Investigating Three Particle Correlations in Pseudo-Rapidity for the Λ0 , Ξ 0 , and Ω− Baryons

Abstract

The aim of this research is to study three particle correlations in pseudo-rapidity for the $\Lambda^0$,$\Xi^0$, and $\Omega^-$ hyperons with a focus on their baryon and strangeness quantum numbers. The two primary questions asked are, into which particles are these quantum numbers typically conserved, and what are their correlations in momentum space. The research investigates these problems by exploring plausible correlations in the two quantum numbers as a function of their pseudo-rapidity, in order to probe particle production i.e. hadronization mechanisms and subsequent collective effects under the soft QCD regime. To achieve this, the Monte-Carlo event generator Pythia8 which in turn employs the Lund String Model to describe hadronization processes is used. Soft non-diffractive events are generated for proton-proton collisions at $\sqrt{s} = 13.6$ TeV to better simulate real world experiments and to facilitate a better analysis. Further, three particle correlation functions are used to measure the difference in the pseudo-rapidity of the three main particles of interest and the hadrons balancing their baryon and strangeness numbers. The results of this research show that the strangeness number is typically conserved in anti-strange mesons in particular, those of the kaon family, and the baryon number is conserved over a relatively wider variety of baryons. Overall, the investigation reveals that the quantum numbers are strongly correlated over shorter distances, being located in close proximity to one another in momentum space. An interesting outcome of the research indicates that the strangeness quantum number travels further in momentum space than the baryon quantum number. However this effect decreases as the strangeness number of the baryons balancing baryons of interest increases with possible reasons for this phenomena discussed at the end. The research further aims to aid in the development of the novel technique of three particle correlations to probe QCD, as well as extending existing studies into the particle production mechanisms and their subsequent evolutions, especially in the soft QCD domain.

Popular Abstract

Have you ever gazed out into the night sky and wondered where we came from? What if I told you that the universe is humming a delicate tune, a cosmic symphony, that holds the answer to this question and many more!

At CERN’s Large Hadron Collider (LHC) the world’s largest particle accelerator, protons (one of the building blocks of atoms) are accelerated to near the speed of light and slammed into each other to produce a discotheque of exotic new particles each dancing along to its own tune. Particle physicists from around the world are dedicated to unraveling the mysteries of this cosmic symphony and how exactly the myriad of particles dance to its rhythm. My research is aimed at deciphering one of its most intriguing dancers: the strange quark. Everything is made of atoms, which consist of electrons orbiting a nucleus of protons and neutrons. Electrons are elementary particles, indivisible by nature, while protons and neutrons are made of smaller elementary particles called quarks. These quarks are held together by the strong force—a "glue" for atomic nuclei through another particle called the gluon. Quarks come in six types, or "flavors", including the strange quark, which lives up to its name by resisting decay processes that other quarks readily undergo. By studying strange quarks, we uncover clues about the forces binding matter and the universe’s earliest moments. Right after the Big Bang, the universe was a hot, dense Quark-Gluon Plasma (QGP), where quarks and gluons moved freely. As it cooled, they condensed into the matter we see today. This state of matter is also produced in particle collisions. Thus understanding the behavior of particles post collision reveals insights into the origins of matter itself!

In the past researchers have used two-particle correlations to do this. When particles are created in these via collisions, their trajectories are measured in terms of azimuthal angles (their positions within the detector) and pseudorapidity (their angles relative to the collision). These hold vital clues about the forces acting on them. By looking at the relation between the trajectories of two particles, scientists could then uncover their underlying physics. My research focuses on three-particle correlations i.e. mapping the relation between three particles instead of two. You may be wondering, well why three? What’s the advantage of focusing on this instead of the more traditional two-particle correlation approach? Let me break it down (pun intended). By simply adding one more particle into the mix, we can uncover a much richer understanding of the interactions and movements of these particles, piecing together a cosmic detective story about how they "dance" to the symphony of forces shaping their behavior.

By studying correlations of the strange quarks inside baryons through three-particle correlations, we inch closer to answering universal questions: What are we made of? How did matter around us come to be? How does the universe work? So, the next time you hear about the LHC, remember—we’re not just smashing particles; we’re decoding the universe’s dance, one particle at a time!

• author: Jain, Aditye
• supervisor: Alice Ohlson
• organization: Particle and nuclear physics; Department of Physics
• course: FYSK04 20242
• year: 2025
• type: M2 - Bachelor Degree
• subject: Physics and Astronomy
• keywords: Monte-Carlo Generators, Pythia 8, Three Particle Correlations
• publication/series: Thesis
• language: English
• id: 9183288
• date added to LUP: 2025-01-29 08:19:49
• date last changed: 2025-01-30 03:41:06