Longitudinal Polarization at future e+e−e^+e^- Colliders and Virtual New Physics Effects

The theoretical merits of longitudinal polarization asymmetries of electron-positron annihilation into two final fermions at future colliders are examined, using a recently proposed theoretical description. A number of interesting features, valid for searches of virtual effects of new physics, is underlined, that is reminiscent of analogous properties valid on top of $Z$ resonance. As an application to a concrete example, we consider the case of a model with triple anomalous gauge couplings and show that the additional information provided by these asymmetries would lead to a drastic reduction of the allowed domain of the relevant parameters.Comment: 18 pages and 1 figure. e-mail: [email protected]

The roughness of stylolites: Implications of 3D high resolution topography measurements

Stylolites are natural pressure-dissolution surfaces in sedimentary rocks. We present 3D high resolution measurements at laboratory scales of their complex roughness. The topography is shown to be described by a self-affine scaling invariance. At large scales, the Hurst exponent is $\zeta_1 \approx 0.5$ and very different from that at small scales where $\zeta_2 \approx 1.2$. A cross-over length scale at around \L_c =1~mm is well characterized. Measurements are consistent with a Langevin equation that describes the growth of a stylolitic interface as a competition between stabilizing long range elastic interactions at large scales or local surface tension effects at small scales and a destabilizing quenched material disorder.Comment: 4 pages, 4 figure

Top quark production at future lepton colliders in the asymptotic regime

The production of a tt(bar) pair from lepton-antilepton annihilation is considered for values of the center of mass energy much larger than the top mass, typically of the few TeV size. In this regime a number of simplifications occurs that allows to derive the leading asymptotic terms of various observables using the same theoretical description that was used for light quark production. Explicit examples are shown for the Standard Model and the Minimal Supersymmetric Standard Model cases.Comment: 20 pages and 13 figures. e-mail: [email protected]

Perancangan Buku Esai Foto Dan Media Pendukung Kehidupan Pengrajin Kerang Di Desa Tambak Deres - Sukolilo

Saat ini, dengan banyaknya tempat pariwisata di Indonesia khususnya kota Surabaya kini mengalami peningkatan dari setiap tahunnya . Dengan banyaknya tempat Wisata yang ada di Kota Surabaya, Desa Tambak Deres merupakan suatu Desa yang memiliki kelebihan dan keunggulan dibandingkan dengan desa lainnya. Keunggulan yang dimiliki Desa tambak Deres ialah aktifitas kegiatan para pengrajin kerang yang membuat suatu kerajinan dari bahan dasar Kerang. Kerajinan inilah yang patut dilestarikan karena mengandung nilai seni yang tinggi. Diharapkan melalui perancangan Buku Esai Foto ini Desa Tambak Deres dapat menjadi tempat wisata dan meningkatkan segi perdagangan di kota Surabaya. Buku Esai Foto ini menonjolkan kegiatan sehari - hari dimulai dari proses pencarian kerang hingga hasil jadi Kerajinan kerang yang siap dipasarkan

Equal Time Correlations in Haldane Gap Antiferromagnets

The $S=1$ antiferromagnetic Heisenberg chain both with and without single ion anisotropy is studied. Using the recently proposed density matrix renormalization group technique we calculate the energy gaps as well as several different correlation functions. The two gaps, $\Delta_{||}, \Delta_\perp$, along with associated correlation lengths and velocities are determined. The numerical results are shown to be in good agreement with theoretical predictions derived from the nonlinear sigma model and a free boson model. We also study the $S=1/2$ excitations that occur at the ends of open chains; in particular we study the behavior associated with open boundary conditions, using a model of $S=1/2$ spins coupled to the free bosons.Comment: 32 pages, uufiles encoded REVTEX 3.0, 19 postscript figures included, UBCTP-93-02

SUSY Scalar Production in the Electroweak Sudakov Regime of Lepton Colliders

We consider the production of SUSY scalar pairs at lepton colliders, for c.m. energies much larger than the mass of the heaviest SUSY (real or virtual) particle involved in the process. In that energy regime, we derive the leading and subleading terms of the electroweak Sudakov logarithms in the MSSM, first working at one loop with physical states and then resumming to all orders with asymptotic expansions. We show that the first order of the resummed expression reproduces the physical one loop approximation, and compute systematically the possible effects on various observables both at one loop and to all orders. We discuss the regimes and the processes where the one loop approximation can or cannot be trusted, working in an energy range between 1 TeV and 4 TeV under a "light" SUSY mass assumption. As a byproduct of our analysis, we propose a determination of the MSSM parameter tan(beta) showing how a relative accuracy of about 25 percent can be easily achieved in the region tan(beta)>14, under reasonable experimental assumptions.Comment: 35 pages and 15 figures e-mail: [email protected]

The role of universal and non universal Sudakov logarithms in four fermion processes at TeV energies: the one-loop approximation revisited

We consider the separate effects on four fermion processes, in the TeV energy range, produced at one loop by Sudakov logarithms of universal and not universal kind, working in the 't Hooft xi=1 gauge. Summing the various vertex and box contributions allows to isolate two quite different terms.The first one is a combination of vertex and box quadratic and linear logarithms that are partially universal and partially not universal and independent of the scattering angle theta. The second one is theta-dependent, not universal, linearly logarithmic and only produced by weak boxes. We show that for several observables, measurable at future linear e+e- colliders (LC, CLIC), the role of the latter term is dominant and we discuss the implications of this fact for what concerns the reliability of a one-loop approximation.Comment: 22 pages and 13 figures; version to appear in Phys.Rev.D. e-mail: [email protected]

High Magnetic Field ESR in the Haldane Spin Chains NENP and NINO

We present electron spin resonance experiments in the one-dimensional antiferromagnetic S=1 spin chains NENP and NINO in pulsed magnetic fields up to 50T. The measured field dependence of the quantum energy gap for B||b is analyzed using the exact diagonalization method and the density matrix renormalization group method (DMRG). A staggered anisotropy term (-1)^i d(S_i^x S_i^z + S_i^z S_i^x) was considered for the first time in addition to a staggered field term (-1)^i S_i^x B_st. We show that the spin dynamics in high magnetic fields strongly depends on the orthorhombic anisotropy E.Comment: 4 pages, RevTeX, 4 figure

A Model-independent Description of New Physics effects in e+e- to t tbar

We study the potential of a future $e^+e^-$ collider for the search of anomalous gamma t t bar and Z t t bar couplings, assuming that CP-invariance holds. This is done in a model-independent way, considering that all six possible couplings do appear. Two experimental situations are envisaged, with and without electron beam polarization. Observability limits in the form of domains in the 6-dimensional parameter space are established. Illustrations for specific constrained models are also presented and implications for new physics searches are discussed.Comment: 26 pages and 5 figures. e-mail: [email protected]

Exact Groundstates for Antiferromagnetic Spin-One Chains with Nearest and Next-Nearest Neighbour Interactions

We have found the exact ground state for a large class of antiferromagnetic spin-one chains with nearest and next-nearest neighbour interactions. The ground state is characterized as a matrix product of local site states and has the properties characteristic of the Haldane scenario.Comment: 8 pages, to appear in Z. Phys. B, preprint Cologne-94-474