Mankind has forever sought to determine the most fundamental components of matter. From the atom to the nucleus to the proton and neutron, and finally to the quark, we have asked each step of the way “Is this it or is there something inside?” ATLAS physicists have just taken another step toward tackling that very… [Read more…]
May 30, 2012
About LHsee LHsee is an educational tool available for Android OS mobile smartphones and tablet PCs. It has been custom designed to provide an accurate and interactive visual representation of complex high-energy physics events recorded by the ATLAS detector. Features include live streaming and reconstruction of collision data from the CERN Large Hadron Collider. The… [Read more…]
May 23, 2012
Lily Asquith begins a guide to making music from particles Read more: www.guardian.co.uk
May 17, 2012
In a cavern almost a mile underground in the Black Hills, an experiment called the MAJORANA DEMONSTRATOR, 40 kilograms of pure germanium crystals enclosed in deep-freeze cryostat modules, will soon set out to answer one of the most persistent and momentous questions in physics: are neutrinos their own antiparticles? If the answer is yes, it… [Read more…]
May 16, 2012
In beautiful agreement with the Standard Model, two new excited states (see below) of the Λb beauty particle have just been observed by the LHCb Collaboration. Similarly to protons and neutrons, Λb is composed of three quarks. In the Λb’s case, these are up, down and… beauty. Although discovering new particles is increasingly looking like… [Read more…]
May 7, 2012
By Tommaso Dorigo This week’s graph comes from a recent publication by the CMS experiment, the one I am a proud member of together with about 3000 colleagues from all over the world. CMS (see a 3-D sketch below) is one of the two huge detectors collecting the faint signals of particles produced in the powerful 8-TeV… [Read more…]
May 3, 2012
http://youtu.be/_NMqPT6oKJ8 http://youtu.be/lVefgfmFg9o
April 27, 2012
Leonard Susskind In this note I respond to Vilenkin’s claim that there must have been a beginning. Mithani and Vilenkin have argued that the universe must have had a beginning [1]. I will argue the opposite point of view; namely, for all practical purposes, the universe was past-eternal. To make the point simply, imagine Hilbertville,… [Read more…]
April 26, 2012
In anticipation of the potential for experimental verification of the existence of the Higgs boson?a long-hypothesized particle thought responsible for endowing other elementary particles with mass?the World Leaders Forum hosted a special program, co-sponsored by the Columbia Science Initiative, on April 18 at 4:00 p.m. in the Low Library rotunda. more; http://news.columbia.edu/higgs http://youtu.be/pt8oRWNSwAk http://youtu.be/C0rBKyU1vu0
April 25, 2012
Audrey Mithani, Alexander Vilenkin We discuss three candidate scenarios which seem to allow the possibility that the universe could have existed forever with no initial singularity: eternal infation, cyclic evolution, and the emergent universe. The first two of these scenarios are geodesically incomplete to the past, and thus cannot describe a universe without a beginning.… [Read more…]
April 18, 2012
The is the orchestrated version of the score, a piano is playing the gamma ray, a pizzicato violin is playing the electron, and a pizzicato cello is playing the positron. Click to play. Read more: http://www.isgtw.org/feature/smallest-music-universe
April 17, 2012
A Tentative Gamma-Ray Line from Dark Matter Annihilation at the Fermi Large Area Telescope Christoph Weniger The observation of a gamma-ray line in the cosmic-ray fluxes would be a smoking-gun signature for dark matter annihilation or decay in the Universe. We present an improved search for such signatures in the data of the Fermi Large… [Read more…]
April 16, 2012
Arttu Rajantie One of the most basic properties of magnetism is that a magnet always has two poles, north and south, which cannot be separated into isolated poles, i.e., magnetic monopoles. However, there are strong theoretical arguments why magnetic monopoles should exist. In spite of extensive searches they have not been found, but they have… [Read more…]
April 13, 2012
String Theory predicts the existence of more than the 3 space dimensions and 1 time dimension we are all familiar with. According to string theory, there are additional dimensions that we are unfamiliar with because they are curled up into tiny complicated shapes that can only be seen on tiny scales. If we could shrink… [Read more…]
April 12, 2012
Panagiota Kanti We review the current results for the emission of Hawking radiation by a higher-dimensional black hole during the Schwarzschild and the spin-down phases. We discuss particularly the role of the angular variation of the emitted radiation on the brane during the latter phase, the radiation spectra for gravitons in the bulk, and the… [Read more…]
April 7, 2012
