Using a data set corresponding to an integrated luminosity of formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316305779&_mathId=si2.gif&_user=111111111&_pii=S0370269316305779&_rdoc=1&_issn=03702693&md5=d3ed4e2b5b9f6fb7dd8b454ad4020fac" title="Click to view the MathML source">3 fb−1, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the f&_user=111111111&_pii=S0370269316305779&_rdoc=1&_issn=03702693&md5=eb9fe7373a0fa2f9e69955ed5d96d05a">f" data-inlimgeid="1-s2.0-S0370269316305779-si1.gif"> decay mode, formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316305779&_mathId=si33.gif&_user=111111111&_pii=S0370269316305779&_rdoc=1&_issn=03702693&md5=c67dfc02f6b4d1cad40d5fa82c18f0a7" title="Click to view the MathML source">τeff, is measured to be
formula" id="fm0010">
formulatext stixSupport mathImg" data-mathURL="/science?_ob=MathURL&_method=retrieve&_eid=1-s2.0-S0370269316305779&_mathId=si5.gif&_user=111111111&_pii=S0370269316305779&_rdoc=1&_issn=03702693&md5=755f07b8ecdea72ac1e161f0d70fbb4a" title="Click to view the MathML source">τeff=1.479±0.034 (stat)±0.011 (syst) ps.f">