Particle physics (aka high energy physics, often abbreviated HEP) is the study of the fundamental building blocks of nature. The language of modern HEP is quantum field theory (or QFT), a mathematical framework that combines special relativity and quantum mechanics. The Standard Model (SM) is a popular quantum field theory that describes many aspects of reality to remarkable precision. We test the Standard Model at laboratories all around the world, especially at particle colliders, with the Large Hadron Collider (LHC) at CERN being likely the most well-known because of its unprecedented power.
This post describes HEP subfields, the journals where high energy physicists publish their work, and free HEP resources.
Like many areas of science, HEP is frequently broken into several subsets that depend heavily on one-another. It’s typically first split into experimental and theoretical studies:
Experimental HEP: Experimentalists deal with the construction and operation of particle colliders, detectors, event triggers, event storage, data analysis, and so-on. Oftentimes experiments require huge teams of experimentalists (called collaborations) in order to run successfully. There are three popularly-recognized classes of experiment:
Colliders: Collider experiments work by slamming two known particles into each other at high energy, usually with the hopes of creating new particles in the process. This is what happens at the LHC.
Direct Detection: Direct detection experiments bring together large amounts of matter and wait to see if anything out of the ordinary occurs. For example, some direct detection experiments use giant vats of liquid xenon to look for evidence of dark matter.
Indirect Detection: Indirect detection experiments look for the consequences of new particles interacting with each other. For example, some models predict that dark matter should annihilate with itself and produce certain kinds of cosmic rays, so some indirect detection experiments look for those cosmic rays.
Theoretical HEP: Theoreticians utilize mathematical modeling techniques and computational simulations to interpret existing experimental data and predict future results. This often involves hypothesizing new fundamental particles and forces. Theoretical groups are typically much smaller than experimental groups. Theory can be further subdivided:
Phenomenological HEP: Phenomenologists walk the line between theory and experiment by using model-building techniques to describe generic features of data. By determining quantifiable predictions of new physics models, they provide tools as to discover (or eliminate) new physics. Phenomenologists frequently utilize effective field theory techniques.
Lattice HEP: Lattice theory is a rapidly growing subfield of HEP theory that deals with lattice QFT, a formulation of QFT on a discretized spacetime. Lattice theoreticians use lattice QCD in combination with modern computation power to solve problems in quantum chromodynamics (QCD).
Pure HEP Theory: Pure HEP theorists work on advanced mathematical QFT frameworks that typically generate predictions beyond the discovery reach of modern particle physics experiments. Popular pure theory topics include string theory and quantum gravity.
There are several journals dedicated to HEP, wherein high energy physicists publish articles, including:
APS Physics Review D (PRD or Phys. Rev. D)
Journal of High Energy Physics (JHEP)
Physics Letters B (Phys. Lett. B)
These journals require subscriptions to access. Thankfully, there are online resources that provide many HEP publications for free! The remainder of this post lists some of these resources.
Particle Data Group: (abbreviated PDG) An international group tasked with summarizing the latest and greatest particle physics results. They provide tables of modern particle property measurements, as well as reviews/summaries of important particle physics topics. Their reviews are EXTREMELY useful. Almost anything you’d want to know about HEP and the techniques used therein are contained in a 1600+ page book that the PDG provides online for free.
Particle Data Group - Home Page
Particle Data Group - Reviews, Tables, and Plots
Particle Data Group - PDG Computer Downloads
ArXiv: (pronounced like “archive”) An online archive of publications from several academic areas, 100% free to the public. Physicists post conference proceedings, note collections, and papers intended for journal publication. The arXiv updates often with cutting edge research.
arXiv - Home Page
arXiv [hep-ex] :: High Energy Physics - Experiment
arXiv [hep-lat] :: High Energy Physics - Lattice
arXiv [hep-ph] :: High Energy Physics - Phenomenology
arXiv [hep-th] :: High Energy Physics - Theory
INSPIRE: Another online archive of publications. INSPIRE provides information on many HEP publications, including where to find many publications that are not hosted on the arXiv.
