Search for New Particles in Two-Jet Final States in 7 TeV Proton-Proton Collisions with the ATLAS Detector at the LHC

Abstract

A search for new heavy particles manifested as resonances in two-jet final states is presented. The data were produced in 7 TeV proton-proton collisions by the LHC and correspond to an integrated luminosity of 315 nb⁻¹ collected by the ATLAS detector. No resonances were observed. Upper limits were set on the product of cross section and signal acceptance for excited-quark (q*) production as a function of q* mass. These exclude at the 95% C.L. the q* mass interval 0.30<m(q*)<1.26 TeV, extending the reach of previous experiments.

Composite GUTs: models and expectations at the LHC

“…In that case the diquark could be copiously produced at the LHC, where it should be seen as a resonance in the channel pp → jj. The exclusion limits from Tevatron and LHC collaborations are comparable, with model dependent mass bounds mT 1 TeV [102][103][104].…”

“…There exist several experimental studies on diquarks at Tevatron [102] and recently also at the LHC [103,104], although they focus on diquark resonant production and decay to dijets, and therefore their bounds are easily evaded in our scenario. 38 Instead, we expect the discovery of our third-generation diquarks to come from the study of events with ttbb finals states, when 38 Nonetheless, the possibility is open that T couples to light generations more strongly than naively expected (for instance to right-handed quarks, if their degree of compositeness is large).…”

Naturalness confronts nature: searches for supersymmetry with the CMS detector in pp collisions at √s = 8 and $13$ TeV

“…The functional form in Eqn. B.1 was also used in previous searches [157,267,277,275,272,271,269,268,278,276,273,274,270,298] to describe the data. In Fig.…”

NLO QCD corrections to the resonant vector diquark production at the LHC

“…Such a signal will not go unnoticed and will be fairly very distinct at large invariant mass values, as the significantly huge QCD background falls rapidly for large dijet invariant mass. Both ATLAS and CMS Collaborations have looked at the dijet signal and already put strong constraints on the mass of such resonances [22][23][24][25][26][27]. We should however note that the production of such colored particles will be beset with significant contributions from QCD corrections, and therefore it becomes important to understand how much the leading order (LO) rates might change once these corrections are included.…”