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Using the large samples of B meson pairs produced at the SLAC B-Factory we are investigating CP violation (related to the matter dominance in the Universe), quark transitions (Flavor Physics, CKM matrix), fundamental symmetries in nature (T, CPT) and heavy meson dynamics (QCD).
Our results test the Standard Model and may reveal new physics.

The SLAC B-Factory consists of a specially built asymmetric electron-positron collider (PEP-II) and the BABAR detector. It is located at Stanford University, close to San Francisco. Here are some facts:

  • 620 researchers from 80 Institutes in 11 countries.
  • 2006: 65 publications (PRL/PRD) in a single year.
  • 272 total journal publications in 03/2001-09/2007.
  • Current (September 07) Data Sample: 477fb-1 (45fb-1 off resonance)
  • PEP-II top luminosity: 12.1x1033cm-2s-1 (design: 3x1033).
  • Best 24 hours Recorded Luminosity: 911pb-1
  • First data: May 24 1999.
BABAR on YouTube (2007) PPARC Press Release (23 June 2006) BABAR on the BBC (2002)
Discovery: BABAR announces the observation of D mixing (13 March 2007). Read the PPARC press release here and download the paper from here.
200 papers: BABAR submits its 200th journal publication (April 2006), five years after the first one. Read the SLAC press release here . BABAR results are published in Physical Review Letters and Physical Review D. We have 30 "top-cited" papers (more than 50 SPIRES citations), three of them already above the 200 mark!
Discovery: BABAR finds new exotic particle (01 July 2005). Read the SLAC press release here and download the paper from here [Phys. Rev. Lett. 95, 142001 (2005)]. This was one of the 100 Top Science Stories of 2005 in Discover magazine.
Discovery: BABAR announces the observation of Direct CP Violation in B0 -> K+ pi- (02 August 2004). Read the PPARC press release here and download the paper from here [Phys. Rev. Lett. 93, 131801 (2004)].
Discovery: BABAR finds new charm meson with unexpected mass(28 April 2003). Read the SLAC press release here and download the paper from here [Phys. Rev. D 69, 031101 (2004)].
Computing: The BABAR database store passed the 500Terabyte mark in April 2002, making it the largest known single database in the world. See the SLAC Press release.
Discovery: BABAR announces first observation of CP violation in the B meson system (5 July 2001). We measured:

sin(2beta) = 0.59 +- 0.14 (stat) +- 0.05 (syst)
[ PDF or PS version of Phys. Rev. Lett. 87, 091801 (2001)]

N.Y. Times article Economist article Washington Post article

Babar at Liverpool
The focus of the group (5 academics, 3 full time researchers, 1 PhD student) is CP violation. We have pioneered the measurement of the CKM angle alpha with B to rhorho decays. We are doing measurements of sin(2beta) in penguin dominated b to s modes, which could reveal effects from new particles at higher energy scales. Since 2006 we are involved in studies of D meson mixing.
We have led the photon/pi0 reconstruction and we are responsible for the luminosity measurement in BABAR. David Payne is convener of the Neutrals Analysis Working Group.
In the past we have been involved in Charmonium B decays and sin2beta, and B mixing and lifetime measurements using dilepton events.

Our hardware contribution was the development, design and construction of the endcap Electromagnetic Calorimeter.
BABAR computing at Liverpool is provided by a dedicated 82-CPU Linux farm with a total of 4Tb of disk, as well as through the MAP2 supercomputer in the department.
Eight PhDs have been already awarded and one more is in preparation in our group.



Contact: Christos Touramanis, phone: (0151)7946970

BABAR detector picture

BABAR detector photo
BABAR detector photos

Complete EMC Endcap

The BABAR Endcap Calorimeter
800 CsI(Tl) crystals in 10 modules. Shown with some of our engineers that designed, built, and installed the system.

Aerial view of SLAC

Stanford Campus, Main Quad
Stanford University

BABAR-Liverpool pages maintained by C. Touramanis. Last update 4 Jan. 2006