# Presentation: 359834

## Status and Physics Opportunities with BABAR

***Status and Physics Opportunities with BABAR***

***David B. MacFarlane******SLAC***
***Representing the BABAR Collaboration***

## Pillars of BABAR physics program

***Highly constrained and redundant set of precision tests of weak interactions in the Standard Model***
***Searches for physics beyond the Standard Model in a well understood & characterized environment***

**Sensitivity to New Physics at LHC mass scales through rare decays and *****CP***** violation**
**Discovery potential from large data sample across a whole range of beauty, charm, tau, two-photon, ISR physics**

**Full program of flavor physics/CP violation measurements will provide a legacy of fundamental constraints on future New Physics discoveries**

**Challenging measurements at the edge of sensitivity benefit enormously from operation of both PEP-II & KEK B Factories **

- Feb 24, 2006

**The *****BABAR***** Collaboration**
- 11 Countries
-    80 Institutions
- 623 Physicists

- Feb 24, 2006

## Integrated data sample to date

***Integrated data sample to date***

- Feb 24, 2006

## PEP-II overall parameters and goals

| Parameter | Units | Design | Oct 2005 |
| --- | --- | --- | --- |
| I+ | mA | 2140 | 2940 |
| I- | mA | 750 | 1740 |
| Number of bunches |  | 1658 | 1732 |
| y* | mm | 15-20 | 11 |
| Bunch length | mm | 15 | 11-12 |
| y |  | 0.03 | 0.044-0.065 |
| Luminosity | x1033 | 3.0 | 10.0 |
| Int lumi / day | pb-1 | 130 | 727.8 |

***PEP-II overall parameters and goals***

- Feb 24, 2006

## A day in the life of a B Factory

- Feb 24, 2006

## PEP-II overall parameters and goals

| Parameter | Units | Design | Oct 2005 | 2007 goal |
| --- | --- | --- | --- | --- |
| I+ | mA | 2140 | 2940 | 4000 |
| I- | mA | 750 | 1740 | 2200 |
| Number of bunches |  | 1658 | 1732 | 1732 |
| y* | mm | 15-20 | 11 | 8-8.5 |
| Bunch length | mm | 15 | 11-12 | 8.5-9 |
| y |  | 0.03 | 0.044-0.065 | 0.054-0.07 |
| Luminosity | x1033 | 3.0 | 10.0 | 20 |
| Int lumi / day | pb-1 | 130 | 727.8 | 1300 |

***PEP-II overall parameters and goals***

- Feb 24, 2006

## Projected data sample growth

***Projected data sample growth***

**Integrated Luminosity [fb****-1****]**

**12**

**17**

**20**

***L*****peak**** = 9x10****33**

- Feb 24, 2006

## Prepared for higher peak luminosity

***Prepared for higher peak luminosity***

**DIRC ********PID)**
- 144 quartz bars
- 11000 PMs

**1.5T**** solenoid**

**EMC**
- 6580 CsI(Tl) crystals

**D****rift ****C****hamber**
- 40  layers

**I****nstrumented ****F****lux ****R****eturn**
- Iron / Resistive Plate Chambers or Limited Streamer Tubes  (muon / neutral hadrons)

**S****ilicon ****V****ertex ****T****racker**
- 5 layers, double sided strips

- e (3.1GeV)

- e (9GeV)

**Background conditions reliably extrapolated based on beam currents & luminosity**

**All other systems fully capable of highest luminosities**

- Feb 24, 2006

## DCH electronics upgrade

***Phase 1 (Summer 2004)***
- Ship only 1/2 waveform information (3216 bytes)  from frontends
- 4.2% hit loss due to subtle DAQ error discovered at end of July & now repaired
***Phase 2 (Oct 2005) ***
- Larger FPGA for feature extraction before transmission
- New boards installed during Oct

