(Two news stories covering recent research in quantum physics: a rare particle’s decay is validated for the first time, confirming predictions in the Standard Model of QT [but dimming hopes of more exotic particles, for now]; and, new research on exotic forms of matter called cuprates seems to indicate a ‘holographic duality’ hidden beneath the quantum world, lending support to String Theory.)
When Protons Collide – A Rare Meson May Appear, But Quickly Decays
Physicists working with two sophisticated detectors attached to the Large Hadron Collider (LHC) located at CERN in Switzerland have observe a rare form of particle decay that adds further support for the Standard Model — the current, dominant model describing how things work on the scale of the exceedingly small.
These rare particles are called B-sub-s particles (which are types of mesons) and their decay into fundamental particles called muons (which are electron-like particles with greater mass) is predicted to occur just three times in a billion decay events.
B-sub-s particles are generated through proton collisions; they are composed of two “flavors” of quarks (subatomic “building block” particles that, in groupings of three, form hadrons like protons and neutrons): bottom quarks and anti-strange quarks (the antimatter counterparts to strange quarks). These exotic particles are so unstable that they rapidly decay — on the order of a billionths of a second — into lighter, more stable particles (the observed muons).
Analyzing massive amounts data from two experimental detector systems — the CMS (Compact Muon Solenoid) and the LHCb (LHCbeauty) detectors — the research teams have now sifted through the results of enough particle collisions and identified a sufficient number of these decay events to confirm that the predictions of the Standard Model (SM) for such decays is just about right.
This corroboration is important insofar as larger deviations from the values predicted in SM would indicate the presence of other forces or particles — perhaps more “exotic” particles like the superpartner particles predicted by Super Symmetry (SUSY) theory. SUSY is an elegant theory of particle physics closely tied with tenets of String Theory; both theories have been “on the rocks” lately with the confirmation of a Higgs-like boson but no other new particles (but see the second article below for more on String Theory)..
However, it is still possible that physicists may find evidence of some of these other exotic particles in future, higher-energy collision experiments (like the related, but even rarer, B-sub-d, which is made of a bottom quark and an anti-down quark). But that will have to wait until 2015 and beyond as the LHC is shut down for repairs until then.
The LHC researchers announced their new findings July 19 at the EPS-HEP conference in Stockholm, Sweden.
Some source material for this news item came from the Live
Science article: ‘Rare Particle Discovery Dims Hopes for Exotic Theories’ by Clara Moskowitz
A Hidden Holographic Duality May Lay Beneath the Quantum World
A holographic image is a recording of a 2D interference pattern (of light waves) that encodes 3D information; thus the image, when properly illuminated by a coherent light source, generates a 3D reconstructed image of the original holographic object. The idea that our universe bears structural similarity to such holographic images was quite fashionable in the 1980’s, then fell from favor…then returned in a somewhat new form in the early 2000’s (Wheeler, 2003) with the idea that the universe is composed of information that can only be perceived — by us — in a limited (lower) dimensional form (thus akin to a 2D holographic image).
The essential idea being utilized here is that the 2D image (the interference pattern) contains more information (regarding a third dimension) than can be perceived by looking at the interference pattern alone. This “deeper” dimensional reality is quite different from the lower-dimensional information that we perceive.
In 1997, mathematician Juan Maldecena first posited a mathematical principle that described the quantum universe in holographic terms, that is, that events taking place in a 3D region of space corresponded to very different events taking place on that regions 2D boundary (this mathematical correspondence applied as well to 4D regions and events on a 3D boundary, and so on).
This 2D boundary has been likened to the surface of a quantum “pond” to conceptualize events like wave-particle duality and other phenomenon.
Observing only the pond’s surface, splashes correspond to particles and the ripples from these splashes correspond to waves. In each case, the surface experiences forms of turbulence. This surface turbulence is linked to different events in the interior of the pond. Maldecena showed that where the force of gravity comes into play, there is an odd inverse relationship between surface events and events “below” the surface; when the surface is turbulent, the interior is “calm” (gravity-free); when the surface is calm (“gravity-free”), the interior is turbulent.
This idea extends the conventional view of quantum physics that describes the universe in terms of energy fields with “point-like” disturbances to these field manifesting as particles, and more diffuse disturbances manifesting as waves. This conventional view of the quantum realm has held for many decades but recent investigations into a strange class of metal-based materials seems to warrant a paradigm shift more akin to Maldecena’s description.
