For the series "ideas worth spreading", CMS has copied the nice idea of ATLAS of producing an animated gif with increasing data leading to the Higgs boson discovery.
This is the mass distribution of Higgs boson candidates, detected by collecting events featuring four charged leptons (electrons or muons). The leptons are combined in pairs, and one pair (of same flavour) will usually yield a mass in the ballpark of the Z boson mass; the other pair will have lower energy if it is produced by an off-shell Z boson. Of course all four-lepton pairs compatible with quality criteria are kept, and the mass distribution thus contains a majority of events due to standard model production of ZZ pairs. This is the peaking background at masses above 180 GeV.
Carlo Rubbia discussed the prospects of constructing a muon collider to produce large amounts of Higgs bosons and study their properties in detail, crucially measuring the natural width of the particle, and testing couplings to a precision that LHC can't arrive at, to verify whether the particle is the Standard Model Higgs or if there are anomalies. The talk is discussed in detail in this report
Here I just recall a question I asked Rubbia after the talk:
A short note to mention that starting today, and until Friday, I will be blogging from the "Neutrino Telescopes" conference in Venice. This is a conference dedicated to the study of neutrinos, and will feature many interesting talks on high-energy physics and astrophysics. I will paste here some of the material, but if you are interested in the topic you should check out the blog site of the conference, http://neutel11.wordpress.com/
The LHCb collaboration published on the Cornell Arxiv yesterday a preprint describing the observation of a rare decay of the B_c meson. In this landscape of failed SUSY searches, no-shows of new resonances in dilepton mass spectra, flat dijet mass histograms, and a general gloomy feeling that the Higgs is all we'll get this decade at the high-energy frontier, it is nice to turn to the beautiful little jewels that are still there to be unearthed in heavy meson spectroscopy.
Now that the first of the Moriond conferences is over, and just as the second one starts, it is time to have a detached view at the Higgs boson results presented there this far by the CMS and ATLAS collaborations, to summarize where we stand and what new information we have gained since last fall, when some new results appeared for the HCP conference.
I read with interest the recent disclosure that several biologists suggest they have proven Dollo's Law
(that biological evolution is irreversible, a 1-way path through genetic change and time) is at the very least not perfect and perhaps may simply be wrong.
Never having taken a biology course much less one on evolutionary theory I can't say I know anything much about Dollo's proposition other than that he posed it over 100 years ago and that Richard Dawkins supposedly characterized it more as a statement about probabilities.
Nel 1929 Bruno Rossi, ricercatore presso l’istituto di fisica sperimentale
dell’Università di Firenze [...] intuì quella che sarebbe stata la sua ragione di vita: indagare sulla natura di questi corpuscoli ionizzanti provenienti dall’alto. Doveva realizzare un circuito che permettesse di rivelare e contare le coincidenze che si verificavano in una certa unità di tempo e realizzò uno strumento molto semplice, il circuito a coincidenze.
L’involucro dei tubi Geiger è collegato al polo negativo di una batteria da 1200 volt (non
disegnata). La scarica nei tubi genera un impulso di tensione negativa sulle resistenze da
Understanding and explaining how the Universe works has always been a ultimate goal for mankind. It is impossible to live our conscious existence without asking ourselves whether there is a meaning, a design, or if our existence is just the result of chance; and to avoid asking ourselves what happens after we die, if we will live again, and similar questions. Accepting our mortality is really hard without embracing a potential explanation, a hope, or some kind of faith.
Last week a new important paper appeared in the Arxiv: "MSSM Higgs Boson Searches at the LHC:Benchmark Scenarios after the Discovery of a Higgs-like Particle"
, by M.Carena, S.Heinemeyer, O. Stal, C.Wagner, and G.Weiglein. The paper fills a void that was created after the discovery of the Higgs particle last July by the ATLAS and CMS experiments: a thorough assessment of what constraints on the allowed chunks of SUSY parameter space in the light of the existence of a neutral scalar at 125 GeV.
The technical details of Big Bang, inflationary cosmology, and selected alternative theories are on offer. Popular accounts of the big bang theory, cosmic inflation, and the creation of the universe often leave out details a consumer of science would like to know. Scholarly monographs published the old fashioned way can cost hundreds of dollars per copy, and too often are locked away in university libraries. For general public availability, I present my monograph on the cosmology of the early universe.