Author: Albert M. SirunyanPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Searches for Physics Beyond the Standard Model with the MT2 Variable in Hadronic Final States with and Without Disappearing Tracks in Proton-proton Collisions at √s
Author: Albert M. SirunyanSearch for New Physics with the MT2 Variable in All-jets Final States Produced in Pp Collisions at Sqrt(s)
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A search for new physics is performed using events that contain one or more jets, no isolated leptons, and a large transverse momentum imbalance, as measured through the MT2 variable, which is an extension of the transverse mass in events with two invisible particles. The results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and that corresponds to an integrated luminosity of 2.3 inverse femtobarns. The observed event yields in the data are consistent with predictions for the standard model backgrounds. The results are interpreted using simplified models of supersymmetry and are expressed in terms of limits on the masses of potential new colored particles. Assuming that the lightest neutralino is stable and has a mass less than about 500 GeV, gluino masses up to 1550-1750 GeV are excluded at 95% confidence level, depending on the gluino decay mechanism. For the scenario of direct production of squark-antisquark pairs, top squarks with masses up to 800 GeV are excluded, assuming a 100% branching fraction for the decay to a top quark and neutralino. Similarly, bottom squark masses are excluded up to 880 GeV, and masses of light-flavor squarks are excluded up to 600-1260 GeV, depending on the degree of degeneracy of the squark masses.
Search for New Physics in Fully Hadronic Nal States Using the MT2 Variable at a Center-of-mass Energy of 13 TeV with the CMS Detector
Author: Jason GranPublisher:
ISBN: 9781369147391
Category :
Languages : en
Pages : 139
Book Description
An inclusive search for new physics in events with fully hadronic final states using the MT2 variable is presented. The results are based on a sample of 13 TeV center-of-mass energy proton-proton collisions, corresponding to 2.3 fb-1 of integrated luminosity collected with the CMS detector at the LHC in 2015. No excess event yield above the Standard Model background expectation is observed. The results are interpreted as limits on simplified models of supersymmetry, expressed as limits on the masses of potential new colored particles. Assuming a stable LSP with mass less than 500 GeV, gluino masses up to 1550-1750 are excluded at 95% confidence level, depending on the gluino decay mechanism. For models of direct squark pair production, top squarks with masses up to 800 GeV are excluded. Bottom squarks with masses up to 880 GeV are excluded. Light flavor squarks with masses up to 600-1260 GeV, depending on the degeneracy of squark masses, are excluded.
Search for Exotic Long-lived Particles Using Disappearing Tracks with the CMS Experiment in Proton-proton Collisions at √s
Author: Viktor Gerhard KutznerPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
Weak Scale Supersymmetry
Author: Howard BaerPublisher: Cambridge University Press
ISBN: 1009289845
Category : Science
Languages : en
Pages : 557
Book Description
This OA text develops the basic concepts of supersymmetry for experimental and phenomenological particle physicists and graduate students.
The Anomalous Magnetic Moment of the Muon
Author: Fred JegerlehnerPublisher: Springer Science & Business Media
ISBN: 3540726330
Category : Science
Languages : en
Pages : 433
Book Description
This book reviews the present state of knowledge of the anomalous magnetic moment a=(g-2)/2 of the muon. The muon anomalous magnetic moment is one of the most precisely measured quantities in elementary particle physics and provides one of the most stringent tests of relativistic quantum field theory as a fundamental theoretical framework. It allows for an extremely precise check of the standard model of elementary particles and of its limitations.