INSPIRE - Home Page
CERN Document Server: A directory of pretty much everything CERN makes public, including results from the CMS and ATLAS experiments.
CERN Document Server - Home Page
HEPData: Did you find an awesome plot in a publication and want the exact values used by the authors? It’s worth checking HEPData, an open-access repository of data generated by the HEP community.
HEPData - Home Page
Summer Schools: There are many summer schools that provide professional training to physics graduate students and postdocs. These schools often publish compilations of notes from their events which are more pedagogical than most technical publications. Here’s a few of those schools:
Theoretical Advanced Study Institute in Elementary Particle Physics (TASI)
École de Physique des Houches (often simply “Les Houches”)
Mainz Institute of Theoretical Physics (MITP) Summer School
The Coordinated Theoretical-Experimental Project on QCD (CTEQ) Summer School
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CERN’s plan for 100-km collider makes the LHC look like a Hula Hoop
CERN’s plan for 100-km collider makes the LHC look like a Hula Hoop
The big Hadron Collider has produced a fantastic deal of amazing science, most famously the Higgs Boson — but physicists at CERN, the international organization behind the LHC, are already looking forward to the next version. And the proposed Future round Collider, at 100 kilometers or 62 miles around, would be quite an enhance.
The concept isn’t brand-new; CERN has had people looking into it for…
Built by the European Organization for Nuclear Research, it is both the largest single machine on Earth AND the world’s largest particle collider. What is it?
Plasma Wakefield Acceleration, A Step Toward Smaller Particle Colliders
New Post has been published on http://www.newsnish.com/technology/science/plasma-wakefield-acceleration-a-step-toward-smaller-particle-colliders/
Plasma Wakefield Acceleration, A Step Toward Smaller Particle Colliders
A study led by researchers from UCLA and the U.S. Department of Energy’s SLAC National Accelerator Laboratory has demonstrated a more efficient way to accelerate positrons, the antimatter opposites of electrons. The method may help lead to much smaller but more powerful linear electron-positron colliders — machines that could be used to understand the properties of nature’s fundamental building blocks.
Plasma Wakefield Acceleration, A Step Toward Smaller Particle Colliders
The research team had previously shown that boosting the energy of charged particles by having them “surf” a wave of ionized gas, or plasma, works well when accelerating electrons. While this method by itself could lead to smaller accelerators, electrons are only half the equation for future colliders. Now the researchers have achieved another milestone by applying the technique to positrons at SLAC’s Facility for Advanced Accelerator Experimental Tests. The research was published August 26 in Nature.
Researchers study matter’s fundamental components and the forces between them by smashing highly energetic particle beams into one another. Europe’s Large Hadron Collider, for example, works by colliding protons at extremely high energies.
But many scientists believe building a collider that smashes electrons and positrons together would be a major advance. This is because unlike protons, which are composed of three quarks, electrons and positrons are elementary or fundamental particles and therefore collisions between them would be far cleaner and easier to study.
If we want to continue to probe the structure of matter, to understand what the smallest constituents of nature are and how they interact, we have to think big and plan for the long term. Possibilities include machines that would dwarf the Large Hadron Collider, and neutrino beams crossing half a continent
Just over a year ago I was up a mountain, in fog and hail, at the South-Western tip of Sicily. Along with about fifty other delegates, I was discussing the future of particle physics. This was the Erice meeting where we drafted the update of the European Strategy for particle physics. Although the meeting was convened by the council of CERN, it concerned much more than the future of the laboratory in Geneva that currently runs the Large Hadron Collider - the 27km circumference accelerator where the Higgs boson was recently discovered.
What we require is an apparatus to give us a potential of the order of the order of 10 million volts which can be safely accommodated in a reasonably sized room and operated by a few kilowatts of power. We require too an exhausted tube capable of withstanding this voltage... I see no reason why such a requirement cannot be made practical.
Ernest Rutherford, speech at the opening of the Metropolitan - Vickers High Tension Laboratory, Manchester, England, 1930
