We report full QCD simulations on a 16 3 x4 lattice. For two degenerate flavors no finite-temperature phase transition is found for quark masses of ma =0.01 and 0.025, where a is the lattice spacing, while for three degenerate flavors a first-order transition is easily seen for ma =0.025. Nature, with nearly massless up and down quarks and one heavier strange quark, lies between these two cases. For m u ja =0.025 and m s a =0.1 we find that mK/m p =0.46(1) and that no transition occurs, calling into question the existence of a QCD phase transition.

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We have observed the decays B° -» K*(892)°j and B~ -> K*(892)~ry, which are evidence for the quark-level process b -• 57. The average branching fraction is (4.5 ± 1.5 ± 0.9) x 10~5. This value is consistent with standard model predictions from electromagnetic penguin diagrams. PACS numbers: 13.40.Hq, 14.40.Jz One-loop, flavor-changing neutral current diagrams, meson decays [1]. They were later identified as a possible known as penguins, were originally introduced into the source of direct CP violation in kaon decay, and hence as theory of weak decays to explain the AI = \ rule in K a contribution to e! /e [2]. Their importance in B meson 674 0031 -9007/93/71 (5)/674(5)$06.00

We present a new high-statistics measurement of the cross section for the process e+e~e+e m. +m at a center-of-mass energy of 29 GeV for invariant pion-pair masses M(m+m ) between 350 MeV/c' and 1.6 GeV/c2. We observe the f~( 1270) and measure its radiative width to be 3. 15+0.0420. 39 keV. We also observe an enhancement in the~+~spectrum near 1 GeV. General agreement is found with unitarized models of the yy~m m. reaction that include finalstate interactions.

We evaluate the infinite volume, continuum limits of eight hadron mass ratios predicted by lattice QCD with Wilson quarks in the valence (quenched) approximation. Each predicted ratio differs from the corresponding observed value by less than 6%.Typeset Using REVTEX 1