Hint of an elementary particle vanishes under LHC scrutiny

Subject: Science and Technology

Context:

An intriguing anomaly in data gathered by the Large Hadron Collider (LHC) that raised hopes of a new elementary particle has turned out to be a fluke.

More in the news:

In 2014, LHC scientists at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland, discovered that some massive particles decay more often into electron-positron pairs than into muon-antimuon pairs.
This imbalance defied the standard model of physics, which predicts both pairs to occur with roughly the same frequency.

About CERN:

CERN is the European Organization for Nuclear Research where scientists probe the fundamental structure of the universe.
CERN was established in 1954. It has 23 member states. 22 members are European countries. Israel is the only non-European nation that has full membership in CERN.
India is the associate member of CERN and USA has observer status at CERN.
CERN is located in Geneva and it is an official Observer to the United Nations (UN).
Functions of CERN:
Its most important function is to provide the particle accelerators and other related infrastructure required for high-energy physics research.
CERN operates the largest particle physics laboratory in the world. Originally, the laboratory was solely used to study atomic nuclei. Later, it is also being used for research in higher-energy physics to study interactions between subatomic particles.

Facilities at CERN:

Through international collaborations, many experiments have been conducted at CERN.
There is a large computing facility at the main site, where data from experiments is stored and analyzed. In 2016, 49 petabytes of datawas generated by CERN.
The laboratory is also a major wide area network (WAN) hub. This is to enable researchers to remotely access the facilities present at the laboratory. In 1989, World Wide Web (WWW) was invented by a scientist at CERN.

What is Large Hadron Collider (LHC)?

The Large Hadron Collider is a giant, complex machine built to study particles that are the smallest known building blocks of all things.
Structure: LHC is a 27-km-long track-loop buried 100m underground on the Swiss-French border.
Operation: In its operational state, it fires two beams of protons almost at the speed of light in opposite directions inside a ring of superconducting electromagnets.
- Guided by magnetic field: The magnetic field created by the superconducting electromagnets keeps the protons in a tight beam and guides them along the way as they travel through beam pipes and finally collide.
- High precision: The particles are so tiny that the task of making them collide is akin to firing two needles 10 km apart with such precision that they meet halfway.
- Supercooled: Since the LHC’s powerful electromagnets carry almost as much current as a bolt of lightning, they must be kept chilled. It uses liquid helium to keep its critical components ultracold at minus 271.3 degrees Celsius, which is colder than interstellar space.

Experiments:

ATLAS is the largest general-purpose particle detector experiment at the LHC
The Compact Muon Solenoid (CMS) experiment is one of the largest international scientific collaborations in history, with the same goals as ATLAS, but which uses a different magnet-system design.)

Achievements:

‘God Particle’ discovery: Scientists at CERN had announced the discovery of the Higgs boson or the ‘God Particle’ during the LHC’s first run.
This led to Peter Higgs and his collaborator François Englert being awarded the Nobel Prize for physics in 2013.
The Higgs boson is the fundamental particle associated with the Higgs field, a field that gives mass to other fundamental particles such as electrons and quarks.
‘New Physics’ beyond Standard Model: After the discovery of the Higgs boson, scientists have started using the data collected as a tool to look beyond the Standard Model, which is currently the best theory of the most elementary building blocks of the universe and their interactions.

What you need to know about matter and antimatter?

The universe consists of a massive imbalance between matter and antimatter.
Antimatter and matter are actually the same, but have opposite charges, but there’s hardly any antimatter in the observable universe, including the stars and other galaxies.
In theory, there should be large amounts of antimatter, but the observable universe is mostly matter.
This great imbalance between matter and antimatter is all tangible matter, including life forms, exists, but scientists don’t understand why.

What happens when matter and antimatter meet?

When antimatter and matter meet, they annihilate, and the result is light and nothing else. Given equal amounts of matter and antimatter, nothing would remain once the reaction was completed. As long as we don’t know why more matter exists, we can’t know why the building blocks of anything else exist, either.
This is one of the biggest unsolved problems in physics. Researchers call this the “baryon asymmetry” problem.
Baryons are subatomic particles, including protons and neutrons. All baryons have a corresponding antibaryon, which is mysteriously rare.
The standard model of physics explains several aspects of the forces of nature. It explains how atoms become molecules, and it explains the particles that make up atoms.