Steps+for+finding+the+cosmic+rays

=Cosmic Rays=

Cosmic Rays are particles, muons, that come from outer space and penetrate the atmosphere. Many can't get through the earth's atmosphere because the cosmic rays cannot last for a long amount of time. If they come down at a almost straight angle, they may be able to live long enough to penetrate the atmosphere and come down to the earth's surface. The muons can not go through the ground, and so they can only come into the detector when there is a hole. The point of our experiment is to find out how big the hole is from the surface to the detector using what we find out about cosmic rays and our ability to use the detector. We can cut out all of the muons that were in the normal data from the detector by setting perimeters on where the cosmic rays would be coming in. It would come in from the top or from a slight angle and go straight through the detector without a curve. We made two equations for this (shown in the histograms below) and made graphs with the data to look at the cosmic rays through a different perspective.

Sum of Eta:

This data set shows that there are spikes between 5 and -5. Our equation for Sum of Eta is Eta1+Eta2. Because Eta sum should be centered around 0, which it is, we know that these are manly going straight through from the x axis coming out at us. There are other muons that show that it was a little to the left and right, but we expected that when we gave some leeway.

Delta Phi:



This graph has a much different graph then Sum Eta. The equation for Delta Phi is the absolute value of Phi2-Phi1. With the z axis coming out at us, we see that sutracting Phi1 from Phi2 gives us around 0 which is what we wanted. The data is not perfect because some of these particles from far away can be off of the particles in the detector. This does show us that there is a large amount around 0 and one which shows us the leeway with this data set as well.

11/16/11 Today we worked on cutting our data even more. We looked at the data that we had made out of our 100 thousand events, and from this we could see where the cosmic rays were around, which was around pi for phi and 0 for eta, which is what we expected. Because of this we are now making more cuts to our data to look specifically at this cosmic ray section, which we are making: eta: -.2 to .2 phi: 3.1 to 3.2

11/20/11



This is delta phi, and this is shows where the cosmic rays are because we made cuts to the data



We also made cuts on this data in order to show the cosmic rays better

Here is the data

Now that we have cut the data, we can now see how there are cosmic rays in the event, and we found out that they are coming from the left of the detector. We said this because the data showed a high amount of particles to the left in eta, and straight up in phi. Now that we know this, we can start to figure out the dimensions of the hole, and these cosmic rays will help us get to this conclusions. I think that we can find out the exact angle of the farthest particles hitting the detector, and these particles will be the outside of the circle that is our hole. Once we find that out, we can use the distance from the ground to the cms to find out what is the length of the cylinder. Then, we can also find where the hole ends on the other side because we can look at the angle of the cosmic rays coming in using eta, and we can find the circumference of the circle. Knowing all of this information will give us the answer of how big the hole. It will also tell us the gap where we can find cosmic rays in the detector.

Sum of Eta after the cuts. The cuts made to this data were between -.5 and .5 so that we can clearly see all of the data where we found the cosmic rays.

Delta Phi after the cuts: These cuts are from 3.14 to 3.157. These cuts show the cosmic rays clearer than before.


 * Showing where the Cosmic Rays are coming from:**
 * ETA**

Eta1 and eta2 show where the majority of the particles are coming from. As shown above, we see that the particles are coming more from the left because of the higher peak in the histogram.

Phi1 and phi2 show how the cosmic rays are coming mainly straight down in the detector, which is what we expect since they are coming from space and going to the earth.
 * PHI**

This is another good screen shot of the cosmic rays coming from the left

SUMMARY
//week of 12/7/11// What we did for our CMS data this week is finalize looking at the muon events, and understanding our data through looking at our graphs in many eyes. We were not able to see a lot in common when highlighting certain points in our histograms where the muons were coming in. I was able to put up all of the final data in excel, and we were not successful in seeing a common relationship between the graphs. The first thing that we did in order to put up the graphs in many eyes is cutting the data back down to our ending filters with eta and phi. These cuts are shown down below in the final cuts to the data. After doing this, we copied the data into many eyes, and we looked at the many differences between the different filters in the data set. We went to eta1 or eta2, and we highlighted all of the data that showed where we might find the cosmic rays. We knew where to look for them by noticing the amount of particles around our filtered areas. (-.2 to .2). By going through different categories to see where the highlighted data would match up, I think that I did not have much success in finding a good match in our data that had a lot of meaning. After thinking about this, I thought that it made a lot of sense to me because of what I was looking at. I was looking at the x axis and the z axis, along with the mass and other things. When looking at the cosmic rays coming down through eta (the top of the detector), we are seeing the cosmic rays coming from outspace, or the outside. The particles come down the tunnel and go into the CMS, but they cant come in from the bottom or anything else around them because cosmic rays are not able to make it all the way through. Therefore, looking at the x axis or z axis for the particles would be a scatter of where ever the muons are coming in, which is mainly around the one part of the detector since it is coming from one place in the top. That is why looking at the highlighted particles from the around straight up muons would not show us a lot when looking at the x and z axis. Mass would not be a big factor in trying to find group of highlighted particles together because the mass is all distributed, and ‍‍not all muons weigh the same. ‍‍ This is why I was not able to succeed in finding good information. I thought good things to look at would be the y axis for the particles, and this might show some of the straight up and down cosmic rays if there were any. We know that most of the cosmic rays were coming in from the left, showing that the tunnel was coming in from the left. This is important to knowing where the muons are coming in because we know that there are not many, or maybe none, cosmic rays coming in from straight up and down in the detector.

media type="custom" key="11611326": My Many Eyes account. You can see all of the graphs that I have made

**//__‍‍‍‍Final Cuts to the Data__//**
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