Observability of bbZ Events at CMS as a Benchmark for MSSM bbH Search

The Z boson production in association with two b quarks is studied as a benchmark for MSSM bbH production with H->tautau decay in CMS. An analysis using Z bosons in real data can be used to test the methods and techniques needed for reconstructing the Higgs boson. The bbZ measured from data can be used to verify the theoretical predictions for the cross section, and Z boson and b quark transverse momentum distributions. Understanding the bbZ production at LHC helps us to understand and better trust the predictions for the associated Higgs bosons production

A Novel Method of Microendoscopic GRIN Lens Implantation for In Vivo Imaging of Mouse Neural Tissue

Työn tarkoituksena oli suunnitella ja toteuttaa luotettava, nopea ja tarkka keino mikroendoskooppisten GRIN-linssien implantoimiseksi. Aikaisemmat implantointitavat toteutettiin manuaalisesti (käsin), jonka seurauksena implantointi oli usein epätarkkaa. Implantointi oli jaettu kahteen eri vaiheeseen virusvektori ekspressioviiveen seurauksena, joka vaikutti negatiivisesti implantointitarkkuuteen. Tämä prosessi yhdistettiin yhdeksi kirurgiaksi suunnitteluratkaisun avulla käyttäen kahta neulankärkeä, jotka ovat yleisiä käyttötavaroita neurologiseen tutkimukseen erikoistuneissa laboratorioissa. Laite koostuu lukuisista 3D-tulostetuista osista, vertikaalisista ruuviaktuaattoreista, kontaktisensoreista, Arduino-piiristä sekä ruiskumännästä ja kahdesta neulasta. 3D-tulostetut osat tulostettiin Prusa i3 Mk2 -tulostimella 0.4- ja 0.12 mm suutikärkiä käyttäen PLA- muovista. Kontrollointiohjelmisto kirjoitettiin C# -kielellä Arduino IDE:tä hyödyntäen. Laitteen toimivuus varmistettiin agargeelillä, jolla simuloitiin aivokudosta. Laite omaa minimaalisen X- ja Y-aksiaalisen heilumisen ja mitättömän Z-aksiaalisen heilumisen. Laite on kykeneväinen lukuisiin yhtäjaksoisiin implantointikirurgioihin sekä on helposti ja halvasti tuotettavissa.The goal of this thesis was to engineer a reliable, fast and accurate method for microendoscopic GRIN lens implantation. The previous method involved manual installation and often proved inaccurate due to relatively small margin of error in implantation. Additionally, the process was divided into two separate surgeries due to viral vector expression delay. To mimic the previous process a mechanical solution was implemented. The solution involved designing a 3D-printed ensemble capable of accurately implanting a GRIN lens to a desired location without causing unnecessary trauma to surrounding tissue. The implantation process was combined to a single surgery with design solutions and utilized two injection needles which are commonplace equipment in laboratories specialized in neurological research and animal testing. The ensemble is comprised of multiple 3D-printed chasses, vertical screw actuators, contact sensors, Arduino chip and a syringe with two needles. The parts were printed with PLA on a Prusa i3 Mk2 with 0.4 and 0.12mm nozzles. All designs were made in Autodesk fusion 360. The control software was written in C# using Arduino libraries. The ensemble was tested using simulated neural matter via agar gel. The ensemble holds minimal X- and Y-axial sway and negligible Z-axial sway. Additionally, the ensemble is capable of multiple surgeries in a row and is easily and cheaply manufactured

Search for Higgs Bosons in SUSY Cascades in CMS and Dark Matter with Non-universal Gaugino Masses

In grand unified theories (GUT), non-universal boundary conditions for the gaugino masses may arise at the unification scale, and affect the observability of the neutral MSSM Higgs bosons (h/H/A) at the LHC. The implications of such non-universal gaugino masses are investigated for the Higgs boson production in the SUSY cascade decay chain gluino --> squark quark, squark --> neutralino_2 quark, neutralino_2 --> neutralino_1 h/H/A, h/H/A --> b b-bar produced in pp interactions. In the singlet representation with universal gaugino masses only the light Higgs boson can be produced in this cascade with the parameter region of interest for us, while with non-universal gaugino masses heavy neutral MSSM Higgs boson production may dominate. The allowed parameter space in the light of the WMAP constraints on the cold dark matter relic density is investigated in the above scenarios for gaugino mass parameters. We also demonstrate that combination of representations can give the required amount of dark matter in any point of the parameter space. In the non-universal case we show that heavy Higgs bosons can be detected in the studied cascade in parameter regions with the WMAP preferred neutralino relic density.Comment: LaTeX (svjour,rotating,multirow,url,subfig,psfrag), 18 pages, 36 eps figure

"Pay Now, Argue Later" Rule – Before and After the Tax Administration Act

The South African Revenue Service (SARS) is entrusted with the duty of collecting tax on behalf of the South African government. In order to ensure effective and prompt collection of taxes, the payment of tax is not suspended pending an objection or an appeal, unless directed otherwise. This is also known as the "pay now, argue later" rule, and, for value-added tax purposes, is provided for in terms of section 36 of the Value-Added Tax Act 89 of 1991. The "pay now, argue later" rule in terms of section 36 of the Value-Added Tax Act prima facie infringes on a taxpayer's right of access to the courts as envisaged in section 34 of the Constitution. This is due to the fact that a taxpayer is obliged to pay tax before being afforded the opportunity to challenge the assessment in a court. In Metcash Trading Ltd v Commissioner for the South African Revenue Service, the Constitutional Court held the "pay now, argue later" rule in terms of section 36 to be constitutional. Olivier, however, does not agree with the court on several matters. Amongst the problems she indicates are that the taxpayer does not have access to the courts at the time the rule is invoked, and that the court did not consider the fact that there might be less invasive means available which would ensure that SARS's duty is balanced with the taxpayer's right of access to the courts. Guidelines were also issued which provide legal certainty regarding the factors SARS may consider in determining whether the payment of tax should be suspended or not. These guidelines also evoked some points of criticism. Since 1 October 2012, the "pay now, argue later" rule has been applied in terms of section 164 of the Tax Administration Act 28 of 2011. The question arises whether this provision addresses the problems identified in respect of section 36 of the Value-Added Tax Act and the guidelines. In comparing these sections, only slight differences emerged. The most significant difference is that section 164(6) of the Tax Administration Act stipulates that the enforcement of tax be suspended for a period when SARS is considering a request for suspension. Section 164(6) does not provide a solution to the problems identified regarding section 36 of the Value-Added Tax Act. It is even possible that this section could give rise to further problems. Therefore, the legislature has failed to address the imbalance between the duties of SARS and the right of a taxpayer to access the courts.   

Ideal tau tagging with the multivariate data-analysis toolkit TMVA

Peer reviewe

CMS The Computing Project : Technical Design Report

Peer reviewe

Search for neutral color-octet weak-triplet scalar particles in proton-proton collisions at root s=8TeV

Peer reviewe

Search for new physics in events with same-sign dileptons and jets in pp collisions at √s=8 TeV

Peer reviewe

Identification techniques for highly boosted W bosons that decay into hadrons

Peer reviewe