Detection of New Heavy Gauge Bosons W' in CMS

A first feasibility study of the search for a new heavy charged gauge boson with the CMS detector at the Large Hadron Collider LHC is presented. The used model assumes the existence of a heavy carbon copy of the Standard Model W (Reference Model by Altarelli), generically denoted as W'. Such a boson has been investigated in the decay channel W' --> mu nu using the full detector simulation including minimum bias events (pile-up) according to the luminosity expected in the first years. All relevant Standard Model backgrounds have been considered. Such a new boson is expected to be discovered, if existing, with a mass up to 4.6 TeV for an integrated luminosity of 10 fb^-1. The range can be expanded to 6.1 TeV with an integrated luminosity of 300 fb^-1. If no signs for a Wprime boson appear 95 % CL exclusion limits of 4.7 TeV and 6.2 TeV can be set, respectively

Detection of New Heavy Charged Gauge Bosons in the Muon plus Neutrino Channel

This note presents a feasibility study of the search for a new heavy charged gauge boson with the CMS detector at the Large Hadron Collider LHC. The model assumes the existence of a heavy carbon copy of the Standard Model W (Reference Model by Altarelli) generically denoted as Wprime. Such a boson has been investigated in the decay channel Wprime --> \mu \nu using the full detector simulation including minimum bias events (pile-up) according to the expected first years of luminosity. All relevant Standard Model backgrounds have been considered. Such a new boson is expected to be discovered, if existant, with a mass of 0.1-4.6 TeV for an integrated luminosity of 10 fb^-1. The range can be expanded to 6.1 TeV with an integrated luminosity of 300 fb^-1. If no signs for a Wprime boson appear 95% CL exclusion limits of 4.7 TeV and 6.2 TeV can be set respectively

Phylogenetic signals in the climatic niches of the world’s amphibians

The question of whether closely related species share similar ecological requirements has attracted increasing attention, because of its importance for understanding global diversity gradients and the impacts of climate change on species distributions. In fact, the assumption that related species are also ecologically similar has often been made, although the prevalence of such a phylogenetic signal in ecological niches remains heavily debated. Here, we provide a global analysis of phylogenetic niche relatedness for the world's amphibians. In particular, we assess which proportion of the variance in the realised climatic niches is explained on higher taxonomic levels, and whether the climatic niches of species within a given taxonomic group are more similar than between taxonomic groups. We found evidence for phylogenetic signals in realised climatic niches although the strength of the signal varied among amphibian orders and across biogeographical regions. To our knowledge, this is the first study providing a comprehensive analysis of the phylogenetic signal in species climatic niches for an entire clade across the world. Even though our results do not provide a strong test of the niche conservatism hypothesis, they question the alternative hypothesis that niches evolve independently of phylogenetic influences

Report on the Workshop on Sustainable Software Sustainability 2019 (WOSSS19)

This report is based on the discussions and presentations that took place at the Workshop on Sustainable Software Sustainability (www.software.ac.uk/wosss19) in April 2019 (WOSSS19). It captures the state of the art for a range of Software Sustainability themes that were brought up by the organisers and attendees of the workshop

Implementation of a model-independent search for new physics with the CMS detector exploiting the world-wide LHC Computing Grid

With this year's start of CERN's Large Hadron Collider (LHC) it will be possible for the first time to directly probe the physics at the TeV-scale at a collider experiment. At this scale the Standard Model of particle physics will reach its limits and new physical phenomena are expected to appear. This study performed with one of the LHC's experiments, namely the Compact Muon Solenoid (CMS), is trying to quantify the understanding of the Standard Model and is hunting for deviations from the expectation by investigating a large fraction of the CMS data. While the classical approach for searches of physics beyond the Standard Model assumes a specific theoretical model and tries to isolate events with a certain signature characteristic for the new theory, this thesis follows a model-independent approach. The method relies only on the knowledge of the Standard Model and is suitable to spot deviations from this model induced by particular theoretical models but also theories not yet thought of. Future data are to be compared to the expectation in several hundreds of final state topologies and a few variables of general sensitivity to deviations like invariant masses. Within this feasibility study, events are classified according to their particle content (muons, electrons, photons, jets, missing energy) into so called event classes. A broad data scan is performed by investigating distributions searching for significant deviations fr om the Standard Model. Systematic uncertainties are rigourously taken into account within the analysis. Several theoretical models such as supersymmetry, new heavy gauge bosons and microscopic black holes as well as possible detector effects in the early data have been fed into the search algorithm as benchmark scenarios and proof the ability to supplement the traditional model-driven searches. Due to the enormous computing resource required for such an analysis performing a multitude of classical analyses in parallel the approach would not be feasible without the increasing performance and decreasing costs of modern computing systems. The LHC and its experiments with expected data rates of several 10~PetaBytes per year face this challenge with a distributed, locally organized computing and storage network: the LHC Computing Grid. The CMS tools embedded in such an environment and its application are demonstrated within this work

Searches for Supersymmetry in All-Hadronic and Lepton+Jets+MET Final States in CMS

Soon after the LHC goes online, one of the primary topics for the CMS experiment will be the search for new phenomena like Supersymmetry (SUSY). If SUSY manifests itself at a low mass scale it might be found already in the early phase of the LHC. A generic signature for SUSY in $pp$-collisions is a large multiplicity of hard jets, high missing transverse energy (\mbox{$\not \hspace{-0.11cm} E_T$}), and possibly leptons in the final state. The CMS search strategy and prospects for SUSY discovery in the all-hadronic final states and in events including additional charged leptons are reviewed

Detection of New Heavy Charged Gauge Bosons with the Future CMS Detector

In this thesis a feasibility study of the search for a new heavy harged gauge boson ac- cording to the Reference Model by Altarelli with the CMS detector at the LHC is presented. The model assumes the existence of a heavy carbon copy of the Standard Model W with identical couplings, a suppressed coupling to W and Z bosons, and, among others, the de- cay into a charged lepton and a light neutrino. These particles, generically denoted as W ′ have been investigated in the decay channel W ′ → µν using the full detector simulation and including minimum bias events (pile-up) according to the low luminosity phase of the LHC. All Standard Model backgrounds have been considered. The discovery mass range for such new bosons is determined to be 0.14.6 TeV for an integrated luminosity of one year LHC operation (10 fb−1). The range an be expanded to 6.1 TeV with an integrated luminosity of 300 fb−1. If no signs appear 95% CL exclusion limits of 4.7 TeV and 6.2 TeV can be set respectively

Detection of new heavy gauge bosons W' in CMS

A first feasibility study of the search for a new heavy charged gauge boson with the CMS detector at the Large Hadron Collider LHC is presented. The used model assumes the existence of a heavy carbon copy of the Standard Model W (Reference Model by Altarelli), generically denoted as W'. Such a boson has been investigated in the decay channel W' --> mu nu using the full detector simulation including minimum bias events (pile-up) according to the luminosity expected in the first years. All relevant Standard Model backgrounds have been considered. Such a new boson is expected to be discovered, if existing, with a mass up to 4.6 TeV for an integrated luminosity of 10 fb^-1. The range can be expanded to 6.1 TeV with an integrated luminosity of 300 fb^-1. If no signs for a Wprime boson appear 95 % CL exclusion limits of 4.7 TeV and 6.2 TeV can be set, respectively