Valentina Dutta, an Indian woman with brown hair, smiles into the camera.

Higgs Boson, High-energy Particle Physics Spurs Dutta's Research

By Kirsten Heuring Email Kirsten Heuring

Heidi Opdyke

Carnegie Mellon University's Valentina Dutta is on the lookout for evidence of subatomic particles known as the Higgs boson interacting with each other.

Dutta, assistant professor of physics, shared her research into high-energy particle physics with undergraduate students at a lecture in January. She focused on her work with Large Hadron Collider's (LHC) Compact Muon Solenoid (CMS) experiment at CERN. A major goal of the CMS experiment is investigating the Higgs boson, an elementary particle in the Standard Model of Particle Physics.

"I was really interested in this global collaboration of scientists all working together on this big project to discover something fundamentally new about the universe. That's what really got me interested in physics," Dutta said.

The Higgs boson is a physical indication of the Higgs field, a quantum field that exists throughout the universe. Associated with the Higgs field is the Higgs potential, which represents the distribution of potential energy. The shape of the Higgs potential is linked to the evolution of the early universe, and understanding it may give us a better understanding of the universe and its ultimate fate.

To investigate the Higgs boson, researchers study proton-proton collisions with the CMS detector. As the protons collide at high energies, the collisions can produce particles up to thousands of times the mass of the proton, which would typically decay into lighter and more stable particles. Based on how these particles decay, the detector can measure their properties, and researchers can determine what happened during the collision.

"Higgs bosons can interact with each other, and the strength of their interaction can tell you something about the shape of the Higgs potential, which is quite important for the field," Dutta said.

Dutta also shared her work to help improve the CMS experiment through the high granularity calorimeter (HGC) upgrade.

The HGC will replace current CMS detectors in regions that face the most radiation. A next-generation imaging calorimeter, the HGC will significantly increase the precision with which the LHC collisions are imaged. The number of individual measurements per picture will increase from about 20,000 in current detectors to about 6 million in the HGC. The measurements of individual particles will go from the handful of numbers that the current detector provides to a high-resolution 3D picture of how the particles interact when traversing the detector.

The HGC will be composed of 30,000 20-centimeter hexagonal modules. The modules — essentially radiation tolerant digital cameras — will be tiled to form wheels several meters in diameter. The wheels will then be stacked to form the full 3D detector. In total, the HGC will require 600 square meters of active silicon sensors.

Dutta is part of a team building and testing 5,000 of these modules in the group's Wean Hall laboratory with the help of engineers, technicians and students. The effort is led by Dutta; John Alison, assistant professor in physics; and Manfred Paulini, professor of physics and the Mellon College of Science associate dean for research.

"The HGC will provide us with new capabilities in terms of better spatial resolution, and it can help us to do the kind of physics that we want to do better," Dutta said.

Since 2022, Gillian Ryan, associate teaching professor and director of undergraduate affairs has organized an annual physics lecture featuring departmental faculty for undergraduate students.

"The researchers in our department are at the cutting edge, and we want to make sure our students know that research exists here and what it means," said Gillian Ryan, associate teaching professor and director of undergraduate affairs. "We really wanted to provide an opportunity for students to go to a lecture that is at a level where they can understand what's going on, and that builds a lot of excitement."

Grace Daja, a first-year in the Mellon College of Science, said the talk helped her better understand high-energy particle physics.

"I'm interested in studying either particle physics or astrophysics. Professor Dutta did a great job explaining the area," Daja said.

Mariel Peczak, a junior in physics, conducts undergraduate research on a different part of the CMS experiment.

"I wanted to see a different part of the CMS experiment that I wasn't working on and get a different perspective on what research looks like," Peczak said. "It was nice to see things were accessible to everyone, but even going in with some idea, I still left with more information."