV error on Higgs mass comes from Marciano’s talk for current value
Of SLD A_LR, the 10 GeV error on Higgs comes from Mandelkern talk this improvemnst comes fomr
PEP-N neasurement only

## Importance of R #2

- Testing the consistency of the SM requires a variety of
- Measurements for which radiative corrections play a crucial
- Role. Example: g-2/2

- Hadronic vacuum polarization cannot
- be calculated from 1st principles: phenomenolgical models (QCD + ) combined with R. Bulk of error  comes from s < 2.5 GeV

- SUSY

- Current errors:= { 3       4         62}x10-11

-                                                2.6   New physics?
- Final goal of expt ±40 x 10-11 _reduce SM error by 50%, _
- _rely on e+e- data only: R ____ ~2% 2m____<____s<2.5 GeV_

**Notes:**
Errors on calculation of alpha_u came from Marician and Mandekern talks the
Cenatrl expt value from E821 webpage and talks by Gray and Phemom 2001 and Hughes CERN seminar 
For the BNL expt is correct the Mandeljern number appears to be incorrect,
Note 62  67 total error because of additioanl diagrams 2nd order vacuum polarization (small) and 
A diagram for three gluons
The 62 is dominated  by data below 1.8 and is weighted by 1/s^2
The new results using only data e+e- (no Tau decay no PQCD)
according to PEP-N are that <1.4 has an error of 29 ppm (new Novosibirsk),
1.4—2.5  is 40 ppm  Diego >2.5 4623 

## PEP-N Collider

## PEP-N Collider

- _PEP-N Collider_

- e- energy: variable 0.1 to 0.8 GeV at < 80 mA
- e+ energy: fixed 3.1 GeV at 2140 mA (from LER)
- Luminosity: 1031 at 0.8 GeV e-

- low E beam of PEPII
- Parasitic non-interfering
- running with
- Babar

- VLER: **new** e- ring
-  0.1 to 0.8 GeV

- PEP II LER

## PEP-N Detector

- _PEP-N Detector_

-  cm = 0.8
- event rate: < 1 Hz
-  Low p tracks: He TPC
-  magnet: 0.1-0.3 T vertical B field (must NOT disturb LER and HER)
- Pb/sci.fi  EM calorimeter excellent E/E, t/t
-  n, nbar, : Fe/Scint Had cal

-  requirements for R:
-  hermetic detector,
-  reconstruct complete event

- Detector similar to KLOE,
- no new technology: entirely
- feasible

## Proposed PEP-N Schedule

- Summer 2002    PEP-N Proposal approved
- Summer 2003    Injector gun, linac and
-                            transport lines installed LER and HER  mods
- October 2003    First injector beam tests
- Summer 2004   VLER ring installed
-                           Detector magnet & Detector installed
- October 2004    First VLER injected beam tests
- January 2005    First collisions

## E2 Conclusion on PEP-N

- The determination of R in this energy range is of particular
- importance, and is timely.Rstat is negligible, however no clear
- demonstration that Rsys to 2% (dominated by acceptance) is
-  achievable. Studies stimulated by Snowmass are ongoing: ex:

- A CLEO-c 10 9 J/ run  precision determination of J/ br’s.  Useful for PEP-N precision determination of acceptance.

- Detector design, based on KLOE, although still evolving
- is sound and involves no new technology

- Collaboration ~65 people is small, more members are sought. LOI review 9/01. 1st data 2005?

- Conclude:The physics program of PEP-N is well defined,
- important and unique and can be accomplished in 5 years. Control of systematic errors needs to be evaluated.

