A paper entitled “Measurement of Bbar0 → D(*)0Kbar(*)0 Branching Fractions” became the focus of celebrations in early April, as it became the 200th to be submitted for publication by the BaBar Collaboration. With this submission, BaBar can also look back on five years of broad-ranging, significant science publications.
On average, BaBar has published one paper a week since mid-2004 in Physical Review Letters or Physical Review D. Among the latest publications on the decays of the B mesons, the main purpose for building BaBar, are results from the study of the properties of the leptons in the B 7rarr; Xsll decays, which are highly sensitive to possible contributions from unseen physics processes; a search of CP violation with an unprecedented sensitivity of 0.3% in events where both the B mesons decay through semileptonic channels; and the most accurate single measurements of the side Vub of the unitarity triangle.
The 200th paper describes a new approach to measuring accurately the angle γ in the unitarity triangle, one of three angles governing CP violation in B mesons (BaBar Collaboration 2006). Although the new approach does not appear to work as well as theorists expected, it illustrates the approach at BaBar of constantly trying to invent new methods and helps in understanding what may or may not be possible in similar studies at the Large Hadron Collider.
The wide breadth of physics addressed in BaBar’s publications is equally impressive. Thedetector was built to study the decay of B-mesons, yet about 30% of BaBar papers focus on charm and tau particles – research for which the detector was not specifically designed, but at which it excels. The recent list of publications includes the observation of a new charmed baryon, the Λc(2880), a detailed study of the decays of the recently discovered DsJ(2316) and DsJ(2460) mesons, the search for the lepton-flavour violating decay of the tau lepton into an electron and a photon, and the first observation of decays of the U(4S) mesons into other U mesons and two pions.
The researchers on BaBar look forward to many more publications in the future and appear on track to have submitted 250 papers by early 2007.
Further reading
BaBar Collaboration, B Aubert et al. 2006 http://arXiv.org/abs/hep-ex/0604016.
