Search for New Phenomena in Dijet Mass and Angular Distributions from $pp$ Collisions at $\sqrt{s}$
Search for New Phenomena in Dijet Mass and Angular Distributions from $pp$ Collisions at $\sqrt{s}$

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Published: 2016

Total Pages: 21

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This Letter describes a model-agnostic search for pairs of jets (dijets) produced by resonant and non-resonant phenomena beyond the Standard Model in 3.6 fb-1 of proton–proton collisions with a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The distribution of the invariant mass of the two leading jets is examined for local excesses above a data-derived estimate of the smoothly falling prediction of the Standard Model. The data are also compared to a Monte Carlo simulation of Standard Model angular distributions derived from the rapidity of the two jets. No evidence of anomalous phenomena is observed in the data, which are used to exclude, at 95% CL, quantum black holes with threshold masses below 8.3 TeV, 8.1 TeV, or 5.1 TeV5.1 TeV in three different benchmark scenarios; resonance masses below 5.2 TeV for excited quarks, 2.6 TeV in a W' model, a range of masses starting from mZ' = 1.5 TeV and couplings from gq = 0.2 in a Z' model; and contact interactions with a compositeness scale below 12.0 TeV and 17.5 TeV respectively for destructive and constructive interference between the new interaction and QCD processes. These results significantly extend the ATLAS limits obtained from 8 TeV data. As a result, gaussian-shaped contributions to the mass distribution are also excluded if the effective cross-section exceeds values ranging from approximately 50–300 fb for masses below 2 TeV to 2–20 fb for masses above 4 TeV.

Search for New Phenomena in Dijet Mass and Angular Distributions from Pp Collisions at [mml
Search for New Phenomena in Dijet Mass and Angular Distributions from Pp Collisions at [mml

Author:

Publisher:

Published: 2016

Total Pages: 21

ISBN-13:

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This Letter describes a model-agnostic search for pairs of jets (dijets) produced by resonant and non-resonant phenomena beyond the Standard Model in 3.6 fb-1 of proton-proton collisions with a centre-of-mass energy of √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. The distribution of the invariant mass of the two leading jets is examined for local excesses above a data-derived estimate of the smoothly falling prediction of the Standard Model. The data are also compared to a Monte Carlo simulation of Standard Model angular distributions derived from the rapidity of the two jets. No evidence of anomalous phenomena is observed in the data, which are used to exclude, at 95% CL, quantum black holes with threshold masses below 8.3 TeV, 8.1 TeV, or 5.1 TeV5.1 TeV in three different benchmark scenarios; resonance masses below 5.2 TeV for excited quarks, 2.6 TeV in a W' model, a range of masses starting from mZ' = 1.5 TeV and couplings from gq = 0.2 in a Z' model; and contact interactions with a compositeness scale below 12.0 TeV and 17.5 TeV respectively for destructive and constructive interference between the new interaction and QCD processes. These results significantly extend the ATLAS limits obtained from 8 TeV data. As a result, gaussian-shaped contributions to the mass distribution are also excluded if the effective cross-section exceeds values ranging from approximately 50-300 fb for masses below 2 TeV to 2-20 fb for masses above 4 TeV.

Search for New Phenomena in the Dijet Mass Distribution Using Pp Collision Data at S
Search for New Phenomena in the Dijet Mass Distribution Using Pp Collision Data at S

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Published: 2015

Total Pages:

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Dijet events produced in LHC proton-proton collisions at a center-of-mass energy \(\sqrt{s}=8\) TeV are studied with the ATLAS detector using the full 2012 data set, with an integrated luminosity of 20.3 fb-1. Dijet masses up to about 4.5 TeV are probed. Resonancelike features are not observed in the dijet mass spectrum. Limits on the cross section times acceptance are set at the 95% credibility level for various hypotheses of new phenomena in terms of mass or energy scale, as appropriate. The analysis excludes excited quarks with a mass below 4.06 TeV, color-octet scalars with a mass below 2.70 TeV, heavy W' bosons with a mass below 2.45 TeV, chiral W* bosons with a mass below 1.75 TeV, and quantum black holes with six extra space-time dimensions with threshold mass below 5.66 TeV.

Search for New Phenomena in the Dijet Mass Distribution Using [math Display
Search for New Phenomena in the Dijet Mass Distribution Using [math Display

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Publisher:

Published: 2015

Total Pages:

ISBN-13:

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Dijet events produced in LHC proton-proton collisions at a center-of-mass energy \(\sqrt{s}=8\) TeV are studied with the ATLAS detector using the full 2012 data set, with an integrated luminosity of 20.3 fb-1. Dijet masses up to about 4.5 TeV are probed. Resonancelike features are not observed in the dijet mass spectrum. Limits on the cross section times acceptance are set at the 95% credibility level for various hypotheses of new phenomena in terms of mass or energy scale, as appropriate. The analysis excludes excited quarks with a mass below 4.06 TeV, color-octet scalars with a mass below 2.70 TeV, heavy W' bosons with a mass below 2.45 TeV, chiral W* bosons with a mass below 1.75 TeV, and quantum black holes with six extra space-time dimensions with threshold mass below 5.66 TeV.

Strong Coupling Gauge Theories In The Lhc Perspective (Scgt 12) - Proceedings Of The Kmi-gcoe Workshop
Strong Coupling Gauge Theories In The Lhc Perspective (Scgt 12) - Proceedings Of The Kmi-gcoe Workshop

Author: Yasumichi Aoki

Publisher: World Scientific

Published: 2014-01-13

Total Pages: 499

ISBN-13: 9814566268

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This volume contains contributions which are largely focused on strong coupling gauge theories and the search of theories beyond the standard model, as well as new aspects in hot and dense QCD — particularly in view of the LHC experiments and the lattice studies of conformal fixed point.It contains, among others, many of the latest and important reports on walking technicolor and related subjects in the general context of conformality, discussions of phenomenological implications with the LHC, as well as the theoretical ones through lattice studies. Nonperturbative studies like lattice simulations and stringy/holographic approaches are extensively elaborated in close relation to phenomenological studies. Also, heavy ion experiments at LHC are discussed in such nonperturbative approaches.

The Dijet Mass Spectrum and Angular Distributions with the D0 Detector
The Dijet Mass Spectrum and Angular Distributions with the D0 Detector

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Publisher:

Published: 1996

Total Pages: 22

ISBN-13:

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We present preliminary results from an analysis of dijet data collected during the 1994-95 Tevatron Collider run with an integrated luminosity of 91 pb−1. Measurements of dijet mass spectra and dijet angular distributions in {anti p}p collisions at (square root)s- = 1.8 TeV are compared with next-to-leading order QCD theory.

Measurement of Dijet Angular Distributions at Sqrt{s}
Measurement of Dijet Angular Distributions at Sqrt{s}

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Publisher:

Published: 2009

Total Pages: 7

ISBN-13:

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We present the first measurement of dijet angular distributions in p{bar p} collisions at (square root)s = 1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an integrated luminosity of 0.7 fb−1 collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV−1 scale extra dimensions. For all models considered, we set the most stringent direct limits to date.