[ad_1]
The bible of particle physics is dying for an upgrade. And physicists can have what it takes: certain particles and forces can look in the mirror and not recognize each other. That, in itself, would send the so-called standard model in free fall.
Almost all the fundamental reactions between the subatomic particles of the universe are similar when they are returned to a mirror. We then say that the mirror image, called parity, is symmetrical, or has symmetry of parity, in physics.
Of course, not everyone follows the rules. We know for example that reactions involving the weak nuclear force, which is also strange for many other reasons, violate the symmetry of parity. It is therefore logical to think that other forces and particles of the quantum world are also precursors of rules in this domain.
Physicists have ideas about these other hypothetical reactions that would not resemble each other in the mirror and thus violate the symmetry of parity. These strange reactions could point us to a new physics that could help us move beyond the standard model of particle physics, our current summary of everything that is subatomic.
Unfortunately, we will never see most of these strange reactions in our atom breakers and our labs. Interactions are simply too rare and weak to be detected with our instruments, which are suitable for other types of interactions. But there may be rare exceptions. Researchers at the world's largest atom breaker, the Large Hadron Collider (LHC) near Geneva, are looking for these rare interactions. Until now, they arrived empty-handed, but even this result is enlightening. These negative results help eliminate unsuccessful assumptions, allowing physicists to focus on more promising leads in the hunt for new physics. [18 Times Quantum Particles Blew Our Minds]
Mirror mirror on the wall
One of the most important concepts of all physics is that of symmetry. You can even reasonably argue that physicists are just hunters of symmetry. The symmetries reveal the fundamental laws of nature that govern the inner workings of reality. Symmetry is a big problem.
So what is it? Symmetry means that if you edit an element in a process or interaction, the process remains the same. Physicists then say that the process is symmetrical with respect to this change. I am deliberately vague because there are so many different types of symmetry. For example, sometimes you can change the sign of the charges on the particles, sometimes you can run processes forward or backward in time, and sometimes a mirror version of the process.
The latter, who looks at a process in the mirror, is called the symmetry of parity. Most subatomic interactions in physics give you exactly the same result whether they are done in front of you or in the mirror. But some interactions violate this symmetry, such as the weak nuclear force, especially when neutrinos are produced during interactions involving this force.
Neutrinos always turn "backwards" (in other words, the axis of their rotation is oriented away from their direction of movement), while the antineutrinos turn in "before" (their axis of rotation is oriented right backward). This means that there are very subtle differences in the number of neutrinos and antineutrinos produced when you run a normal experiment as opposed to a reverse experiment that relies on a weak nuclear force. [Strange Quarks and Muons, Oh My! Nature’s Tiniest Particles Dissected]
Broken mirrors
To our knowledge, the weak nuclear force and the weak nuclear force alone violate the symmetry of parity. But maybe it's not alone.
We know that physics must exist beyond what we currently understand. And some of these hypothetical ideas and concepts also violate the symmetry of parity. For example, some of these theories predict subtle asymmetries in otherwise normal interactions involving particle types that the LHC generally examines.
Of course, these hypothetical ideas are exotic, complex and very difficult to test. And in many cases, we do not know exactly what we are looking for.
The problem is that even though we know that our current conception of the particle world, called the standard model, is incomplete, we do not know where to look to replace it. Many physicists were hoping that the LHC would reveal something – a new particle, a new interaction, whatever – that would indicate something new and exciting, but all of this research failed until the end of the day. present.
Many of the old vanguard theories for what goes beyond the standard model (like supersymmetry) are slowly being excluded. This is where the violation of parity-symmetry might be useful.
Almost all of the standard hypothetical extensions of the standard model include the limitation that only the weak nuclear force violates parity symmetry. (This is part of the basic mathematics of the models, in case you wonder how it works.) This means that concepts such as supersymmetry, axions and leptoquarks all prevent this symmetry from breaking exactly where it is and nowhere else.
But, listen, if these common extensions are not extended, it may be time to broaden our horizons.
Peeling back parity
For this reason, a team of researchers has searched for parity violations in a data cache published by the Compact Solonoid Solenoid (CMS) experiment at the LHC; they detailed their results in a study published April 29 on the pre-print server arXiv. This was a pretty tricky search because the LHC is not really configured to look for parity violations. But researchers have cleverly found a way to do this by examining the remains in interactions between other particles.
Result: no index of violation of the parity was found. Hooray for the standard model (again). While it is a little disappointing that this research does not open a new frontier of physics, it will help clarify future research. If we continue to look for and still find no evidence of parity violation outside the weak nuclear force, we know that anything that exceeds the standard model must have some of the same mathematical structures as this basic theory and only allow for the weak nuclear force to look different in the mirror.
Originally published on Science live.
[ad_2]
Source link