# It From Bit - How To Get Rid Of Dark Energy

Jan 18 2010 | 62 comment(s)

Our universe expands, and this expansion is accelerating. Current consensus is to attribute this acceleration to a mysterious form of energy: dark energy. This dark energy density is very tiny and therefore only notable at cosmic length scales. When expressed in natural units, the cosmic dark energy density has a value of 10-123. This tiny value presents a big mystery. Straightforward estimates for the dark energy density based on quantum field theoretical considerations result in values (again in natural units) close to unity.

# Triggering - The Subtle Art Of Being Picky

Jan 17 2010 | 29 comment(s)

The success of today's particle physics experiments relies to a surprisingly large extent on a seldom told functionality of the giant apparata that detect the faint echoes of subatomic particles hitting or punching through their sensitive regions: the capability of triggering.

# Feynman Explains Quarks With A Burp

Jan 16 2010 | 2 comment(s)

"One way of thinking about the confinement problem was suggested by e+ e- annihilation into hadrons. Initially, the virtual photon dissociates into a quark $q$ and an antiquark $\bar q$ that move with almost the speed of light back-to-back. Feynman had argued that additional $q \bar q$pairs would be produced in the region between them, along the line separating the initially produced $q \bar q$. The new pairs and original $q \bar q$would rearrange and become a bunch of outgoing mesons [...].

# The Say Of The Week

Jan 14 2010 | 0 comment(s)

"The threat is much stronger than its execution"

Aaron Nimzovich (complaining to the arbiter of a chess match that his opponent had put a cigar in his mouth, after the arbiter had pointed out that the cigar was unlit).

# New Rare B Decays Nailed By CDF: The Door To New Physics ?

Jan 13 2010 | 1 comment(s)

The CDF Collaboration has recently produced a new analysis of proton-antiproton collisions at the now second-world-best collision energy of 1.96 TeV. They searched for very rare decays of the B mesons, particles composed of, would you guess, a b-quark and a lighter partner orbiting around each other.

# An appetizer: Rare B Decay Asymmetries

Jan 12 2010 | 1 comment(s)

As if taken by a spell, my joking claim to be on strike in the last post grew to become one of the longest streaks of absence from blogging of the last few months, for a series of irrelevant reasons tightly packed together.

In the meantime I have tried to put together an article on a recent very interesting measurement performed by the CDF collaboration: a study of very rare decays of B mesons, which can now not only determine the rate of said decays, but also have a taste at subtle kinematical effects in the distribution of the final states. The distributions are a new key to discriminate the existence of new physics in these rare processes.

# Businessweek takes on the LHC

Jan 11 2010 | 10 comment(s)

# The Approved CMS Phi Signal From 900 GeV Data

Jan 08 2010 | 19 comment(s)

Shoot. Today I am on strike.

This morning I decided to post here an article describing the details of a new result just approved by the CMS collaboration, the observation of a nice signal of phi meson decays. It is a result of which I am quite proud, and although not really a big deal, it is a nice way to start the new year, while we wait for more data from the LHC.

I had just finished writing the 200-lines piece describing the likelihood fit to the mass distribution, when I decided to save the draft with the "publish" box unmarked, to give it a last reading before submitting it. And the crazy web interface logged me off the site instead!

# It From Bit: The Case Of Gravity

Jan 07 2010 | 126 comment(s)

Three weeks of speculations have come to an end. Since this morning Verlinde's paper is available on arXiv.

# Three Top Quarks: A Door To New Physics ?

Jan 06 2010 | 11 comment(s)

Today's visit to the Cornell Arxiv, the repository where scientific papers on physics, astrophysics, mathematics, and a few other disciplines are made publically accessible before getting published on paper, was a productive one. Some casual browsing allowed me to learn a few random things on topics I know little or nothing about; but what really made my day was reading study by a few distinguished theorists (Vernon Barger, Wai-Yee Keung, and Brian Yencho), who considered a collider signature I had been fantasizing about in the past.