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"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All Posts filed under »High Energy Physics«
Sheldon Lee Glashow: particle physics in the US
… a personal view I present my views on the future of America’s program in particle physics. I discuss a variety of experimental initiatives that do have the potential to make transformative impacts on our discipline and should be included in our program, as well as others that do not and should not…. Read more […]
Neutrinos from outer space open new eye in the sky
May 15, 2013
Fancy seeing the sky in neutrino? Supermassive black holes and enormous stellar explosions may give up their secrets now thatneutrinos from space can be detected. The South Pole IceCube neutrino observatory has seen a handful of ghostly high-energy neutrinos that almost certainly came from outer space, opening up the skies for neutrino astronomy. “We are witnessing the birth […]
Goldstone Bosons as Fractional Cosmic Neutrinos
May 10, 2013
Steven Weinberg It is suggested that Goldstone bosons may be masquerading as fractional cosmic neutrinos, contributing about 0.39 to what is reported as the effective number of neutrino types in the era before recombination. The broken symmetry associated with these Goldstone bosons is further speculated to be the conservation of the particles of dark matter. […]
Nima Arkani-Hamed: Why the Higgs Has to Exist
May 1, 2013
The Inevitability of Physical Laws: Why the Higgs Has to Exist Nima Arkani-Hamed Institute for Advanced Study October 26, 2012 – 5:30pm Our present framework for physics is difficult to modify without destroying its marvelous, successful properties. This provides a strong check on theoretical speculations and helps guide us to a small set of candidates […]
ALPHA weighs in on antimatter
April 30, 2013
Description and first application of a new technique to measure the gravitational mass of antihydrogen Physicists have long wondered whether the gravitational interactions between matter and antimatter might be different from those between matter and itself. Although there are many indirect indications that no such differences exist and that the weak equivalence principle holds, there […]
The Higgs Particle
April 21, 2013
what is it, and why do we badly need it? Wolfgang Bietenholz We sketch in simple terms the concept of the Higgs mechanism, and its importance in particle physics. To the best of our knowledge, the world consists of only very few types of elementary particles, the smallest entities of matter, which are indivisible. They […]
Pulsar interpretation for the AMS-02 result
April 20, 2013
Peng-Fei Yin, Zhao-Huan Yu, Qiang Yuan, Xiao-Jun Bi The AMS-02 collaboration has just published a high precision measurement of the cosmic positron fraction $e^+/(e^- + e^+)$, which rises with energy from $\sim 5$ GeV to $\sim 350$ GeV. The result indicates the existence of primary electron/positron sources to account for the positron excess. In this […]
Τhe Shrinking Proton: Particle Is Smaller Than Thought
April 14, 2013
How many protons can dance on the head of a pin? The answer is nowhere near as straightforward as one may think — and it might offer new insights into one of the most well-tested theories in physics. An international team of scientists recently tried to find out the actual size of a proton, one […]
First result from the AMS experiment
April 3, 2013
The Alpha Magnetic Spectrometer (AMS) Collaboration announces the publication of its first physics result in Physical Review Letters. The AMS Experiment is the most powerful and sensitive particle physics spectrometer ever deployed in space. As seen in Figure 1, AMS is located on the exterior of the International Space Station (ISS) and since its installation […]
LHC upgrade to open up ‘new realm of particle physics’
April 2, 2013
Engineers have begun a major upgrade of the Large Hadron Collider (LHC). Their work should double the energy of what’s already the most powerful particle accelerator in the world. BBC News is the first to be allowed to see inside the LHC – on the French-Swiss border – to watch the work being carried out. […]
Searching for supersymmetry: some frustration but no despair
March 18, 2013
Supersymmetry is simply beautiful. It is the largest possible space-time symmetry of nature and it relates space and time with a fundamental quantum property of elementary particles, the spin. Supersymmetry predicts a wealth of new particles, superparticles, some of which could constitute the mysterious astrophysical dark matter. There is only one small problem: so far, […]
Charged Black Hole Remnants at the LHC
March 16, 2013
G.L. Alberghi, L. Bellagamba, X. Calmet, R. Casadio, O. Micu We investigate possible signatures of long-lived (or stable) charged black holes at the Large Hadron Collider. In particular, we find that black hole remnants are characterised by quite low speed. Due to this fact, the charged remnants could, in some cases, be very clearly distinguished […]
