Search for Resonances Decaying to a Z Boson and a Photon in the ATLAS Detector Using Data from the Large Hadron Collider

Search for Resonances Decaying to a Z Boson and a Photon in the ATLAS Detector Using Data from the Large Hadron Collider PDF Author: N. P. Readioff
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Languages : en
Pages :

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Search for Resonances Decaying to a Z Boson and a Photon in the ATLAS Detector Using Data from the Large Hadron Collider

Search for Resonances Decaying to a Z Boson and a Photon in the ATLAS Detector Using Data from the Large Hadron Collider PDF Author: N. P. Readioff
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Physics with Photons Using the ATLAS Run 2 Data

Physics with Photons Using the ATLAS Run 2 Data PDF Author: Stefano Manzoni
Publisher: Springer
ISBN: 3030243702
Category : Science
Languages : en
Pages : 265

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Book Description
The work presented in this book is based on the proton-proton collision data from the Large Hadron Collider at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector in 2015 and 2016. The research program of the ATLAS experiment includes the precise measurement of the parameters of the Standard Model, and the search for signals of physics beyond the SM. Both these approaches are pursued in this thesis, which presents two different analyses: the measurement of the Higgs boson mass in the di-photon decay channel, and the search for production of supersymmetric particles (gluinos, squarks or winos) in a final state containing two photons and missing transverse momentum. Finally, ATLAS detector performance studies, which are key ingredients for the two analyses outlined before, are also carried out and described.

Searches for Dijet Resonances

Searches for Dijet Resonances PDF Author: Lydia Audrey Beresford
Publisher: Springer
ISBN: 331997520X
Category : Science
Languages : en
Pages : 175

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Book Description
This book addresses one of the most intriguing mysteries of our universe: the nature of dark matter. The results presented here mark a significant and substantial contribution to the search for new physics, in particular for new particles that couple to dark matter. The first analysis presented is a search for heavy new particles that decay into pairs of hadronic jets (dijets). This pioneering analysis explores unprecedented dijet invariant masses, reaching nearly 7 TeV, and sets constraints on several important new physics models. The two subsequent analyses focus on the difficult low dijet mass region, down to 200 GeV, and employ a novel technique to efficiently gather low-mass dijet events. The results of these analyses transcend the long-standing constraints on dark matter mediator particles set by several existing experiments.

Search for Scalar Diphoton Resonances in the Mass Range 65-600 GeV with the ATLAS Detector in [math Display

Search for Scalar Diphoton Resonances in the Mass Range 65-600 GeV with the ATLAS Detector in [math Display PDF Author:
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Category :
Languages : en
Pages :

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A search for scalar particles decaying via narrow resonances into two photons in the mass range 65-600 GeV is performed using 20.3 fb−1 of √s=8 TeV pp collision data collected with the ATLAS detector at the Large Hadron Collider. The recently discovered Higgs boson is treated as a background. No significant evidence for an additional signal is observed. The results are presented as limits at the 95% confidence level on the production cross section of a scalar boson times branching ratio into two photons, in a fiducial volume where the reconstruction efficiency is approximately independent of the event topology. Lastly, the upper limits set extend over a considerably wider mass range than previous searches.

Advances in Jet Substructure at the LHC

Advances in Jet Substructure at the LHC PDF Author: Roman Kogler
Publisher: Springer Nature
ISBN: 3030728587
Category : Science
Languages : en
Pages : 287

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Book Description
This book introduces the reader to the field of jet substructure, starting from the basic considerations for capturing decays of boosted particles in individual jets, to explaining state-of-the-art techniques. Jet substructure methods have become ubiquitous in data analyses at the LHC, with diverse applications stemming from the abundance of jets in proton-proton collisions, the presence of pileup and multiple interactions, and the need to reconstruct and identify decays of highly-Lorentz boosted particles. The last decade has seen a vast increase in our knowledge of all aspects of the field, with a proliferation of new jet substructure algorithms, calculations and measurements which are presented in this book. Recent developments and algorithms are described and put into the larger experimental context. Their usefulness and application are shown in many demonstrative examples and the phenomenological and experimental effects influencing their performance are discussed. A comprehensive overview is given of measurements and searches for new phenomena performed by the ATLAS and CMS Collaborations. This book shows the impressive versatility of jet substructure methods at the LHC.

