Search for magnetic monopoles in sqrt(s) = 7 TeV pp collisions with the ATLAS detector

TL;DR

This paper reports a search for magnetic monopoles in 7 TeV proton-proton collisions using the ATLAS detector, setting upper limits on production cross sections due to no observed monopole events.

Contribution

First search for magnetic monopoles at 7 TeV with ATLAS, establishing new upper limits on their production cross sections across a range of masses.

Findings

No monopole events observed in the signal region.

Upper limit on production cross section is 2 fb in the fiducial region.

Cross section limits vary from 145 fb to 16 fb depending on monopole mass.

Abstract

This Letter presents a search for magnetic monopoles with the ATLAS detector at the CERN Large Hadron Collider using an integrated luminosity of 2.0 fb^-1 of pp collisions recorded at a center-of-mass energy of sqrt(s)=7 TeV. No event is found in the signal region, leading to an upper limit on the production cross section at 95% confidence level of 1.6/epsilon fb for Dirac magnetic monopoles with the minimum unit magnetic charge and with mass between 200 GeV and 1500 GeV, where epsilon is the monopole reconstruction efficiency. The efficiency epsilon is high and uniform in the fiducial region given by pseudorapidity |eta|<1.37 and transverse kinetic energy 600-700<E^kin sin(theta)<1400 GeV. The minimum value of 700 GeV is for monopoles of mass 200 GeV, whereas the minimum value of 600 GeV is applicable for higher mass monopoles. Therefore, the upper limit on the production cross section at 95% confidence level is 2 fb in this fiducial region. Assuming the kinematic distributions from Drell-Yan pair production of spin-1/2 Dirac magnetic monopoles, the efficiency is in the range 1%-10%, leading to an upper limit on the cross section at 95% confidence level that varies from 145 fb to 16 fb for monopoles with mass between 200 GeV and 1200 GeV. This limit is weaker than the fiducial limit because most of these monopoles lie outside the fiducial region.