Ultrarelativistic Black Hole Formation
March 13, 2013
William E. East, Frans Pretorius We study the ultrarelativistic head-on collision of equal mass particles, modeled as self-gravitating fluid spheres, by numerically solving the coupled Einstein-hydrodynamic equations. We focus on cases well within the kinetic energy dominated regime, where between 88-92% (γ=8 to 12) of the initial net energy of the spacetime resides in the […]
Observing Matter-Antimatter Oscillations
March 5, 2013
D-mesons are the fourth in a quartet of neutral mesons to be observed oscillating into their antiparticle partners While quantum mechanics is by now a well-established theory, it nonetheless still fascinates both newcomers and experts alike with unusual phenomena. The paradox of Schrödinger’s cat and the subtleties of the two-slit interference are timeless classics. Another […]
Particle physics research sheds new light on possible ‘fifth force of nature’
February 22, 2013
In a breakthrough for the field of particle physics, Professor of Physics Larry Hunter and colleagues at Amherst College and The University of Texas at Austin have established new limits on what scientists call “long-range spin-spin interactions” between atomic particles. These interactions have been proposed by theoretical physicists but have not yet been seen. Their […]
Alpha Magnetic Spectrometer to release first results
February 18, 2013
By Jonathan Amos The scientist leading one of the most expensive experiments ever put into space says the project is ready to come forward with its first results. The Alpha Magnetic Spectrometer (AMS) was put on the International Space Station to survey the skies for high-energy particles, or cosmic rays. Nobel Laureate Sam Ting said […]
Neutrinos, the standard model misfits
February 12, 2013
For years, scientists thought that neutrinos fit perfectly into the standard model. But they don’t. By better understanding these strange, elusive particles, scientists seek to better understand the workings of all the universe, one discovery at a time. by Joseph Piergrossi Neutrinos are as mysterious as they are ubiquitous. One of the most abundant particles […]
Particle Physics in the Sky
February 4, 2013
Much can be learned about hypothetical particles called axions by studying the evolution of massive stars. Read more: http://physics.aps.org
Black Hole Complementarity and the Harlow-Hayden Conjecture
January 22, 2013
Leonard Susskind Black hole complementarity, as originally formulated in the 1990′s by Preskill, ‘t Hooft, and myself is now being challenged by the Almheiri-Marolf-Polchinski-Sully firewall argument. The AMPS argument relies on an implicit assumption—the “proximity postulate—which says that the interior of a black hole must be constructed from degrees of freedom that are physically near […]
LHC to stir up hot particle soup before 2013 shut down
January 2, 2013
by Jacob Aron At the foot of the misty mountains a mighty ring was forged – again! For one month, the Large Hadron Collider will smash two types of particles in a single magnetic ring. So far, the LHC at CERN, near Geneva, Switzerland, has been colliding beams of identical types of particles, which are spun around […]
Direct Detection of Dark Matter through Quantum Decoherence
December 22, 2012
C. Jess Riedel Astrophysical and cosmological observations suggest that the majority of mass in the universe is made up of invisible dark matter. Although various pieces of indirect evidence about its nature have been collected, the direct detection of dark matter has eluded experimental searches despite extensive effort. If the mass of dark matter is […]
CERN’s LHC experiment ALICE, ITS Upgrade
December 15, 2012
http://youtu.be/WMNrPatNKoU ALICE New Silicon Tracker 3D Animation This 3D animation, illustrates the design plans for the upgrade of the ALICE Inner Tracking System (ITS).The upgrade of the ITS will take place during the LHC long shutdown in 2017/18. The ITS is the central most detector within ALICE, currently composed of three separate detectors (the Silicon […]
LHC may have produced a previously undetected form of matter
November 28, 2012
Teams at the Large Hadron Collider must be developing a knack for producing tangible evidence of theoretical particles. After orchestrating 2 million collisions between lead nuclei and protons, like the sort you see above, the collider’s Compact Muon Solenoid group and researchers at MIT suspect that stray, linked pairs of gluon particles in the mix […]
Higgs boson is too saintly and supersymmetry too shy
November 23, 2012
by Michael Slezak HOPES of using the Higgs boson and the elegant theory of supersymmetry as shortcuts to discovering the mysteries of the universe are evaporating fast. That’s the verdict of a major update from the Large Hadron Collider in CERN, near Geneva, Switzerland – the first since a boson resembling the Higgs was spotted […]
Why do physicists care so much about finding the Higgs boson?