Igor I. Smolyaninov As demonstrated by Chernodub, strong magnetic field forces vacuum to develop real condensates of electrically charged rho mesons, which form an anisotropic inhomogeneous superconducting state similar to Abrikosov vortex lattice. As far as electromagnetic field behaviour is concerned, this state of vacuum constitutes a hyperbolic metamaterial [1]. Here we demonstrate that spatial… [Read more…]
April 5, 2012
The LHC has started proton collisions at the unprecedent energy of 4 TeV per beam. This video celebrates the new milestone and explains the physics challenges and ecxpectations for the two larger experiments ATLAS and CMS through the words of the current physics coordinators Richard Hawkings and Greg Landsberg. cdsweb.cern.ch Read more: cdsweb.cern.ch/record/1435792
March 27, 2012
By NATALIE ANGIER Scientists are a famously anonymous lot, but few can match in the depths of her perverse and unmerited obscurity the 20th-century mathematical genius Amalie Noether. Albert Einstein called her the most “significant” and “creative” female mathematician of all time, and others of her contemporaries were inclined to drop the modification by sex.… [Read more…]
March 27, 2012
John P. Ralston Planck’s constant was introduced as a fundamental scale in the early history of quantum mechanics. We find a modern approach where Planck’s constant is absent: it is unobservable except as a constant of human convention. Despite long reference to experiment, review shows that Planck’s constant cannot be obtained from the data of… [Read more…]
March 24, 2012
Seong Chan Park In low-scale gravity models, a particle collider with trans-Planckian collision energies can be an ideal place for producing black holes because a large amount of energy can be concentrated at the collision point, which can ultimately lead to black hole formation. In this article, the theoretical foundation for microscopic higher dimensional black… [Read more…]
March 14, 2012
Humankind is constantly inventing new ways to stay in touch. But in some situations it’s difficult to keep the lines of communication open. A space shuttle’s radio falls silent when the craft slips behind a neighboring planet. A submarine loses contact when deep water blocks signals from the surface. Scientists recently proved possible a new… [Read more…]
March 10, 2012
… at sqrt(s) = 7 TeV CMS Collaboration A search for microscopic black holes in pp collisions at a center-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 4.7 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. Events with large total transverse energy have… [Read more…]
March 10, 2012
… at the \sqrt{s} = 7 TeV LHC Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, Joel W. Walker In Profumo di SUSY, we presented evidence that CMS&ATLAS may have already registered a handful of deftly camouflaged supersymmetry events at the LHC in the multijet channels. Here, we explore the prospect for corroboration of this… [Read more…]
March 7, 2012
The plot is thickening for the still-hidden Higgs boson. Two US-based experiments report new, hopeful hints of the slippery particle, but one of the two main detectors at the Large Hadron Collider (LHC) says an existing signal has started to fade away. The announcements, all made today at the Recontres de Moriondmeeting in La Thuile, Italy,… [Read more…]
March 6, 2012
by Lisa Grossman The Tevatron may now be defunct, but it is still detangling the nature of matter from beyond the grave. The late particle-smasher’s two main experiments, CDF and DZero, have released the most precise measurement yet of the mass of the W boson, one of the fundamental particles in the standard model of… [Read more…]
March 5, 2012
Geneva, 5 March 2012. Results presented by the LHCb collaboration this evening at the annual ‘Rencontres de Moriond’ conference, held this year in La Thuile, Italy, have put one of the most stringent limits to date on the current theory of particle physics, the Standard Model. LHCb tests the Standard Model by measuring extremely rare… [Read more…]
March 5, 2012
Raphael Bousso In this colloquium-level account, I describe the cosmological constant problem: why is the energy of empty space at least 60 orders of magnitude smaller than several known contributions to it from the Standard Model of particle physics? I explain why the “dark energy” responsible for the accelerated expansion of the universe is almost… [Read more…]
March 2, 2012
… points to Higgs mass and tests Standard Model The world’s most precise measurement of the mass of the W boson, one of nature’s elementary particles, has been achieved by scientists from the CDF and DZero collaborations at the Department of Energy’s Fermi National Accelerator Laboratory. The new measurement is an important, independent constraint of… [Read more…]
March 2, 2012
