To end my series on the Higgs Boson, I thought I’d explain the possibility of an ‘Unhiggs’.

All particles exist in states that may be characterized by three properties- a certain energy, momentum and mass. Most particles of the Standard Model cannot exist in another state with all these properties scaled up or down by a common factor. For example, the mass of electrons remains constant, regardless of their energy or momentum. However, certain particles, like the massless photons can exist with their properties scaled equally, and are thus called scale invariant. Even neutrinos, having a negligible mass, are nearly scale invariant.

Unparticle Physics is a theory postulated by Howard Georgi in 2007, which conjectures matter that cannot be explained in terms of particles using the Standard Model, because its components are scale invariant., i.e, certain ‘particles’ may be scale invariant, without having zero mass. These are called unparticles.

Unparticles have not yet been observed, but are predicted to couple with normal matter weakly at observable energies, having many properties akin to those of neutrinos. Interaction of ordinary particles, causing the interaction of the Standard Model and Banks-Zaks fields, would appear to have “missing” energy and momentum that would not be detected by the experimental apparatus. Certain distinct distributions of missing energy would also signify the production of unparticles.

The idea of the Unhiggs was proposed in 2009. The parameters of the Unhiggs are continuous. In this sense, the Unhiggs is itself a continuum, and can be thought of as a collection of many Higgs bosons, each carrying a fraction of the Unhigg’s total value. The Unhiggs is postulated to be quite similar to the Higgs, except for the fact that it demonstrates unparticle behavior and hence, does not fit in with the Standard Model. However, while the Higgs and the Unhiggs have similar properties, the postulated Unhiggs also provides a solution to the hierarchy problem (the Higgs Boson being much lighter than the Planck mass), as it is scale invariant.

Do B masons hold the answer?

ELASTIC “unparticles” could explain a mysterious signal glimpsed at a particle collider a year ago. That would link a tenuous but intriguing idea to one of the biggest mysteries in physics: why matter prevails over antimatter in the universe
“I think this will increase the unparticle’s credibility as a theory,” says Run-Hui Li of Yonsei University in Seoul, South Korea, the leader of one of two teams proposing the link.
Matter and antimatter are thought to have been created in equal amounts after the big bang, yet something has caused matter to be far more dominant than antimatter, at least in our patch of the universe.
A possible explanation is that some physical processes favour matter. For example, according to the standard model of particle physics, particles known as B mesons constantly switch, or mix, between their matter and antimatter forms. Because it is slightly easier for an anti-B meson to become a normal B meson than vice versa, an imbalance accrues. This “uneven mixing” gets transferred to the particles produced when B mesons decay, but alone is not big enough to explain the observed matter-antimatter asymmetry.
Previously, several teams have glimpsed examples of asymmetryeven larger than the standard model predicts. In May 2010, researchers at the Fermi National Accelerator Laboratory in Batavia, Illinois, reported a 1 per cent preference for the number of B mesons produced in their particle smasher, the Tevatron (arxiv.org/abs/1005.2757). This is 40 times larger than the imbalance predicted by the standard model.
Two separate groups now suggest an explanation for this larger asymmetry lies in the unparticle, a hypothetical entity conjured up in 2007 by theorist Howard Georgi of Harvard University. Georgi suggested that a property known as scale invariance – seen in fractal-like patterns that remain unchanged even when you zoom in and out to different scales, like the branching of redwood trees and the jagged edges of coastlines – could apply to individual particles too. The charge and spin of unparticles would be fixed but, counter-intuitively, their mass would somehow vary depending on the scale at which an observer viewed the particle.
Such unparticles could play a role in a popular proposed extension to the standard model, known as supersymmetry.
Xiao-Gang He and his colleagues at Shanghai Jiao Tong University in China calculate that unparticles might also affect the lifetimes of B mesons. That is because quantum mechanics dictates that if they exist, “virtual” versions must exist too. Such transient unparticles would pop in and out of existence and could sometimes affect the lifetimes of real B mesons. And if this influence differed between the B meson and its antimatter counterpart, it could enhance the already uneven mixing predicted by the standard model enough to account for the mysterious Tevatron signal (Journal of Physics Letters B, DOI:10.1016/j.physletb.2011.03.001).
The unparticle’s elastic mass means it could conceivably have avoided detection in the Tevatron until now. A separate group led by Li has come to a similar conclusion arxiv.org/abs/1012.0095.
Bruce Hoeneisen, a member of the Fermilab team that saw the B meson imbalance in 2010, says other options, including new types of quarks not currently included in the standard model, could explain the Tevatron signal. He also cautions that the Tevatron finding requires confirmation….by Kate McAlpine - newscientist.com

The hunt for the Un-universe
FORMER US Defense Secretary Donald Rumsfeld famously distinguished between “known knowns”, “known unknowns” and “unknown unknowns”. It’s a distinction that should ring clear bells with Harvard physicist Howard Georgi, because he’s choosing to make the same distinction between different types of matter.
Most of us are familiar with the “known knowns” of matter – ordinary stuff, such as tables, chairs, quarks and electrons. Many physicists spend their days hunting for “known unknowns”, like the Higgs boson and the particles that make up dark matter. But Georgi has gone a step further. He is dabbling in the world of the “unknown unknowns” by proposing the existence of an entirely new type of matter unlike anything we have encountered before. He calls it the unparticle.
Unparticles are slippery customers. Breaking all the rules that constrain normal particles, they can shift identity and masquerade as fractions of particles. “It’s very difficult to even…. Read more: newscientist.com

Photo Source: CERN

I just had a look at the most recent New Scientist at our local library, because the cover lured me in with its title ‘Welcome to the Un-universe – Unparticles, Ungravity, Unmissable’. The first thing that came to my head was the tune of George Clinton’s ‘Undisco Kidd’, but then my thoughts move on to the possibility of ‘Mutable Unmatter’! I knew that physicists are talking about ‘dark matter’, ‘anti matter’ and even ‘strange matter’ – but ‘un-matter’? Hmh.

I opened the magazine and was greeted by another headline: ‘‘Have we been missing an entirely different kind of matter?’ So what is the matter? Howard Georgi, who researches this kind of ‘missing matter’, calls it ‘unparticles’, because it does not behave like particles. Apparently, ‘unparticles interact very weakly with ordinary matter’ – so instead they are ‘checking how this might affect everything from the orbit of Mercury to the production of black holes at the LHC (Large Hadron Collider).’ Black Holes on Earth? Whoops.

Anyway, if you do not fancy looking things up in the New Scientist, here is a brief article, not quite as entertaining as the New Scientist article, though, which ends with a brilliant Howard Georgi statement, namely: ‘All I knew was that I had found something cool and I wanted other people to take a look and see what kinds of weird things they might be capable of doing – what mysteries they might solve.’

The first mystery seems to be the word ‘Unparticle Physics’ itself, as stated by a website on nano-biotechnology: ‘Unparticle Physics – It’s not a typo, it’s a new theory’. We shall wait and see what kinds of ‘matter mutations’ will be induced through these particles – or ‘unparticles’…