Exploring New Physics in LHC Data: Insights from a Resonance Search Study

In summary, the conversation discusses a paper and a plot showing data and theoretical predictions for a specific resonance. The data points in the region of interest do not deviate significantly from the predicted background, but there is a noticeable deviation in the last few bins. The speaker suggests that this may be due to an issue with the theoretical prediction for the QCD contribution. The other person expresses confusion and the speaker explains that QCD is a complex topic and predictions often rely on assumptions and approximations. They also note that it is surprising that most of the region is well-described and some deviation at the edge of the phase space is expected.
  • #1
Malamala
299
27
Hello! The attached pic is from this paper. So on the y you have counts and on the x you have a certain parameter used to search for a certain resonance. The colored part is the Standard Model (SM) prediction and the black dots are the obtained data while the dashed lines are the simulated prediction for the contribution of this new resonance. Obviously no deviation is observed in the region of interest. However if you look in the last 5-7 bins (maybe except the last 2), especially in the bottom plot, the data points deviate significantly from the predicted background. Is it because the simulation didn't focus much there (as it is outside the region of interest for the specific resonance) or it can be something deeper (the points seems to be quite a few sigma below the predicted model)? If the simulations are correct over the whole presented range, shouldn't these points be closer (within the error bars) to the predicted model? Thank you!
 

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  • #2
Probably an issue with the theoretical prediction for the QCD contribution. If you would have systematic uncertainties shown in this plot they would probably cover the observed deviation.
 
  • #3
mfb said:
Probably an issue with the theoretical prediction for the QCD contribution. If you would have systematic uncertainties shown in this plot they would probably cover the observed deviation.
Thank you for your reply! I am still a bit confused. An issue with the theoretical prediction doesn't mean there is something we don't understand about that particular region of phase space?
 
  • #4
It means QCD is complicated. Predictions often have to rely on some assumptions, approximations, experimental data as input and so on. I'm more surprised that most of the region is so well-described. Some deviation at the edge of the phase space with such a steep distribution is perfectly plausible.
 

Related to Exploring New Physics in LHC Data: Insights from a Resonance Search Study

1. What is the LHC and why is it important for exploring new physics?

The Large Hadron Collider (LHC) is the world's largest and most powerful particle accelerator. It is located at the European Organization for Nuclear Research (CERN) in Switzerland and is used to study the fundamental building blocks of matter and the laws of nature. The LHC is important for exploring new physics because it allows scientists to recreate the conditions of the early universe and study the behavior of particles at extremely high energies, which can provide insights into the nature of the universe.

2. What is a resonance search study and how does it help in the search for new physics?

A resonance search study is a type of analysis that looks for evidence of new particles or phenomena by searching for "bumps" or excesses in the data at specific energy levels. These bumps can indicate the presence of a new particle that is not predicted by the current understanding of physics. By studying the characteristics of these bumps, scientists can gain insights into the properties and interactions of new particles, which can lead to a better understanding of the underlying physics of our universe.

3. What are some current theories or models that the resonance search study is testing?

The resonance search study can test a variety of theories and models, including supersymmetry, dark matter, and extra dimensions. These theories attempt to explain some of the mysteries in physics, such as the origin of mass and the existence of dark matter. By searching for new particles or phenomena, the resonance search study helps to either confirm or rule out these theories and narrow down the possibilities for new physics beyond the Standard Model.

4. How do scientists analyze the data from the resonance search study?

The data from the resonance search study is analyzed using advanced statistical techniques and computer algorithms. Scientists look for patterns and anomalies in the data that could indicate the presence of new particles. They also compare the data to theoretical predictions and simulations to determine if there are any discrepancies that could be explained by new physics. This analysis process is repeated multiple times to ensure the accuracy and reliability of the results.

5. What are some potential implications of the results from the resonance search study?

The results from the resonance search study can have significant implications for our understanding of the universe. If new particles or phenomena are discovered, it could lead to the development of new theories and models that can better explain the fundamental laws of nature. It could also provide insights into the origin of the universe and the role of dark matter. On the other hand, if no new physics is found, it could confirm the predictions of the Standard Model and provide further evidence for its validity. Either way, the results of the resonance search study will have a profound impact on the field of particle physics and our understanding of the universe.

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