Quest for quirky quantum particles may have struck gold Evidence for elusive Majorana fermions raises possibilities for quantum computers. Eugenie Samuel Reich Getting into nanoscience pioneer Leo Kouwenhoven’s talk at the American Physical Society’s March meeting in Boston, Massachusetts, today was like trying to board a subway train at rush hour. The buzz in the corridor was… [Read more…]
February 27, 2012
Many a time I have stressed on this blog that neutrinos are boring, though I should specify that they are boring from the point of view of a theoretical physicist. For experimentalists, on the other hand, neutrinos are first of all annoying. Indeed, taking part in a neutrino experiment seems the shortest path to trouble,… [Read more…]
February 27, 2012
What is matter, anyway? What does it have to do with math? And why aren’t you made of Jesus? Delving deeper into the theory of (almost) everything – the Standard Model of particle physics. http://youtu.be/Fxeb3Pc4PA4
February 25, 2012
In the middle 1970s a team of scientists announced their discovery of a new fragment of matter and named it “Mandela Particle” (in honor of Nelson Mandela). The “discovery” was later found to be a mistake, due to faulty equipment…. Read also: adsabs.harvard.edu
February 22, 2012
by Edwin Cartlidge It appears that the faster-than-light neutrino results, announced last September by the OPERA collaboration in Italy, was due to a mistake after all. A bad connection between a GPS unit and a computer may be to blame. Physicists had detected neutrinos travelling from the CERN laboratory in Geneva to the Gran Sasso… [Read more…]
February 14, 2012
Scientists at the Large Hadron Collider (LHC) will increase the energies of the bunches of subatomic particles called protons that it smashes together. The boost should improve the collider’s chances of discovering “new physics” and definitively confirming or denying the existence of Higgs boson particle. The proton beams’ energies will be increased by 14%, for… [Read more…]
February 13, 2012
Professor Jon Butterworth, member of the High Energy Physics group on the Atlas experiment, provides an overview of his work at the Large Hadron Collider (LHC).
February 9, 2012
In December 2011, the elusive Higgs boson was back in the limelight when hints of the particle emerged in the wreckage of proton collisions at the world’s most powerful particle smasher – the Large Hadron Collider (LHC) near Geneva, Switzerland. There have been no new collisions since, but researchers from the LHC’s two main detectors… [Read more…]
February 1, 2012
Thomas K. Gaisser This paper reviews the status of the search for high-energy neutrinos from astrophysical sources. Results from large neutrino telescopes in water (Antares, Baikal) and ice (IceCube) are discussed as well as observations from the surface with Auger and from high altitude with ANITA. Comments on IceTop, the surface component of IceCube are… [Read more…]
January 31, 2012
John Ellis, Mary K. Gaillard, Dimitri V. Nanopoulos The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible production in e+ e-, pbar p and pp collisions, in particular. Until recently, the most sensitive searches for the Higgs… [Read more…]
January 31, 2012
SPEAKER: Eva Halkiadakis We present an update on a number of searches for New Physics, including SUSY and Exotica, based on the recent LHC data, up to the full statistics of ~5/fb recorded by the CMS experiment in 2011. (Video in CDS: Press here) Read more: indico.cern.ch Read also: Lazy photon among the missing in exotic LHC… [Read more…]
January 27, 2012
The question of whether normal matter’s shadowy counterpart anti-matter exerts a kind of “anti-gravity” is set to be answered, according to a new report. Normal matter attracts all other matter in the Universe, but it remains unclear if anti-matter attracts or repels it. A team reporting in Physics Review Letters says it has prepared stable pairs of… [Read more…]
January 22, 2012
Claudio Germana ABSTRACT Recent results from the OPERA experiment reported a neutrino beam traveling faster than light. The experiment measured the neutrino time of flight (TOF) over a baseline from the CERN to the Gran Sasso site. The neutrino beam arrives 60 ns earlier than a light ray would do. Because the result has an… [Read more…]
January 17, 2012
L. Bellagamba, R. Casadio, R. Di Sipio, V. Viventi We investigate possible signatures of black hole events at the LHC in the hypothesis that such objects will not evaporate completely, but leave a stable remnant. For the purpose of defining a reference scenario, we have employed the publicly available Monte Carlo generator CHARYBDIS2, in which… [Read more…]
January 16, 2012
Richard Feynman was a brilliant Nobel Prize winning physicist with a “rock ‘n roll” personality Richard Feynman was a talented mathematician and Nobel-prize winning physicist whose startlingly clear answers to questions earned him the unofficial title, the “Great Explainer”. As a student at Far Rockaway High School in Queens, a borough of New York City,… [Read more…]
