Horizon

Five days ago, hundreds of the world's brainiest people

descended on a hotel in Chicago.

Good morning, ladies and gentlemen.

They have come to hear news from particle physicists

working at CERN.

Last year, researchers there had started running

the Large Hadron Collider at the highest energy ever...

...and a rumour quickly emerged.

They were on the brink of a huge discovery.

We started hearing these mysterious noises

about something going on at CERN.

This may be what I have been spending an entire lifetime

waiting for.

A strange bump on a graph suggested that they might have discovered

a brand-new particle...

...that could revolutionise physics...

Right here, right now at CERN, in 2016,

is THE most exciting time and place in the history of science.

If you want, really, to change the conditions of humanity,

then you need breakthroughs.

...and could change our understanding of how everything works.

The discovery of a new particle may mean a complete rethinking

of the conceptual basis of the physics world.

For the last eight months,

it looked like the universe was about to be turned upside down...

...and Horizon has been inside CERN following the story.

I doubt that it will be named after me,

but I can think of it like this, that it might be!

There was a short circuit on a circuit-breaker developed

which arced and damaged the nearby equipment.

Two teams of physicists...

...one massive machine...

and a dream.

Was the bump was just a glitch in the data,

or the biggest physics discovery in over a century?

A Nobel prize is possible.

Bonjour. Bienvenue a CERN.

This is the European Organization for Nuclear Research - CERN.

CERN is home to half of the world's particle physicists...

...and the biggest particle-hunting machine that has ever been built.

The Large Hadron Collider, or LHC.

Inside this pipe, two beams of protons

are sent hurtling around a 27km loop

before being smashed together

to create subatomic particles.

In November 2015, researchers here got

a tantalising glimpse of what they thought might be

a brand-new particle.

A particle that could transform our understanding

of how the universe works.

Now they're trying to find it.

The Large Hadron Collider has been hunting for particles since 2009...

...and it's the job of British physicist Mike Lamont

to keep it running.

Today, it's having one of its off days.

This is not a cock-up.

We stop because,

as you can see,

there's a huge amount of stuff down here -

big systems, cooling, ventilation,

cryogenics, etc,

and this stuff needs a bit of periodic tender loving care.

With over 4,000 miles of cabling and 100,000 processor cores,

the LHC is one of the most complicated machines in the world.

She is not a simple beast to operate,

and a lot of time we spend wrestling it under control.

We need very powerful magnets to bend the beam around in a circle,

so basically, these are superconducting magnets,

they're cooled with superfluid helium at 1.9K.

The fact that this actually works at all

is a real testament to an awful lot of hard work, modern technology,

planning, precision on a completely remarkable scale.

With the hunt on for a potential new particle,

Mike and his team are trying to run the LHC

at its highest ever energy,

and it's making their job more challenging than usual.

We had a very interesting month,

with a number of fairly major technical problems,

including the famous weasel,

which took us out for about six days,

but from now on, after this maintenance period,

it's pedal to the metal for two or three months.

To try and find new particles,

the LHC does something that was once completely out of our grasp.

It recreates the conditions that existed just after the Big Bang.

The Big Bang was an explosion that happened

at the beginning of the universe, when all matter was created.

So, this is the year zero, and if we draw a line...

From this point, the universe expanded,

getting cooler, its energy dispersing.

...to where we are in the universe now, where humans exist,

that's 14 billion years.

We know that when the universe was 9 billion years old,

the sun was formed,

and over 8 billion years before that,

the first stars were born,

but the LHC is able to look even further back in time

to when all that existed were the fundamental building blocks

of the universe - particles.

So, in a way, the Large Hadron Collider

is like a time machine,

trying to create the conditions that happened

just in the few millionths of a second after the Big Bang

to see what particles existed when the energy density

of the universe was really, really high.

To do this, the LHC makes use of

one the most famous scientific discoveries ever made.

What we're doing is using the very high energy of the protons

in the collision using Einstein's equation E = mc2...

...which tells us that mass and energy are equivalent,

so we have protons and they're going round and round the LHC,

and we have one set of protons going round this way

and we have another set of protons

which are going around in the opposite direction,

getting faster and faster, closer to the speed of light,

and more and more energetic.

Then we get one proton beam

and the other proton beam

going at the highest energies,

and then we smash them together.

At the moment of collision,

the energy is converted into mass

in the form of thousands of particles.

Although most will be ones we already know about,

the hope is that undiscovered particles might also be created

that could help explain some of the mysteries

of how the universe was formed.

But creating particles is just the beginning.

Detecting them requires

some of the most sophisticated machines in the world.

I come into the cavern hundreds of times in a year

and every time I walk in,

my jaw still drops a little bit when I see ATLAS.

We built this thing. We REALLY built this thing.

Dave Charlton runs the snappily named

A Toroidal Large Hadron Collider Apparatus, known as ATLAS.

It's the largest particle detector on the LHC circuit.

The collisions take place right in the centre of the experiment,

about 30 metres away from where we're standing.

ATLAS has seven different detecting systems

arranged in layers around the collision point.

They're poised to capture evidence of the particles

that have been produced.

Dave hopes that ATLAS will lead the hunt for the potential new particle,

but he's not the only one

with a giant particle detector at his disposal.

There's another massive detector on the LHC circuit -

the Compact Muon Solenoid.

CMS.

It's run by Italian physicist Tiziano Camporesi.

The croissant has become something almost associated to me

because I've grown into the habit of bringing croissants every morning

to the crew which is working at the experiment.

So now, if I show up without croissants,

they are disappointed.

No, actually, I like this... I like this habit.

You know, when you have a ritual,

you don't want to change it because it will bring bad luck.

Tiziano's machine, CMS, is very similar to Dave's.

CMS is big. It's a 14,000-tonne object...

...which basically is five storeys high

and something like 26 metres long.

But ATLAS is slightly bigger.

Look at the size of it. As you can see,

it's really a huge experiment.

25 metres high, 45 metres long.

These detectors are purposefully designed

to do the same thing in two different ways.

You could see it as an oversized camera,

something like a 100-megapixel camera.

Nowadays, a digital camera might be 25 megapixels, 25 million channels,

but we're able to read out our 100 million channels

40 million times a second.

The idea is that new particles

will be seen by both detectors independently.

It can help ensure their findings are valid,

but that doesn't stop both teams

wanting to be first to make a discovery.

We understand that there is some healthy competition

between us and ATLAS, so we are convinced that CMS is better.

There IS a rivalry between the experiments.

We don't want to lose.

If CMS and ATLAS detect a new particle,

it could be the most important physics discovery in over 100 years.

Ah, you've made it! Come on in. We can talk about some physics.

It's going to be fun.

By the beginning of the 20th century,

particle physicists like Professor Jim Gates

had ascertained that milk, bowls, glasses -

in fact, everything we see around us -

is made from atoms...

...and that atoms themselves are made of even smaller subatomic particles.

From the 1950s, hundreds of particles were discovered...

There was this strange quark -

and this was not the order in which they were discovered -

and then the top quark...

and the most familiar particle of them all, the electron.

All of our electronics come from this.

And so we kept discovering particles -

neutrino, gluon...