**Chris O'Grady, Matt Weaver, Ryan Herbst, Jinlong Zhang, Karl Bouldin, Mike Kelsey**

**Endplate FEX extraction code now in production **

- Feb 24, 2006

## IFR upgrade with LSTs

**Bottom & top sextants installed summer 2004**
**Remaining sextants delayed until summer 2006**

- Feb 24, 2006

## Impact on physics performance

- Feb 24, 2006

## BABAR & Belle physics results

***BABAR & Belle physics results***

|  | BABAR | Belle |
| --- | --- | --- |
| Journal Papers | 187 | 160 |

- Feb 24, 2006

## Weak Interaction in Standard Model

**Unitarity Triangle as a summary of Standard Model *****b***** physics**

- Feb 24, 2006

## Classic indirect constraints

**2008: ~5%**

- Feb 24, 2006

## Weak Interaction in Standard Model

**Unitarity Triangle as a summary of Standard Model *****b***** physics**

**CKM elements & quark masses are fundamental constants emerging from EW symmetry breaking**

- Feb 24, 2006

## CP violation in B decays

**CPV through interference of decay amplitudes**

- Feb 24, 2006

## CP Violation in the B System

***CP Violation ******in the B System***

**CPV through interference between mixing and decay amplitudes**

**Directly related to CKM angles for single decay amplitude**

- Feb 24, 2006

## CPV in charmonium modes

**Interference of *****b***** ******** *****c***** tree decay with mixing**

***CPV in charmonium modes***

- Feb 24, 2006

## Measuring time-dependent CP asymmetries

***Measuring time-dependent CP asymmetries***

- Tagging performance: Q = 30.5%

- Feb 24, 2006

## sin2 results from charmonium modes

***sin2************ results from charmonium modes***

*BABAR PUB-04/038*

**Update for ICHEP04**

***B******A******B******AR***

***B******A******B******AR***

- Feb 24, 2006

## Evolution of sin2 measurements

**Present CKM fit**

**Present WA**

- Feb 24, 2006

## CPV in charmless modes

**Interference of suppressed **
***b***** ******** *****u***** tree decay with mixing**

***CPV in charmless modes***

- Feb 24, 2006

## Consistency of CP results for B  ππ

***Consistency of CP results for B ************ ******ππ***

**Belle observes significant direct *****CP***** violation in this mode while BABAR result is consistent with no *****CP***** violation**

- Feb 24, 2006

## Method not too promising for 

- Feb 24, 2006

## Recent breakthrough: B   decays

- Feb 24, 2006

## Summary of constraints on 

***Summary of constraints on *********

- Mirror solutions disfavored

***BABAR only***

**A good example of new analysis ideas emerging with data in hand**

- Feb 24, 2006

## Projections for  measurement

**Projection**
**2 ab**

**3 scenarios **
**for ***********************************BF***
**Expected value**
** ******
** ******

**With a 1 ab****-1**** sample:**
**Will improve errors on *****S***** and *****C***** from *****B***** ******** ********
**Should observe *****B***** ******** ***************************** ***
**Confirm that “mirror solution” in *****B***** ******** ********** is disfavored by Dalitz analysis in *****B***** ******** ***********π***

- Feb 24, 2006

## Remarkably good progress on gamma!

**Interference of color-allowed and color-suppressed tree decays**

**“****GLW”,”ADS”,”GGSW”**

- Feb 24, 2006

## Dalitz plot analysis for gamma

**Idea: Increase *****B***** decay interference through *****D***** decay Dalitz plot**** **

**Another example of new analysis ideas emerging with data in hand**

**Method first shown by Belle**

- Feb 24, 2006

## Projections for  measurement

**Luminosity             (ab****-1****)**

** ****GGSZ **
** ****GGSZ + GLW **
** ****GGSZ + GLW + ADS**

** ****r****B**** = 0.1**

**projected systematic error**

**Error as a function of r****B**

**Example of impact of value for r****B**** on the error on **********, using the GGSZ****method in BABAR**

**Error as a function of integrated luminosity for r****B****=0.1**

**Error on ********  (deg)**

- Feb 24, 2006

## Direct CP violation measurements

**2008: ~2%**

**2008: 10****o**

**2008: 5-10****o**

- Feb 24, 2006

## Summary of UT triangle constraints

***Summary of UT triangle constraints***

**Paradigm change!**

**Now: looking for New Physics as correction to CKM**

- Feb 24, 2006

## Direct & indirect measurements

***Direct & indirect measurements***

**Overconstrained: growing set of independent measurements are consistent with CKM picture**

- Feb 24, 2006

## Angle measurements only

***Angle measurements only***

**New *****B***** Factory milestone: Comparable UT precision from *****CPV***** in *****B***** decays alone**

**Overconstrained: subsets of measurements can be used to test for new physics**

- Feb 24, 2006

## CPV in Penguin Modes

**Interference of suppressed **
***b***** ******** *****s***** Penguin decay with mixing**

***CPV in Penguin Modes***

**Another implication of overconstrained: redundant approaches to same CKM parameter**

- Feb 24, 2006

## Potential New Physics contributions

***Potential New Physics contributions***

**“****Internal Penguin”**

- Feb 24, 2006

## Revealing new physics

- LHC

*B* Factory

- Squark mass matrix (*d* sector)

- Feb 24, 2006

## Summary after summer 2005 updates

- No sign of Direct *CP*

- 2.4 between *CP* violation in s-penguin vs sin2** (cc)

**Summer 05 results**

- About 0.5 loss vs Winter 2005 due to shift in charmonium average

- Charmonium

- s-Penguins

- Feb 24, 2006

## Evolution of SK measurements

***Evolution of S************K****** measurements***

- Feb 24, 2006

## How good is the SM prediction?

- 2-body:
- Beneke, PLB 620 (2005) 143

- 3-body:
- Cheng, Chua & Soni,
- hep-ph/0506268

**Calculations within framework of QCD factorization**

- Feb 24, 2006

## Evolution by summer 2008

***Evolution by summer 2008***

***K**************

**4******** discovery region if non-SM **
**physics is 0.19 effect**

**2004=240 fb****-1**
**2008=1.0 ab****-1**

**Individual modes reach 4-5 sigma level**

- Projections are statistical errors only;
- but systematic errors at few percent level

