Physics

WIMP- Is This 3 Sigma Signal The Road To Dark Matter?

Cryogenic Dark Matter Search (CDMS) collaborators are reporting what could be a weakly interacting massive particle (WIMP) signal at the 3-sigma level. In common parlance, that is 99.7 confidence- which sounds high.  But to physicists it really means they ...

Article - Hank Campbell - Apr 16 2013 - 11:54am

Rescinded: The Light Matter Proposal: A Big Picture View

I have decided to rescind this proposal.  Stars in a galaxy travel at one velocity, light at the speed c.  There is only one velocity involved in applying the product rule to the definition of a force as a change in momentum.  Note that is not a trivial a ...

Blog Post - Doug Sweetser - Mar 3 2015 - 12:23pm

Physics Psychics? How Alice And Bob Talk, Without Saying A Word

In quantum physics, objects can be in more than one place at a time and future events can change the past- don't get caught up too much in that or you won't sleep at night. A new paper says quantum physics can be even spookier. Using the “chained ...

Article - News Staff - Apr 18 2013 - 12:13pm

Kentucky Windage, For Science: Using Black Holes To Measure The Universe's Rate Of Expansion

Calibration does not always mean fixing a device, it sometimes means adjusting to solve a problem.  In the early years of America, the famous Kentucky longrifles that conquered the frontier (and some British) had fixed sights. Since they couldn't be ...

Article - Hank Campbell - May 23 2013 - 10:21am

CP Violation In D Mesons: New Physics Or Standard Physics?

One of the most intriguing effects in subatomic physics is the phenomenon of violation of the discrete symmetry called "CP". It is intriguing at various levels. First of all, CP violation is intriguing because of the depth of the concept: proof o ...

Article - Tommaso Dorigo - Apr 24 2013 - 12:31am

The Plot Of The Week- Z Plus Jets

ATLAS has just produced a very nice new study of jet production in Z-boson events. I will describe a sample graph below, but before I do I find it useful to explain to the less knowledgeable among you what a hadronic jet is, just in case you've been a ...

Article - Tommaso Dorigo - Apr 30 2013 - 1:08am

The Quote Of The Week- Four-Jet Events at 130 GeV

"A detailed study of four-jet hadronic events at LEP 1.5 has been reported by the ALEPH collaboration. From selected four-jet events, the invariant masses of jet pairs are computed, and out of the three jet combinations, the one with the lowest diffe ...

Blog Post - Tommaso Dorigo - May 3 2013 - 8:02am

The Overconstrained Standard Model

With the Higgs boson in the bag, the game called "global fit" that particle physicists have been playing for a couple of decades has changed significantly. The knowledge of the Higgs boson mass provided by the measurements obtained by the ATLAS a ...

Article - Tommaso Dorigo - May 6 2013 - 12:48pm

Not Just Football Or Basketball- Scientists Demonstrate Pear-Shaped Atomic Nuclei

While school-age models of atomic nuclei show them as being spherical, like a basketball, they are more like the shape of a football.  Yet for some particular combinations of protons and neutrons, nuclei can also assume very asymmetric shapes, like a pear ...

Article - News Staff - May 9 2013 - 11:00am

CDF Memories, Circa 1992

In 1992 the top quark had not been discovered yet, and it did not make much sense for the CDF collaboration to have a full meeting devoted solely to it; rather, analyses targeting the search of the top quark were presented at a meeting which dealt with bot ...

Article - Tommaso Dorigo - May 11 2013 - 1:54pm