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The recently measured yeast transcriptional network is analyzed in terms of simplified Boolean network models, with the aim of determining feasible rule structures, given the requirement of stable solutions of the generated Boolean networks. We find that, for ensembles of generated models, those with canalyzing Boolean rules are remarkably stable, whereas those with random Boolean rules are only m
New experimental lifetimes for two levels in doubly ionized tungsten, W III, have been obtained using the time-resolved laser-induced-fluorescence technique. Theoretical oscillator strengths obtained from a HFR calculation including the effects of core-polarization are reported for all transitions from levels below E < 70000 cm(-1) and with log g f >= -2, thus greatly extending our knowledge of th
Radiative lifetimes of eight odd-parity states of Pt II, in the energy range from 51 408 to 64 388 cm−1, have been measured by means of the time-resolved laser-induced-fluorescence technique. Free, singly ionized platinum ions were obtained in a laser-produced plasma and a tunable laser with 1.5 ns duration pulse was used to selectively excite the Pt+ ions. The comparison of the experimental resul
This thesis aims to describe the little group scaling and how it simplifies the calculation of scattering amplitudes. The little group has the defining property that it leaves a particular four-momentum invariant, which is used to describe how the internal structure of a particle is transformed under the little group. An important part in the study of little group scaling is the spinor-helicity fo
Vi studerar stjärnors rörelser i Vintergatan med N-body simuleringar och stora astrometriska dataset från ESAs rymdteleskop Gaia. Vi identifierar två kinematiska populationer för vita dvärgar i Solens kvarter. Vi undersöker även ansamlade halon och avslöjar två nya hastighetsstrukturer. Slutligen, våra simuleringar visar att radiell migrering som en funktion av vertical action beror på diskmassa.We study stellar motions in the Milky Way with N-body simulations and large astrometric samples from ESA's Gaia mission. We identify two kinematic populations for white dwarfs in the Solar neighbourhood. We also investigate the accreted halo and reveal two new structures. Finally, our simulations show that radial migration as a function of vertical action depends on disc mass.
Centre for Mathemat ica l Sc iences Div is ion of Mathemat ics and Numerica l Analys is Course Analysis for MATA21 Analysis in One Variable, Spring 2023 Course Information Lecturer: Jan-Fredrik Olsen Teaching assistants: Joakim Cronvall, Alex Bergman Number of students: 82 newly registered and 20 re-registered. 30 students answered the course evaluation, of which 23 are enrolled on BSc Physics and
https://www.maths.lu.se/fileadmin/maths/Matematik_NF/Kursutvaerderingar/VT2023/MATA21VT23.pdf - 2026-05-28
We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain the low-energy constants of chiral perturbation theory. Bounds are produced for 2, 3 or more flavours in meson-meson scattering with equal meson masses, up to and including next-to-next-to-leading order (NNLO), using the second and higher derivatives of the amplitude. We enhanc
The Pythia event generator is used in several contexts to study hadron and lepton interactions, notably p p and p p ¯ collisions. In this article we extend the hadronic modelling to encompass the collision of a wide range of hadrons h with either a proton or a neutron, or with a simplified model of nuclear matter. To this end we model hp total and partial cross sections as a function of energy, an
The extraction of the W-boson mass, a fundamental parameter of the Standard Model, from hadron-hadron collision requires precise theory predictions. In this regard, angular coefficients are crucial to model the dynamics of W-boson production. In this work, we provide, for the first time, angular coefficients at NNLO QCD + NLO EW accuracy for finite transverse momentum W-boson at the LHC. The corre
Jet quenching in heavy ion collisions and in particular the sub-structure of quenched jets are promising tools for investigating the microscopic processes underlying jet quenching and the background medium's response to energy and momentum depositions. A quantitative understanding of the data can, however, be complicated by the presence of initial state radiation in reconstructed jets. Using an ex
Different aspects of the strong interaction in particle collisions are studied. Most of the work is based on the Lund string fragmentation model for hadron production. A model which incorporates interference between identical bosons in the string model is presented. With this model the consequences for the Bose-Einstein effect are investigated in detail. What happens at the end of the QCD cascades
We develop a general recipe for constructing orthogonal bases for the calculation of color structures appearing in QCD for any number of partons and arbitrary N-c. The bases are constructed using hermitian gluon projectors onto irreducible subspaces invariant under SU(N-c). Thus, each basis vector is associated with an irreducible representation of SU(N-c). The resulting multiplet bases are not on
Using Chiral Perturbation Theory at one-loop we analyze the consequences of twisted boundary conditions. We point out that due to the broken Lorentz and reflection symmetry a number of unexpected terms show up in the expressions. We explicitly discuss the pseudo-scalar octet masses, axial-vector and pseudo-scalar decay constants and electromagnetic form-factors. We show how the Ward identities are
General-purpose Monte Carlo event generators have become important tools in particle physics, allowing the simulation of exclusive hadronic final states. In this article we examine the PYTHIA 8 generator, in particular focusing on its parton-shower algorithms. Some relevant new additions to the code are introduced, that should allow for a better description of data. We also implement and compare w
Gravitational scattering in the ADD-model is considered at both sub- and transplanckian energies using a common formalism. By keeping a physical cut-off in the KK tower associated with virtual KK exchange, such as the cut-off implied from a finite brane width, troublesome divergences are removed from the calculations in both energy ranges. The scattering behavior depends on three different energy
Abstract in UndeterminedIn this article we describe Professor, a new program for tuning model parameters of Monte Carlo event generators to experimental data by parameterising the per-bin generator response to parameter variations and numerically optimising the parameterised behaviour. Simulated experimental analysis data is obtained using the Rivet analysis toolkit. This paper presents the Profes
We study the radiation of a highly energetic partonic antenna in a colored state traversing a dense QCD medium. Resumming multiple scatterings of all involved constituents with the medium we derive the general gluon spectrum which encompasses both longitudinal color coherence between scattering centers in the medium, responsible for the well known Landau-Pomeranchuk-Migdal (LPM) effect, and transv
We apply the resummed version of the Luscher formula to analyze finite volume corrections to the mass of the nucleon and of heavy mesons. We show that by applying the subthreshold expansion of the scattering amplitudes one can express the finite volume corrections in terms of only a few physical observables and the size of the box. In the case of the nucleon, the available information about the qu
In this paper we derive an integral equation for the evolution of unintegrated (longitudinally) polarized quark and gluon parton distributions. The conventional Catani-Ciafaloni-Fiorani-Marchesini (CCFM) framework is modified at small x in order to incorporate the QCD expectations concerning the double ln(2)(1/x) resummation at low x for the integrated distributions. Complete Altarelli-Parisi spli
