They came together most likely because they were detected in the same/similar analysis. There are probably hundreds of analysis performed in parallel on the LH

They came together most likely because they were detected in the same/similar analysis. There are probably hundreds of analysis performed in parallel on the LHCb data sets, by different sub-groups of the collaboration, looking at different reactions / channels etc. It could also be that they grouped several results together because they are similar. There is always an internal review process, and committee meetings (for the final "go ahead, publish") can impose a granularity on the time of release. Could also be that the paper is already on the arXiv for days, and this is just the common press release.