How a ‘Strange’ Superconducting Material Redefines Quantum Dynamics
Quantum Mechanics is exceptionally good as describing most of the events that transpire on the sub-atomic level of matter. But for a strange class of metallic materials known as cuprates, conventional quantum mechanical theories seem to be defied.
Cuprates are copper-containing (composite)metals that exhibit a property called high-temperature superconductivity. Under certain conditions, the conductive particles In these materials interact in a “strongly correlated” manner; they essentially lose their individuality and engage is a “swarm effect” in which each particle’s wave form overlaps to such a great degree that it is as if there were but one, superconducting particle at work.
Matter existing in such a strongly correlated state exhibits varied and unexpected properties that in some forms cannot be explained by known quantum mechanical methods/formulas. There must be some “deeper” (higher dimensional) dynamics at work.
As it turns out, Maldecena’s theory is quite useful in predicting these strange behaviors.
New research by physicists at the University of California-Santa Barbara (Horowitz et al) investigated the deeper phenomena that are connected to the “surface-level” behavior of these cuprate materials. By calculating what must be happening in this deeper level (i.e., beneath the pond’s surface), the researchers were able to derive a formula describing the superconductivity of cuprates (previously only observed in laboratory experiments) in terms of electrons moving through a crystal lattice. The application of holographic duality mathematics accurately described and predicted cuprate superconductive behavior.
The Return of String Theory …?
Intriguingly, the results seem to indirectly support fundamental concepts of String Theory. String Theory is an elegant, geometrical-mathematical theory that combines quantum mechanics and gravitational theory and which posits elaborately contorted*, vibrating “strings” underlying the quantum world; different conformations of these strings give rise to the various particles; their differing vibrational patterns conferring various physical properties. String theory is unproven, being purely mathematical with no experimental validation.
(Note: These highly complex structures, known as Calabi-Yao shapes, exhibit the mathematical property of symmetry duality which allows solving of one shape’s equation by looking at its “mirror” version’s equation. For some curious reason, the mirror version equation of each Calabi-Yao shape is always simpler to solve. This duality is similar in structure to the holographic duality of Maldecena).
However, it seems that this interior — this higher dimensional region — is linked to the surface (lower dimensional space) in ways that only a merging of String Theory with Particle Theory can rationally, and accurately, describe.
Returning to our quantum pond metaphor:
For this holographic duality or correspondence to work, the 3D interior of our pond must be described according to the mathematical formulas of String Theory in which all particles — electrons, protons, neutrons and even (unproven) “gravitons” and the others — are each a different kind of one-dimensional string, with their properties (e.g., mass, spin, etc.) being determined by the vibrational state of the strings. As strings split and re-connect, this activity determines the different interactions between the particles.
There appearance of normal matter (what we see when looking at the “calm” 2D boundary or pond surface) corresponds to very complex behavior going on below the surface (in the invisible, higher dimensional realm)…and vice versa: to understand the complex behavior of surface particles (their “turbulence”), the theory tells you to look at the interior situation, which is much simpler; the surface turbulence is mathematically equivalent to calm dynamics beneath.
“To understand this relationship, the crucial aspect is when the gravity theory is easy to analyze, then the particles on the boundary are interacting very strongly with each other.” [quote source, see below for link]
The ability to explain this curious and contrasting inter-relationship between surface and interior — between lower and higher dimensions — is what makes the holographic duality theory so powerful.
Beyond cuprate superconductivity, the theory can even be used to describe what goes on inside an unusual type of electrically charged, “corrugated” black hole; certain strongly-correlated matter on a 2D boundary (the surface) corresponds to a black hole (the 3D interior). So, an electron falling onto the surface vanishes into the collective (singular) physics of the pond interior (in this example, the black hole).
The theory is allowing physicist to probe the curious states of matter observed in lab experiments by thinking differently about their underlying physical reality.
The new research (Horowitz et al) was published online in the June 24 edition of the Journal of High Energy Physics.
Some source material (including image, quote) for this post came from the Wired article ‘Holographic Duality’ Hints at Hidden Subatomic World’ by Natalie Wolchover (Simons Science News)