Roger Dashen

Roger Frederick Dashen (born May 5, 1938 in Grand Junction , Colorado , † May 25, 1995 in La Jolla ) was an American theoretical physicist who dealt with quantum field theory and elementary particle physics.

Dashen studied physics at Harvard University (where he also played on the football team), where he graduated in 1960 "summa cum laude". He then went to Caltech , where he received his doctorate in 1964 . Then he was at Caltech and from 1967 at the Institute for Advanced Study , where he became a professor in 1969. In 1966 he became a Sloan Research Fellow . In 1986 he became a professor at the University of California, San Diego (UCSD), from 1988 as head of the faculty. He played a leading role in establishing a supercomputing center at UCSD and in establishing the Institute for Theoretical Physics of the National Science Foundation at the University of California, Santa Barbara .

In the 1960s he worked, partly in collaboration with Murray Gell-Mann, with current algebras of elementary particle physics and with models of chiral symmetry. In 1964, together with Steven Frautschi , he tried to calculate the mass difference between protons and neutrons within the S-matrix theory, which is attributed to electromagnetic interactions. In the 1970s, together with Brosl Hasslacher and André Neveu , he investigated quantum field theoretical model theories (such as the Sine-Gordon model and the Gross-Neveu model) for extended particles and semiclassical approximations ( WKB approximation ) for their analysis. They developed the Dashen-Hasslacher-Neveu method (DHN) for the quantization of solitons , which uses path integrals . After Polyakov discovered instantons in quantum chromodynamics (QCD) , he investigated them with David Gross and Curtis Callan . In the 1980s he dealt with lattice scale theories and found with Neuberger (independently of Giorgio Parisi ) an upper bound for the Higgs boson mass.

Dashen also dealt with sound propagation in the ocean (also with military applications in mind), applying quantum field theoretical methods (such as path integrals and the renormalization group ) to the problem of random sound scattering in the ocean. He partly worked with his JASON colleagues Kenneth Watson and Frederik Zachariason . Dashen was a senior scientific advisor to the US Navy , u. a. in the committee for the safety of the SSBNs , the missile-carrying submarines, and in questions of anti-submarine defense. He was also a member of the JASON Defense Advisory Group .

Dashen had been a member of the American Academy of Arts and Sciences since 1979, and a member of the National Academy of Sciences since 1984 . In 1994 he became a Fellow of the American Physical Society .

He was married and had two daughters.

Fonts

• Roger Dashen and Stephen Adler : Current Algebras. Applications to Particle Physics . Benjamin 1968

Web links

• Obituary at the University of California
• Biography at the APS
• Oral History Interview

Remarks

1. ^ Dashen and Frautschi: S-Matrix Method for Calculating electromagnetic corrections to strong interactions . In: Physical Review B . Volume 135, 1964, p. 1190
2. ^ Dashen, Hasslacher and Neveu: Non Perturbative Models and extended hadron models in field theory , Part 1 Semiclassical Functional Methods . In: Physical Review D . Volume 10, 1974, p. 4114, part 2 Two dimensional models and extended hadrons . In: Physical Review D . Volume 10, 1974, p. 4 130; The Particle Spectrum in Model Field Theories from semiclassical functional integral techniques . In: Physical Review D . Volume 11, 1975, p. 3424; Semiclassical bound states in an asymptotically free theory . In: Physical Review D . Volume 12, 1975, p. 2443
3. ↑ Callan, Dashen and Gross: The structure of the gauge theory vacuum . In: Physics Letters B . Vol. 63, 1976, p. 334; Toward a theory of the strong interactions . In: Physical Review D . Volume 17, 1979, p. 2717
4. ↑ From the assumed triviality of theories. After later work by Kuti, Lee, Shen et al. a. the resulting upper limit in the Glashow-Weinberg-Salam theory (standard model of the electroweak interaction) is 700 GeV. ${\displaystyle {\phi }^{4}}$
5. ^ Dashen, Watson, Zachariason, Walter Munk and Stanley Flatté: Propagating Sound in a fluctuating ocean . Cambridge University Press, 1979