A new detector for long-lived particles will help us decipher the Universe
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A new detector for long-lived particles will help us decipher the Universe

With the CODEX-b detector currently in construction in Galicia, Spain, a new chapter opens up for the understanding of matter and the laws that govern the cosmos.


The Galician Institute of High Energy Physics (IGFAE) is a joint research center of University of Santiago de Compostela and Xunta de Galicia (the Galician Autonomous Government). The Institute is one of many collaborators CERN, the European laboratory for nuclear research located in Geneva, Switzerland. At CERN, researchers study particle physics through experiments of large complexity. The most important of these experiments is the Large Hadron Collider (LHC).

As IGFAE indicates, the LHC consists of a 27-km tunnel where protons collide at almost the speed of light. Several detectors are placed around these collisions; they work as immense photo cameras to capture the result of each collision. Although they represent the latest technological advances, these cameras are not always capable of capturing everything that happens in the collisions and they can miss details. When the protons collide inside the accelerator, the particles “fly” a distance of a few millimiters to several meters before disappearing, but the existing detectors cannot capture them and reconstruct their path.

The Galician Institute of High Energy Physics cooperates with CERN, home of the world's greatest particle collider, the Large Hadron Collider

Long-lived particles

One of the fundamental missions of these experiments, says the IGFAE note, is to find new or unexpected phenomena that might help understand better some of the mysteries of the Universe, such as Long- Lived Particles (LLP), a type of particles that are especially elusive. Their existence so far has been predicted by several theoretical models and now they could be one step closer to being detected, thanks to CODEX-b.

With this purpose, the Institute is planning to set CODEX-b next to LHCb, one of the giant particle detectors of the LHC.

The LHCb particle detector
El The LHCb particle detector (Photo: CERN)

The detection of long-lived particles can help us gain better understanding of some of the mysteries in the Universe


As a previous step to CODEX-b the IGFAE team is already building the CODEX-beta model, a smaller and cheaper version of the experiment. Construction is expected to end in the next two years. Its goal will be to measure the backgrounds, make preliminary analyses and prove that CODEX-b’s detection technology is feasible.

A map of the future location of CODEX-b inside LHCb at CERN (Photo: CERN)

New physics within our reach

According to Xabier Cid, physics co-ordinator at CODEX-beta, “one of the lessons we have learnt in the ten years LHC has been operating is that we must not have any preconceptions, and we must be as open as possible to analyzing the collision data. The New Physics, which are not contemplated in the Standard Model, could be within reach. We must leave nothing unexplored.

According to the Galician Institute for High Physics, CODEX-b is one of the most promising devices to find long-lived particles or rule out their existence in the next ten years. Discovering a long-lived particle would change our concept of the most fundamental nature, and would be a direct link to some of the most relevant questions of current physics: What is the origin of our Universe? How can we explain its current composition?

In the words of Xabier Cid in the project’s presentation video, “discovering a new long-lived particle would be revolutionary. It could change the current conception of the Universe in aspects as deep as the nature of the smallest things or its original composition.”

The discovery of these particles could help us decipher the nature of the smallest things or the original composition of the Univers.

Source: IGFAE

Long Lived Particles: a new way to dephicer the universe

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