Search for Heavy Di-boson Resonances Decaying to Boosted Hadronic Final States in Proton-proton Collision at √s
Author: Attilio PicazioThe Beyond the Standard Model Working Group
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 153
Book Description
In this working group we have investigated a number of aspects of searches for new physics beyond the Standard Model (SM) at the running or planned TeV-scale colliders. For the most part, we have considered hadron colliders, as they will define particle physics at the energy frontier for the next ten years at least. The variety of models for Beyond the Standard Model (BSM) physics has grown immensely. It is clear that only future experiments can provide the needed direction to clarify the correct theory. Thus, our focus has been on exploring the extent to which hadron colliders can discover and study BSM physics in various models. We have placed special emphasis on scenarios in which the new signal might be difficult to find or of a very unexpected nature. For example, in the context of supersymmetry (SUSY), we have considered: how to make fully precise predictions for the Higgs bosons as well as the superparticles of the Minimal Supersymmetric Standard Model (MSSM) (parts III and IV); MSSM scenarios in which most or all SUSY particles have rather large masses (parts V and VI); the ability to sort out the many parameters of the MSSM using a variety of signals and study channels (part VII); whether the no-lose theorem for MSSM Higgs discovery can be extended to the next-to-minimal Supersymmetric Standard Model (NMSSM) in which an additional singlet superfield is added to the minimal collection of superfields, potentially providing a natural explanation of the electroweak value of the parameter [mu] (part VIII); sorting out the effects of CP violation using Higgs plus squark associate production (part IX); the impact of lepton flavor violation of various kinds (part X); experimental possibilities for the gravitino and its sgoldstino partner (part XI); what the implications for SUSY would be if the NuTeV signal for di-muon events were interpreted as a sign of R-parity violation (part XII). Our other main focus was on the phenomenological implications of extra dimensions. There, we considered: constraints on Kaluza Klein (KK) excitations of the SM gauge bosons from existing data (part XIII) and the corresponding projected LHC reach (part XIV); techniques for discovering and studying the radion field which is generic in most extra-dimensional scenarios (part XV); the impact of mixing between the radion and the Higgs sector, a fully generic possibility in extra-dimensional models (part XVI); production rates and signatures of universal extra dimensions at hadron colliders (part XVII); black hole production at hadron colliders, which would lead to truly spectacular events (part XVIII). The above contributions represent a tremendous amount of work on the part of the individuals involved and represent the state of the art for many of the currently most important phenomenological research avenues. Of course, much more remains to be done. For example, one should continue to work on assessing the extent to which the discovery reach will be extended if one goes beyond the LHC to the super-high-luminosity LHC (SLHC) or to a very large hadron collider (VLHC) with √s ≈ 40 TeV. Overall, we believe our work shows that the LHC and future hadronic colliders will play a pivotal role in the discovery and study of any kind of new physics beyond the Standard Model. They provide tremendous potential for incredibly exciting new discoveries.
Top Quark Physics at Hadron Colliders
Author: Arnulf QuadtPublisher: Springer Science & Business Media
ISBN: 3540710604
Category : Science
Languages : en
Pages : 166
Book Description
This will be a required acquisition text for academic libraries. More than ten years after its discovery, still relatively little is known about the top quark, the heaviest known elementary particle. This extensive survey summarizes and reviews top-quark physics based on the precision measurements at the Fermilab Tevatron Collider, as well as examining in detail the sensitivity of these experiments to new physics. Finally, the author provides an overview of top quark physics at the Large Hadron Collider.
Lectures on LHC Physics
Author: Tilman PlehnPublisher: Springer
ISBN: 3319059424
Category : Science
Languages : en
Pages : 340
Book Description
With the discovery of the Higgs boson, the LHC experiments have closed the most important gap in our understanding of fundamental interactions, confirming that such interactions between elementary particles can be described by quantum field theory, more specifically by a renormalizable gauge theory. This theory is a priori valid for arbitrarily high energy scales and does not require an ultraviolet completion. Yet, when trying to apply the concrete knowledge of quantum field theory to actual LHC physics - in particular to the Higgs sector and certain regimes of QCD - one inevitably encounters an intricate maze of phenomenological know-how, common lore and other, often historically developed intuitions about what works and what doesn’t. These lectures cover three aspects to help understand LHC results in the Higgs sector and in searches for physics beyond the Standard Model: they discuss the many facets of Higgs physics, which is at the core of this significantly expanded second edition; then QCD, to the degree relevant for LHC measurements; as well as further standard phenomenological background knowledge. They are intended to serve as a brief but sufficiently detailed primer on LHC physics to enable graduate students and all newcomers to the field to find their way through the more advanced literature, and to help those starting to work in this very timely and exciting field of research. Advanced readers will benefit from this course-based text for their own lectures and seminars. .