Scientists have successfully measured the strong force, which holds the particles that make up protons and neutrons together, with an unprecedented level of precision. Although it is the most powerful of all the fundamental forces, its strength is still more uncertain compared to the others. Accurately measuring the strong force is crucial for understanding the nature of the world.
Unlike the other fundamental forces such as gravity, electromagnetic force, and weak force, which weaken as particles move further apart from each other, the strong force increases in strength. This creates exotic effects that neutralize it, making direct measurement challenging.
According to Stefano Camarda, a researcher at the CERN particle physics laboratory in Switzerland, the strong force can only be observed indirectly. Improving the measurement of this force has been a slow process since the mid-80s.
Camarda and his team used the ATLAS experiment at the Large Hadron Collider (LHC) to achieve a significant improvement in precision, reducing the relative uncertainty in the force’s strength to 0.8%. This represents a two to three-fold improvement compared to previous measurements.
The researchers measured the strong force by colliding pairs of protons, resulting in the creation of a particle called a Z boson. If there were no force mediating the interactions between protons, the Z boson would remain stationary. However, the strong force imparts a small “kick” to the particle, altering its momentum based on the magnitude of the strong force.
This measurement is essential because the value of the strong force contributes significantly to the uncertainty in the standard model of particle physics. The accuracy of predictions and computations at the LHC depends on knowing the exact value of the strong force. Improving its uncertainty is vital for identifying potential physics beyond the standard model.
The strong force also plays a crucial role in our understanding of the universe’s fate. It is speculated that the universe could end through a phenomenon called vacuum decay, where a quantum fluctuation leads to the creation of a small bubble of unusual space-time known as pure vacuum, which rapidly expands and engulfs the entire cosmos. The probability of this happening is low, but uncertainty in this scenario is influenced by the value of the strong force.
Despite this achievement, our knowledge of the strong force still lags behind our precise calculations of other fundamental forces. Furthermore, measuring the strong force remains challenging, and it’s unlikely that the same level of precision will be achieved soon, even with improved data. However, proposals for a new collider at CERN specifically designed to study the Z boson offer hope for reaching greater precision in the future.
Insights:
– The strong force, responsible for binding particles within protons and neutrons, has been measured with unmatched precision using the ATLAS experiment at the Large Hadron Collider (LHC).
– Precise measurement of the strong force is crucial for understanding the nature of the universe and making accurate predictions in particle physics.
– The strong force differs from other fundamental forces by becoming stronger as particles are separated.
– The measurement obtained reduces the uncertainty in the strong force’s strength by a factor of 2 to 3 compared to previous measurements.
– Despite the progress made, our understanding of the strong force still falls short compared to other fundamental forces.
– The value of the strong force has implications for potential physics beyond the standard model and the fate of the universe.
– Future colliders, such as the proposed one at CERN, could further advance our knowledge of the strong force and achieve even greater precision in measurements.
