Physics

Prof. Xerxes Tata
Univ. of Hawaii

Abstract :

The hypothesis of weak scale supersymmetry ameliorates the gauge hierarchy
problem, yields gauge couplings consistent with grand unification, and when
augmented by R-parity conservation, provides natural candidates for the
observed dark matter (DM). However, experiments at the LHC have not turned
up any direct evidence for the existence of superpartners, seemingly in
conflict with early expectations that suggested that superymmetry would be
revealed even at LEP2 or the Tevatron.  We critically re-evaluate the
arguments that led to these expectations and conclude that
phenomenologically viable SUSY spectra with no worse that a few percent
fine-tuning are perfectly possible. While no top-down model that lead to
such spectra has as yet emerged, we show that it is nontheless possible to
abstract many phenomenological implications of natural supersymmetry. We
discuss prospects for SUSY discovery at the (high-luminosity) LHC, and argue
that experiments at the proposed high energy LHC operating at 33 TeV would
allow a definitive search for natural SUSY. We will also mention the
complementary role of experiments at an electron-positron linear collider
with a centre-of-mass energy of 600 GeV for elucidating the nature of a SUSY
discovery in this framework.