University of Cincinnati QuarkNet Center
Submitted by kcecire
on Friday, May 31, 2013 - 17:24
The group is very involved with cosmic ray studies but also active in the LHCb masterclasses.
Description
This group is based at UC with mentors Brian Meadows and Mike Sokoloff. Jeff Rodriguez is the lead teacher.
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U Cincinnati Abstract 2014 - Large Hadron Collider beauty Particle Analysis
T. Baker, K. Debry, B. Shen, R. Swertfeger
D. Whittington (Fairfield High School)
M.Sokoloff (University of Cincinnati)
The purpose of our research was to identify signal and background ranges of particle masses in high energy decays from the Large Hadron Collider beauty (LHCb), and to compare these masses to those recorded by the Particle Data Group (PDG) in order to confirm particle identification. We studied Ωb- to J/Ψ Ω- , Ωb- to Ξ- D0, and Ξb0 to J/Ψ Ξ0(1530) decay channels by plotting particle properties such as momentum, probability of particle, lifetime, energy, mass, and invariant mass using 1D and 2D histograms. We used a linux terminal and ROOT program to write code in C++ that enabled us to graph and manipulate the large amount of data we were given. We applied many cuts on variables such as decay time and mass, fit the peaks with a gaussian fit, and compared the peaks to the mass values given by PDG. Our Ωb- mass was slightly different from that of LHCb’s recent studies, and should be further explored. We searched for but did not find the Ξb0 to J/Ψ Ξ0(1530) decay through invariant mass plots. Additional research should be done to search for evidence of the Ξb0 to J/Ψ Ξ0(1530) decay, and to verify the mass of Ωb- .
U Cincinnati Abstract 2014 - Analysis of Particle Measurements from Large Hadron Collider
T. Baker, K. Debry, B. Shen, R. Swertfeger
D. Whittington (Fairfield High School)
M. Sokoloff (University of Cincinnati)
The purpose of our research was to identify the signal and background regions in particle decay patterns and compare the measurements that to those listed in the Particle Data Group (PDG) in order to verify the particles’ identification. We analyzed Ξ-b , Ξb0 , and Ωb- decay channels by graphing the measurements such as invariant mass in one and two dimensional histograms while attempting to increase the clarity of the signal region by making “cuts” on the data through other measurements of the particle such as the lifetime, energy, and momentum of the particle decay. After making various cuts on the particle masses, we attempt to “fit” the peaks to a gaussian function to determine the most common masses. Comparing the masses to those on PDG, we are able to verify whether the unknown peaks are legitimate or inconclusive. By plotting Ξ-b mass, the histogram illustrated that the mass identified in the data (~5797 MeV) differed from that of the PDG mass (5791.1 ±2.2 MeV), alluding to a possible bias in the detector. In the Ξb0 decay channel we were able to confirm that Ξb0 does indeed decay into Ξ- π+J/Ψ by constructing invariant mass plot and isolating a strong signal at 5788 MeV, which is the mass of the parent particle Ξb0 . Furthermore, there appears to be a strong signal peak at ~3450 MeV in the Ξb0 decay; in the quest to determine this unknown signal, we compared the peak to a similar decay, that of Ξ-b . Alas, the the peak found at 3450 MeV was not a part of the Ξ-b. Further research may be done to to determine unknown peak at 3450 MeV along with the mass of Ωb- particle. Additional data and effective cuts must be applied to find a more consistent mass.
U Cincinnati Abstracts 2013, Three abstracts
University of Cincinnati QuarkNet Center
Improving the significance of Ξ0 signal by making quality cuts to π– daughters
David Caggiano (Anderson High School), Evan Cornuelle (Turpin High School),
Elizabeth Eadie (Summit Country Day School) and Brianna Poll (McAuley High School)
John-Paul Gates (Springboro High School) and Mike Sokoloff (University of Cincinnati)
The purpose of our research was to study XiC0 (Ξ0 → Ξ–π+; Ξ– → Λπ–; Λ → π–p) using the data from LHCb experiment at CERN. The first thing we did was to add cuts to the daughter particles. After the signal was improved slightly with the first daughters, the other daughters were added one by one as well as other cuts. This process was repeated until reaching the parent particle. While adding cuts to the daughters, we had a pass graph, which represents the entries that passed the cuts stated, and a fail graph, for the entries that failed one or more of the cuts. After improving the signal, we tried a single Gaussian fit. Once the residuals of the fit were reasonable, we inserted a table that represented the sigma value, which was 8.4 ± 0.7 for the XiC0. We repeated this process with the OmegaC0 (Ω0 → Ω–π+; Ω– → ΛK–; Λ → π–p), and got a reasonable signal. We then attempted the decay chain of OmegaC+ (Ω+ → Ω–K+π+; Ω– → ΛK–;Λ → π–p), but there was no noticeable peak and the cuts used did not help to reveal one.
