La Jornada: Mexicans design and build particle detector; install it at CERN, the goal

For the first time, a particle detector designed and built by Mexican scientists could be installed in Alice, one of the four large experiments of the Large Hadron Collider (LHC), at CERN, the largest particle physics laboratory in the world.

The device, called MID, will allow us to study what happens to matter when it is subjected to extreme conditions, such as those that existed in the first moments of the universe. It will also help investigate how little-known or exotic particles form and behave.

“We are recreating minidroplets of the early universe and we are studying them through the traces they leave in particle detectors,” said Antonio Ortiz Velásquez, researcher in the Department of High Energy Physics of the Institute of Nuclear Sciences of the National Autonomous University of Mexico and leader of the MID project.

The study of what happens when nuclei of heavy atoms collide at speeds close to the speed of light began about four decades ago. The first experiments took place in the mid-1980s at CERN, the next generation of experiments was developed in the United States and then at the Large Hadron Collider, where the large ion collision experiment, Alice, was built.

“As there are questions that we have not yet been able to resolve due to limitations of the device we currently have, it was decided to update the experiment and take advantage of the potential of the high luminosity LHC to do heavy ion collision physics from 2036 to 2041.”

The update of the experiment is called Alice 3 and will have new systems to follow the path of the particles and know what type they are. The MID will be one of these detectors.

The MID project will allow the identification of muons – fundamental particles –, through machine learningan artificial intelligence tool that will help analyze the traces left by particles and drive new discoveries.

Ortiz Velásquez reported that the Mexican project began to be designed in 2018 and considers phases with stages planned for 2032, 2036 and 2041. Currently, the prototypes of the equipment necessary to detect traces of particles are being built in the laboratories of UNAM and other participating institutions and it is expected that the first cameras will begin to be built in Mexico in 2028 for completion in 2032.

For the project to be completed within the planned times, it will be necessary to have the financial support of the Ministry of Science, Humanities, Technology and Innovation, explained the researcher.

Superior efficiency

The detector will be made up of bars that reproduce light signals when a particle passes through them. This signal will be captured using fiber optics and a light detector, which will allow the muons to be identified.

“The goal is for this technology to help us identify muons with an efficiency greater than 95 percent.”

Ortiz Velásquez mentioned that, although devices of this nature have been built in Mexico in the past, it has never been done with this capacity and precision. While previous devices had less than 100 channels to capture particle signals, the new system will be able to read up to 10,000.

“In addition, it would have a well-defined program to study quark and gluon plasma.”

Quark-gluon plasma is a state of matter that occurs at extreme temperatures and densities, similar to those that existed in the first moments of the universe. Under these conditions, quarks and gluons, which are bound within particles such as protons and neutrons, can move freely.

He mentioned that one of the biggest challenges faced in building the detector is achieving the best efficiency at the lowest cost.

“Mexico has major national problems and in this technology that we propose we are reducing costs, so that it is an economical technology, with excellent physical performance.”

In a context of great challenges for the country, the researcher considered that promoting basic science such as that promoted in this project is also a way to contribute to the development of the country.

“It is an engine that encourages the training of specialized personnel, the development of technology, learning in the processing of large volumes of data, and collaboration networks are woven between all participants.”

The MID project involves more than 50 people from five countries: Mexico, the United States, the Czech Republic, Hungary and Pakistan. For Mexico, the Institute of Nuclear Sciences and the Institute of Physics of the UNAM, the Benemérita Universidad Autónoma de Puebla, the Autonomous University of Sinaloa, the National Technological Institute of Mexico and the Center for Research and Advanced Studies participate.

“If a Mexican project like this one, which includes a particle identification device, was accepted by Alice-CERN, it not only represents a great achievement for the country, but also demonstrates that Mexico is a reliable partner in research under high international standards,” he concluded.