# Presentation: 892619

## BTeV Status

- Penny Kasper
- Fermilab
- July 3, 2004

- Presented at Beach2004,  IIT, Chicago , July 3, 2004

## What is BTeV?

- Tevatron p-p collider  experiment, at Fermilab:
- Forward spectrometer @ C0 interaction region
- Beauty and charm physics:
- Precision measurements of SM parameters
- Exhaustive search for new physics.
- BTeV is a part of broad program to address fundamental questions in flavor physics.
- Details at: http://www-btev.fnal.gov.

- Penny Kasper, Fermilab

- July 3, 2004

## A Brief History of BTeV

- June 2000: Stage I approval from lab.
- May 2002: Stage I approval for descoped detector.
- October 2003: “P5 supports the construction of BTeV as an important project in the world-wide quark flavor physics area.”
- Office of Science – “Facilities for the Future of Science, a 20 year Outlook”  – BTeV given priority 12 out of 28
- 2004: DOE – 4 stage approval process
- Completed reviews for first 2 stages with positive recommendations
- Final schedule and budget profile in the fall.
- DOE requires very conservative schedule – BTeV is still competitive in decay modes with all charged tracks and dominant in modes with neutrals. (PAC June 2004, P5 July 2004)
- Start Construction  2005 (in President’s FY05 budget)
- Start data taking 2009

- Penny Kasper, Fermilab

- July 3, 2004

## Physics Goals

- CP violation in SM is unique, predictive and testable
- Almost any extension of SM has new sources of CPV
- Measure  CP violation in B(uds) , Bs mixing, rare b decay rates,  CP violation and rare decays in the charm sector.
- Precise measurement of SM parameters
- Make an exhaustive search for physics beyond SM
- Look for rare/forbidden decays
- Test for inconsistencies in the Standard Model: If found, go beyond the SM and elucidate the new physics.

- Penny Kasper, Fermilab

- July 3, 2004

## Why do b and c Physics at Tevatron?

-   Large samples of b quarks
-   Get  41011 b hadrons per 107s at L = 21032 cm-2s-1
-   e+e- (4S) get 2108 B hadrons per 107s at 1034 cm-2s-1

-   Bs, b and other b-flavored hadrons are accessible
-     for study at the Tevatron
-   Charm rates are  10 larger than b rates

- Nominal  Tevatron parameters :
-   CMS energy = 2 TeV
-   Peak Luminosity L = 21032 cm-2s-1
-   Integrated luminosity  1.6 fb-1/year
-   Time/crossing = 396 ns
-   Interaction region z= 30cm and x,y= 50m
-   bb cross section = 100 b

- Penny Kasper, Fermilab

- July 3, 2004

## Why look in the Forward Region?

- BTeV detects in the forward region ( from 1.9 to 4.5)

- b production angle

- b production angle

-   Better decay length separation
-   Less multiple scattering

-   More BB in the Detector
-   Better away side tagging

- (-ln(tan[/2])

- Penny Kasper, Fermilab

- July 3, 2004

## The BTeV Detector

-   Vertex pixel (50m  400m)
-     detector in dipole magnet
-   RICH for particle ID
-   PbWO4 crystal EM calorimeter
-   Vertex separation Trigger at L1
-     (primary vertex reconstructed)
-   Powerful high speed DAQ
-     (output rate at 4KHz)

- Main/Unique Features

- Penny Kasper, Fermilab

- July 3, 2004

## Summary of Required Measurements for CKM Tests

- Penny Kasper, Fermilab

- July 3, 2004

## Pixel Vertex Detector

**  ****Low occupancy**
**  ****Excellent signal/noise**
**  ****Fast readout**
**  ****Excellent resolution (****5-10 ********m****  **
**   ****in 1999 FNAL test beam run) **
**  ****radiation hard**** sensors and        readout chips (demonstrated in exposures at IUCF) **
**Used in lowest level trigger**

