Improving the sensitivity of a search for coalescing binary black holes with non-precessing spins in gravitational wave data

We demonstrate the implementation of a sensitive search pipeline for gravitational waves from coalescing binary black holes whose components have spins aligned with the orbital angular momentum. We study the pipeline recovery of simulated gravitational wave signals from aligned-spin binary black holes added to real detector noise, comparing the pipeline performance with aligned-spin filter templates to the same pipeline with non-spinning filter templates. Our results exploit a three-parameter phenomenological waveform family that models the full inspiral-merger-ringdown coalescence and treats the effect of aligned spins with a single effective spin parameter chi. We construct template banks from these waveforms by a stochastic placement method and use these banks as filters in the recently-developed gstlal search pipeline. We measure the observable volume of the analysis pipeline for binary black hole signals with total mass in [15,25] solar masses and chi in [0, 0.85]. We find an increase in observable volume of up to 45% for systems with 0.2 <= chi <= 0.85 with almost no loss of sensitivity to signals with 0 <= chi <= 0.2. We demonstrate this analysis on 25.9 days of data obtained from the Hanford and Livingston detectors in LIGOs fifth observation run.