Search for Resonances in Diphoton Events at $\sqrt{s}

Search for Resonances in Diphoton Events at $\sqrt{s} PDF Author:
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ISBN:
Category :
Languages : en
Pages : 50

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Book Description
Searches for new resonances decaying into two photons in the ATLAS experiment at the CERN Large Hadron Collider are described. The analysis is based on proton-proton collision data corresponding to an integrated luminosity of 3.2 fb-1 at √s = 13 TeV recorded in 2015. Two searches are performed, one targeted at a spin-2 particle of mass larger than 500 GeV, using Randall-Sundrum graviton states as a benchmark model, and one optimized for a spin-0 particle of mass larger than 200 GeV. Varying both the mass and the decay width, the most significant deviation from the background-only hypothesis is observed at a diphoton invariant mass around 750 GeV with local significances of 3.8 and 3.9 standard deviations in the searches optimized for a spin-2 and spin-0 particle, respectively. The global significances are estimated to be 2.1 standard deviations for both analyses. As a result, the consistency between the data collected at 13 TeV and 8 TeV is also evaluated. Limits on the production cross section times branching ratio to two photons for the two resonance types are reported.

Search for Scalar Diphoton Resonances in the Mass Range 65{u2013}600 GeV with the ATLAS Detector in Pp Collision Data at S

Search for Scalar Diphoton Resonances in the Mass Range 65{u2013}600 GeV with the ATLAS Detector in Pp Collision Data at S PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
A search for scalar particles decaying via narrow resonances into two photons in the mass range 65–600 GeV is performed using 20.3 fb−1 of √s=8 TeV pp collision data collected with the ATLAS detector at the Large Hadron Collider. The recently discovered Higgs boson is treated as a background. No significant evidence for an additional signal is observed. The results are presented as limits at the 95% confidence level on the production cross section of a scalar boson times branching ratio into two photons, in a fiducial volume where the reconstruction efficiency is approximately independent of the event topology. Lastly, the upper limits set extend over a considerably wider mass range than previous searches.

A Search for Massive Resonances in Final States with Boosted Top-antitop Pairs Decaying Into a Lepton and Jets with the ATLAS Detector at the Large Hadron Collider

A Search for Massive Resonances in Final States with Boosted Top-antitop Pairs Decaying Into a Lepton and Jets with the ATLAS Detector at the Large Hadron Collider PDF Author: Janna Katharina Behr
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Search for High-mass Z Gamma Resonances at Sqrt(s)

Search for High-mass Z Gamma Resonances at Sqrt(s) PDF Author:
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Category :
Languages : en
Pages :

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Book Description
A search for massive resonances decaying to a Z boson and a photon is performed in events with a hadronically decaying Z boson candidate, separately in light-quark and b quark decay modes, identified using jet substructure and advanced b tagging techniques. Results are based on samples of proton-proton collisions collected with the CMS detector at the LHC at center-of-mass energies of 8 and 13 TeV, corresponding to integrated luminosities of 19.7 and 2.7 inverse femtobarns, respectively. The results of the search are combined with those of a similar search in the leptonic decay modes of the Z boson, based on the same data sets. Spin-0 resonances with various widths and with masses in a range between 0.2 and 3.0 TeV are considered. No significant excess is observed either in the individual analyses or the combination. The results are presented in terms of upper limits on the production cross section of such resonances and constitute the most stringent limits to date for a wide range of masses.

A Search for New Diboson Resonances in the Boosted Semi-leptonic Final State at √s

A Search for New Diboson Resonances in the Boosted Semi-leptonic Final State at √s PDF Author: Ryne Michael Carbone
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Models of a neutral, narrow scalar boson (spin-0), charged and neutral vector bosons (spin-1) coupling to the Standard Model gauge bosons, and a neutral Randall-Sundrum bulk graviton (spin-2) are considered. The search significantly improves the limits produced in recent searches.