In the realm of high-energy physics, a team of researchers from the Université Paris-Saclay, including François Arleo, Djessy Bourgeais, Maxime Guilbaud, Greg Jackson, and Víctor Valencia Torres, have been delving into the intricacies of photon production in proton-lead (pPb) collisions at the Large Hadron Collider (LHC). Their work, published in the journal Physical Review C, sheds light on the complex interplay between nuclear parton distribution functions (nPDFs) and medium-induced radiation effects, offering valuable insights for the energy sector, particularly in understanding and optimizing particle accelerator technologies.
The researchers focused on a phenomenon known as fully coherent radiation, which arises from parton multiple scattering within the nuclear medium. This effect can significantly influence the nuclear dependence of prompt photon production, a process where high-energy photons are produced directly in the collision or through the fragmentation of partons. The study found that at backward rapidity—where particles are emitted in the direction of the incoming proton—the photons are particularly sensitive to fully coherent energy loss (FCEL). Conversely, at forward rapidity, where particles are emitted in the direction of the incoming lead nucleus, fully coherent energy gain (FCEG) plays a dominant role due to the prevalence of a specific scattering channel, $qg \to qγ$.
The implications of these findings extend beyond the realm of pure physics research. Understanding these nuclear effects is crucial for improving the accuracy of nPDFs, which are essential for predicting the behavior of particles in high-energy collisions. This, in turn, can enhance the design and operation of particle accelerators, which are not only pivotal for fundamental research but also have practical applications in energy production, medical imaging, and materials science.
Moreover, the researchers demonstrated that virtual photon production, or Drell-Yan (DY) process, is less affected by fully coherent radiation. This makes the DY process an excellent tool for probing nPDFs. By reweighting nPDF sets at next-to-leading order using realistic pseudo-data for LHC Run 3, the researchers showcased the potential of the DY process in refining our understanding of nuclear parton distributions. This could lead to more precise predictions and better-informed decisions in the development of advanced energy technologies.
In summary, the study provides a deeper understanding of the complex interactions occurring in pPb collisions at the LHC. By elucidating the role of fully coherent radiation and its impact on photon production, the researchers have contributed valuable insights that could enhance the accuracy of nPDFs and improve the design of particle accelerators. These advancements, in turn, can drive progress in various fields, including energy production and medical technology. The research was published in Physical Review C, a leading journal in the field of nuclear physics.
This article is based on research available at arXiv.