Search for Doubly Charged Higgs Boson Pair Production in p(p)over-bar Collisions at root s=1.96 TeV

We present a search for pair production of doubly charged Higgs bosons in the processes q (q) over bar -> H++H-- decaying through H-+/-+/- ->tau(+/-)tau(+/-), mu(+/-)tau(+/-), mu(+/-)mu(+/-). The search is performed in p (p) over bar collisions at a center-of-mass energy of root s = 1:96 TeV using an integrated luminosity of up to 7:0 fb(-1) collected by the D0 experiment at the Fermilab Tevatron Collider. The results are used to set 95% C. L. limits on the pair production cross section of doubly charged Higgs bosons and on their mass for different H-+/-+/- branching fractions. Models predicting different H-+/-+/- decays are investigated. Assuming B(H-+/-+/- -> tau(+/-)tau(+/-)) = 1 yields an observed (expected) lower limit on the mass of a left- handed H-L(+/-+/-) boson of 128 (116) GeV and assuming B(H-+/-+/- -> mu(+/-)tau(+/-)) = 1 the corresponding limits are 144 (149) GeV. In a model with B(H-+/-+/- -> tau +/-tau(+/-) B(H-+/-+/- -> mu(+/-)tau(+/-)) = B(H-+/-+/- -> mu(+/-)mu(+/-) ) 1/3, we obtain M(H-L(+/-+/-)) > 130 (138) GeV.