**4.25 cm**

- 30 stations, 130cm

- Penny Kasper, Fermilab

- July 3, 2004

## Forward Tracking 

- 7 Stations – Silicon strips and straws

- 3 views
- Momentum resolution <1%

- Penny Kasper, Fermilab

- July 3, 2004

## Straw Detector – beam test

- TDC Spectrum
- FWHM =  8.1 ns => 486 .
- RMS = 206 .
- MWPC position resolution =144 .
- Quadrature Subtraction gives
-         _Straw Resolution =148 ___.
- This meets the needs for BTeV Forward Tracking

- Penny Kasper, Fermilab

- July 3, 2004

## Ring Imaging Cerenkov Counter

-   Gas radiator (C4F8O) detected on planes of Multi-Anode PMTs
-   Liquid radiator (C5F12) detected on array of side mounted PMTs

**MAPMT array**

**Gas**
**C****4****F****8****O**
**n=1.00138**

- Liquid
**C****5****F****12**
**N=1.29**

- Penny Kasper, Fermilab

- July 3, 2004

## Rich Detector – beam test (I)

- Design
- Small section of full RICH
- Sizes as current design of full RICH

- Goal
- Full system test of real RICH design (as much as possible)
- Systems test:  photon detectors, real readout electronics, mechanical design
- Plus reasonable HV, BV, LV, mirror, cooling, gas, shielding (mag+em), alignment, etc...

- Penny Kasper, Fermilab

- July 3, 2004

## Rich Detector – beam test (II)

- First Rings in air

- Penny Kasper, Fermilab

- July 3, 2004

## Lead Tungstate EM Calorimeter

-   PWO 2828mm2  22cm tapered crystals
-   Excellent energy and spatial resolution
-   Fast, compact, radiation hard

- Beam tests (Protvino):
-  established energy and position resoln.
-  Studied radiation damage and recovery
-  Calibration methods.
-  Crystals from 4 vendors

- Penny Kasper, Fermilab

- July 3, 2004

## Muon Detector

- Prototype Planks in test beam

- 3 stations of steel proportional tubes
- 2 toroids – independent momentum measurement

- Penny Kasper, Fermilab

- July 3, 2004

## BTeV Trigger

-  Reconstructs primary vertex and looks for detached decays every crossing
-  Made possible by vertex detector (3D space points with excellent  resolution and low occupancy)
-  Pipelined and parallel processing with 1 TB of buffer
-  3 Stage Trigger
-      L1: FPGAs and DSPs
-      L2/L3: Linux PCs

-  Level 1:  accepts >50% B events  that pass analysis cuts, rejects 98% light quark background.
-  Level 2: accepts 90% of B events from Level 1, rejects 90% background from Level 1
-  Level 3: rejects another factor of 2 in background, does full offline reconstruction

- 50 kHz
- 5 kHz
- 2.5 – 4 kHz

- Penny Kasper, Fermilab

- July 3, 2004

## Trigger R&D : Farm pre-prototype

- 4 DSPs

- High speed
- Data I/O controller
- (Buffer Manager)

- PTSM interface

- GL1 interface

- Penny Kasper, Fermilab

- July 3, 2004

## Summary of CKM Physics Reach 2 fb-1

- J/l+l-

|      Reaction |  B (B)(x10-6) | # of Events | S/B |    Parameter | Error or (Value) |
| --- | --- | --- | --- | --- | --- |
| Bo+- |          4.5 |    14,600 |    3 |   Asymmetry |       0.030 |
| Bs Ds K- |      300 |       7500 |    7 |        |          8o |
| BoJ/KS  , J/l+ l- |      445 |  168,000 |  10 |      sin(2) |       0.017 |
| Bs Ds- |    3000 |    59,000 |    3 |          xs |         (75) |
| B-Do (K+-) K- |        0.17 |         170 |    1 |  |           |
| B-Do (K+K-) K- |        1.1 |      1,000 | >10 |        |          13o |
| B-KS - |       12.1 |      4,600 |     1 |  |       <4o  + |
| BoK+- |       18.8 |    62,100 |   20 |        |  theory errors       |
| Bo+- |       28 |      5,400 |   4.1 |  |  |
| Booo |         5 |         780 |   0.3 |  |          ~4o |
| BsJ/ |     330 |      2,800 |   15 |  |  |
| BsJ/ |     670 |      9,800 |   30 |           sin(2 |        0.024 |

- Penny Kasper, Fermilab

- July 3, 2004

**Notes:**
Point out that there are several ways to measure , so can resolve ambiguities; other ways of resolving ambiguities in beta.
Error estimate on alpha is a guess. Can do better on chi by using electron modes. 

