Induced top Yukawa coupling and suppressed Higgs mass parameters

In the scenarios with heavy top squarks, mass parameters of the Higgs field must be fine-tuned due to a large logarithmic correction to the soft scalar mass. We consider a new possibility that the top Yukawa coupling is small above TeV scale. The large top mass is induced from strong Yukawa interaction of the Higgs with another gauge sector, in which supersymmetry breaking parameters are given to be small. Then it is found that the logarithmic correction to the Higgs soft scalar mass is suppressed in spite of the strong coupling and the fine-tuning is ameliorated. We propose an explicit model coupled to a superconformal gauge theory which realizes the above situation.Comment: RevTeX4 style, 10 pages, 3 figure

K→2πK \to 2 \pi Decay in the Nambu-Jona-Lasinio Model

We study the $K \to 2 \pi$ decays using the $U_L(3) \times U_R(3)$ version of the Nambu-Jona-Lasinio model with the effective $\Delta S = 1$ nonleptonic weak interaction. The $\Delta I = {3/2}$ amplitude is in reasonable agreement with experimental data. On the other hand, the calculated $\Delta I = {1/2}$ amplitudes strongly depend on the mass of the low-lying scalar-isoscalar $\sigma$ meson, and therefore give a strong constraint on the parameters of the model.Comment: 10 pages, 3 Postscript figures, Talk given at YITP Workshp: From Hadronic Matter to Quark Matter: Evolving View of Hadronic Matter, Kyoto, Japan, Oct. 30-Nov. 1, 1994, to be published in Prog. Theor. Phys. Supp

Doubly magic nuclei from Lattice QCD forces at MPS=M_{PS}=469 MeV/c2^2

We perform ab initio self-consistent Green's function calculations of the closed shell nuclei $^{\rm 4}$He, $^{\rm 16}$O and $^{\rm 40}$Ca, based on two-nucleon potentials derived from Lattice QCD simulations, in the flavor SU(3) limit and at the pseudo-scalar meson mass of 469~MeV/c$^{\rm 2}$. The nucleon-nucleon interaction is obtained using the HAL QCD method and its short-distance repulsion is treated by means of ladder resummations outside the model space. Our results show that this approach diagonalises ultraviolet degrees of freedom correctly. Therefore, ground state energies can be obtained from infrared extrapolations even for the relatively hard potentials of HAL QCD. Comparing to previous Brueckner Hartree-Fock calculations, the total binding energies are sensibly improved by the full account of many-body correlations. The results suggest an interesting possible behaviour in which nuclei are unbound at very large pion masses and islands of stability appear at first around the traditional doubly-magic numbers when the pion mass is lowered toward its physical value. The calculated one-nucleon spectral distributions are qualitatively close to those of real nuclei even for the pseudo-scalar meson mass considered here.Comment: 7 pages, 4 figures, RIKEN-QHP-286, RIKEN-iTHEMS-Report-1

An x-ray detector using PIN photodiodes for the axion helioscope

An x-ray detector for a solar axion search was developed. The detector is operated at 60K in a cryostat of a superconducting magnet. Special care was paid to microphonic noise immunity and mechanical structure against thermal contraction. The detector consists of an array of PIN photodiodes and tailor made preamplifiers. The size of each PIN photodiode is $11\times 11\times 0.5\ {\rm mm^3}$ and 16 pieces are used for the detector. The detector consists of two parts, the front-end part being operated at a temperature of 60K and the main part in room temperature. Under these circumstances, the detector achieved 1.0 keV resolution in FWHM, 2.5 keV threshold and 6\times 10^{-5} counts sec^{-1} keV^{-1} cm^{-2} background level.Comment: 8 pages, 5 figures, submitted to Nucl. Instr. Meth.

Geometric Bremsstrahlung in the Early Universe

We discuss photon emission from particles decelerlated by the cosmic expansion. This can be interpretated as a kind of bremsstrahlung induced by the Universe geometry. In the high momentum limit its transition probability does not depend on detailed behavior of the expansion.Comment: 20 pages, No figure

Celebrating 70: An Interview with Don Berry

Donald (Don) Arthur Berry, born May 26, 1940 in Southbridge, Massachusetts, earned his A.B. degree in mathematics from Dartmouth College and his M.A. and Ph.D. in statistics from Yale University. He served first on the faculty at the University of Minnesota and subsequently held endowed chair positions at Duke University and The University of Texas M.D. Anderson Center. At the time of the interview he served as Head of the Division of Quantitative Sciences, and Chairman and Professor of the Department of Biostatistics at UT M.D. Anderson Center.Comment: Published in at http://dx.doi.org/10.1214/11-STS366 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org