New Applicant Grant

The discovery of a Higgs boson at LHC could indicate that there is more than one.
Our most popular theory for Dark Matter, supersymmetry, predicts the existence
of 5 Higgs bosons, and searching for another is now a very high priority. This is
particularly timely in 2015 as the restart of the LHC at (or close to) is design energy means
that heavy objects will be produced much more easily than before. There is therefore
an excellent opportunity to look for new heavier Higgs bosons. In supersymmetry
the most likely decay mode of such a particle is into pairs of 'tau' leptons. Warwick has a
lot of expertise in the study of the first Higgs boson to these particles, and it is natural to
try to extend our studies to a possible heavier particle.
The increased LHC beam energy might produce other heavy particles. For example a
Warwick student is preparing to search for a new heavy boson (W') resembling the W boson
of the weak nuclear force. His studies include this boson decaying into an ordinary W boson
and a Z. This grant should allow us to extend that search to also cover decay to a W and a
Higgs, with both of these decaying into 'jets'. This is not currently studied in ATLAS but
should be the most sensitive mode for a high-mass W'
Whether either of these possibilities really occurr we do not know - but we can
only find out by looking.

Particle physics would be transformed by a discovery in either area. These are
both somewhat exploration studies, but the return if they are successful
would be immense.
The former will tell us that the Higgs boson sector is much more complex than
the single particle of the Standard Model. It hints at dark matter and would help
narrow the search for it.
The latter would indicate a new force in nature, a revolutionary discovery if it occurred.

There is no direct practical impact in either case, but the increase in our understanding of the world would be enormous.