## Comparisons to Belle/BaBar

-  No Bs, Bc and b at B-factories
-  Number of flavor tagged B0+- (BR=0.4510-5)

|  | L(cm-2s-1) |  | #B0/107s | rec | D2 | #tagged |
| --- | --- | --- | --- | --- | --- | --- |
| e+e- | 1034 | 1.1nb | 1.1108 | 0.45 | 0.26 | 56 |
| BTeV | 21032 | 100b | 1.51011 | 0.021 | 0.1 | 1426 |

-  Number of B-D0K- (Full product BR=1.710-7)

|  | L(cm-2s-1) |  | #B0/107s | rec | # |
| --- | --- | --- | --- | --- | --- |
| e+e- | 1034 | 1.1nb | 1.1108 | 0.4 | 5 |
| BTeV | 21032 | 100b | 1.51011 | 0.007 | 176 |

- Penny Kasper, Fermilab

- July 3, 2004

## New Physics (1)

- Decays that occur in the SM only through loops are particularly sensitive to “new physics”
- The leptonic decay b***s*+- is sensitive to the actual form of the new interactions as one can measure M(+-)  and Dalitz plot as well as total rate

| Reaction | B(10-6) | Yield/year | S/B |
| --- | --- | --- | --- |
| BK* | 1.5 | 2530 | 11 |
| BK | 0.4 | 1470 | 3.2 |

- Penny Kasper, Fermilab

- July 3, 2004

## New Physics (2)

- SM predicts ACP(B0 *** ***Ks)= ACP(B0 *** ***Ks)
- B- *****- ** *penguin only, ACP ~ 0 in SM but interference between penguin and super-penguin amplitudes could give rise to large asymmetry

- Penny Kasper, Fermilab

- July 3, 2004

## 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.

| Mode | BTeV (107s) |  |  | B-Factory (500 fb-1) |  |  |
| --- | --- | --- | --- | --- | --- | --- |
|  | Yield | Tagged | S/B | Yield | Tagged | S/B |
| BsJ/() | 12650 | 1645 | >15 | - | - | - |
| B- K- | 11000 | n/a | >10 | 1000 | n/a | 4 |
| B0 Ks | 2000 | 200 | 5.2 | 350 | 90 | 4 |
| B0 K*+- | 2530 | n/a | 11 | ~50 | ~50 | 3 |
| Bs +- | 6 | 0.7 | >15 | - | - | - |
| B0 +- | 1 | 0.1 | >10 | 0 | - | - |
| D*+D0+,D0K+ | ~108 | ~108 | large | 8105 | 8105 | large |

- Penny Kasper, Fermilab

- July 3, 2004

## Comparison to LHCb

-   bb(LHCb) = 5bb(BTeV)
-    tot(LHCb) = 1.6tot(BTeV)
-  Interactions/Crossing
-      3 lower than BTeV

- LHCb  advantages:

- BTeV  advantages:
- Detached vertex trigger at lowest  level
- Higher rate DAQ
- Better resolution EMCAL

- BTeV and LHCb have comparable sensitivites in charged modes, BTeV is superior in modes with ’s and 0’s

- Penny Kasper, Fermilab

- July 3, 2004

## Summary and Conclusions

- BTeV will make critical contributions to our knowledge of CP violation as attention turns from initial observations to the work of finding out if the Standard Model explanation is correct and complete.
- BTeV is not just doing SM physics. It is sensitive enough to reveal new phenomena
- Level 1 trigger based only on presence of detached vertices – BTeV can investigate any new ideas that might arise.
- Positive recommendations from DOE reviews
- Tevatron has recently made significant improvements in luminosity and overall performance.

- Penny Kasper, Fermilab

- July 3, 2004