Search for Pair-produced Resonances Decaying to Jet Pairs in Proton{u2013}proton Collisions at $\sqrt{s}$

Search for Pair-produced Resonances Decaying to Jet Pairs in Proton{u2013}proton Collisions at $\sqrt{s}$
Author:
Publisher:
Total Pages: 22
Release: 2015
Genre:
ISBN:

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Results are reported of a general search for pair production of heavy resonances decaying to pairs of hadronic jets in events with at least four jets. The study is based on up to 19.4 fb–1 of integrated luminosity from proton–proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The first assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Furthermore, previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV.

Search for Narrow High-mass Resonances in Proton-proton Collisions at $\sqrt{s}$

Search for Narrow High-mass Resonances in Proton-proton Collisions at $\sqrt{s}$
Author:
Publisher:
Total Pages: 23
Release: 2015
Genre:
ISBN:

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A search for a narrow, high-mass resonance decaying into Z and Higgs (H) bosons is presented. The final state studied consists of a merged jet pair and a [tau] pair resulting from the decays of Z and H bosons, respectively. This analysis is based on a data sample of proton-proton collisions at a center-ofmass energy of 8 TeV, collected with the CMS experiment in 2012, and corresponding to an integrated luminosity of 19.7 fb-1. In the resonance mass range of interest, which extends from 0.8 to 2.5 TeV, the Z and H bosons are produced with large momenta, which implies that the final products of the two quarks or the two [tau] leptons must be detected within a small angular interval. A combination of all possible decay modes of the [tau] leptons, production cross sections in a range between 0.9 and 27.8 fb are excluded at 95% confidence level, depending on the resonance mass.

Searches for Dijet Resonances

Searches for Dijet Resonances
Author: Lydia Audrey Beresford
Publisher: Springer
Total Pages: 175
Release: 2018-09-04
Genre: Science
ISBN: 331997520X

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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 Heavy Resonances Decaying to Tau Lepton Pairs in Proton-proton Collisions at $\sqrt{s}$

Search for Heavy Resonances Decaying to Tau Lepton Pairs in Proton-proton Collisions at $\sqrt{s}$
Author:
Publisher:
Total Pages:
Release: 2016
Genre:
ISBN:

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A search for heavy resonances that decay to tau lepton pairs is performed using proton-proton collisions at \sqrt{s}$ = 13 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 2.2 inverse femtobarns. The observations are in agreement with standard model predictions. An upper limit at 95% confidence level on the product of the production cross section and branching fraction into tau lepton pairs is calculated as a function of the resonance mass. For the sequential standard model, the presence of Z' bosons decaying into tau lepton pairs is excluded for Z' masses below 2.1 TeV, extending previous limits for this final state. For the topcolor-assisted technicolor model, which predicts Z' bosons that preferentially couple to third-generation fermions, Z' masses below 1.7 TeV are excluded, representing the most stringent limit to date.

Search for Pair-produced Resonances Decaying to Jet Pairs in Proton-proton Collisions at [arrow]"

Search for Pair-produced Resonances Decaying to Jet Pairs in Proton-proton Collisions at [arrow]
Author:
Publisher:
Total Pages: 31
Release: 2015
Genre:
ISBN:

Download Search for Pair-produced Resonances Decaying to Jet Pairs in Proton-proton Collisions at [arrow]" Book in PDF, Epub and Kindle

Results are reported of a general search for pair production of heavy resonances decaying to pairs of jets in events with at least four jets. The study is based on up to 19.4 inverse femtobarns of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The first assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV.

Search for High-mass Z$\gamma$ Resonances in $\mathrm{ E }^{+}\mathrm{ E }^{-}\gamma $ and $ \mu^{+}\mu^{-}\gamma$ Final States in Proton-proton Collisions at $\sqrt{s}$

Search for High-mass Z$\gamma$ Resonances in $\mathrm{ E }^{+}\mathrm{ E }^{-}\gamma $ and $ \mu^{+}\mu^{-}\gamma$ Final States in Proton-proton Collisions at $\sqrt{s}$
Author:
Publisher:
Total Pages:
Release: 2016
Genre:
ISBN:

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This paper describes the search for a high-mass narrow-width scalar particle decaying into a Z boson and a photon. The analysis is performed using proton-proton collision data recorded 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 Z bosons are reconstructed from opposite-sign electron or muon pairs. No statistically significant deviation from the standard model predictions has been found in the 200-2000 GeV mass range. Upper limits at 95% confidence level have been derived on the product of the scalar particle production cross section and the branching fraction of the Z decaying into electrons or muons, which range from 280 to 20 fb for resonance masses between 200 and 2000 GeV.

Search for Narrow Resonances Decaying to Dijets in Proton-proton Collisions at {u221A}s

Search for Narrow Resonances Decaying to Dijets in Proton-proton Collisions at {u221A}s
Author:
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Total Pages:
Release: 2016
Genre:
ISBN:

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In this study, a search for narrow resonances in proton-proton collisions at √s = 13 TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4 fb–1. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W' bosons below 2.6 TeV. These results significantly extend previously published limits.

Search for High-mass Resonances Decaying Into $ZZ$ in P$\bar{p}$ Collisions at $\sqrt{s}

Search for High-mass Resonances Decaying Into $ZZ$ in P$\bar{p}$ Collisions at $\sqrt{s}
Author:
Publisher:
Total Pages: 13
Release: 2011
Genre:
ISBN:

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The authors search for high-mass resonances decaying into Z boson pairs using data corresponding to 6 fb−1 collected by the CDF experiment in p{bar p} collisions at √s = 1.96 TeV. The search is performed in three distinct final states: ZZ → ll−l+l−, ZZ → l+l−??, and ZZ → l+l−jj. For a Randall-Sundrum graviton G*, the 95% CL upper limits on the production cross section times branching ratio to ZZ,?(p{bar p} → G* → ZZ), vary between 0.26 pb and 0.045 pb in the mass range 300