Researchers at CERN’s ATLAS experiment at the Large Hadron Collider have presented a new way to search for dark matter via nearly visible jets, representing a major paradigm shift in the field. Their work provides new directions and stringent upper bounds in ongoing efforts to understand dark matter.
Researchers are studying whether dark matter particles are actually produced in Standard Model particle jets.
The existence of dark matter is a long-standing mystery in our universe. Dark matter makes up about a quarter of our universe, but does not interact significantly with ordinary matter. The existence of dark matter has been confirmed by a series of astrophysical and cosmological observations, including the latest stunning images taken by the James Webb Space Telescope. However, to date, no experimental observations of dark matter have been reported. The existence of dark matter has been a question that has been investigated by high-energy scientists and astrophysicists around the world for decades.
Advances in dark matter research
“That’s why we carry out research in basic science, to explore the deepest secrets of the universe. Large Hadron Collider at CERN “This is the largest experiment ever carried out, and the particle collisions that created conditions similar to the Big Bang can be used to look for signs of dark matter ,” said Professor Deepak Kar, from the Faculty of Physics at the University of the Witwatersrand in Johannesburg. South Africa. .
A graphical representation of how a nearly visible jet would appear on the ATLAS detector if it were present. Credit: CERN
While working on the ATLAS experiment at CERN, Carr and former PhD student Sukanya Sinha (now a postdoctoral researcher at the University of Manchester), discovered a new way to search for dark matter. Their research was published in the journal, Physics Letter B.
A new approach to detecting dark matter
“There have been a large number of dark matter searches at the LHC over the last few decades, and they have focused on weakly interacting massive particles, called WIMPs,” Carr said. “WIMPS are one class of particles hypothesized to explain dark matter because they do not absorb or emit light and do not interact strongly with other particles. However, since no evidence of the existence of WIMPs has been found so far, we realize that the search for dark matter requires a quantum leap.
Dr Sukanya Sinha and Professor Deepak Kar. Credit: Intelligence University
“What we’re asking is whether dark matter particles are actually produced in the Standard Model particle stream,” Carr said. This led to the discovery of a new detector signature known as a nearly visible jet, which scientists had never seen before.
Collisions of high-energy protons often produce parallel jets of particles, collected in so-called jets, from the decay of ordinary quarks or gluons. Semi-visible flows may arise when virtual dark quarks decay partly into Standard Model quarks (known particles) and partly into stable dark hadrons (“the invisible part”). Because they are produced in pairs, usually in conjunction with additional standard model jets, energy imbalance or energy loss in the detector occurs when all the jets are not perfectly balanced. The direction of the lost energy often corresponds to one of the most visible beams.
This makes the search for nearly visible jets very difficult, as signatures of these events can also appear due to incorrect jet measurements on the detector. Carr and Sinha’s new method for searching for dark matter opens up a new direction in the search for the existence of dark matter.
“While my doctoral thesis did not contain the discovery of dark matter, it set the first and fairly stringent constraints on this mode of production, and is already inspiring further research,” Sinha said.
The ATLAS collaboration at CERN has highlighted this as one of the key results to be announced at the summer conference.
Reference: “Investigation of nearly non-resonant visible jet production using ATLAS Run 2 data” by The ATLAS Collaboration, 11 November 2023, Physics Letter B.
doi: 10.1016/j.physletb.2023.138324
Experiments at the Large Hadron Collider in Europe, such as the ATLAS calorimeter shown here, provide more precise measurements of fundamental particles. Image source: Maximilian Price, CERN
Atlas Experience
The ATLAS experiment is one of the most important scientific endeavors at CERN, the European Organization for Nuclear Research. It is a key part of the Large Hadron Collider (LHC), the world’s largest and most powerful particle accelerator. Located near Geneva, ATLAS, which stands for “A Toroidal LHC ApparatuS,” focuses on exploring fundamental aspects of physics.
ATLAS was designed to explore a wide range of scientific questions. It aims to understand the fundamental forces that have shaped our world since the beginning of time and that will determine its fate. One of its main goals is to study the Higgs boson, a particle associated with the Higgs field, which gives mass to other particles. The discovery of the Higgs boson in 2012, a joint effort between ATLAS and the CMS (Compact Muon Solenoid) experiment, was a landmark achievement in physics.
The experiment also looks for signs of new physics, including the origin of mass, extra dimensions and particles that could form dark matter. ATLAS does this by analyzing the countless particles produced when protons collide at nearly light speed inside the LHC.
The ATLAS detector itself is a technological marvel. It is very large, measuring about 45 meters long, 25 meters in diameter, and weighing about 7,000 tons. The detector consists of different layers, each designed to detect different types of particles resulting from proton-proton collisions. It includes a suite of technologies: trackers to detect particles’ trajectories, calorimeters to measure their energy, and muon spectrometers to identify and measure muons, a type of heavy electron that is the basis for much physics research.
The data collected by ATLAS is enormous, often described in petabytes. This data is analyzed by a global community of scientists, contributing to our understanding of fundamental physics and potentially leading to new discoveries and technologies.
2023-11-28 23:29:29
#revolutionary #approach #Large #Hadron #Collider
