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After a brief discussion of the statistics available to the four LEP experiments at the time of writing and an overview of B-event characteristics, the authors consider in particular the theory, practice and potential pitfalls of neural networks, a new approach to B tagging which attracted a great deal of interest. They then consider some of the QCD aspects of heavy flavour physics. Finally there
We present a method to combine the all-order treatment of the High Energy Jets exclusive partonic Monte Carlo (HEJ) with the parton shower of Pythia8, while retaining the logarithmic accuracy of both. This procedure enables the generation of fully realistic and hadronised events with HEJ. Furthermore, the combination of the two allorder treatments leads to improvements in the quality of the descri
A framework of operator product expansion (OPE) allows us to study high-energy behaviour of Green functions. A calculation of such Green functions within chiral perturbation theory (PT) or resonance chiral theory (RT) and subsequent matching of the result to the OPE enables us to determine constraints for unknown parameters of the effective theories. We present such procedure for Green functions i
The present status of Chiral Perturbation Theory (ChPT) in the strong mesonic sector is discussed. A very short introduction to ChPT is followed by an overview of existing two-loop calculations and the determination of the Low-Energy-Constants (LECs). I discuss the case of $\eta\to\pi\pi\pi$ decays in somewhat more detail and finish by mentioning some recent work on partially quenched ChPT and on
This talk describes the reasons why $\eta$ and $\eta^\prime$ decays are an interesting topic of study for both theory and experiment. The main part discusses the results of the recent calculation of $\eta\to3\pi$ at two-loop order in ChPT. Some puzzling aspects of the results compared to earlier dispersive calculations are highlighted. I also like to remind the reader of the use of $\eta$ and $\et
Rescattering effects in the 3π system in the A1 region are studied with a method, which fulfils unitarity and has the proper analytic structure. Fairly small effects are obtained which confirm the result found in amplitude analyses, neglecting rescattering corrections, that the phases of the JP = 1+ amplitudes vary only very little over the A1 region. Similar results hold for the Q enhancement.
Gaia is ESA’s ambitious space astrometry mission with a foreseen launch date in early 2012. Its main objective is to perform a stellar census of the 1000 Million brightest objects in our galaxy (completeness to V=20 mag) from which an astrometric catalog of micro-arcsec level accuracy will be constructed. A key element in this endeavor is the Astrometric Global Iterative Solution (AGIS) - the math
Diffractive hard scattering is interpreted as the effect of soft gluon exchanges between the emerging energetic quarks and the nucleon's color field, resulting in an overall color singlet exchange. Summing multiple gluon exchanges to all orders leads to exponentiation and an amplitude in analytic form. Numerical evaluation reproduces the precise HERA data and gives new insights on the density of g
We consider exclusive double diffractive production of polarised axial-vector χ c(1 +) and tensor χ c(2 +) charmonia in proton-(anti)proton collisions at Tevatron energy. The corresponding amplitudes for these processes are derived within the k t-factorisation approach. Contributions from different polarisation states of axial-vector and tensor charmonia are quantified. Corresponding experimental
A package written in C for identifying variable dependencies in tables of data is presented. The key ingredient is the δ-test, which establishes dependency structures by exploiting the properties of continuous functions using conditional probabilities formed out of the data. The method estimates most relevant variables, embedding dimensions and noise levels. The program, which is self-contained, a
By using the Langevin equation with complex action it is possible to generate (complex) configurations in the charged sector of gauge theories. We test the algorithm in the case of two-dimensional U(1) gauge theory and are able to measure the string tension with great precision and modest use of computer time for a separation of the charged particles where a conventional Wilson loop would have a v
October is coming to an end as we release this sixth and last episode of the first season (not to worry, we are already planning a second season). This time Nic and Rebecca have invited Paul McMillan to the mic and chat with him about our galaxy, the Milky Way, and his involvement in ESA's Gaia satellite . Thereafter they take a closer look at the Pleiades.
Transformation and adaptation Transformation and adaptation: A research programme on the preconditions for governance and human progress Adaptation and transformation have for long been key subjects of study of many sciences ranging from evolutionary biology to business administration. This programme seeks to analyze the dynamic relationship between the environment (broadly defined) on the one han
https://www.pi.lu.se/sites/pi.lu.se/files/transformation_and_adaptation.pdf - 2026-05-28
This article is over 5 years old, and the information may therefore be outdated. Smith & Meissner are two researchers who have been hand-picked to find molecular clues to healing processes in the heart and blood vessels. A cardiologist and a molecular biologist who complement one another and work together to move research forward, Gustav Smith and Anja Meissner are one of the “tandem pairs” in
https://www.staff.lu.se/article/tandem-researchers-smith-meissner - 2026-05-27
Background and Aims The island of Gotland in the Baltic Sea had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at ca 17 ka BP. Plants present on Gotland must have arrived by long distance dispersal, so populations are expected to exhibit reduced levels of genetic diversity compared with surrounding mainlands. However, orchids have very small seeds, Background and AimsThe island of Gotland in the Baltic Sea has had no contact with surrounding continental areas since the withdrawal of the Weichselian ice sheet at approx. 17 ka BP. Plants present on Gotland must have arrived by long-distance dispersal, so populations are expected to exhibit reduced levels of genetic diversity compared with populations on surrounding mainlands. However, orchids
This thesis gives a thorough description of the icing mechanisms in gas turbines, the underlying physics of ice and ice types that can form in gas turbines. The primary intention of this thesis is to investigate the icing condition regions leading to ice formation in gas turbines. The icing problem in gas turbines is explained in detail in this thesis. The different ice types, icing mechanism
In this fourth episode of the podcast Nic and Rebecca invited Laura Hrastar to the mic and chatted with her about life and work at Max IV - which is a Swedish national laboratory producing brilliant synchrotron radiation for various research projects . Thereafter they take a closer look at the galaxy listed as the 31st object in the Messier Catalogue.