Improving the significance of - mass plot by making quality cuts to π– daughters
Evan Cornuelle (Turpin High School)
John-Paul Gates (Springboro High School) and Mike Sokoloff (University of Cincinnati)
The purpose of our research is to improve the signal to background ratio of the Ξ+ → Ξ–ππ;
Ξ– → Λ&pi–; Λ → pπ–. All of the data is from experiments conducted at the LHCb in CERN. The procedure in use to achieve this goal, starting from the last decay in the cascade, is to make selection on the mass distribution entries until the signal is visible above the background. Then move to the parent particle and repeat up the decay chain. Selections used in the study include probabilities that a track is electronic noise, lifetime, particle identification, position, mass, and corrected mass. Certain selections are used at different stages in the decay chain resulting in an Ξ+ mass measurement of 2468.84 ± 0.12 MeV / c2, a sigma of 6.3 ± 0.1 /c2 and signal entries of 7181 ± 129. Results of the Ξ+ are used to look at the Ξ0 particle; this is inconclusive, as there is not a signal in the analyzed data. A further study on the Ξ+ would include analysis on the systematics that are involved with this mass study. A further study involving the Ξ0 would be useful given that more data is used in the mass study.
Improving the significance of Ξ+ mass plot by making quality cuts to &pi– daughters
David Caggiano (Anderson High School), Evan Cornuelle (Turpin High School) and
Elizabeth Eadie (Summit Country Day School)
John-Paul Gates (Springboro High School) and Mike Sokoloff (University of Cincinnati)
The purpose of our research was to study Ξ+ (Ξ+→ Ξ– π+π+; Ξ– → Λπ–; Λ → π–p) using the data from LHCb experiment at CERN. Our first action was to find and apply appropriate cuts to the first daughter particles. After we improved the signal peak and eliminated portions of the background, we repeated the process to the other daughter particles. Each time we repeated this process further up the decay chain, the signal improved more and more. In addition to having a histogram of the data that passed the cuts, we also had one containing all of the failed entries. When our signal was improved and all of our cuts were made, we fitted the histogram with a single Gaussian fit. When the fit and its residuals were reasonable, we inserted a table with the sigma value, which was 6.4 ± 0.2 for the Ξ+. Our next step was to look up the decay chain one more step, and study Ξ0 (Ξ0 → Ξ+π–; Ξ+ → Ξ–π+π+; Ξ– ® Λπ–; Λ → π–p), but there was no peak and our cuts did not reveal one.
First Post
In the first class, I learned a bit more than I had about how Energy is measured in a particle collision. I'm still having issues with the exact methods of calculating momentum, but I have a general idea. After the class, I walked away with one big question. I understand that the standard model is essentially based off a numbering system, but I'm curious as to whether that numbering system just happened to be subjectively true or if it's just a good way to understand the basic interactions of particles.
Summer workshop 2012 agenda
You'll find it and more at: /content/cms-data-workshop-cincinnati.
Introduction to Particle Physics
I enjoyed hearing the extended explanation of the Standard Model by Jeff yesterday. It is interesting to hear the basic science questions asked by particle physicists. I too am wondering about what mass really is and how a particle can come from energy. I am interested in looking up some applied information on my own, specifically how accelerators are being used to determine protein structure and how muons mutate DNA. This is going to be an interesting week!
1st day of Quarknet
First off, I need to say I’m very excited to be in this group. I have always been curious about dark matter, dark energy and the inner workings of the universe. My first day of Quarknet consisted of a lot of loose ends being tied together: words being put to shapes and figures that I had seen (the tesseract) or actually understanding the data that was put in front of me (The Standard Model poster). Also the clarification that the Gluon was the Strong Nuclear Force and it has most of the mass in a proton clarified a lot of things.
Also I have always looked at time as a 4th dimension. However the explanation that it is perpendicular the the x,y and z axes kind of blew my mind. Trying to ‘see’ this is kind of odd. I guess I’m trying to reconcile this.
I guess my question revolves around how mass or energy is borrowed from the vacuum. In my mind something has to be there to be borrowed from. Could this material that is borrowed from some form of dark matter? We are just able to ‘see’ it’s manifestation of it in these proposed / observable particles under these extreme conditions.
1st day of particle physics workshop
I always look forward to this particle physics workshop every year. It's a time to make new friends and renew old friendships. Every day seems like I learned something new and reinforce what been learned previously in the past. For some reason I never put two and two together and for some reason I didn't realize antimatter and dark matter are 2 different things. Also for some reason I missed that gluons are what holds a nucleus together. Today we discussed up-and-coming events with dark matter. Looking forward to learning about dark matter in the up-and-coming week. Also found out for some reason I can't post my picture.
Klein Bottle in 4D
During our discussion today about the standard model and alternative theories. We talked about Dark Matter, Dark Energy, and eventually string theory and multiple dimensions. I had only heard of a teserac and had never hearrd of Klein Bottles. I'm still trying to wrap my head around how to visualize the Klein bottle as being contained in four dimensions. But that is what makes this phun! I'll just shake my head yes and smile.
Welcome UC group members!
Welcome to the University of Cincinnati Center group. To start, here are three things you can do right now:
Create/edit your site profile (please do ASAP!)
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5. In the "Account" page, you can change your password and upload an avatar image
6. In the "Personal information" page, you can add whether you are a QN teacher, your contact info, etc.
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2. Choose "My groups"
3. Choose "University of Cincinnati QuarkNet Center"
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