4 ms·

Is it this paper they are talking about? http://inspirehep.net/record/1380182 http://inspirehep.net/record/1380182 "This result, which is the first measurement

by tobias2014 11y ago

Is it this paper they are talking about? http://inspirehep.net/record/1380182 http://inspirehep.net/record/1380182 "This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the Standard Model." To see how much this is relevant see for example http://blogs.scientificamerican.com/observations/five-sigmawhats-that/ http://blogs.scientificamerican.com/observations/five-sigmaw... Usually physicists claim "evidence" for something at 3 standard deviations and "discovery" at 5 standard deviations.

buovjaga 11y ago
Yes, you found the right paper, it is mentioned here: https://cmns.umd.edu/news-events/features/3188 https://cmns.umd.edu/news-events/features/3188 "The research paper, “Measurement of the ratio of branching fractions...,” The LHCb Collaboration, is scheduled to appear online August 31, 2015 and to be published September 4, 2015 in the journal Physical Review Letters."
nitrogen 11y ago
I think you may be conflating deviation from expectation, which is just a percentage dependent on the width of the distribution, with statistical significance. An experiment with 5 std. dev. significance[0][1] could still confirm a value that is 2.1 std. dev. above the center of the range[2] that was originally predicted. Corrections welcome. [0] https://en.wikipedia.org/wiki/Standard_deviation#Experiment.2C_industrial_and_hypothesis_testing https://en.wikipedia.org/wiki/Standard_deviation#Experiment.... [1] https://en.wikipedia.org/wiki/Statistical_significance#Stringent_significance_thresholds_in_specific_fields https://en.wikipedia.org/wiki/Statistical_significance#Strin... [2] https://en.wikipedia.org/wiki/Standard_deviation#/media/File:Standard_deviation_diagram.svg https://en.wikipedia.org/wiki/Standard_deviation#/media/File...
- grkvlt 11y ago
  No, he is right. In particle physics standard deviation from the normal distribution of results is used to show that a result is significant and new (i.e. a previously unknown partcle) rather than just random noise.[1][2] The 'sigma' notation is then used to show how many standard deviations away the result is, such as in the Higgs discobery, when a '5 sigma' standard was used to confirm discovery. [3] The references linked probably explain this a lot better than I have. [1] http://blogs.scientificamerican.com/observations/five-sigmawhats-that/ [2] http://physics.stackexchange.com/questions/8752/standard-deviation-in-particle-physics [3] http://understandinguncertainty.org/explaining-5-sigma-higgs-how-well-did-they-do

buovjaga 11y ago

Yes, you found the right paper, it is mentioned here: https://cmns.umd.edu/news-events/features/3188 https://cmns.umd.edu/news-events/features/3188 "The research paper, “Measurement of the ratio of branching fractions...,” The LHCb Collaboration, is scheduled to appear online August 31, 2015 and to be published September 4, 2015 in the journal Physical Review Letters."

nitrogen 11y ago

I think you may be conflating deviation from expectation, which is just a percentage dependent on the width of the distribution, with statistical significance. An experiment with 5 std. dev. significance[0][1] could still confirm a value that is 2.1 std. dev. above the center of the range[2] that was originally predicted. Corrections welcome. [0] https://en.wikipedia.org/wiki/Standard_deviation#Experiment.2C_industrial_and_hypothesis_testing https://en.wikipedia.org/wiki/Standard_deviation#Experiment.... [1] https://en.wikipedia.org/wiki/Statistical_significance#Stringent_significance_thresholds_in_specific_fields https://en.wikipedia.org/wiki/Statistical_significance#Strin... [2] https://en.wikipedia.org/wiki/Standard_deviation#/media/File:Standard_deviation_diagram.svg https://en.wikipedia.org/wiki/Standard_deviation#/media/File...

grkvlt 11y ago
No, he is right. In particle physics standard deviation from the normal distribution of results is used to show that a result is significant and new (i.e. a previously unknown partcle) rather than just random noise.[1][2] The 'sigma' notation is then used to show how many standard deviations away the result is, such as in the Higgs discobery, when a '5 sigma' standard was used to confirm discovery. [3] The references linked probably explain this a lot better than I have. [1] http://blogs.scientificamerican.com/observations/five-sigmawhats-that/ [2] http://physics.stackexchange.com/questions/8752/standard-deviation-in-particle-physics [3] http://understandinguncertainty.org/explaining-5-sigma-higgs-how-well-did-they-do