## CLEO-c

- Now that the asymmetric B factories have achieved high luminosity, CLEO proposes to focus on measurements in the 3.5-5.0 GeV region, including
- Charm Decay constants fD, fDs
- Charm Absolute Branching Fractions
- Semileptonic form factors
- Vcd & Vcs
- QCD studies including
**Charmonium and bottomonium spectroscopy **
**Glueball and exotic searches**
**Measurement of R between 3 and 5 GeV, via scans**
**Measurement of R between 1 and 3 GeV, via ISR**
- Search for new physics via charm mixing, CP violation and rare decays
- decay physics

## CLEO Run Plan

- 2002: Prologue: Upsilons ~1-2 fb-1 each at Y(1S),Y(2S),Y(3S),...
-           Spectroscopy, matrix element, ee, B  hb
-           10-20 times the existing world’s data

- 2003: (3770) – 3 fb-1
-           30 million events, 6 million *tagged* D decays
-           (310 times MARK III)

- 2004:                            – 3 fb-1
-           1.5 million DsDs events, 0.3 million *tagged* Ds decays
-          (480 times MARK III, 130 times BES)

- 2005: (3100), 1 fb-1 (3686)
- –1 Billion J/ decays
-           (170 times MARK III, 20 times BES II)

**C**
**L**
**E**
**O**
**-**
**c**

- A 3 year
- program

## Advantages of Running on Threshold Resonances

- Charm events produced at threshold are extremely clean
- Double tag events are pristine
- These events are key to making absolute branching fraction measurements
- Signal/Background is optimum at threshold
- Neutrino reconstruction is clean
- Quantum coherence aids D mixing and CP violation studies

## CLEO III Detector = CLEO-c Detector 

- 1.5 T now,... 1.0T later

- 93% of 4
- p/p = 0.35% @1GeV
- dE/dx: 5.7%  @minI

- 93% of 4
- E/E = 2% @1GeV
-          = 4% @100MeV

- 83% of 4
- % Kaon ID with
- 0.2%  fake @0.9GeV

- 85% of 4
- For p>1 GeV

- Trigger: Tracks & Showers
- Pipelined
- Latency = 2.5s

- Data Acquisition:
- Event size = 25kB
- Thruput < 6MB/s

- CLEO III Detector = CLEO-c Detector

## 1st results from CLEO III datafor LEPPHO 2001

- Yield           BR(BK)(x10-6)
- BK CLEOIII  CLEO(1999)

-                     (Preliminary)
- Good agreement: CLEOIII:II/II.V

## Modifications and Issues

**The CLEO-III Detector**
**Silicon vertex detector may be replaced with wire vertex chamber**
**Lower solenoid field strength to 1 T from 1.5 T (machine issues)**
**The dE/dx and Ring Imaging Cerenkov counters are expected to work well over the CLEO-c momentum range**
**Electromagnetic calorimeter works well and has fewer photons to deal with**
**Triggers will work as before**
**Minor upgrades may be required of Data Acquisition system to handle peak data transfer rates**
**CESR conversion to CESR-c will be discussed in summary talk of working group M2  (next speaker)**

- CLEO-III works well
- in this energy range and at these rates with little modification

## Tagging Techniques Signal Purity

- D mesons have many large Br’s (~1-15%) with high reconstruction eff. Tagging efficiency
- based on several
- modes is 20%.
- S/B = 5000/1!

- ~ Zero background in hadronic tag modes
- *Measure Br (D X) by
-  Br = # of X/# of D tags
- # of D's is well determined

- Single
- Tag

- Double
- Tag

## Example: Ds+  

- Example: Ds+  

- Fully reconstruct one D
- Require one additional charged track and no additional photons
- Compute MM2 Peaks at zero for Ds+   decay.
- No need to identify muon-helps systematic error
- Can identify electrons to check background level
- Expect resolution of ~Mo

- 2

- Ds  

- (Now: ±35%)

## CLEO-c Charm Decay Measurements

| Topic | Reaction | Energy
MeV | L
fb-1 | Current
Sensitivity | CLEO-c
Sensitivity |
| --- | --- | --- | --- | --- | --- |
| Decay Constant: |  |  |  |  |  |
|  |  | 3770 | 3 | UL | 2.3% |
|  |  | 4140 | 3 | 35% | 1.7% |
|  |  | 4140 | 3 | 60% | 1.6% |
| Absolute Branching fractions: |  |  |  |  |  |
|  |  | 3770 | 3 | 2.4% | 0.6% |
|  |  | 3770 | 3 | 7.2% | 0.7% |
|  |  | 4140 | 3 | 25% | 1.9% |
|  |  | 4600 | 1 | 26% | 4% |