January 5, 2012
John H. Schwarz This lecture presents a brief overview of the early history of string theory and supersymmetry. It describes how the S-matrix theory program for understanding the strong nuclear force evolved into superstring theory, which is a promising framework for constructing a unified quantum theory of all forces including gravity. The period covered begins… [Read more…]
December 23, 2011
W.-D. Schlatter (CERN), P. M. Zerwas (DESY) After a brief introduction to the theoretical basis of the Higgs mechanism for generating the masses of elementary particles, the experimental searches for Higgs particles will be summarized, from bounds at LEP to inferences for LHC. The report will focus on the Standard Model, though some central results… [Read more…]
December 22, 2011
The Large Hadron Collider (LHC) on the Franco-Swiss border has made its first clear observation of a new particle since opening in 2009. Known as Chi-b (3P), it is a boson – the label given to particles that can carry the forces of nature. The as-yet unpublished discovery isreported on the Arxiv pre-print server. The… [Read more…]
December 21, 2011
RECENT hints of a featherweight Higgs boson don’t just take us nearer to a complete standard model of physics. The results affect a possible link between the Higgs and dark matter, the invisible stuff making up 80 per cent of the universe’s matter. The Higgs is the last remaining hole in the standard model, the… [Read more…]
December 14, 2011
The second-biggest structure in human history will seek to answer deep cosmic mysteries Neutrinos may or may not move faster than light, but regardless, they’re special little things. They speed through the planet, and through you, and through everything; but, chargeless and puny, they interact with their surroundings so minimally that other particles hardly take… [Read more…]
December 13, 2011
The main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass constrained to the range 115.5-131 GeV by the ATLAS experiment, and 115-127 GeV by CMS 13 December 2011. In a seminar held at CERN today, the ATLAS and CMS experiments presented the status of their… [Read more…]
December 11, 2011
by Matt Strassler 1. Production of the Standard Model Higgs Particle 2. Decays of the Standard Model Higgs 3. Seeking and Studying the Standard Model Higgs Particle
December 6, 2011
Read also: Cern scientist expects ‘first glimpse’ of Higgs boson (8-12-2011) by Ian Sample – guardian.co.uk Rumours abound that Cern scientists have finally glimpsed the long-sought Higgs boson. We asked physicists to share their thoughts on the elusive entity…. …… I asked some physicists to share, in a couple of simple sentences, their hunches on what gives… [Read more…]
December 6, 2011
Researchers in Japan have developed what may be the first string-theory model with a natural mechanism for explaining why our universe would seem to exist in three spatial dimensions if it actually has six more. According to their model, only three of the nine dimensions started to grow at the beginning of the universe, accounting… [Read more…]
December 4, 2011
(update 9-12-2011) Higgs mass: 124.6 GeV CMS, 126 GeV ATLAS Higgs rumors (from here): 126 GeV – 3.5 sigma in ATLAS and 2.5 sigma at 124 GeV for CMS … …. read also: Higgs Expectations , by Tommaso Dorigo Higgs Boson Mass predicted by the Four Color Theorem Ashay Dharwadker, Vladimir Khachatryan 28 Dec 2009 Abstract: We show… [Read more…]
December 3, 2011
Jonas Mureika, Piero Nicolini, Euro Spallucci We introduce analytical quantum gravity modifications of the production cross section for terascale black holes by employing an effective ultraviolet cut off ℓ. We find the new cross sections approach the usual “black disk” form at high energy, while they differ significantly near the fundamental scale from the standard… [Read more…]
November 28, 2011
You wait decades for discoveries that could revolutionise physics, then three come along at once “THE universe is not only queerer than we suppose, but queerer than we can suppose,” as geneticist J. B. S. Haldane once remarked. In recent decades, physicists have done their best to prove Haldane wrong, by supposing some very queer… [Read more…]
November 20, 2011
D. Nanopoulos Abstract Recent developments/efforts to understand aspects of the brain function at the subneural level are discussed. MicroTubules (MTs), protein polymers constructing the cytoskeleton, participate in a wide variety of dynamical processes in the cell. Of special interest to us is the MTs participation in bioinformation processes such as learning and memory, by possessing… [Read more…]
November 19, 2011
…. Suggestive Correlations in the ATLAS and CMS High Jet Multiplicity Data Tianjun Li, James A. Maxin, Dimitri V. Nanopoulos, Joel W. Walker We present persistently amassing evidence that the CMS and ATLAS Collaborations may indeed be already registering supersymmetry events at the Large Hadron Collider (LHC). Our analysis is performed in the context of… [Read more…]