- Luminosity expectations:

**2008**

**2004**

***f******0******K******S***
***K******S************0***
*********K******S***
*********’******K******S***
***KKK******S***

- Feb 24, 2006

## Possible evolution of SM deviations

**Number of **
**standard deviations**

**Integrated luminosity (fb****-1****)**

***********K******S***

*****’******K******S***

**average**

**Assuming fluctuations around****present central values**

- Feb 24, 2006

## Global CKM fit: 2008

***Global CKM fit: 2008***

**95% contours**

- Feb 24, 2006

## An opportunity for 2010?

***An opportunity for 2010?***

**Buchalla, Hiller, Nir, Raz**
**hep-ph/0503151**

**SM + various New Physics**

**NP in Z-Penguins**

**NP in gluonic-Penguins**

**NP in chromomagnetic operator**

**New physics modifies Wilson Coefficients**

- Feb 24, 2006

## Discriminating among NP models

**Exploit the pattern of deviations ****S among the various  modes to discriminate between models**

**Three NP models, six scenarios:**
** ****NP only in the ****Z****0****-penguin**** coupling**
** ****NP in ****Kaluza-Klein ****gluon excitations**
** ****NP in ****chromo-magnetic**** operator**** **

**Exclusion vs luminosity**

- Feb 24, 2006

## UT constraints on any New Physics

- now

***UT constraints on any New Physics***

- Assumption: no NP in trees [almost any NP model]

**95% contours**

**Significant constraint on all New Physics models in LHC era**

- Feb 24, 2006

## Bounds on new physics

- Model independent

**Mass scale being probed for unit coupling:**
- (now) ~ 5 TeV
- (2008) ~ 10TeV

**Introduce new physics in mixing diagram**

- Feb 24, 2006

## New CKM constraints in sight

**2008: Possible discovery**

**Possible discovery: 2007**

- Feb 24, 2006

## Search for B  

- +e+e

- BaBar
- SL tags
- 230M BB

- Current BaBar
- 90% C.L.

**Close to discovery of the mode or of NP**** **

- Expectations from U.T. fit

- Signal for Br=10-3

**Single-beam technique critical**

***Search for B ************ *********

- Feb 24, 2006

## Future projections

- 90% Upper Limit on

**2008**

***Future projections***

- Feb 24, 2006

## Complementarity with LHC

***Complementarity with LHC***

- today

-  2008

- Approx...

- 2HDM

**Constraints from *****B***** **************, *****B***** *********s*********

- Feb 24, 2006

## Lepton-flavor violation & mSUGRA

- Feb 24, 2006

## Physics from future doublings

***Physics from future doublings***

**Discrepancy for penguin asymmetries becomes significant on average**

**ICHEP06**

**Pioneering measurements of ********** reach **
**10-15****o**

**Inclusive *****Vub***** reaches 6.5%**

- Feb 24, 2006

## Physics from future doublings

***Physics from future doublings***

**Ultimate precision of photon spectrum in *****B***** ******** *****s*********

**LP07**

**Determination of *****V******td***** from *****B***** to ********

**Discovery of *****B***** ******** ***********0************0***

- Feb 24, 2006

## Physics from future doublings

***Physics from future doublings***

**Discovery of *****B***** ******** ********

**Precision determination of *****V******ub***** from inclusive & exclusive modes to ~5%**

**ICHEP08**

**Measurement of ********** to better than 10****o**

**Asymmetry in *****B***** to ***********’K***** reaches 5 sigma**

- Feb 24, 2006

## Summary: Physics reach of BABAR

***Goal for 2005-2006: double current data set***
- Delay in Run 5 can be overcome by summer 2006 with extended running period, with substantial reduction in errors on CP violation asymmetries in rare decay modes
- Error on average of Penguin modes should reach 0.06
***Goal for 2007-2008: double again to ~1 ab******-1***
- Individual Penguin modes with errors in range 0.06-0.12
- Suite of fundamental Standard Model measurements with substantially improved levels of precision
***Beyond 2008 might offer exciting opportunities if New Physics has been seen by B Factories & LHC***

**Sensitivity to New Physics through rare decays, *****CP***** violation, & large data sample with a significant discovery potential**
**Full program of flavor physics/CP violation measurements provide fundamental constraints on future New Physics discoveries**

- Feb 24, 2006

## A vision for the longer-term future?

- Positrons

- Electrons

- Gun

- 3 GeV

- 3 GeV

- Dump

- 5 GeV

- 1 GeV
- DR

- Transport

- E+ source

- Make up E

- Raimondi, Seeman

- IP

**Strong physics case for a 10****36**** facility**

**Machine has significant technical overlap with ILC, including damping rings, acceleration sections, and final focus**
**Appears to be possible to reach 10****36**** with substantially smaller backgrounds, allowing (re-)use of existing detectors**

- Feb 24, 2006