November 23, 2012
By Daisy Yuhas If you’ve read anything about the Higgs boson, you probably know that this particle is special because it can explain how fundamental particles acquire mass. Specifically, evidence of the boson is evidence that an omnipresent Higgs field exists—one that slows particles down and makes them heavy. But there’s a misconception that sometimes […]
CMS Data for the Public
November 21, 2012
The CMS experiment at the LHC has released a portion of its data to the public for use in education and outreach. Explore this page to find out more about the data and how to analyse it yourself. Press here
Demystifying the Higgs Boson with Leonard Susskind
November 20, 2012
Professor Susskind presents an explanation of what the Higgs mechanism is, and what it means to “give mass to particles.” He also explains what’s at stake for the future of physics and cosmology. http://youtu.be/JqNg819PiZY
Particle Decays Point to an Arrow of Time
November 19, 2012
An experiment studying B meson decays makes a direct observation of time-reversal violation without relying on assumed relationships with other fundamental symmetries Time moves irrevocably in one direction. Things get old, decay, and fall apart, but they rarely ever reassemble and grow young. But at the particle level, time’s arrow is not so clearly defined. […]
The underground lab searching for wimps
November 18, 2012
At Gran Sasso National Laboratory, nearly a mile beneath an Italian mountain range, physicists are trying to isolate the particles they believe hold the universe together Drive west along Italy’s Autostrada 24 and you will come to the Gran Sasso mountain range 80 miles before Rome. This is one of Italy’s most spectacular national parks […]
Unexpected ‘ridge’ seen in CMS collision data again
October 31, 2012
Jon Cartwright The first data from proton–lead collisions at the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) at CERN include a “ridge” structure in correlations between newly generated particles. According to theorists in the US, the ridge may represent a new form of matter known as a “colour glass condensate”. This […]
The large hadron collider and the Higgs boson
October 25, 2012
UCL lunch hour lecture UCL runs a series of public lectures at lunchtime. On Tuesday I gave one of these, about the news from the energy frontier, including the discovery on the fourth of July this year. Here is the recording. For the past two years, until the end of last month, I was convener […]
ATLAS Experiment: Search for dark matter candidates
October 23, 2012
Search for dark matter candidates and large extra dimensions in events with a jet and missing transverse momentum with the ATLAS detector A search for new phenomena in events with a high-energy jet and large missing transverse momentum is performed using data from proton-proton collisions at sqrt(s)=7 TeV with the ATLAS experiment at the Large […]
Constraints on the Universe as a Numerical Simulation
October 10, 2012
Silas R. Beane, Zohreh Davoudi, Martin J. Savage Observable consequences of the hypothesis that the observed universe is a numerical simulation performed on a cubic space-time lattice or grid are explored. The simulation scenario is first motivated by extrapolating current trends in computational resource requirements for lattice QCD into the future. Using the historical development […]
The ATLAS Collaboration: Search for supersymmetry …
October 7, 2012
… at √s = 7 TeV in final states with large jet multiplicity, missing transverse momentum and one isolated lepton with the ATLAS detector Read more at : cdsweb.cern.ch
Huge cosmic-ray observatory set for Siberia
September 19, 2012
Construction has begun in the Tunka Valley near Lake Baikal in Siberia, Russia, on the world’s largest cosmic-ray observatory. The first prototypes for the $46m Hundred Square-km Cosmic Origin Explorer (HiSCORE) are now being installed and when complete by the end of the decade the facility will consist of an array of up to 1000 […]
Heavy photons are too light to be behind dark matter
September 15, 2012
SADLY, dark matter is not made of light. That may sound obvious, but many physicists were hoping that photons – particles of light – could help us to piece together the nature of the mysterious stuff thought to make up 85 per cent of the universe’s matter. Instead, readings from Vitor Cardoso of the Technical […]
LHC collides protons with lead ions for the first time
September 13, 2012
At 1.26am today the Large Hadron Collider (LHC) collided protons with lead ions for the first time. The switch to colliding different types of particle, rather than like with like, presents technical challenges. “First of all, the collisions are asymmetric in energy which presents a challenge for the experiments,” says accelerator physicist and lead-ion team […]
Catcher of elusive neutrinos takes shape at Fermilab
September 8, 2012
Huge plastic blocks were being set in place this week to help catch some of the most elusive, mysterious particles known. The NuMI Off-Axis Neutrino Appearance experiment (NOvA) neutrino detector in Ash River, Minnesota, is set to start taking data in 2013. The experiment will study the properties of neutrinos, near-massless elementary particles that are […]
New SUSY Limits From ATLAS
September 4, 2012
By Tommaso Dorigo A new ATLAS search for supersymmetric signatures in 2011 LHC data has appeared last week in the arxiv. The result ? No hint of a signal, not even for ready money. So if you are on a hurry, you can just have a glance at the graph below, which summarizes the measurement in […]
What is the smallest possible space in the universe?
