Dighe, Amol and Ghosh, Diptimoy and Godbole, Rohini M. and Prasath, Arun (2012) Large mass splittings for fourth generation fermions allowed by LHC Higgs boson exclusion. In: PHYSICAL REVIEW D, 85 (11).
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In the context of the standard model with a fourth generation, we explore the allowed mass spectra in the fourth-generation quark and lepton sectors as functions of the Higgs mass. Using the constraints from unitarity and oblique parameters, we show that a heavy Higgs allows large mass splittings in these sectors, opening up new decay channels involving W emission. Assuming that the hints for a light Higgs do not yet constitute an evidence, we work in a scenario where a heavy Higgs is viable. A Higgs heavier than similar to 800 GeV would in fact necessitate either a heavy quark decay channel t' -> b'W/b' -> t'W or a heavy lepton decay channel tau' -> nu'W as long as the mixing between the third and fourth generations is small. This mixing tends to suppress the mass splittings and hence the W-emission channels. The possibility of the W-emission channel could substantially change the search strategies of fourth-generation fermions at the LHC and impact the currently reported mass limits.
|Item Type:||Journal Article|
|Additional Information:||Copyright for this article belongs to the American Physical Society|
|Department/Centre:||Division of Physical & Mathematical Sciences > Centre for High Energy Physics|
|Date Deposited:||24 Jul 2012 12:49|
|Last Modified:||24 Jul 2012 12:51|
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