Filetype
This talk discusses two analytical calculations relevant for the Standard Model calculation of the muon g−2. The first part is the recent derivation of the quark-loop as the first term in a well-defined operator-product expansion for the short-distance part of the hadronic light-by-light contribution, as well as the calculation of the next term. The second part is the calculation of finite volume
The first-order electroweak phase transition in the early universe could occur in multiple steps leading to specific multi-peaked signatures in the primordial gravitational wave (GW) spectrum. We argue that these signatures are generic phenomena in multi-scalar extensions of the Standard Model. In a simple example of such an extension, we have studied the emergence of reoccuring and nested vacuum
Within the Standard Model Effective Field Theory framework, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study hadronic tau decays and l-t conversion in nuclei (l = e, µ). Based on available experimental limits, we establish constraints on the Wilson coefficients of the operators contributing t
The spin effects in the hadronization process have been included for the first time in the PYTHIA 8 event generator. The spin effects are limited to the production of pseudo-scalar mesons and are obtained from the propagation of the quark polarization along the fragmentation chain according to the rules of the so-called 3P0 model. The interface between PYTHIA 8 and the package of the 3P0 model is
Gener fungerar som instruktioner för vad cellen skall producera. Det är aktiveringen och hämningen av gener som ger upphov till många olika typer av celler i människans kropp som till exempel hudceller, blodceller och nervceller. Dessa celler samarbetar med varandra för att tillsammans skapa den flercelliga organismen: människan. Det finns två huvudkategorier av celler i kroppen, somatiska celler Scientists are now able to directly convert one somatic cell type into another using a procedure known as direct lineage reprogramming or transdifferentiation. In this procedure, transcription factors which are important for initiating a rewriting of the gene expressions are introduced in the cell. One specific type of reprogramming involves generating dopamine producing neurons from human adult f
In this work we extend two dual color decompositions of Yang-Mills amplitude to one-loop level. Starting from double-copy expression we translate the Yang-Mills integrand into the dual Del Duca-Dixon-Maltoni formulation and subsequently to the dual color-ordered formula. The dual trace factors are obtained after simultaneously solving the one-loop Kleiss-Kuijf relations, the reflection relation, a
We present calculations of charm and beauty production at Tevatron within the framework of k(T)-factorization, using the unintegrated gluon distributions as obtained from the Linked Dipole Chain model. The analysis covers transverse momentum and rapidity distributions and the azimuthal correlations between b and (b) over bar quarks (or rather muons from their decay) which are powerful tests for th
We present work going on calculating the kaon BK parameter in the 1/Nc expansion. The goal of this work is to analyze analytically in the presence of chiral corrections this phenomenologically very important parameter. We present the method used and preliminary results for the chiral limit value for which we get the invariant BKchi=0.29 +- 0.15. We also give some analytical indications of why the
Several distinct color flow topologies are possible in multiparton configurations. A method is proposed to find the correct topology, based on a minimization of the total transverse momentum of produced particles. This method is studied for three-jet [Formula presented] and four-jet [Formula presented] events. It is shown how the basic picture is smeared, especially by parton-shower activity. The
All currently available QCD-inspired models/Monte Carlos for the event structure in high-p T physics are described. Included is information on hard interactions, initial and final state radiation, structure functions, beam jets and fragmentation. Results from a number of comparative Monte Carlo runs are presented, which help to illuminate how the physics content in Monte Carlos may be tested. Spec
A new model of color reconnection in the Monte Carlo generator Herwig 7 is presented. It is based on the minimization of a boost-invariant distance of the parton system, where all partons have momentum as well as spacetime position assigned. We test the influence of both types of variables, namely the rapidity span and transverse distance, on the actual need to reconnect the system to better descr
These are the proceedings of the workshop on ``Effective Field Theories of QCD'' held at the Physikzentrum Bad Honnef of the Deutsche Physikalische Gesellschaft, Bad Honnef, Germany from November 26 to 30, 2001. The workshop concentrated on Chiral Perturbation Theory in its various settings, its relations with lattice QCD and dispersion theory and the use of effective field theories in systems wit
We seek to better understand the relationship between an anisotropic distribution of partons in the initial state of pp-collisions and the amount of elliptic flow. We do this through the implementation of a new model that is based in generating positions for multiparton interactions from the uneven volume created by the overlap of two Gaussians. We then examine how this asymmetric probability dens
This thesis calculates the bremsstrahlung correction beyond the soft-photon approximation for the decay ω → π0 l+ l- . The effect of the radiative corrections on the extraction of the transition form factor from data is investigated. Four different form-factor mod- els are used to compute corrections: vector-meson dominance, lowest-meson dominance, tree-level, and two-hadron saturation. The experi
This document describes the first proof-of-concept version of the PYTHIA7 program. PYTHIA7 is a complete re-write of the PYTHIA program in C++. It is mainly intended to be a replacement for the `Lund' family of event generators, but is also a framework with a structure suitable for implementing any event generator model. In this document, the structure of the program is presented both from the use
Dubbel ickebeskattning på grund av tillämpning av skatteavtal kan definieras som den skattemässiga effekt som inträder då varken hemviststaten eller källstaten har något beskattningsanspråk i förhållande till en viss inkomst men där inkomsten skulle ha beskattats av någon stat i frånvaro av skatteavtalet. Hittills har intresset och förståelsen för de bakomliggande orsakerna varit begränsad och det
Solar mean magnetic field (SMMF) measurements from the Wilcox SolarObservatory and with SOHO/MDI are analyzed using continuous wavelettransforms, SMMF variability is found at a number of temporal scales.Detected SMMF variations with a 1-2 year period is considered to belinked to long-term variations in the internal rotation of the Sun.Intermediate SMMF oscillations with a period of 80-200 days are
Ida har fått ett nytt teleskop av sin farfar och vill nu lära sig använda den. Hon och hennes kusin Malin träffar Sara och Hanna en vacker stjärnklar kväll och får lära känna natthimmeln. När de har lärt sig hitta på natthimmeln lyckas de leta upp planeter, nebulosor och galaxer.Ida has a received a new telescope from her grandfather and now she wants to learn how to use it. She meets up with Malin, Sara and Hanna late at night and together they learn to navigate the night sky and locate some planets, nebulae and galaxies.
