Physics

Stars don't die without being noticed and sometimes the results are pretty spectacular.  At the end of its life cycle, a star begins to collapse and throws new material into space, which eventually becomes incorporated into new planets and life. A University of Missouri professor identified new features in material that is being ejected from the dying star Helix Nebula.  A high-resolution near-infrared image revealed new information about the knots, or the structures that are formed from the emissions of the nebula. In the Helix Nebula, the knots often appear to be comet-shaped. The…

Yesterday I posted a short article whose main purpose was to show a figure I had received from Sven Heinemeyer, a phenomenologist who specializes in the study of Minimal Supersymmetric extensions of the Standard Model (MSSM). Besides predicting a mirror copy of Standard Model (SM) particles, MSSM models are characterized by containing not just one, but five distinct Higgs bosons; over much of the space of possible parameters of these theories, one of the five Higgs bosons is quite similar to the one and only SM Higgs, so that one can discuss the SM Higgs and the lightest neutral scalar of the…

...waiting for a piece I will post tomorrow, to stimulate your curiosity -and allow me to travel from Venice to Patras by ship, with no internet connection. The subject is not only the Higgs mass, but the top quark mass. Which top mass ? The "pole" mass -the real part of the pole in the perturbative top-quark propagator. Have I lost you ? Ok, do not worry -definitions are for theorists. Let us just say that the top quark, being a complicated coloured object which thus cannot live free of the influence of strong interactions,is measurable at a hadron collider like the Tevatron only within…

I posted a very short rough paper here a while back.  "Dark Matter and Energy as Particles and Fields of Unobserved Scalar and Vector Fields (PDF) (rev2).." Since then certain comments and supposed extremely elementary errors have been pointed out.  The following is a referee report from a well respected journal.  These are (mostly) valid critiques stated in a polite and professional manner.  None of the things which were pointed out by bloggers are here, which were for the most part so elementary that if true there would not even have been a peer review.  Title:…

A new public document has been made available on the CMS public web page yesterday morning. It reports on a study of the reach of the CMS detector, with data collectable in 2010, for a signal of large extra dimensions, using the very distinctive signature of a high-energy jet recoiling against -well, recoiling against nothing; or better, something which left our world and entered into another dimension of space. I expect many of you may have already started wondering what the heck I am talking about, so please allow me give you a little background. In 1998 three prominent theorists -Arkani-…

From August 30th to September 2nd I will attend the 29th edition of "Physics in Collision" in Kobe, Japan, to hear a few interesting talks and to present a poster on behalf of CMS, about the search for the Standard Model Higgs boson. Posters are what they sound like -big, illustrated sheets of paper. Many conferences have a "poster session" in which authors of the posters stand in front of their creation and discuss the details with colleagues and answer questions about the contents. Before the poster session, each poster is usually presented by the author with a short oral memo -five minutes…

The Arxiv is an online repository of scientific papers in physics, astronomy, maths, cosmology, computer science, and a few other topics, where papers due to be published on scientific journals are submitted by the authors, and become quickly accessible for free to anybody before the peer-review process ran by the journals is over and they get printed there. While the Arxiv is totally access-free, not everything can be published there: the existence of people with funny ideas on what a scientific paper is or what it should or should not contain makes some pre-filtering on the archived…

Patrick Draper is a graduate student in physics at the University of Chicago and Argonne National Lab. He is a native of Illinois and lives in Hyde Park, Chicago with his wife Karen and parrot Felix, to whom he is grateful for their love, patience, and correcting his sign errors. He is a supporter of the international effort to put a muon collider on Mars, and is waiting for NASA to return his phone calls.I asked Patrick to write here about his studies on the discovery reach for a MSSM Higgs boson after I saw his paper on the arxiv a month ago, and am now glad I did. Enjoy! First, I would…

Just what would time travel look like?  This question was posed to me by a movie director in L.A..  It turns out there are three parts to this question-- what physics suggests, what movies have done in the past, and what looks good. The last is up to her and her special effects staff.  The middle one-- Hollywood traditions for time travel-- are worth examining to scope out possibilities.  I'll then conclude with what I think physics suggests is most likely. Were I to invent categories for movie time travel effects, I'd create the following:   techno with lots of…

Physicists at the National Institute of Standards and Technology (NIST) have devised a viable way to manipulate a single 'bit' in a quantum processor without disturbing the information stored in its neighbors, using polarized light to create "effective" magnetic fields. A great challenge in creating a working quantum computer is maintaining control over the carriers of information, the "switches" in a quantum processor while isolating them from the environment. These quantum bits, or "qubits," have the uncanny ability to exist in both "on" and "off" positions simultaneously, giving quantum…