## Absolute Branching Ratios

- B(D0 K-+)%

- B(Ds 

- B(D+  K- ++)%

- CLEO
- ALEPH
- PDG
- CLEO-c

- CLEO
- MARK III
- PDG
- CLEO-c

- CLEO
- PDG
- CLEO-c

*CLEO-c sets absolute *
*scale for all heavy *
*quark *
*measurements*

## Semileptonic Decay Reconstruction   

**Semileptonic Decay Reconstruction   **

**Tagged events: identify electron plus hadronic tracks ( muons not used)**
**Kinematics at threshold cleanly separates signal from background  **
**Use                                           to separate signal from background**

- 1.0 fb-1

- Excellent separation of  **D********l********  D********kl********  despite B(D********kl******** )~10B( D********l********) **

- 25890

- 3730

## CLEO-C Impact on dB/B

- CLEO-c

- PDG

## A Selection of Other Key CLEO-c Physics

| Semi-lep-tonic Decays | Reaction | Energy
MeV | L
fb-1 | Current
Sensitivity | CLEO-c
Sensitivity |
| --- | --- | --- | --- | --- | --- |
| Vcs |  | 3770 | 3 | 16% | 1.6% |
| Vcd |  | 3770 | 3 | 7% | 1.7% |

| Mode | CLEO-c | BES-II
projected |
| --- | --- | --- |
| #J/ | 109 | 50x106 |
|  | 23,000 | 462 |
|  | 13,000 | 115 |

- On ’, can do charmonium
- Spectroscopy, e.g.: 1P1,c’

- New Physics in D decays:
- Mixing:
- CP violation: ~1%
- Rare Decays: many modes
-         with UL~1-10x10-6

## Comparison with BABAR & BES

| Quantity | CLEO-c | BaBar |
| --- | --- | --- |
|  | 2.3% | 10-20% |
|  | 1.7% | 5-10% |
|  | 0.7% | 3-5% |
|  | 1.9% | 5-10% |
|  | 1.3% | 3% |
|  | 6.0% | 5-15% |

| Quantity | CLEO-c | BES-II |
| --- | --- | --- |
| #J/ | 109 | 5x107 |
| ’ | 108 | 3.9x106 |
| 4.14 GeV | 1fb-1 | 23 pb-1 |
| 3-5 R
Scan | 2% | 6.6% |

**BEPC-II /BES-III a proposed double ring machine L = 2 x 10 ****33  ****(x10 CESR-c) to come online in ~2005 - if approved. Will make an important contribution as data improves and theory sharpens**

## CLEO-c

-   3 fb-1

-   BaBar
-   400 fb-1

- Current

** ****(****not in %)**

- fD

- Comparison between B factories
-  & CLEO-C

## Crucial Validation of Lattice QCD: Lattice QCD will be able to  calculate with accuracies of 1-2%. The CLEO-c decay constant and semileptonic  data will provide a “golden,” and timely test. QCD and charmonium data provide additional benchmarks.
Knowledge of absolute charm branching fractions is now contributing significant errors to measurements involving b’s. CLEO-c can also resolve this problem in a timely fashion
Improved Knowledge of CKM elements, which is now not very good. 

- _Knowledge of absolute charm branching fractions_ is now contributing significant errors to measurements involving b’s. CLEO-c can also resolve this problem in a timely fashion
- _Improved Knowledge of CKM elements_, which is now not very good.

- CLEO-c Physics Impact

- The potential to observe _new forms of matter_ – glueballs, hybrids, etc         –_and new physics_- charm mixing, CP violation, and rare decays      provides a discovery component to the program

| Vcd | Vcs | Vcb | Vub | Vtd | Vts |
| --- | --- | --- | --- | --- | --- |
|  7% | 16% | 5% | 25% | 36% | 39% |
| 1.7% | 1.6% | 3% |   5% |  5% | 5% |

- CLEO-c
- data and
**LQCD**

**CLEO-c**
**Lattice**
**Validation**

**Notes:**
We have seen that with CLEO-c combined with the B factories data that the magnitude of CKM matrix elements can be greatly improved. Reasonable now to ask is that the best one can do? What is the ultimate precision?

