Christopher T. Hill

rdf:langString Christopher T. Hill

rdf:langString Christopher T. Hill

rdf:langString Christopher T. Hill

rdf:langString Topcolor; Top quark condensate; Dimensional deconstruction; Chiral Dynamics of Heavy-Light Mesons; Theory of UHE Cosmic Rays; Soft Nambu-Goldstone Boson model of Dark Matter.

rdf:langString Christopher T. Hill (born June 19, 1951) is an American theoretical physicist at the Fermi National Accelerator Laboratory who did undergraduate work in physics at M.I.T. (B.S., M.S., 1972), and graduate work at Caltech (Ph.D., 1977, Murray Gell-Mann). Hill's Ph.D. thesis, "Higgs Scalars and the Nonleptonic Weak Interactions" (1977) contains one of the first detailed discussions of the two-Higgs-doublet modeland its impact upon weak interactions. Hill is an originator of the idea that the Higgs boson is composedof top and anti-top quarks. This emerged from the concept of thetop quark infrared fixed point,which predicted (1981) that the top quark would be very heavy, contraryto most popular ideas at the time. The fixed point predictionlies within 20% of the observed top quark mass (1995). This impliesthat the top quarks are strongly coupled at very shortdistances and can form a composite Higgs boson, and led to top quark condensates, topcolor, and also dimensional deconstruction, which is a renormalizable, lattice description of extra dimensions of space. The composite Higgs bindingmechanism may be gravitation, which improves the agreement of the fixed point with the top quark mass, and predictsthat there exist many sequential, heavier Higgs bosons with large couplings to all quarks and leptons. This mayexplain the puzzle of the many small parameters in the standard model.Several new heavy Higgs bosons, such as the b-quark Higgs bound state,may be accessible to the LHC in the process (band anti-b quark). Hill coauthored (with Elizabeth H. Simmons) a comprehensive review of strong dynamical theorieswhich has shaped many of the experimental searches for new physics at the Tevatron and LHC. Heavy-light mesons contain a heavy quark and a light anti-quark, and display remarkable chiral dynamics (see chiral symmetry breaking).Hill co-developed the theory whichcorrectly predicted an abnormally long-lived resonance, the and numerous decay modes which havebeen confirmed by experiment. He has also done extensive work on topological interactions and, with collaborators, obtained the full Wess-Zumino-Witten term for the Standard Model, including pseudoscalars, spin-1 vector mesons, and . This revealed new anomalous interactions such as where is a heavy nucleus. Hill is an originator of cosmological models of dark energy and dark matter based upon ultra-low mass bosons associated with neutrino masses and was first to propose that the cosmological constant isconnected to the neutrino mass, as . He has also developed modern theories of the origin of ultra-high-energy nucleons and neutrinos from grand unification relics, such as cosmic strings. With Graham Ross he has focused more recently on spontaneously broken scale symmetry (or Weyl symmetry), where the scale of gravity (Planck mass) and the inflationary phase of the ultra-early universe are generated together as part of a unified phenomenon dubbed "inertial symmetry breaking." Hill is Distinguished Scientist Emeritus at Fermilab, former Head of the Theoretical Physics Department (2005 - 2012) and a Fellow of the American Physical Society (since 1989). He has co-authored three popular books with Nobel laureate Leon Ledermanabout physics and cosmology, and the commissioning of the Large Hadron Collider.