Search for quark contact interactions and extra spatial dimensions using dijet angular distributions in proton-proton collisions at sqrt(s) = 8 TeV

TL;DR

This study searches for signs of quark contact interactions and extra spatial dimensions in proton-proton collisions at 8 TeV, using dijet angular distributions, and sets new limits on the energy scales of these phenomena based on CMS data.

Contribution

It provides the first limits on quark contact interaction scales and extra spatial dimensions using dijet angular distributions at 8 TeV with the CMS detector.

Findings

Excluded quark contact interaction scales up to 9.0 and 11.7 TeV.

Set lower limits between 5.9 and 8.4 TeV on virtual graviton exchange.

Dijet distributions agree with perturbative QCD predictions.

Abstract

A search is presented for quark contact interactions and extra spatial dimensions in proton-proton collisions at sqrt(s) = 8 TeV using dijet angular distributions. The search is based on a data set corresponding to an integrated luminosity of 19.7 inverse femtobarns collected by the CMS detector at the CERN LHC. Dijet angular distributions are found to be in agreement with the perturbative QCD predictions that include electroweak corrections. Limits on the contact interaction scale from a variety of models at next-to-leading order in QCD corrections are obtained. A benchmark model in which only left-handed quarks participate is excluded up to a scale of 9.0 (11.7) TeV for destructive (constructive) interference at 95% confidence level. Lower limits between 5.9 and 8.4 TeV on the scale of virtual graviton exchange are extracted for the Arkani-Hamed--Dimopoulos--Dvali model of extra spatial dimensions.