Scientists are starting to find answers to some profound questions such as these, thanks to a breakthrough in the calculations needed to understand the strong nuclear force that comes from the motion of nature's basic building blocks, subatomic particles called quarks and gluons.
The strong nuclear force that binds these particles together, which is also called quantum chromodynamics, is one of the four basic forces of nature, along with gravity, electromagnetism and the weak force. The strong nuclear force is very powerful at short ranges, binding quarks and gluons into neutrons and protons at the core of atoms.
The basic equations that describe the nuclear force have been known since the mid 1970s, and were the subject of the 2004 Nobel Prize in physics. But physicists still know very little of how the force described by these equations binds protons and neutrons into the nuclei of atoms.
Now a team of researchers using a supercomputer and a method called lattice quantum chromodynamics have been able to calculate interactions among neutrons and protons from the properties of quarks and gluons. The lattice essentially divides the space-time continuum into a four-dimensional grid, allowing the researchers to examine the effects of the strong force, which becomes important at distances of one 100-trillionth (or 10 -15) of a meter or less. The new calculation is a first step toward understanding how nuclear forces emerge from the interactions between quarks and gluons, said Martin Savage, a University of Washington physics professor who is part of the research team.
"We're showing that techniques exist today to compute a nuclear reaction from the underlying theory of strong interactions," Savage said. "It is a simple reaction in terms of neutrons and protons, but it is a start."
In fact, it is enough for theoretical physicists to begin tackling questions such as how the universe might be different if quarks were slightly lighter or heavier than they actually are. The work also will let researchers perform calculations that could, for instance, provide clearer understanding of what the interior of a body such as a neutron star looks like.
"This will help us to understand how finely tuned the universe is," Savage said. "If you change the values of the fundamental constants of nature, would the universe still produce stars? Or humans?"
The work is described in a paper published July 7 in Physical Review Letters. Other authors are Silas Beane, an assistant professor of physics at the University of New Hampshire; Paulo Bedaque, an assistant professor of physics at the University of Maryland; and Konstantinos Orginos, an assistant professor of physics at the College of William and Mary in Virginia and a member of the theory group at the Thomas Jefferson National Accelerator Facility in Virginia. Beane also is affiliated with the Jefferson facility. The work was paid for in part by grants from the U.S. Department of Energy and the National Science Foundation.
Having a framework to calculate nuclear interactions in terms of quarks and gluons paves the way for reaching a greater understanding of the nature of the universe, particularly as supercomputers become increasingly powerful in the coming years, Savage said.
"We can start to explore how the structure of nuclei would change if the quark masses differed from the values found in nature," he said. "We hope we can determine if the quark masses in nature, or values very close to them, are required for carbon-based life to exist in our universe, or if any old quark masses would do."
Vince Stricherz | EurekAlert!
Shape matters when light meets atom
05.12.2016 | Centre for Quantum Technologies at the National University of Singapore
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Materials Sciences
05.12.2016 | Power and Electrical Engineering