LHCb confirms existence of exotic hadrons

by : Cian O'Luanaigh

The Large Hadron Collider beauty (LHCb) collaboration today announced results that confirm the existence of exotic hadrons – a type of matter that cannot be classified within the traditional quark model. Hadrons are subatomic particles that can take part in the strong interaction – the force that binds protons inside the nuclei of atoms. Physicists have theorized since the 1960s, and ample experimental evidence since has confirmed, that hadrons are made up of quarks and antiquarks that determine their properties. A subset of hadrons, called mesons, is formed from quark-antiquark pairs, while the rest – baryons – are made up of three quarks. But since it was first proposed physicists have found several particles that do not fit into this model of hadron structure. Now the LHCb collaboration has published an unambiguous observation of an exotic particle – the Z(4430) – that does not fit the quark model.

The Belle Collaboration reported the first evidence for the Z(4430) in 2008. They found a tantalizing peak in the mass distribution of particles that result from the decays of B mesons. Belle later confirmed the existence of the Z(4430) with a significance of 5.2 sigma on the scale that particle physicists use to describe the certainty of a result. LHCb reports a more detailed measurement of the Z(4430) that confirms that it is unambiguously a particle, and a long-sought exotic hadron at that. They analysed more than 25,000 decays of B mesons selected from data from 180 trillion (180 ×10^12) proton-proton collisions in the Large Hadron Collider. "The significance of the Z (4430) signal is overwhelming – at least 13.9 sigma – confirming the existence of this state," says LHCb spokesperson Pierluigi Campana. "The LHCb analysis establishes the resonant nature of the observed structure, proving that this is really a particle, and not some special feature of the data."

Source : CERN

Inflation, Symmetry, and B-Modes

We examine the role of using symmetry and effective field theory in inflationary model building. We describe the standard formulation of starting with an approximate shift symmetry for a scalar field, and then introducing corrections systematically in order to maintain control over the inflationary potential. We find that this leads to models in good agreement with recent data. 

On the other hand, there are attempts in the literature to deviate from this paradigm by envoking other symmetries and corrections. In particular: in a suite of recent papers, several authors have made the claim that standard Einstein gravity with a cosmological constant and a massless scalar carries conformal symmetry. They further claim that such a theory carries another hidden symmetry; a global SO(1,1) symmetry. By deforming around the global SO(1,1) symmetry, they are able to produce a range of inflationary models with asymptotically flat potentials, whose flatness is claimed to be protected by these symmetries. 

Image : alice.loria.fr

These models tend to give rise to B-modes with small amplitude. Here we explain that these authors are merely introducing a redundancy into the description, not an actual conformal symmetry. Furthermore, we explain that the only real (global) symmetry in these models is not at all hidden, but is completely manifest when expressed in the Einstein frame; it is in fact the shift symmetry of a scalar field. When analyzed systematically as an effective field theory, deformations do not generally produce asymptotically flat potentials and small B-modes, but other types of potentials with B-modes of large amplitude; nicely compatible with recent BICEP2 data. Such simple models typically also produce the observed red spectral index, Gaussian fluctuations, etc. In short: simple models of inflation, organized by expanding around a shift symmetry, are in excellent agreement with recent data.

Link : http://arxiv.org/pdf/1403.5253

Claim New Study, Every Blackhole is a Portal to Another Universe

A black hole is a region of spacetime from which gravity prevents anything, including light, from escaping. The theory of general relativity predicts that a sufficiently compact mass will usually deform spacetime to form a black hole. Around a black hole, there is a mathematically defined surface called an event horizon that marks the point of no return.  [wikipedia]

The new theory was developed by Jorge Pullin of the State University of Louisiana and Rodolfo Gambino of the University of the Republic of Uruguay. The two scientists decided to study the predictions of the theory of quantum gravity in black holes. More specifically, they applied the equations of quantum gravity in a non-rotating black hole with spherical symmetry.

As described in other theories, as the matter approaches the core of the black hole, the gravitational field becomes more and more powerful, but it does not disappear into a spacetime singularity as the prevailing theory states. According to the study results of the two researchers, the matter does not disappear in the middle of the hole but continues its way up the other end and into another universe. “Like part of a cosmic Russian doll, our universe may be nested inside a black hole that is itself part of a larger universe.

image: http://www.shutterstock.com/pic.mhtml?id=25016035

In turn, all the black holes found so far in our universe—from the microscopic to the supermassive—may be doorways into alternate realities.” According to the new equations, the matter black holes absorb and seemingly destroy is actually expelled and becomes the building blocks for galaxies, stars, and planets in another reality. Essentially, every black hole contains a smaller alternate universe. And our universe might just exist inside a black hole of a galaxy in a much larger universe. So within the 100 billion galaxies in our known universe lies 100 billion universes in the galactic black holes of our universe, with 100 billion more galaxies each containing another universe with more galaxies, and so on infinitely.

The new model isn't the first to propose that other universes exist inside black holes. Damien Easson, a theoretical physicist at Arizona State University, has made the speculation in previous studies. “What is new here is an actual wormhole solution in general relativity that acts as the passage from the exterior black hole to the new interior universe,” said Easson, who was not involved in the new study. So the idea that black holes are portals to other worlds rather than a place of absolute destruction is not new. But they all stumbled on the spacetime singularity.

This is the first time when this barrier is bypassed with the help of scientific tools. The results of the study were published in the journal Physical Review Letters. Furthermore, a recent study published in the scientific journal Nature shows that our entire universe may have been born out of a black hole from another universe. In other words, the Big Bang was really just an extension of a black hole in a different universe.

Source : http://www.whydontyoutrythis.com/2014/03/every-black-hole-contains-another-universe-claims-new-study.html