Physics at Future Linear Colliders

This article summarises the physics at future linear colliders. It will be shown that in all studied physics scenarios a 1 TeV linear collider in addition to the LHC will enhance our knowledge significantly and helps to reconstruct the model of new physics nature has chosen.Comment: Invited talk at the Lepton Photon Symposium 2005, Upsala, Sweden, July 2005, V2: minor improvement

Status of electroweak tests with heavy quarks

The measurements of the partial decay-widths and forward-backward asymmetries for \rm{Z} \rightarrow \bb and \rm{Z} \rightarrow \cc test the Z couplings to the initial state \ee pair and th e heavy quarks in the final state. The four LEP detectors have registered about four million hadronic Z decays each and SLD at SLC has recorded 300000 Z decays with highly polarised electron be ams. The high statistics as well as the good tracking, vertexing and particle identification capabilities of the detectors allow high precision measurements of these quantities. The measurements of the electroweak observables with heavy quarks are reviewed. The results of the different analyses are combined and interpreted within the framework of the Standard Model of electroweak interactio ns. In all cases good agreement with the Standard Model predictions is found, severely limiting the room for modifications of these quantities from new physics

Building blocks for powerful ideas: designing a programming language to teach the beauty and joy of computing

Snap! is a cloud-native graphical programming environment and an online community. It is the programming language made for UC Berkeley’s popular introductory CS course named “The Beauty and Joy of Computing”. Snap! is taught in colleges and high schools across the U.S. from Palo Alto to Philadelphia. It has been translated to more than 40 languages and is used around the world—from Göttingen to Beijing—for teaching and research. Snap! has been designed for inclusion. Its low floor welcomes beginners and its multi-media capabilities invite creative thinkers of all ages. At the same time, Snap! offers sophisticated abstractions that make it suitable for an intellectually rigorous introduction to computer science.Snap! es un entorno de programación gráfica nativo de la nube y una comunidad en línea. Es el lenguaje de programación creado para el popular curso introductorio de CS de UC Berkeley llamado “La belleza y la alegría de la informática”. Snap! se imparte en colegios y escuelas secundarias de los EE. UU., desde Palo Alto hasta Filadelfia. Se ha traducido a más de 40 idiomas y se utiliza en todo el mundo, desde Gotinga hasta Beijing, para la enseñanza y la investigación. Snap! ha sido diseñado para su inclusión. El nivel bajo le da la bienvenida a principiantes y sus capacidades multimedia que invitan a pensadores creativos de todas las edades. Al mismo tiempo Snap! ofrece abstracciones sofisticadas que lo hacen adecuado para una introducción intelectualmente rigurosa a la informática

A Laser Cavity for Polarised Positron Production?

LAL & DESYPolarised positrons in the ILC are attractive for physics reasons and polarised positron production with Compton scattering has the advantage that the source is independent from the electron arm. In this note some ideas are presented, how this might be achieved using storage devices like a laser cavity and an accumulator ring

Model Independent Limit of the Z-Decay-Width into Unknown Particles

Using the LEP lineshape data combined by the LEP electroweak working group and the left-right asymmetry measured at SLD an almost model independent limit on the decay width of the Z into unpredicted modes is derived. Assuming only that the \rm{Z} \rightarrow \ee and \rm{Z} \rightarrow \mumu decays can be selected cleanly a limit of \Gnew < 6.3 \MeV at 95\% confidence level is derived

Studies for a Photon Collider at the ILC

One option at the International Linear Collider is to convert the electron beams into high energy photon beams by Compton scattering a few millimetres in front of the interaction region. Selected physics channels for this option have been analysed and technical issues have been studied. So far no showstoppers for this option have been found.Comment: V2: Minor changes, accepted by NI

Corrections to Quark Asymmetries at LEP

The most precise measurement of the weak mixing angle sin^2(theta) at LEP is from the forward-backward asymmetry e+e- --> bbbar at the Z-pole. In this note the QED and electroweak radiative corrections to obtain the pole asymmetry from the measured asymmetry for b- and c-quarks have been calculated using ZFITTER, which has been amended to allow a consistent treatment of partial two-loop corrections for the b-quark final asymmetries. A total correction of dAfbb=0.0019+/-0.0002 and dAfbc=0.0064+/-0.0001 has been found, where the remaining theoretical uncertainty is much too small to explain the apparent discrepancy between sin^2(theta) obtained from Afbb and from the left-right asymmetry at SLD

International Linear Collider Reference Design Report : Volume 2: Physics at the ICL

This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described

The growth mechanism of lithium dendrites and its coupling to mechanical stress

Operando high-resolution light microscopy with extended depth of field is used to observe large regions of an electrode during electrodeposition of lithium. The analysis of the morphology of the evolving deposit reveals that besides electrochemistry, mechanics and crystalline defects play a major role in the growth mechanism. Based on the findings, a growth mechanism is proposed that involves the diffusion of lithium atoms from the lithium surface into grain boundaries and the insertion into crystalline defects in the metal. Crystalline defects are a result of plastic deformation and hence mechanical stimulation augments the insertion of lithium