Department of Physics & Astronomy

Owen Long

Owen Long

Owen R. Long


Physics 3015

Telephone: 951-827-6084
Email: owen.long@ucr.edu
Fax: 951-827-4529

Research Interests:

  • Experimental High Energy Physics: CP violation and physics beyond the standard model


Ph.D. 1997, University of Pennsylvania

Current Research:

My current research is focused on searching for new phenomena from physics beyond the Standard Model of particle physics. In supersymmetric models with R-parity conservation, the lightest supersymmetric particle is stable and may make up the majority of the dark matter in the universe. The experimental signature at the LHC would be events with large missing energy in the transverse direction, coming from the lightest supersymmetric particles, which escape undetected. My work on the CMS experiment at the Large Hadron Collider is a search for supersymmetry in events with large missing transverse energy and b-quark jets.  Our most recent work has used the novel technique of "Higgs tagging" to enhance our sensitivity.

I have also performed many searches for new phenomena in the decays of bottom and charm hadrons using data collected by the BaBar experiment. Decays that are forbidden or occur only at the one-loop level within the Standard Model offer a window to new physics at high energy scales. In many new physics scenarios, these decays are enhanced by one-loop Feynman diagrams with virtual new particles. My latest work on lepton-flavor-violating flavor- changing-neutral-current decays have led to greatly improved model independent limits on flavor-changing operators from new physics.

I have been an active member of the Babar Collaboration since 1997. The Babar experiment at the Stanford Linear Accelerator Center is dedicated to the study of CP violation in B meson decays. The measurement of sin(2β), the CP asymmetry in the decay B0 → J/ψ Ks, was the first precision test of the Kobayashi-Maskawa mechanism for CP violation.  I played a central role in the measurement of sin(2β) as one of the primary analysts and as working group co-convener. I also investigated the feasibility of determining γ, another Unitarity Triangle angle, from direct CP violation in B → D K decays and contributed to the determination of the Unitarity Triangle α in the B → ρ ρ system.  Kobayashi and Maskawa were awarded the Nobel Prize in physics in 2008 after their theory was experimentally confirmed.  


U.S. Department of Energy's Outstanding Junior Investigator Award (2005)

Selected Publications and Preliminary Results:

  1. The CMS Collaboration, "Search for supersymmetry in the multijet and missing transverse momentum final state in pp collisions at 13 TeV", SUS-15-002, Phys. Lett. B 758, 152 (2016).
  2. The CMS Collaboration, "Searches for electroweak neutralino and chargino production in channels with Higgs, Z, and W bosons in pp collisions at 8 TeV", SUS-14-002, Phys. Rev. D 90, 092007 (2014).
  3. The CMS Collaboration, "Search for electroweak production of higgsinos in channels with two Higgs bosons decaying to b quarks in pp collisions at 8 TeV," SUS-13-022 (Feb. 2014).
  4. The CMS Collaboration, "Search for gluino mediated bottom- and top-squark production in multijet final states in pp collisions at 8 TeV," SUS-12-024, Phys. Lett. B 725, 243 (2013).
  5. The CMS Collaboration, "Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV," SUS-12-003, Phys. Rev. D 86, 072010 (2012).
  6. J. P. Lees et al. (The Babar Collaboration), "Search for the decay modes D0 → e+e-, D0 → μ+μ-, and D0 to e+μ-," Phys. Rev. D 86, 032001 (2012).
  7. J. P. Lees et al. (The Babar Collaboration), "Search for the decay modes B± → h± τ l," Phys. Rev. D 86, 012004 (2012).
  8. J. P. Lees et al. (The Babar Collaboration), "Measurements of branching fractions and CP asymmetries and studies of angular distributions for B → φφK decays," Phys. Rev. D 84, 012001 (2011).
  9. B. Aubert et al. (The Babar Collaboration), "Improved measurement of B+ → ρ+ ρ0 and Determination of the Quark-Mixing Phase Angle α," Phys. Rev. Lett. 102, 141802 (2009).
  10. B. Aubert et al. (The Babar Collaboration), "Search for the decay B+ → K+ τ μ,"  Phys. Rev. Lett. 99, 201801 (2008).
  11. B. Aubert et al. (The Babar Collaboration), "Search for the decay B0 → KS KS KL," Phys. Rev. D 74, 032005 (2006).
  12. B. Aubert et al. (The Babar Collaboration), " Search for B± →[K π±]DK± and upper limit on the b→u amplitude in B±→DK±," Phys. Rev. Lett. 93, 131804 (2004).
  13. O. Long, M. Baak, R. N. Cahn and D. Kirkby, "Impact of tag-side interference on time dependent CP asymmetry measurements using coherent B0B0 pairs," Phys. Rev. D 68, 034010 (2003).
  14. B. Aubert et al. (The Babar Collaboration), "Measurement of the CP-violating asymmetry amplitude sin(2β) with B0 mesons," Phys. Rev. Lett. 89, 201802 (2002).
  15. B. Aubert et al. (The Babar Collaboration), "A study of time dependent CP-violating asymmetries and flavor oscillations in neutral B decays at the Υ(4S)," Phys. Rev. D 66, 032003 (2002).
  16. B. Aubert et al. (The Babar Collaboration), "Observation of CP violation in the B0 meson system," Phys. Rev. Lett. 87, 091801 (2001).
  17. B. Aubert et al. (The Babar Collaboration), "Measurement of CP-violating asymmetries in B0 decays to CP eigenstates," Phys. Rev. Lett. 86, 2515 (2001).

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