Minimal matter at the large hadron collider

We classify all possible new U(1)(Y) circle times SU(2)(L) circle times SU(3)(c) multiplets that can couple to pairs of SM particles. Assuming that production of such new particles is dominated by their gauge interactions we study their signals at LHC, finding the following five main classes: (i) lepto-quark 2l2q signals; (ii) di-lepton 4l signals; (iii) di-quarks 4j signals, (iv) heavy-lepton 2l2V signals and (v) heavy quarks 2j2V signals, where V denotes heavy SM vectors (with W being associated to exotic fermions). In each case we outline the most promising final states, the SM backgrounds and propose the needed searches. (C) 2009 Elsevier B.V. All rights reserved.