The enhancement of the decay Upsilon(1D) -> eta Upsilon(1S) by the axial anomaly in QCD

It is shown that the rates of the decays Upsilon(1^3D_1) -> eta Upsilon(1S) and Upsilon(1^3D_2) -> eta Upsilon(1S) should be comparable to and likely exceed that of the recently discussed in the literature two-pion transition Upsilon(1D) -> pi pi Upsilon(1S). The reason for this behavior is that the discussed eta transitions are enhanced by the contribution of the anomaly in the flavor singlet axial current in QCD.Comment: 11 page

Case Histories of Settlement Performance Comparisons on Ground Improvement Using Soil Stiffness

Ground improvements often aim to reduce settlement risks for foundations and this requires reliable methods of prediction. Current approaches are based on empirical procedures and methods developed over 30 years ago. This has resulted historically in designs and installations of unnecessarily sophisticated foundations. In addition many developments now encountered by ground improvement contractors involve previously developed or ‘brownfield’ sites made up of heterogeneous and variable made ground. Methods to predict settlements traditionally use destructive and invasive approaches such as SPT or CPT that can be insensitive to time dependent changes, which often occur when brownfield sites are improved. By comparison geophysical methods are both non-invasive and non-destructive. One such technique that has demonstrated considerable promise is that of continuous surface wave determinations, which allows stiffness depth profiles to be obtained in a cost effective way. A recently developed method to determine settlements from these data has shown through four case studies presented in this paper to accurately predict settlements measured from zone tests. Thus offers a potentially more reliable way to predict settlement profiles than traditionally used methods

Supersymmetric Singlet Majorons and Cosmology

We examine cosmological constraints on the lepton number breaking scale in supersymmetric singlet majoron models. Special attention is drawn to the model dependence arising from the particular choice of a certain majoron extension and a cosmological scenario. We find that the bounds on the symmetry breaking scale can vary substantially. Large values of this scale can be allowed if the decoupling temperature of smajoron and majorino exceeds the reheating temperature of inflation. In the opposite case an upper bound depending on the majoron model can be obtained which, however, is unlikely to be much larger than $10^{10}$ GeV.Comment: 14 pages, 2 figures, IC/94/40, SNUTP 94-15, TUM - TH - 164/9

Origins and renormalization of the superparticle spectrum

The importance of Yukawa contributions to the renormalization of the spectrum in non-minimal supersymmetric models is illustrated in the cases of explicit lepton number violation (leading to the possibility of singly produced sneutrinos at LEP energies), an intermediate scale singlet neutrino and negative mass squared parameters (possibly modifying fine-tuning considerations), and a grand-unified sector. The relevance of model-dependent renormalization to the supersymmetric flavor problem is emphasized. Sources of the flavor problem, some of which are newly identified, as well as possible solutions, are discussed and classified. It is then shown that gravitational interactions could lead (via a quadratically divergent singlet) to simple realizations of some of the low-energy frameworks that attempt to resolve the flavor problem.Comment: 11 pages. LaTex + espcrc2.sty (included). Talk presented at Supersymmetry 9

Solving the Gravitino Problem by Axino

In a large class of supersymmetric (SUSY) axion model the mass of axino \axino (a fermionic superpartner of the axion) is predicted as m_{\axino} \lesssim {\cal O}(1) keV. Thus, the axino is the lightest SUSY particle (LSP). We pointed out that such a light axino provides a natural solution to the gravitino problem, if the gravitino is the next LSP. We derive a constraint on the reheating temperature $T_R$ of inflation, $T_R \lesssim 10^{15}$ GeV for the gravitino mass $m_{3/2} \simeq 100$ GeV, which is much weaker than that obtained in the minimal SUSY standard model.Comment: 7 pages; revised version for publication in Phys. Lett.

Discrete Gauge Symmetries in Axionic Extensions of the SSM

We examine discrete gauge symmetries in axionic extensions of the SSM which provide a solution of the $\mu$-problem. Automatic-PQ symmetry and proton stability are shown to be guaranteed by certain discrete symmetries. Focusing on the L-violating discrete symmetries we discuss two sources of neutrino masses and their relevance for the solar neutrino problem.Comment: 13 pages, TUM-TH-150/92, MPI-Ph/92-7

Prospects for detection of Υ(1D)→Υ(1S)ππ\Upsilon(1D) \to \Upsilon(1S) \pi \pi via Υ(3S)→Υ(1D)+X\Upsilon(3S) \to \Upsilon(1D) + X

At least one state in the first family of D-wave $b \bar b$ quarkonium levels has been discovered near the predicted mass of 10.16 GeV/$c^2$. This state is probably the one with J=2. This state and the ones with J=1 and J=3 may contribute a detectable amount to the decay $\Upsilon(1D) \to \Upsilon(1S) \pi \pi$, depending on the partial widths for these decays for which predictions vary considerably. The prospects for detection of the chain $\Upsilon(3S) \to \Upsilon(1D) + X \to \Upsilon \pi \pi + X$ are discussed.Comment: 4 pages, LaTeX, 1 figure, to be published in Phys. Rev. D, comment added after Eq. (2

From Planck to GUT via Dimensional Transmutation

Consider a gauge singlet superfield S coupled to a pair of adjoint fields in a SUSY-GUT. If the tree-level vacuum is flat in S, the vev which defines the GUT scale will be determined via dimensional transmutation at a scale M where the soft-breaking (mass)^2 vanishes as a result of running from $M_{Pl} = (8 \pi G_N)^{-1/2}$. Because of the large number of adjoint fields $N_A$ coupled to S, one finds that M can be generically close to $M_{GUT} = 2 \times 10^{16} GeV$: $M \simeq M_{Pl} \exp[-16 \pi^2 \log(3/2) / (N_A+4) \lambda^2]$, where $\lambda$ is a Yukawa $\sim$ 0.7. This work examines the symmetries and dynamical constraints required in a SUSY-GUT in order that the desired flatness in S is achieved, and that this flatness may survive in a supergravity framework.Comment: 13 pages, 1 figure, uses Latex and epsf, reference adde

Exchange Current Operators and Electromagnetic Dipole Transitions in Heavy Quarkonia

The electromagnetic E1 and M1 transitions in heavy quarkonia ($c\bar c$, $b\bar b$, $c\bar b$) and the magnetic moment of the $B_c^\pm$ are calculated within the framework of the covariant Blankenbecler-Sugar (BSLT) equation. The aim of this paper is to study the effects of two-quark exchange current operators which involve the $Q\bar Q$ interaction, that arise in the BSLT (or Schr\"odinger) reduction of the Bethe-Salpeter equation. These are found to be small for E1 dominated decays such as $\psi(nS)\to \chi_{cJ} \gamma$ and $\Upsilon(nS)\to \chi_{bJ} \gamma$, but significant for the M1 dominated transitions. It is shown that a satisfactory description of the empirical data on E1 and M1 transitions in charmonium and bottomonium requires unapproximated treatment of the Dirac currents of the quarks. Finally, it is demonstrated that many of the transitions are sensitive to the form of the $Q\bar Q$ wavefunctions, and thus require a realistic treatment of the large hyperfine splittings in the heavy quarkonium systems.Comment: 30 pages, 2 figures, uses Feynmf. Submitted to Nucl. Phys. A Accepted versio