## B Physics 

- The unitarity triangle construction summarizes a set of overconstrained measurements of the quark sector of  the Standard Model

- What are the ultimate experimental and theoretical limits on
- the precision of such tests?
- If new phenomena are found at LHC/LC..... can precision heavy quark (or **) physics help elucidate the situation?

- Goal:
- I. measure the sides and angles of the unitarity triangle inconsistency 
- New Physics
- II.Search for rare decays to the theory limit 
- New Physics

## Models that may modify the Unitarity Triangle

- Supersymmetry
- 43 phases, 80 constants
- MSSM - with or without new flavor structure
- Strongly coupled EW sector
- Fourth generation
- Flavor changing *Z**0* couplings
- Multi-Higgs doublet models
- Left-right symmetric models
- Extra *d*-type singlet quarks
- Non-commutative geometry
- Extra dimensions
- + many more
- There is a substantial literature on how these models could change the observed pattern of *CP* asymmetries, modify rare decay rates and angular distributions, *etc.*

## B physics Experiments Running, Planned & Proposed

- E2 goal compare physics reach of running & planned facilities to proposed facilities

- There are three new proposed facilities: Giga-Z  at the LC and Super B factories at KEK & SLAC. How do they compare to the the planned and existing facilities?

- Method: (I) benchmark modes ex: sin2,
- (II) particular strengths

|  | e+e- (2001) | e+e- (2005) | BTeV/LHC-b /107 s |
| --- | --- | --- | --- |
| sin2 | 0.14 | 0.037 | 0.014/0.02   |

- e+e- : =1nb Babar/Belle
-  500 fb-1 = 1x 109 B (cumulative) 2005
- B+ B0 only at Y(4S)

- Hadronic: = 100/500 b      BTeV/LHC-b
- (~2007) (2-10)x1011 B/ 107s
-  B+ B0 Bs Bc b

## Giga-Z at LC as a B Factory

- LEP/SLC made significant contributions to B physics
- The LC may run at the Z0 pole: Br(Z  bb) =15%
- @ L = 5 x 1033  50 days for 109 Z
- 109 Z   3 x 108  B’s possible within normal LC running
- 1010 Z  3 x 109 B’s 150 days/yr 3-5 yrs: dedicated facility

- Two
- options

- Comparison to existing e+e- B fac:
- Comparable statistics
- Large boost: separation of two B’s
- & better decay length resolution
- Large AFB with polarized beams
- good initial state charge tagging
- All B flavors produced B+ B0 Bs /\b

- Comparison to LHC-b/BTeV
- Much lower B rate
- But: all B’s triggered &
- reconstructed
- Clean environment

**Notes:**
LEP had 4 million hadron Z (Rb = 0.22) so 8e5 bb or 1.6e6 b 

## Giga-Z as a B Factory

- Paucity of Giga-Z specific studies, mainly repetiton
- of B-factory/BTeV

- Particular strengths of Giga-Z:

- bs probes new physics (best U.L:ALEPH) Giga-Z  br/br ~4% at **10****9 ****Z** (~10 evts at e+e-), not possible @ BTeV/LHC-b

- Bs mixing xs ~ 60 (109 Z)
- resolution limit xs ~120
- hadron machines xs ~80

- polarized /\b (unique)
- tests chirality of bs: b
- Also possible at BTeV/LHC-b

- Conclusion: Giga Z strengths need careful assessment, (ongoing)
- 3-5 yrs for Giga-Z = 1 yr BTeV/LHC-b sin2 precision

|  | e+e- (2005) | BTeV/LHC-b /107 s | 109 Z | 1010 Z (3-5 yrs) |
| --- | --- | --- | --- | --- |
| sin2 | 0.037 | 0.014/0.02 | 0.04 | 0.013 |

