eRHIC gets to the heart of the matter

Apr 26, 2006
Physicist Abhay Deshpande overlooking the Relativistic Heavy Ion Collider
Physicist Abhay Deshpande overlooking the Relativistic Heavy Ion Collider.

At the U.S. Department of Energy's Brookhaven National Laboratory, scientists have proposed a new way of studying the structure of matter down to a level never before observed. Their proposal is the "eRHIC" collider, a planned upgrade to Brookhaven's giant particle accelerator, the Relativistic Heavy Ion Collider (RHIC).

"The eRHIC facility will give physicists the ability to make some very important and unique particle and nuclear-physics measurements," said Abhay Deshpande, a physicist at Stony Brook University and the RIKEN BNL Research Center, who is part of the eRHIC team. "It promises significant leaps in physicists' understanding of the structure of nucleons (protons and neutrons) and of nuclei, which make up more than 99 percent of the matter around us."

Deshpande discussed the design of the eRHIC detector at the 2006 American Physical Society national meeting in Dallas, Texas.

The eRHIC facility will be built alongside the existing RHIC ring. It will produce a beam of electrons (hence the "e" in eRHIC) that will move at nearly the speed of light. RHIC and eRHIC will overlap at one point, allowing the RHIC ions and the eRHIC electrons to collide. This collision will create an explosion of particles that will then be extensively studied using a large detector built around the collision point. In essence, the electrons will be used to probe the matter contained within the ions, with very high precision.

Analyzing these collisions will help scientists answer fundamental questions in physics, such as how quarks and gluons combine to create protons, what role the gluons play in the formation of nuclei at very high energies, and why scientists have yet to observe free quarks (those not bound within protons or neutrons).

Another longstanding problem, which involves a property called "spin," will be addressed with extreme precision. The laws of quantum mechanics state that the spins of quarks and gluons should add up, such that the spin of a proton should equal the sum of the spins of the quarks and gluons that comprise it. However, according to experimental data, this doesn't happen. The sum of the spin of the quarks only accounts for about 30 percent of the proton's spin.

If eRHIC turns on according to current plans, which could make the facility operational as early as 2015, Deshpande and his colleagues hope to shed light on this and other basic questions that physicists still have no answers for. Addressing these problems will lead to new insights into the nature of matter itself.

Link: Relativistic Heavy Ion Collider

Source: Brookhaven National Laboratory, by Laura Mgrdichian

Explore further: Finding faster-than-light particles by weighing them

add to favorites email to friend print save as pdf

Related Stories

Computer-assisted accelerator design

Apr 22, 2014

Stephen Brooks uses his own custom software tool to fire electron beams into a virtual model of proposed accelerator designs for eRHIC. The goal: Keep the cost down and be sure the beams will circulate in ...

Recommended for you

Finding faster-than-light particles by weighing them

11 hours ago

In a new paper accepted by the journal Astroparticle Physics, Robert Ehrlich, a recently retired physicist from George Mason University, claims that the neutrino is very likely a tachyon or faster-than-light par ...

Controlling core switching in Pac-man disks

Dec 24, 2014

Magnetic vortices in thin films can encode information in the perpendicular magnetization pointing up or down relative to the vortex core. These binary states could be useful for non-volatile data storage ...

World's most complex crystal simulated

Dec 24, 2014

The most complicated crystal structure ever produced in a computer simulation has been achieved by researchers at the University of Michigan. They say the findings help demonstrate how complexity can emerge ...

Atoms queue up for quantum computer networks

Dec 24, 2014

In order to develop future quantum computer networks, it is necessary to hold a known number of atoms and read them without them disappearing. To do this, researchers from the Niels Bohr Institute have developed ...

New video supports radiation dosimetry audits

Dec 23, 2014

The National Physical Laboratory (NPL), working with the National Radiotherapy Trials Quality Assurance Group, has produced a video guideĀ to support physicists participating in radiation dosimetry audits.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.