tag:blogger.com,1999:blog-4990922102626688253.post2302565249823745279..comments2023-04-15T11:42:35.385-04:00Comments on Go To Hellman: Are Neutrinos Superluminal? Judge for Yourself.Erichttp://www.blogger.com/profile/14172740163003223132noreply@blogger.comBlogger2125tag:blogger.com,1999:blog-4990922102626688253.post-72240352721010810712011-09-24T18:57:03.006-04:002011-09-24T18:57:03.006-04:00Steve, one of the questions asked after the presen...Steve, one of the questions asked after the presentation concerned the beam profile. The issue is that the proton pulse is measured at the source; the detector samples only a small area of the 2.8 km wide neutrino beam. One possibility is that the the timing of the pulse varies across the beam profile- imagine sweeping a flashlight across an aperture. In response, Autiero remarked that the proton beam profile was remarkably stable and well characterized.Erichttps://www.blogger.com/profile/14172740163003223132noreply@blogger.comtag:blogger.com,1999:blog-4990922102626688253.post-81940337298998604662011-09-24T17:57:35.723-04:002011-09-24T17:57:35.723-04:00The six-sigma claim is for the whole pulse, not ju...The six-sigma claim is for the whole pulse, not just the leading and trailing edges. Although the edges might unduly influence the fit, there is some detail in-between that might fit better with the 60.7 ns extra shift. Unfortunately, the preprint only shows the full pulse data to a resolution of 150 ns, so it's anyone's guess.<br /><br />Also worth noting is that the six-sigma claim seems to depend on an assumption that may or may not be valid: that the shape of the neutrino pulse is exactly the same as the shape of the proton pulse, except for a constant vertical scale factor (of about 1:6,000,000,000,000,000,000).<br /><br />As far as I can tell, the statistical modeling assumed there was only one unknown parameter - the time shift. The probability that a proton resulted in a neutrino detection was assumed to be constant across the pulse. If it were higher at the beginning of the pulse than at the end, the best fit might have had a smaller time shift, or even if not, the confidence interval for the time shift might have been wider. I say more about that here: http://www.stevekass.com/2011/09/24/my-0-02-on-the-ftl-neutrino-thing/Stevehttps://www.blogger.com/profile/14920869631724472667noreply@blogger.com