What is the real aim of LHC... what is it going to discover?

The purpose of the LHC accelerator is to serve four particle physics experiments which are attached to it: ATLAS, ALICE, CMS and LHCb. Each of those is specialized in measuring certain quantities to be used by theoretical particle physicists. Their objective is to study different aspects of how matter behaves at its most fundamental level, such as where does mass come from and why particles have the masses they have, understanding why there are so many different particles, etc.

This is fundamental science. There is no direct application of it to our daily lives. However, the engineering used to build and operate the accelerator and the detectors has applications in people's daily lives. You are in front of one such spinoff right now: you are using a browser to navigate the Internet, and the principles behind how the browser operates (protocols) was something first built at the CERN facilities, the same which operate the LHC and its four detectors.

<QUOTE>what is it going to discover?</QUOTE>

They don't know. That is why they built it -- so that they discover whatever it is they will be able to discover.

When scientists try to find more about Nature, they don't predispose to discover any particular thing except finding out more about Nature. In the case of the four particle detectors, there are many questions raised by the theoretical physicists that need to be answered, and admittedly some more questions that might appear, and that is why they have built the accelerator and the detectors.

In my opinion, the biggest spinoff of these experiments is their people. Many of those people still continue to study and teach new scientists, but some also end up working outside science after a few years and incorporating many different industries -- materials science, software, medicine, finance, etc.

It's purpose is to discover what subatomic particles make protons and neutrons. We already know that there are 8-10 different subatomic particles, but believe that there are more primordial particles that make up these subatomic particles. That is the only purpose for the LHC, besides the stations around the loop where you can tap into the beam and see the smallest structures in a particular sample.

It is to discover the Higgs boson, the particle which gives mass to particles.

The LHC is designed to break down particles with mass(namely neutrons, protons and quarks) into the particles which transmit the basic forces of the universe.