2018 QuarkNet Workshop, University of Oregon

Principal Investigator:

    Dr. Yasar Onel

Associate Professors:

    Dr. Jane Nachman

Technicians:

Dr. Burak Bilki, Dr. James Wetzel

Teacher\Mentors:    

Peter G. Bruecken, Michael Grannen and Moira Truesdell

Students:

Nick Arevelo, William Fawcett,  Andrew Haffarnan, Bridget Quesnell, Sam Snow and Archie Weindruch

During the summer of 2015, The University of Iowa involved six students from Bettendorf High School and 3 teachers in research activities.  The work was directed by our Principal investigator, Dr. Yasar Onel and mentored by three of the teachers, Peter Bruecken, Michael Grannen and Moira Truesdell.  The summer activities focused two projects:  Preparing scintillating plates for CERN test beam and building 100 models of CMS.  These projects were extensions from the 2014 summer work.

Activity 1: Scintillating plates:

After a successful summer of 2014, the team continued work by refining our procedure and using a more standard test plate.  The work involved preparing 5 test plates for a beam at CERN.  Unlike last year, we used a different configuration of test plate to get more comparable results.  The tests last year proved promising but needed to be refined further for comparison.  The group prepared 5 plates for the beam and sent them to CERN for testing.

Activity 2: Building a demonstration model of CMS:

After our 2014 contribution to creating a 3D-printed model of CMS, an order for 100 copies of said model were ordered.  Our group worked on printing and constructing the models for delivery.  They also refined the mobile application, which would simulate a collision on a mobile application while observing the actual model.  The application focused on using a cosmic ray to activate a simulation of a collision at CERN.  The students produced

Three of the students aided a graduate student in executing his grant to build a demonstration model of The Compact Muon Solenoid (CMS) at CERN.  The students drew parts in a proprietary program for a 3D printer, programmed Arduino® controller boards and helped design the assembly of the printer.  The task consisted of making a 1/160 scale drawing of each functional part of CMS and printing the separate parts on the 3D printer.  The students then programmed the controller boards to simulate, using lights, the particle interactions in the model when a cosmic ray triggered an event.  The students programmed a Silicon Photomultiplier board to sense the presence of a cosmic ray and trigger a string of interactions in the model.  Later, an app for mobile devices would enhance the event for observers of the model.  The students drew and printed many parts for the demonstration as well as programmed some of the light boards for the model.

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 Ω_b^- to J/Ψ Ω^- , Ω_b^- to Ξ^- D⁰, and  Ξ_b⁰ 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 Ω_b^- mass was slightly different from that of LHCb’s recent studies, and should be further explored. We searched for but did not find the Ξ_b⁰ to J/Ψ Ξ⁰(1530) decay  through invariant mass plots. Additional research should be done to search for evidence of the  Ξ_b⁰ to J/Ψ Ξ⁰(1530) decay, and to verify the mass of Ω_b^- .

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 ,} Ξ_b⁰ _, and Ω_b^-   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 Ξ_b⁰  decay channel we were able to confirm that  Ξ_b⁰  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 Ξ_b⁰ . Furthermore, there appears to be a strong signal peak at ~3450 MeV in the Ξ_b⁰ 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 Ω_b^-  particle. Additional data and effective cuts must be applied to find a more consistent mass.