The discussion centers around the number of observations related to the Higgs boson prior to its official announcement in July 2012, specifically focusing on the concept of "photos" of decay products and the statistical significance required for discovery. Participants explore the nature of these observations, the methodology of particle detection, and the implications of data analysis in confirming the existence of the Higgs boson.
Participants express differing views on the terminology used to describe observations of the Higgs boson and the significance of statistical thresholds. There is no consensus on the exact number of observations or the implications of the data analysis methods discussed.
Participants highlight the complexity of distinguishing signal from background in particle physics and the role of statistical analysis in confirming particle existence. The discussion reflects uncertainties regarding the definitions and interpretations of data in particle detection.
Yes, I'm aware that 'taking a photo of a particle' does not have the same properties as 'taking a photo of a human'. Nevertheless, scientists need to rev up their particle accelerator and obtain data. Many of these acquisitions of data do not contribute to the existence of the Higgs but some of them do. So how many were there for the Higgs. In the OP I mentioned that I read somewhere that for the top quark that number was 37.Orodruin said:You do not take photos of elementary particles. You observe their interactions and effects in particle detectors.
gamow99 said:I read somewhere
We knew what to look for the whole time. The mass was unknown, but that simply means you look at all possible mass values.fresh_42 said:By analyzing the data of previous collisions, have there been found indications of Higgs prior to 2012, after the physicists knew what to look for?
How much data you need depends on the signal strength, the detector performance, the amount of background, and a bit of randomness. The experiments updated their results once in a while with more data, at the time where the significance was close to 5 standard deviations they decided to make a press conference. A few events more or less wouldn't have changed that.gamow99 said:Further, why would x number of photos yield a five sigma degree of certainty but not x - 1?
Excellent answer. Thanks very much for your help. This is exactly what I wanted to hear.mfb said:We knew what to look for the whole time. The mass was unknown, but that simply means you look at all possible mass values.
The 2011 dataset was sufficient to get a hint of a possible new particle at 125 GeV already, but more collisions (from 2012) were needed to clearly confirm that it is a new particle.
At the time of the Higgs discovery, ATLAS and CMS each had about 150-200 Higgs to two photon decays and ~5 Higgs to four lepton decays in the dataset. For individual events, you can never be sure what caused them, finding the Higgs and distinguishing it from background requires a statistical analysis.How much data you need depends on the signal strength, the detector performance, the amount of background, and a bit of randomness. The experiments updated their results once in a while with more data, at the time where the significance was close to 5 standard deviations they decided to make a press conference. A few events more or less wouldn't have changed that.
This Insights article discusses some of the concepts