1 Erratum to: Eur. Phys. J. C (2016) 76:181 DOI 10.1140/epjc/s10052-016-4021-0

In the acknowledgments, the sentence “This work is under a Ramón y Cajal contract” must be replaced by “This work is under a Ramón y Cajal contract and is supported by the I\(+\)D Grant FIS2014-54800-C2-2-P”.