In an emergent spacetime framework where relative distances between quantum systemsare determined by the mutual information between the systems, an entangled pairmust be shown to have a non-zero distance even though its mutual information is maximalby virtue of being maximally entangled. This report shows that in fact an entangledpair is only maximally entangled in some degrees of freedom such as spin, and when oneintroduces other quantum degrees of freedom the mutual information is no longer maximaland so a non-zero distance can be recovered. In light of a conjectured relationshipbetween Einstein–Rosen Bridges (ER) and entangled Einstein–Podolsky–Rosen (EPR)pairs called ER = EPR, what appeared as a wormhole forming between the two quantumsystems was an artefact of our ignorance of all quantum information associated with thesystems. / I ett ramverk för emergent rumstid där relativa avstånd mellan kvantsystem bestäms av ömsesidig information mellan systemen måste ett sammanflätat par påvisas ha ett nollskiltavstånd även fast dess ömsesidiga information är maximal eftersom de är maximaltsammanflätade. Detta examensarbete visar att ett sammanflätat par är endast maximaltsammanflätade i vissa frihetsgrader som spinn, och när man introducerar andra frihetsgrader så är ömsesidiga informationen inte längre maximal och således kan man få ettnollskilt avstånd. Med hänsyn till ett förmodat förhållande mellan Einstein–Rosen bryggor(ER) och sammanflätade Einstein–Podolsky–Rosen par som benämns ER = EPR,det som framstår vara ett maskhål mellan två kvantsystem var således ett artefakt av vår ignorans för all kvantinformation associerat med systemen.

No description available.

Compact smooth n-dimensional manifolds admit handle decompositions. Here a k-handleis a product of disks of dimension k and (n-k) and the decomposition says how the handles areglued together. If the manifold is connected it has a handle decomposition with only one0-handle. The dimension k de Rham cohomology of a manifold is its closed k-forms divided byits exact k-forms. We compute the de Rham cohomology from a handle decomposition, bytreating all handles as having infinitesimal size. This gives a description in terms of forms on the0-handle that satisfies certain conditions at the boundary. We work this out for spheres of anydimension and for orientable surfaces.

The Future Circular electron-positron Collider (FCC-ee) is a high luminosity frontier particle accelerator for high precision measurements of the heaviest fundamental particles and possible evidence of new physics. Heavy Neutral Leptons (HNLs) are examples of new particles with discovery potential at the FCC-ee that could answer some of the most substantial questions in particle physics, such as how neutrinos oscillate between flavour eigenstates. Their estimated discovery region at the FCC-ee includes masses and mixing angles that allow the HNLs to attain long-lived properties. Therefore, long-lived signatures such as displaced vertices can be considered in this search for these particles. This thesis presents the first sensitivity analysis of these long-lived HNLs in the FCC-ee framework for the experimental run at the Z pole. The signal simulation used the Type I Seesaw mechanism with one benchmark HNL mixing with electron flavours and leptonic final states with electrons and electron neutrinos. An analysis of the signal and background is given, which results in a proposed event selection to reduce the background and increase the signal sensitivity. The final results include a sensitivity plot as a function of mass and mixing angle. This first successful implementation of a HNL analysis in future colliders can be used as a foundation for future explorations of long-lived HNLs at FCC-ee.

Observations of gamma-rays have been made from objects such as active galaxies and supernova remnants and also as diffuse emission from the Galactic ridge. The study of gamma-rays can provide information about production mechanisms and tell us about cosmic ray acceleration. In the high energy regime, the dominant mechanism for gamma-ray production is the decay of neutral pions produced in interactions of accelerated cosmic ray nuclei and interstellar matter. Having an accurate model for this is an integral part in the study of gamma-rays and the sources in which they are produced. We present here a parametric model for calculations of inclusive cross sections for stable secondary particles (gamma-rays, electrons, positrons, nue, anti nue, numu and anti numu) produced in proton-proton interactions. The model is based on the up-to-date proton-proton interaction model by Kamae et al., which includes the diffraction dissociation process, violation of the Feynman scaling law and the logarithmically rising inelastic proton-proton cross section. To improve fidelity to experimental data for lower energies, two baryon resonance excitation processes were added to the model: one representing the Δ(1232) and the other multiple resonances with masses around 1600 MeV/c^2. The parametric model predicts the spectra for all secondary particles to be harder by about 0.05 in power-law index than that of the incident proton and their inclusive cross sections to be larger than those predicted by previous models based on Feynman scaling. The transverse momentum distributions for gamma-rays have also been calculated from the described proton-proton interaction model, showing the potential of also having a parametric model for the transverse momentum distributions. / QC 20101117

