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Evidence for an Anomalous
Like-Sign Dimuon
Charge Asymmetry


The DØ Collaboration

May 2010
DZero's collaboration banner


        Summary
On May 16, 2010, the DØ Collaboration submitted a paper to Physical Review D announcing the first evidence for anomalous CP-violation in the mixing of neutral B mesons, seen in 6.1 fb-1 of proton-antiproton collisions at √s = 1.96 TeV:  arXiv.org:1005.2757,  plots. The paper was published on 8/16/10: Phys. Rev. D 82, 032001 (2001), with an accompanying "Physics" Viewpoint article.  Here is a link to papers that cite this result – the paper reached SPIRES TOPCITE=50+ status in September 2010.
A short paper summarizing the result was submitted by editor request to Physical Review Letters on July 2:  arXiv.org:1007.0395, which was published on 8/16/10 as well: Phys. Rev. Lett. 105, 081801 (2010), and here are more papers that cite the result.

Abstract We measure the charge asymmetry A of like-sign dimuon events in 6.1 fb-1 of pp collisions recorded with the DØ detector at a center-of-mass energy √s = 1.96 TeV at the Fermilab Tevatron collider. From A, we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: Aslb = -0.00957 ± 0.00251 (stat) ± 0.00146 (syst). This result differs by 3.2 standard deviations from the standard model prediction Aslb(SM) = (–2.3+0.5–0.6)×10-4 and provides first evidence of anomalous CP-violation in the mixing of neutral B mesons.   Cross section measurements in the 2.3ifb analysis  

        Talks
  •  Fermilab "Wine and Cheese" seminar Guennadi Borissov, Lancaster University May 14, 2010
  •  Flavor Physics and CP Violation conference, Turin Gustaaf Brooijmans, Columbia University May 25, 2010
  •  LHCb Experiment meeting, CERN Iain Bertram, Lancaster University May 25, 2010
  •  Johns Hopkins workshop, Baltimore Dmitri Tsybychev, SUNY Stony Brook May 25, 2010
  •  Brookhaven forum, BNL Dmitri Tsybychev, SUNY Stony Brook May 26, 2010
  •  Lancaster/Manchester/Imperial College seminar Guennadi Borissov, Lancaster University May 28, 2010
  •  TRIUMF seminar Wendy Taylor, York University June 3, 2010
  •  University of Chicago seminar Mark Williams, Lancaster University June 7, 2010
  •  SLAC seminar Rick Van Kooten, Indiana University June 8, 2010
  •  Physics at the LHC conference, DESY Iain Bertram, Lancaster University June 11, 2010
  •  CERN seminar Bruce Hoeneisen, Universidad San Francisco de Quito, Ecuador June 14, 2010
  •  Rencontres de Blois Derek Strom, University of Illinois at Chicago July 17,2010
  •  ICHEP, Paris Bruce Hoeneisen, Universidad San Francisco de Quito, Ecuador July 24, 2010

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        Questions? – Please contact DZero's co-spokespeople, Dmitri Denisov and Stefan Söldner-Rembold
        Last update: September 28, 2010