After a long summer hiatus, here is a simple warm-up plot:
It displays the results of ATLAS and CMS searches for h→τμ decays, together with their naive combination. The LHC collaborations have already observed Higgs boson decays into two 2 τ leptons, and should be able to pinpoint h→μμ in Run-2. However, h→τμ decays (and lepton flavor violation in general) are forbidden in the Standard Model, therefore a detection would be an evidence for exciting new physics around the corner. Last summer, CMS came up with their 8 TeV result showing a 2.4 sigma hint of the signal. Most likely, this is just another entry in the long list of statistical fluctuations in the LHC run-1 data. Nevertheless, the CMS result is quite intriguing, especially in connection with the LHCb hints of lepton flavor violation in B-meson decays. Therefore, we have been waiting impatiently for a word from ATLAS. ATLAS is taking his time, but finally they published the first chunk of the result based on hadronic tau decays. Unfortunately, it is very inconclusive. It shows a small 1 sigma upward fluctuation, hence it does not kill the CMS hint. At the same time, the combined significance of the h→τμ signal increases only marginally, up to 2.6 sigma.
So, we are still in a limbo. In the near future, ATLAS should reveal the 8 TeV h→τμ measurement with leptonic tau decays. This may clarify the situation, as the fully leptonic channel is more sensitive (at least, this is the case in the CMS analysis). But it is possible that for the final clarification we'll have to wait 2 more years, once enough 13 TeV data is analyzed.