The Stockholm Educational Air Shower Array (SEASA) project is deploying an array of plastic scintillator detector stations on school roofs in the Stockholm area. Signals from GPS satellites are used to time synchronise signals from the widely separated detector stations, allowing cosmic ray air showers to be identified and studied. A low-cost and highly scalable data acquisition system has been produced using embedded Linux processors which communicate station data to a central server. Air shower data can be visualised in real-time using a Java-applet client. The design and performance of the first three detector stations located at the AlbaNova University Centre are presented. The detectors have been running since the beginning of October 2005 and the data from this period is analysed to assess the stability and performance of the detector array. A total of 503 showers with a primary particle energy above 1016 eV, hitting all three detector stations simultaneously, have been detected during this period. The read out and data-base system used to collect the data are described together with a quicklook tool for ensuring the integrity of the data. A preliminary study of the acceptance of the detector array as a function of weather conditions, to be used in future studies of cosmic ray anisotropy, is presented. The acceptance of the single detector stations is found to decrease with increasing atmospheric pressure and to stay constant over a large range of temperatures. The acceptance of the entire array of detector stations is found to have a stronger continuous dependence on temperature than single stations. The dependence of the array acceptance on pressure is inconclusive. The ability of the array to reconstruct the primary cosmic ray direction is assessed with simulations. A critical feature for the reconstruction is the time resolution of the system. The performance of the GPS system is therefore tested, and the time resolution is found to be better than 15 ns for all tested GPS units. The angular resolution of the array for this time resolution is found to be (7.0\pm0.3)^{\circ}. As the time resolution is expected to decrease for a larger array of detectors, the dependency of the time resolution on the angular resolution is derived. The measured distribution of the primary cosmic ray arrival direction is derived and compared to the expected distribution to check the performance of the system. The agreement between the distributions is good and the GPS timing system can therefore be concluded to work well. The simulations also show that the energy threshold of the array is slightly above 1016 eV. A preliminary study of the cosmic ray anisotropy is presented. The hypothesis of an isotropic flux of cosmic rays was tested using a two point correlation function. The probability that the observed flux is a random sampling from an isotropic flux was checked with a Kolmogorov test and it was found to be 82%. The hypothesis of an isotropic flux is therefore supported. / QC 20101116

QC 20101123

QC 20101124

Atomic nuclei are complex many-body systems and exhibit an interplay between single-particle and collective degrees of freedom. In order to describe and predict the “behavior” of nucleons inside the nuclei a variety of theoretical models have been created, each applicable to their own domain of nuclear phenomena. Experimental information is needed in order to test and improve the various theoretical models with the ultimate goal of creating unified theory of nuclear structure. In-beam γ-ray spectroscopy is one way of probing the inner structure of nuclei and it is the subject of this thesis, which describes the first identification of excited states in the extremely neutron deficient nuclei 106Te and 107Te. The experiments were performed at the Accelerator Laboratory of the University of Jyväskylä, Finland, using the recoil-decay tagging technique. Prompt γ rays emitted following fusion evaporation reactions were detected by the Jurogam detector array and the selection of the γ rays of interest was based on the recoil identification provided by the RITU gas-filled recoil separator and the GREAT focal plane spectrometer. The production cross sections were estimated to be 25nb and 1μb for 106Te and 107Te, respectively. In case of the nucleus 106Te, several γ rays have been observed. A vibrational-like yrast band has been suggested. For 107Te a number of γ rays have been assigned and a tentative partial level scheme has been suggested. The experimental data have been compared to shell model calculations. / QC 20101115

No description available.