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Archive for the ‘cosmology’ category: Page 138

Apr 21, 2023

Probing fundamental symmetries of nature with the Higgs boson

Posted by in categories: cosmology, particle physics

Where did all the antimatter go? After the Big Bang, matter and antimatter should have been created in equal amounts. Why we live in a universe of matter, with very little antimatter, remains a mystery. The excess of matter could be explained by the violation of charge-parity (CP) symmetry, which essentially means that certain processes that involve particles behave differently to those that involve their antiparticles.

However, the CP-violating processes that have been observed so far are insufficient to explain the matter–antimatter asymmetry in the universe. New sources of CP violation must be out there—and might be hiding in interactions involving the Higgs boson. In the Standard Model of particle physics, Higgs-boson interactions with other particles conserve CP symmetry. If researchers find signs of CP violation in these interactions, they could be a clue to one of the universe’s oldest mysteries.

In a new analysis of its full dataset from Run 2 of the LHC, the ATLAS collaboration tested the Higgs-boson interactions with the carriers of the weak force, the W and Z bosons, looking for signs of CP violation. The collaboration studied Higgs-boson decays into two Z bosons, each of which transforms into a pair of leptons (an electron and a positron or a muon and an antimuon), thus resulting in four charged leptons. The researchers also studied interactions in which two W or Z bosons combine to produce a Higgs boson. In this case, one quark and one antiquark are produced together with the Higgs boson, creating ‘jets’ of particles in the ATLAS detector.

Apr 21, 2023

Dark Order in the Universe: Distant Galaxies Align To Support Einstein’s General Relativity

Posted by in category: cosmology

Scientists have confirmed that intrinsic alignments of galaxies can probe dark matter and dark energy on a cosmological scale, supporting general relativity at vast spatial scales. However, the nature of dark energy and cosmic acceleration remains unresolved.

Einstein would nod in approval. General relativity may apply even in the farthest reaches of the universe.

Now, scientists from international research institutions, including Kyoto University, have confirmed that the intrinsic alignments of galaxies have characteristics that allow it to be a powerful probe of dark matter and dark energy on a cosmological scale.

Apr 21, 2023

A scientific triumph: Danish student uncovers the secret of black holes

Posted by in category: cosmology

Black holes have always been fascinating to scientists and the general public alike. They are so mysterious that even light can’t escape.

Apr 21, 2023

This Is Extraordinary: Gravity Can Create Light, All on Its Own

Posted by in categories: cosmology, physics

Right after the Big Bang, gravitational waves may have built on each other to create huge standing waves of gravitational energy.

Apr 21, 2023

The DarkSide experiment extends its search to dark matter–nucleon interactions

Posted by in categories: cosmology, particle physics

The DarkSide experiment is an ambitious research effort aimed at detecting dark matter particle interactions in liquid argon using a dual-phase physics detector located at the underground Gran Sasso National Laboratory. These interactions could be observed by minimizing background signals, and this could be possible thanks to the remarkable discrimination power of the scintillation pulse of liquefied argon in the DarkSide-50 detector, which can separate nuclear recoil events associated with these interactions from more than 100 million electronic recoil events linked to radioactive background.

The large team of researchers involved in the DarkSide experiment has recently been using the detector to search for lighter particles. The results of a new search for dark matter–nucleon interactions, published in Physical Review Letters, allowed them to set new constraints for sub-GeV/c2 dark matter.

“The DarkSide-50 experiment was designed as a test for the use of from underground sources, naturally depleted in the radioactive 39 Ar, for very large scale dark matter searches,” Cristiano Galbiati a Researcher at Princeton University and the Gran Sasso Science Institute, told Phys.org. “It is remarkable to see how a group of young researchers within the collaboration was able to exploit the apparatus to extract the best limit for dark matter searches that were not part of the original scope of the experiment. If anything, the ingenuity and resolve of this group should be credited for this important result.”

Apr 21, 2023

Chandra X-ray Observatory identifies new stellar danger to planets

Posted by in categories: cosmology, existential risks

Astronomers using data from NASA’s Chandra X-ray Observatory and other telescopes have identified a new threat to life on planets like Earth: a phase during which intense X-rays from exploded stars can affect planets over 100 light-years away. This result, as outlined in our latest press release, has implication for the study of exoplanets and their habitability.

This newly found threat comes from a supernova’s blast wave striking dense gas surrounding the exploded star, as depicted in the upper right of our artist’s impression. When this impact occurs it can produce a large dose of X-rays that reaches an Earth-like planet (shown in the lower left, illuminated by its host star out of view to the right) months to years after the explosion and may last for decades. Such intense exposure may trigger an extinction event on the planet.

A new study reporting this threat is based on X-ray observations of 31 and their aftermath—mostly from NASA’s Chandra X-ray Observatory, Swift and NuSTAR missions, and ESA’s XMM-Newton—show that planets can be subjected to lethal doses of located as much as about 160 light-years away. Four of the supernovae in the study (SN 1979C, SN 1987A, SN 2010jl, and SN 1994I) are shown in composite images containing Chandra data in the supplemental image.

Apr 20, 2023

New look at ‘Einstein rings’ around distant galaxies just got us closer to solving the dark matter debate

Posted by in categories: cosmology, physics

Physicists believe most of the matter in the universe is made up of an invisible substance that we only know about by its indirect effects on the stars and galaxies we can see.

We’re not crazy! Without this “dark matter”, the universe as we see it would make no sense.

But the nature of dark matter is a longstanding puzzle. However, a new study by Alfred Amruth at the University of Hong Kong and colleagues, published in Nature Astronomy, uses the gravitational bending of light to bring us a step closer to understanding.

Apr 20, 2023

Strange ‘Anomalies’ In Spacetime Could Be Revealing New Physics, Scientists Say

Posted by in categories: cosmology, physics

ABSTRACT breaks down mind-bending scientific research, future tech, new discoveries, and major breakthroughs. Scientists have made an unprecedented discovery about dark matter by examining anomalies in…

Apr 19, 2023

Is Time Travel Possible In Our Universe?

Posted by in categories: cosmology, media & arts, quantum physics, space travel, time travel

The first 100 people to use code UNIVERSE at the link below will get 60% off of Incogni: https://incogni.com/universe.

Researched and Written by Colin Stuart.
Check out his superb Astrophysics for Beginners course here: https://www.colinstuart.net/astrophysics-course-for-beginner…on-online/

Continue reading “Is Time Travel Possible In Our Universe?” »

Apr 17, 2023

Disentangling the Sun’s Impact on Cosmic Rays

Posted by in categories: cosmology, particle physics

An instrument on the International Space Station has revealed new information about how the Sun’s magnetic field affects cosmic rays on their way to Earth.

Galactic cosmic rays (GCRs) are highly energetic charged particles that are produced through various acceleration mechanisms in astrophysical objects such as supernova remnants. These particles propagate through the Galaxy and can reach the heliosphere, a region dominated by plasma originating from the Sun. Within the heliosphere, GCRs interact with the turbulent plasma environment in a way that decreases their flux, causing them to diffuse in space and to lose energy [1]. Most of the impact of this “solar modulation” on GCRs is independent of particle charge. But GCR drift is also influenced by large-scale gradients in, and curvatures of, the heliospheric magnetic field and by the current sheet—a tenuous structure that separates the heliosphere into regions of opposite magnetic-field polarity [2].