**Notes:**
Superior time resolution

## e+e-  Super B factories (SBF)

- John seem

- History: Workshop on Super
-  B Factories “Beyond 1034”
- June 2000  Michigan
- _[http://www.physics.purdue.edu/10E34](http://www.physics.purdue.edu/10E34)_/
- Calls for: (3 x1035 – 3 x 1036) cm–2s-1

- Follow up session on Super B factories at BCP4 Japan 2/01 : ~1036
*http://www.hepl.phys.nagoya-u.ac.jp/public/bcp4/*

*SUPERBABAR* working group formed 5/01, lead by D. Hitlin
- nucleus of E2 SBF subgroup at Snowmass.
- http://fermi.phys.uc.edu/HyperNews/get/forums/SuperBABAR.html

## e+e-  Super B factories (SBF)

- Plans at  KEK : SUPERKEKB L= 1 x 10 35  (Oide/Ohnishi)
- Several options understudy: upgrade existing machine
- or new machine both in asymmetric format

|  | KEKB
2001 | KEKB2005 | PEPII
2001 | PEPII
2005 | SUPERKEKB | SUPER
BABAR |
| --- | --- | --- | --- | --- | --- | --- |
| Lx1033 | 4.1 | 10 | 3. | 10 | 100 | 1000 |
| #B’s/107s | 8.2 x  107 | 2 x 108 | 6 x 107 | 2 x 108 | 2 x 109 | 2 x 1010 |

- Plans at SLAC SUPERBABAR  L = 1 x 10 36  cm –2 s –1 (Seeman)
- Preliminary studies indicate it may be
- possible to build an e+e- asymmetric collider in PEPII tunnel
- or using SLC arcs
- (See summary talk from M2 for details of both machines)

**Notes:**
10^36 for 10^7 s =  10ab_1 = 10,000 fb^-1 
10^33  for 10^7 s = 10 fb^-1 10^7 BB
10^34 for 10^7 s =100 fb^-1 = 10^8 BB
(so the above number assume that in 2005 PEP-II and KEKB have got to 10^34, 

## Comparison of BTeV and SuperBABAR @ 1036

- 36

- 10

- 3600

- 36

- 10

- 600

- Comparison of *B*TeV and Super*BABAR* @ 1036

- At 1036  # B0  B+ reconstructed in interesting modes
-  is about the same for e+e- and BTeV

- L

- L

## CKM  Reach super B factories & hadron facilities

|  | BTeV
107 s
 | LHC-b
107 s
 | BABAR
BELLE (2005) | 1035
107 s | 1036
107 s
 |  |
| --- | --- | --- | --- | --- | --- | --- |
| sin2 | 0.011 | 0.02 | 0.037 | 0.026 | 0.008 | Equal |
| Sin2”” | 0.05  | 0.05 | 0.14 | 0.1 | 0.032 | Equal |
|  Bs(DsK) | ~70 |  |  |  |  | Had |
|  B(DK) | ~2o |  |   ~200 |  | 1-2.5o | Equal |
| Sin2 |  0.023 |   0.04 |       -- |    -- |   -- | Had |
| Br(B 0 0)  |    -- |     -- |  ~20% | 14% | 6% | e+e- |
| Vub  |    -- |     -- |  ~2.3% |  ~1% (sys) | ~1%
(sys) | e+e- |

- (Table compiled by SBF E2 subgroup & E2 convenors)

**SBF numbers based on BABAR experience need simulations to estimate signal **
**efficiencies & bkgds so that the comparison to BTeV/LHC-b is on an equal footing**

## Rare B decay Reach super B fac. & hadron facilities

- All numbers are per
- year except current
- B factories (cumulative
- Through 2005)
- Best measurement

- Greater reach?
- Hadronic: B
- e+e-: s, , ,K*

- Including additional rare
- b and Bs modes not in
- Table
- 1035 reach < BTeV/LHCb
- 1036 reach ~ BTeV/LHCb

- (Table compiled by
- SBF E2 subgroup
- & E2 convenors)

