Analysis of 3 years of data from the gravitational wave detectors EXPLORER and NAUTILUS

TL;DR

This study analyzed three years of data from resonant bar gravitational wave detectors Nautilus and Explorer, performing coincidence searches and setting upper limits on burst rates, with improved sensitivity and novel methods.

Contribution

It introduces new methodological features for upper limit evaluation and provides the most stringent limits from resonant antennas to date.

Findings

Null detection of coincident gravitational wave events

Upper limits surpass previous resonant antenna results

Limits are competitive with interferometric detectors at h_rss ~1E-19

Abstract

We performed a search for short gravitational wave bursts using about 3 years of data of the resonant bar detectors Nautilus and Explorer. Two types of analysis were performed: a search for coincidences with a low background of accidentals (0.1 over the entire period), and the calculation of upper limits on the rate of gravitational wave bursts. Here we give a detailed account of the methodology and we report the results: a null search for coincident events and an upper limit that improves over all previous limits from resonant antennas, and is competitive, in the range h_rss ~1E-19, with limits from interferometric detectors. Some new methodological features are introduced that have proven successful in the upper limits evaluation.