Stephen Barr

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Stephen M. Barr (* 1953 ) is an American theoretical physicist who studies elementary particle theory and cosmology.

Barr received his PhD from Princeton University in 1978 . He was a postdoctoral fellow at the University of Pennsylvania , Assistant Professor at the University of Washington from 1980 to 1985, and from 1985 to 1987 at the Brookhaven National Laboratory . From 1987 he was a professor at the University of Delaware . There he became director of the Barol Research Institute in 2011.

In 2011 he became a Fellow of the American Physical Society for contributions to GUTs , baryogenesis, and CP violation .

He is one of the authors of the flipped SU (5) -GUT model, which originally appeared as an intermediate stage in the symmetry break of the SO (10) -GUT model. Later he investigated realistic supersymmetric GUTs with calibration group SO (10) with KS Babu. Flipped SU (5) is still (2018) a possible candidate for GUTs, while SU (5) is excluded from proton decay experiments due to the minimal lifetime of the proton .

In the case of the CP violation, he wrote the Barr-Zee diagram (with Anthony Zee ), which generates electrical dipole moments for the electron, neutron and other particles, and the Nelson-Barr mechanism (independent AE Nelson) as a solution to the strong CP Problems.

On baryogenesis, he published a paper with RS Chivukula and Edward Farhi in 1990, which showed that ordinary baryonic matter and dark matter could have been created by the same mechanism in the early universe (asymmetric dark matter).

He has also published books on the relationship between religion and science, such as Modern physics and ancient faith (University of Notre Dame Press 2003). He is a staunch Catholic and received the Papal Benemerenti Medal in 2007 . Barr writes for First Things magazine .

Fonts (selection)

Except for the writings cited in the footnotes.

  • New type of seesaw mechanism for neutrino masses, Phys. Rev. Lett., Vol. 92, 2004, p. 101601.
  • with N. Fortson, P. Sandars: The search for a permanent electric dipole moment, Physics Today, Volume 56, issue 6, 2003, p. 33
  • with CH Albright, KS Babu: Minimality condition and atmospheric neutrino oscillations, Phys. Rev. Lett., Vol. 81, 1998, p. 1167.
  • with CH Albright: Fermion masses in SO (10) with a single adjoint Higgs field, Phys. Rev. D, Volume 58, 1998, p. 013002
  • Grand Unified Theories, in Lerner, Trigg (Ed.), Encyclopedia of Physics, Wiley 2005

Web links

Individual evidence

  1. ^ Barr, A new symmetry breaking pattern for SO (10) and proton decay, Phys. Lett. B, Volume 112, 1982, p. 219
  2. ↑ Babu, Barr, Natural suppression of Higgsino-mediated proton decay in supersymmetric SO (10), Phys. Rev. D, Volume 48, 1993, p. 5354
  3. ^ Barr, Zee, Electric dipole moment of the electron and of the neutron, Phys. Rev. Lett., Vol. 65, 1990, p. 21, Erratum p. 2920
  4. ↑ Nelson, Naturally weak CP violation, Phys. Lett. B, Volume 136, 1984, p. 387
  5. ↑ Barr, P. Langacker, A superweak gauge theory of CP violation, Phys. Rev. Lett., Vol. 42, 1979, p. 1654
  6. ^ Barr, Solving the strong CP problem without Peccei-Quinn symmetry, Phys. Rev. Lett., Vol. 53, 1984, p. 329
  7. ^ Barr, A class of non-Peccei-Quinn models, Phys. Rev. D, Volume 30, 1984, p. 1805
  8. ↑ Barr, Chivukula, Farhi, Electroweak fermion number violation and the production of stable particles in the early universe, Phys. Lett. B, Vol. 241, 1990, pp. 387-391
personal data
SURNAME Barr, Stephen
ALTERNATIVE NAMES Barr, Stephen M.
BRIEF DESCRIPTION American physicist
DATE OF BIRTH 1953