Squarks and Gluinos Searches at the Tevatron

Squarks and Gluinos Searches at the Tevatron
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Release: 2008
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A search for squarks and gluinos performed by the CDF and D0 collaborations is presented. The sample taken during the RunII of the Fermilab TeVatron collider at (square root)s = 1.96 TeV is used. Supersymmetry (SUSY) is one of the most promising ways to solve crucial problems of the Standard Model (SM). This spacetime symmetry links bosons to fermions by introducing supersymmetric partners (sparticles) to all SM particles: squarks and gluinos are SUSY partners of quarks and gluons. The mass difference between the squark mass eigenstates depend on the mass of the corresponding quark. Hence squarks are (to a good approximation) mass degenerate for the two first generations whereas a (potentially) large mixing may appear for the third family, leading to a light stop. The former case corresponds to squarks and gluinos searches whereas dedicated searches for stop are performed for the latter.

Searching for Squarks

Searching for Squarks
Author: Samuel Jones
Publisher: Springer Nature
Total Pages: 223
Release: 2020-08-27
Genre: Science
ISBN: 3030542882

This thesis focuses on searches for squarks with the ATLAS detector in "compressed" scenarios where the scalar top is very close in mass to the lightest supersymmetric particle. These models are theoretically appealing because the presence of a quasi-degenerate scalar top enhances the self-annihilation cross-section of the lightest supersymmetric particle, acting therefore as a regulator of the dark matter relic density. Two main analyses are presented: the first is a search for scalar tops decaying to charm quarks. The identification of jets originating from the charm quark is very challenging due to its short lifetime. The calibration of tools for charm-tagging has paved the way to measuring the decay of the Higgs boson to pairs of charm quarks. The second analysis presented is the development of a novel technique for reconstructing low momentum b-hadrons. This tool has enabled the ATLAS collaboration to explore topologies that were previously inaccessible.

The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction

The Search for Supersymmetry in Hadronic Final States Using Boosted Object Reconstruction
Author: Giordon Stark
Publisher: Springer Nature
Total Pages: 263
Release: 2020-03-13
Genre: Science
ISBN: 3030345483

This thesis represents one of the most comprehensive and in-depth studies of the use of Lorentz-boosted hadronic final state systems in the search for signals of Supersymmetry conducted to date at the Large Hadron Collider. A thorough assessment is performed of the observables that provide enhanced sensitivity to new physics signals otherwise hidden under an enormous background of top quark pairs produced by Standard Model processes. This is complemented by an ingenious analysis optimization procedure that allowed for extending the reach of this analysis by hundreds of GeV in mass of these hypothetical new particles. Lastly, the combination of both deep, thoughtful physics analysis with the development of high-speed electronics for identifying and selecting these same objects is not only unique, but also revolutionary. The Global Feature Extraction system that the author played a critical role in bringing to fruition represents the first dedicated hardware device for selecting these Lorentz-boosted hadronic systems in real-time using state-of-the-art processing chips and embedded systems.

Supersymmetric Beasts and Where to Find Them

Supersymmetric Beasts and Where to Find Them
Author: Marco Valente
Publisher: Springer Nature
Total Pages: 231
Release: 2022-03-05
Genre: Science
ISBN: 3030940470

After an extensive overview of the Standard Model and of the theory and phenomenology of Supersymmetry, this book describes the recent development of the ATLAS Particle Flow algorithm, a hadronic reconstruction technique aiming at enhancing the sensitivity of the experiment to new physics through the combination of the information from different ATLAS sub-detectors. The first ever ATLAS strong SUSY search exploiting this technique is also described, reporting the results and exclusion limits obtained using the complete proton-proton collision dataset recorded by the ATLAS experiment during the second Run of the Large Hadron Collider (LHC).

Farewell to Reality

Farewell to Reality
Author: Jim Baggott
Publisher: Simon and Schuster
Total Pages: 471
Release: 2021-11-15
Genre: Science
ISBN: 1639360387

From acclaimed science author Jim Baggot, a lively, provocative, and “intellectually gratifying” critique of modern theoretical physics (The Economist). In this stunning new volume, Jim Baggott argues that there is no observational or experimental evidence for many of the ideas of modern theoretical physics: super-symmetric particles, superstrings, the multiverse, the holographic principle, or the anthropic cosmological principle. These theories are not only untrue, it is not even science. It is fairy-tale physics: fantastical, bizarre and often outrageous, perhaps even confidence-trickery. This book provides a much-needed antidote. Informed, comprehensive, and balanced, it offers lay readers the latest ideas about the nature of physical reality while clearly distinguishing between fact and fantasy. With its engaging portraits of many central figures of modern physics, including Paul Davies, John Barrow, Brian Greene, Stephen Hawking, and Leonard Susskind, it promises to be essential reading for all readers interested in what we know and don''''t know about the nature of the universe and reality itself.

History of Original Ideas and Basic Discoveries in Particle Physics

History of Original Ideas and Basic Discoveries in Particle Physics
Author: Harvey B. Newman
Publisher: Springer Science & Business Media
Total Pages: 986
Release: 2012-12-06
Genre: Science
ISBN: 1461311470

The International Conference on the History of Original Ideas and Basic Discoveries, held at the "Ettore Majorana" Centre for Scientific Culture in Erice, Sicily, July 27-August 4, 1994, brought together sixty of the leading scientists including many Nobel Laureates in high energy physics, principal contributors in other fields of physics such as high Tc superconductivity, particle accelerators and detector instrumentation, and thirty-six talented younger physicists selected from candidates throughout the world. The scientific program, including 49 lectures and a discussion session on the "Status and Future Directions in High Energy Physics" was inspired by the conference theme: The key experimental discoveries and theoretical breakthroughs of the last 50 years, in particle physics and related fields, have led us to a powerful description of matter in terms of three quark and three lepton families and four fundamental interactions. The most recent generation of experiments at e+e- and proton-proton colliders, and corresponding advances in theoretical calculations, have given us remarkably precise determinations of the basic parameters of the electroweak and strong interactions. These developments, while showing the striking internal consistency of the Standard Model, have also sharpened our view of the many unanswered questions which remain for the next generation: the origin and pattern of particle masses and families, the unification of the interactions including gravity, and the relation between the laws of physics and the initial conditions of the universe.

The Large Hadron Collider

The Large Hadron Collider
Author: Thomas Schörner-Sadenius
Publisher: Springer
Total Pages: 554
Release: 2015-05-15
Genre: Science
ISBN: 3319150014

This comprehensive volume summarizes and structures the multitude of results obtained at the LHC in its first running period and draws the grand picture of today’s physics at a hadron collider. Topics covered are Standard Model measurements, Higgs and top-quark physics, flavour physics, heavy-ion physics, and searches for supersymmetry and other extensions of the Standard Model. Emphasis is placed on overview and presentation of the lessons learned. Chapters on detectors and the LHC machine and a thorough outlook into the future complement the book. The individual chapters are written by teams of expert authors working at the forefront of LHC research.