The members of the OPERA collaboration have taken to heart one of the primary criticisms leveled at their experimental method: the possibility that the particle bunches used might be so long as to introduce sampling errors in their timing measurements. To address this the team have continued their measurements for an additional few weeks, reducing the burst durations from 10.5 microseconds to a mere 3 microseconds. Twenty new neutrino events were detected with the new configuration. (Only 20? Yep. Remember, neutrinos rarely interact, making them extremely difficult to detect.) The result? Once again, the neutrinos from CERN still appear to be arriving at Gran Sasso 60 nanoseconds sooner than expected.
Of course, the bunch length is the only thing changed in this latest run. If there is some systemic error in the experiment, it is still there.
And there is widespread suspicion that there is some systemic error involved in these results. While physicists are giddy about the prospect of new physics to explore, as I pointed out in my previous post on this subject, that excitement is tempered by skepticism. Ultimately, it will be up to other teams to replicate this experiment with different equipment to either validate or refute these results. Already, teams at MINOS and T2K are gearing up to attempt this, but it will take a few years for that to happen.
- The OPERA Collaboration, “Measurement of the neutrino velocity with the OPERA detector in the CNGS beam“, (hep-ex, arXiv:1109.4897)
- Sascha Vongehr, “OPERA Confirms Faster Than Light Neutrinos And Indicates Ultra Superluminal Small Initial Jumps“, Science 2.0
- Jason Palmer, “Neutrino experiment repeat at Cern finds same result“, BBC News
- “Neutrino experiment affirms faster-than-light claim“, Nature News Blog
- Eugenie Samuel Reich, “Neutrino experiment replicates faster-than-light finding“, Nature News
- Jonathan Asaadi, “New measurement by OPERA…same strange result?!?!“, Quantum Diaries
- Brian Dorney, “An Update from OPERA!“, Quantum Diaries
- Tommaso Dorigo, “OPERA Confirms: Neutrinos Travel Faster Than Light!!“, A Quantum Diaries Survivor
- Tommaso Dorigo, “A Few Additional Technicalities On The Opera Measurement“, A Quantum Diaries Survivor
- Matt Strassler, “OPERA’s Next Act“, Of Particular Significance
- Matt Strassler, “OPERA: Comparing the Two Versions“, Of Particular Significance
- Ethan Siegel, “The New OPERA faster-than-light Neutrino Test: Results!“, Starts With A Bang!