Experts investigate the results published by the OPERA experiment

Oct 3, 2011 10:53 GMT  ·  By
This is the experimental setup connecting LHC's SPS to the GSNL OPERA experiment
   This is the experimental setup connecting LHC's SPS to the GSNL OPERA experiment

On September 22, researchers from the Oscillation Project with Emulsion-tRacking Apparatus (OPERA) neutrino experiment, in Italy, proposed that neutrinos can travel faster than light, and provided evidence to support their claims. Now, physicists take a hard look at the numbers.

Based at the Gran Sasso National Laboratory, OPERA collects neutrinos released from the Large Hadron Collider (LHC), which is located about 730 kilometers (453.6 miles) away. Theoretically, light should travel this distance in 2.4 million nanoseconds.

What the Italian research team discovered was that neutrinos traveled this distance 60 nanoseconds faster, which would imply that they move at 1.0025 times the speed of light. Under Albert Einstein's theory of general relativity – the staple of modern physics – that is impossible.

Proportionally speaking, the difference between theory and the actual readings is very tiny, and this is why some top-level scientists at OPERA refused to collaborate on the paper that released the results for peer review and scientific scrutiny.

The CERN Super Proton Synchrotron (SPS) experiment is responsible for producing the neutrinos that travel towards OPERA, by bombarding a graphite target with burst of protons lasting only 10.5 microseconds. The results elementary particles are detected at GSNL.

But there are several potential sources of error in this setup, physicists say. The actual time when the proton beam is released is subject to question, as are the GPS measurements used as reference point. Additionally, there is also a 20 centimeters uncertainty in the measured distance between LHC and OPERA.

An error sufficiently large to account for the 60 nanoseconds of difference between neutrino and light speed could have occurred in either of these sources. In past studies, neutrinos have been demonstrated to travel at 99.9 percent the speed of light, but never faster.

One possible avenue researchers could use to measure whether neutrinos are actually faster than photons would be to fire beams of both particles at the Moon, and then calculate the time it takes for each of them to reach the target, Universe Today reports.

This kind of setup would eliminate the uncertainties related to the short distance separating OPERA from the LHC, which is less than 1,000 kilometers. At such short distances and high particle speeds, the potential for error is great.

In the mean time, physicists will continue to try and emulate the OPERA results, which should provide additional confirmation or denial of the GCNL proposal.