September 3, 2012
Science’s ongoing quest to find the smallest possible objects remains tantalisingly incomplete, as physicist Prof Andy Parker explains. Physics has a problem with small things. Or, to be more precise, with infinitely small things. We imagine that we can move any distance we like, no matter how small. This perception was exploited by Zeno in […]
Rolling in the Higgs (Adele Parody)
August 29, 2012
A Capella Science – Rolling in the Higgs (Adele Parody) http://youtu.be/VtItBX1l1VY
Hadron Collider is a work of art
August 28, 2012
AN EXHIBITION of textiles inspired by the Large Hadron Collider goes on show at the Old Fire Station Gallery next week. The quilts and framed pieces are the work of local artist Kate Findlay who has a studio in Henley and teaches art at St Mary’s School on St Andrew’s Road. She has recently shown […]
Scientists place new limits on sterile neutrinos
August 21, 2012
Two Fermilab experiments have put new boundaries on a search for a possibly undiscovered type of neutrino, leaving prior measurements unexplained. So far, scientists have observed three types, or flavors, of neutrino: the electron neutrino, the muon neutrino and the tau neutrino. But physicists have seen hints that this may not be the whole picture. […]
ICARUS: Neutrinos Travel At Light Speed. Period.
August 14, 2012
By Tommaso Dorigo Little less than one year ago the world of fundamental physics was shaken by the bold claim of the OPERA collaboration, which produced a measurement of the time of flight of neutrinos traveling underground from Geneva to the Gran Sasso mine in central Italy. The beam of neutrinos, produced by the CERN SpS […]
Physicists unveil plans for ‘LEP3′ collider at CERN
August 9, 2012
A group of physicists from Switzerland, Japan, Russia, US and the UK has proposed using the tunnel that currently houses the Large Hadron Collider (LHC) at the CERN particle-physics lab near Geneva for a dedicated machine to study the Higgs boson. The facility, dubbed LEP3, is named after CERN’s previous accelerator, the Large Electron–Positron Collider […]
Physicists see hints of Majorana fermions
August 7, 2012
Evidence for the existence of “Majorana fermions” – theoretically proposed particles that are also their own anti-particles – could be seen in the behaviour of a novel Josephson junction. That is the view of physicists at Stanford University in the US, who have examined the properties of a Josephson junction that incorporates material called a […]
The beauty of the Higgs boson
August 5, 2012
Jeff Forshaw The dust is beginning to settle – a new particle has been discovered using the Large Hadron Collider. Discovering new particles of nature is not an everyday occurrence and we are reasonably entitled to proclaim that this is the arrival of the Higgs. We aren’t certain, though: more careful examination of the particle’s […]
Measuring g with a beam of antihydrogen
August 1, 2012
AEgIS is a physics experiment that takes place at the european laboratory CERN, using the antiprotons delivered by the AD accelerator. AEgIS is a collaboration of physicists from all around the world. The primary scientific goal of the AEgIS experiment is the direct measurement of the Earth’s gravitational acceleration g on antihydrogen. In the first […]
ATLAS: 5.9 Sigma For A 126 GeV Higgs !
July 31, 2012
By Tommaso Dorigo ATLAS has just released a note which summarizes the searches for the standard model Higgs boson in 7-TeV and 8-TeV data. Since July 4th the main improvement is the addition of the WW channel, which had not been shown back then. With it, the combined local significance of the 126 GeV Higgs […]
Answering your Higgs questions
July 27, 2012
Scientists at the Large Hadron Collider (LHC) announced the discovery of a Higgs-like boson on July 4 – but what does that mean? What’s a Higgs boson? And how can a particle be like a Higgs? Read on to learn more about the new particle and how it fits into our world. The following questions were asked […]
May 25, 2013
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