Abstract
Results are presented from a search for production of Higgs boson pairs (HH) where one boson decays
to a pair of b quarks and the other to a τ lepton pair. This work is based on proton-proton collision data
collected by the CMS experiment at ffiffi
s p ¼ 8 TeV, corresponding to an integrated luminosity of 18.3 fb−1.
Resonant and nonresonant modes of HH production have been probed and no significant excess relative to
the background-only hypotheses has been found in either mode. Upper limits on cross sections of the two
HH production modes have been set. The results have been combined with previously published searches
at ffiffi
s p ¼ 8 TeV, in decay modes to two photons and two b quarks, as well as to four b quarks, which also
show no evidence for a signal. Limits from the combination have been set on resonant HH production by
an unknown particle X in the mass range mX ¼ 300 GeV to mX ¼ 1000 GeV. For resonant production of
spin 0 (spin 2) particles, the observed 95% CL upper limit is 1.13 pb (1.09 pb) at mX ¼ 300 GeV and to
21 fb (18 fb) at mX ¼ 1000 GeV. For nonresonant HH production, a limit of 43 times the rate predicted by
the standard model has been set.