November 18, 2011
Tantalising hints of the Higgs boson will be confirmed or ruled out at the LHC in the coming months, say researchers by Ιan Sample Physicists at the Large Hadron Collider near Geneva are edging ever closer to answering one of the most profound questions in particle physics: does the Higgs boson exist? Speaking at a… [Read more…]
November 18, 2011
OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran Sasso UPDATE 18 November 2011 Following the OPERA collaboration’s presentation at CERN on 23 September, inviting scrutiny of their neutrino time-of-flight measurement from the broader particle physics community, the collaboration has rechecked many aspects of its analysis and taken into account valuable… [Read more…]
November 17, 2011
This composition shows a number of diverse astronomical sources where shocks have been detected. Shock waves arise when supersonic flows of plasma are faced with an obstacle, such as a planet or a star with a magnetic field, or when they encounter a slower moving flow. Depicted in the composition are: a bow shock around… [Read more…]
November 15, 2011
Read also: 1. LHCb uses charm to find asymmetry 2.LHCb has evidence of new physics! Maybe 3. New Physics at LHC? An Anomaly in CP Violation By Jason Palmer Large Hadron Collider researchers have shown off what may be the facility’s first “new physics” outside our current understanding of the Universe. Particles called D-mesons seem… [Read more…]
November 15, 2011
Constraining ExtremeNeutrino Speeds at TeV-ZeV Energies with the Diffuse Neutrino Background Brian C. Lacki The only invariant speed in special relativity is c; therefore, if some neutrinos travel at even tiny speeds above c, normal special relativity is incomplete and any superluminal speed may be possible. I derive a limit on superluminal neutrino speeds v… [Read more…]
November 11, 2011
The prediction could help explain some unexpected properties of helium white dwarfs White dwarf stars are glowing embers, the remains of small stars that have run out of fuel to burn Most white dwarfs are hot lumps of charcoal, gradually radiating their heat into space. But a few are made of helium and it is… [Read more…]
November 9, 2011
Marcus Bleicher, Piero Nicolini, Martin Sprenger, Elizabeth Winstanley The possibility of creating microscopic black holes is one of the most exciting predictions for the LHC, with potentially major consequences for our current understanding of physics. We briefly review the theoretical motivation for micro black hole production, and our understanding of their subsequent evolution. Recent work… [Read more…]
November 4, 2011
P.W. Cattaneo Abstract A recent report of superluminal neutrinos from the OPERA experiment appears in contradiction with prediction of energy loss of superluminal neutrino via the pair creation process ν → νe+e−. The same process should result in isolated e+e− pairs in detectors with good tracking capability traversed by a large flux of high energy neutrino like NOMAD.… [Read more…]
November 1, 2011
Stuart Armstrong This paper sets out to solve the Sleeping Beauty problem and various related anthropic problems, not through the calculation of anthropic probabilities, but through finding the correct decision to make. Given certain simple assumptions, it turns out to be possible to do so without knowing the underlying anthropic probabilities. Most common anthropic problems… [Read more…]
November 1, 2011
Searching for an equation S. Esposito We review the non-trivial issue of the relativistic description of a quantum mechanical system that, contrary to a common belief, kept theoreticians busy from the end of 1920s to (at least) mid 1940s. Starting by the well-known works by Klein-Gordon and Dirac, we then give an account of the… [Read more…]
October 31, 2011
Geneva, 31 October 2011. After some 180 days of running and four hundred trillion (4×1014) proton proton collisions, the LHC’s 2011 proton run came to an end at 5.15pm yesterday evening. For the second year running, the LHC team has largely surpassed its operational objectives, steadily increasing the rate at which the LHC has delivered… [Read more…]
October 30, 2011
Steven R. Elliott At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. Studies of double beta decay offer hope for determining the absolute mass scale. In particular, zero-neutrino double… [Read more…]
October 28, 2011
Alternative Discrete Energy Solutions to the Free Particle Dirac Equation Thomas Edward Brennan The usual method of solving the free particle Dirac equation results in the so called continuum energy solutions. Here, we take a different approach and find a set of solutions with quantized energies which are proportional to the total angular momentum…… Read… [Read more…]
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May 31, 2012
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