fbpx

This dazzling experiment holds the key to unlocking the antimatter universe’s mystery

Two views of the LEGEND Illumination Photodetector Fiber Optic Module (top and bottom) with capture filament (green), which is part of the equipment needed to detect mutually killing antineutrinos. Enrico…

Two views of the LEGEND Illumination Photodetector Fiber Optic Module (top and bottom) with capture filament (green), which is part of the equipment needed to detect mutually killing antineutrinos.
Enrico Sassetti
Photographer Enrico Saketti

These gleaming images, taken by photographer Enrico Saketti, reveal important elements of the experiment that could ultimately unravel one of the greatest mysteries of modern physics.

LEGEND is an international project that explains why the universe has more matter than antimatter. Starting this year, its first phase, called the LEGEND-200, will use a sensitive germanium detector at the Gran Sasso National Laboratory in Italy to collect data for the next five years.

Side view of the internal lint bin and locking system. It is used to detect the movement of light from liquid argon and distinguish particle-free non-neutrino double beta decay signal events from background events.

Enrico sachet

Antimatter is composed of antiparticles that have the same mass as “standard” particles, but with different properties (such as charge). LEGEND-200 works on the hypothesis that very small, light, uncharged elementary particles called neutrinos (which are somewhat mysterious in their own right) are their antiparticles. In other words, neutrinos and antineutrinos can be identical and therefore can annihilate similar particles.

Assemble the optical sensor module. This is part of the inner lint box shown below. The optical sensor module consists of a silicon photomultiplier tube coupled to a wavelength variable optical fiber (green).

Assembling the fiber module
Enrico Sassetti

LEGEND-200 explores this possibility by looking for evidence of a rare theoretical process called non-neutrino double beta decay. This is when two neutrons are spontaneously converted into two protons, emitting two electrons and two antineutrinos.

Bottom image of the LEGEND-200 liquid argon freezer and its associated water tank. The inner wall of the aquarium and the outer wall of the refrigerator is covered with a wave mirror film. Its purpose is to convert and reflect the light produced by muons by the Cherenkov effect in the water. Photons are detected by optical sensors. The detector assembly is designed to detect and identify cosmic ray muons. Some of the cosmic ray muons reach the experimental site, even though they are deep beneath the Gran Sasso Mountains. (Reference: Muon flux increased by 106 times (1 million)). If not specified, meson-triggered events can mimic the desired signaling event.

The bottom of the thermostat is filled with liquid argon to hold the fiber optic module
Enrico Sassetti

Theoretically, pairs of antineutrinos emitted by double-decaying germanium nuclei may cancel each other out, leaving only the emitted electrons. This is evidence of an event that selectively destroys reflective material. The first observation of this shows the process of supporting the existence of matter rather than antimatter, which can explain the imbalance between matter and antimatter in the universe.

antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, antimatter, 

Related Posts