Search for Narrow Resonances in Dijet Final States ats=8  TeVwith the Novel CMS Technique of Data Scouting

Abstract

A search for narrow resonances decaying into dijet final states is performed on data from proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 18.8 fb^{-1}. The data were collected with the CMS detector using a novel technique called data scouting, in which the information associated with these selected events is much reduced, permitting collection of larger data samples. This technique enables CMS to record events containing jets at a rate of 1 kHz, by collecting the data from the high-level-trigger system. In this way, the sensitivity to low-mass resonances is increased significantly, allowing previously inaccessible couplings of new resonances to quarks and gluons to be probed. The resulting dijet mass distribution yields no evidence of narrow resonances. Upper limits are presented on the resonance cross sections as a function of mass, and compared with a variety of models predicting narrow resonances. The limits are translated into upper limits on the coupling of a leptophobic resonance Z_{B}^{'} to quarks, improving on the results obtained by previous experiments for the mass range from 500 to 800 GeV.

Revisiting simplified dark matter models in terms of AMS-02 and Fermi-LAT

“…The spin-1 mediator scenario via vector or axial-vector interaction is thus highly constrained by the dijet limit for Z search at the Large Hadron Collider (LHC) [23][24][25]. The collider search is yet less sensitive to the detection of spin-0 mediator scenario through scalar or pseudo-scalar interaction as a result of the m 2 q suppression coming from the Yukawa coupling.…”

LHC constraints on color octet scalars

“…A comparison with the dijet cross-section at the Tevatron revealed that signatures from the MW model are orders of magnitude below the QCD background and no constraint emerged for masses below 350 GeV with λ 4 = λ 5 as large as 10 [12]. Existing LHC searches that can be used to compare the MW model with the two jets channel are: ATLAS-8 TeV [23], ATLAS-13 TeV [28], CMS-8 TeV [29], CMS-13 TeV [30]. For example, ATLAS used its 8 TeV data to conclude that color octet scalars are ruled out below 2.8 TeV [23], but as explained above, their benchmark color octet model, that of Ref.…”

Data Scouting in CMS

“…The collected data, corresponding to 18.8 fb −1 , were used to perform a dijet resonance search analogous to the one carried out in 2011 [4]. The search results were interpreted as limits on the mass and coupling of a hypothetical leptophobic Z' resonance decaying to quarks.…”

“…[19] Figure 1: Left: dijet mass spectrum obtained from 18.8 fb −1 of scouting data collected in 2012, with fit to parameterized background function [4]. Right: limits from a variety of collider experiments on the mass and coupling of a hypothetical leptophobic Z'.…”