- 7.2K/-

- 4.4 k /4.5k

- 10/11
- 2/2

## Technical Challenges

- A

- At 1036 short beam lifetime requires continuous injection.
- Loss rates  x1000 greater than at present
- However sensitivity to lost particles depends on lattice,IR design & detector design
- It is important to perform  simulations with a realistic IR and lattice a.s.a.p.
- Simple scaling from BABAR experience has been used to estimate doses and to develop the following detector conceptual design:

**     ****BABAR               SUPERBABAR         reason for change**
**     ****Silicon                   Si pixels                         occupancy**
**     ****Drift Chamber     Si tracker (or TPC)  accumulated charge**
**     ****DIRC                    superDIRC               remove water standoff box**
**     ****ECAL CsI(Tl)      LSO                          long decay time not rad hard**
**     ****IFR (K ****L****0 ********)          IFR’                          RPC’s******** sci fi (occupancy)**

**Notes:**
LSO = Lutecium sp?

## A compact, high field detector for 1036

**SVT  2 Ly pixel**
**3 Layer Si strip**

**4 Layer Si **
**Strip tracker**

**Compact DIRC**

**LSO EMC**

**3T Coil**

**IFR Fe + **
**scint. fibers**

- G. Eigen

## Conclusions I

-  factories have unique & desirable features but unlikely to provide enough flux to challenge hadron machines for K 

- PEP-N : The physics program is well defined,important &
- unique and can be accomplished in 5 years. Control of
- systematic errors for R needs to be evaluated.

- CLEO-c : x400 increase in D data at threshold.
-    Crucial validation of  Lattice QCD, HQET, ChPTHH, ...
-    A factor 4-12 improvement in key abs. branching fractions
-    Significant improvement in CKM element precision (x 5-10)              c sector (x2-8 ) in b sector (in conjunction with B expts.)
-    Discovery potential :
-    new physics: D mixing & CPV rare D,  decays
-    new forms of matter (glueballs/hybrids)
- accelerator, detector & collaboration in place: 3 year program

## Conclusions II 

- Giga Z strengths: b polarization, xs reach, rare decays with
- , , 0,Vub. Needs careful assessment, (ongoing).
- 3-5 yrs at Giga-Z = 1 year BTeV/LHC-b sin2 precision

- 1035 e+e- B factory : strengths rare decays with ’s , 0 Vub
- 3 yrs  at 1035 = 1 year BTeV/LHC-b sin2 precision

- 1036 e+e- B factory: At 300x current luminosity and assuming detector efficiency can be maintained, would be complementary to LHC-b/BTeV for rare decays, superior for decays with ’s , 0 & Vub, comparable for , , , but not .  Limited Bs and no Bc & b  compared to LHCb and BTeV.
- Implement Lattice/IR designs a.s.a.p. for detailed background
- studies, especially background due to continuous injection. If backgrounds prove tractable an R&D program on the
- machine & detector should be initiated.

## Contributors to E2

- Marina Artuso, Diego Bettoni, Caterina Bloise,Gustavo
- Burdman, Joel Butler, David Cassel, Roberto Calabrese, Franz-Josef Decker, Steve  Dytman, Gerald Eigen, Lawrence Gibbons, Andrei Gritsan, Gudrun Hiller, David Hitlin, Will Johns, Dan Kaplan, Penelope Kasper, Nobu  Katayama, Peter Kim, Rob Kutschke, Jik Lee, David Leith, Xinchou Lou, Mike Luke, Paul Mackenzie, Mark Mandelkern, Yuri Maravin, Bill Marciano,  Klaus Moenig, Yukiyoshi Ohnishi,  Yosuhiro Okada, Sibylle Petrak, Stephen Pordes, Ron Ray, Steven Robertson, Aaron  Roodman,  John Seeman, Tanaji Sen, Ian Shipsey, Abi Soffer, Sheldon Stone, Hitoshi Yamamoto, Zhenguo Zhao.
- Work is ongoing. Results of studies will be included in final
- report.