At the subatomic level, particles interact through force carriers, such as photons for electromagnetism and gluons for the strong force. Unlike photons, gluons carry a color charge, making the strong interaction highly complex and difficult to study.

Recent experiments at the Large Hadron Collider (LHC) have shed light on what happens when high-energy protons pass close to each other. Protons can scatter elastically by exchanging photons or, intriguingly, through a more powerful mechanism involving the exchange of multiple gluons. This exchange is facilitated by a theoretical construct known as the pomeron.

The CMS and TOTEM Collaborations have jointly studied these interactions, focusing on double-pomeron exchange processes. Using advanced tracking detectors placed in the LHC tunnel, they detected scattered protons and created particle-antiparticle pairs, primarily pions and kaons. These measurements enabled precise analysis of the pomeron’s characteristics, such as its coupling strengths and energy dependence.

One significant finding is the detailed measurement of the azimuthal angle distribution between outgoing protons. The data, characterized by a simple cosine shape, provide new insights into the strong force at high energies, revealing the intricate quantum interferences involved.

Looking forward, the research teams aim to explore the nature of resonances produced in these collisions. They hope to uncover new particles, such as the elusive glueball, in the ongoing and future data collection phases at the LHC.

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