It happens in 1995, toward the end of Run 1B of the Fermilab Tevatron, in the middle of a otherwise anonymous store. The CDF detector is taking good data, and the shift crew in the control room take care of the usual business - a look at the colourful monitors that plaster the walls, a check at trigger rates, the logging of a few standard warnings issued by the data acquisition system, and the occasional browsing of e-mails.
"This time we're shooting through a brick!"
Larry Nodulman (during a discussion on the reconstruction of electrons in the CDF II detector, just refurbished with a new set of silicon microstrip layers (SVX'), more powerful and capable of identifying the impact parameter of charged tracks with a dozen micron accuracy, but also heavier and bulkier than its predecessor, and thus providing more material for multiple scattering of particles.)
An international team of high-energy physicists says the discovery of an electrically charged subatomic particle called Zc(4020) is a sign that they have begun to unveil a whole new family of four-quark objects.
The Beijing Spectrometer (BESIII) collaboration previously announced the discovery of a four-quark particle called Zc(3900) in April of this year. The results have come about through a dedicated study of the byproducts of the anomalous Y(4260) particle.
These days I am trying to reconstruct some stories from my old experiment, CDF. The CDF experiment was conceived in 1979 and constructed in the early eighties at the Fermi laboratories in Batavia, near Chicago. CDF took the first proton-antiproton collisions in 1985, and it collected data in1987-88, 1992-96, and 2001-2011, thus becoming the longest-lasting particle physics experiment in the history of science.
Top scientists met at Fermi National Accelerator Laboratory, this past weekend, in the first of a series of face to face meetings which will help determine the course of particle physics in the United States of America for the next decade. This was the first face to face meeting of the Particle Physics Project Prioritization Panel. The community of physicists at and around Fermi National Accelerator Laboratory is only the first which will get to have its s
The results of the LUX experiment are out - and they are negative: no dark matter signal has been spotted by the extra sensitive detector. This is a normal day for you and me, but a gloomy day for those that counted on the neutralino to be the first supersymmetric particle to show up and redeem decades of claims.
The Large Underground Xenon (LUX) experiment is trying to identify the nature of dark matter, an invisible substance that physicists believe is all around us, making up most of the matter in the universe, even though it has effect on our lives.
The umbrella term 'dark matter' encompasses about 25% of the Universe, while what we know as matter makes up about 5%. The rest consists of what is called "dark energy" and no one knows anything about that other than that it is something helps make gravity behave strangely at the very large scale.
Do you remember the dijet bump at 140 GeV that CDF published in March 2011 ? This was a surprising excess in the mass distribution of pairs of jets found in events containing a leptonic W boson decay.
At some point the exact number of particles in a group becomes irrelevant.
But does when a collection of elements forms a "heap"
In recent experiments using ultracold atoms, Heidelberg physicists succeeded in observing the transition to a many-body system well described by an infinite number of particles - a problem philosophers call the sorites paradox. The essential question is when a collection of elements forms a "heap".
Just a quick link today, to acknowledge an interesting report
on the life of physics students in Greece and the present situation with Universities there. And of course, if you wish to practice your Greek, there are more articles there, translated for us by Yiannis Michaloliakos.