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Procedures

Abstract

 

The Muon to Electron (Mu2E) project represents the search for physics beyond the “Standard Model”. We prepared Mylar straws which will be used to make up the trackers. These straws are comprised of aluminum and gold layers and will receive beams of muons. The composition of the straws will facilitate the muon to electron conversion. As of now the next generation of Mu2E: Mu2E-II is being designed and for my experiment I focused on the next generation of straws which may be used for Mu2E-II. The difference with my straws is that the gold layer inside the straw was removed and the aluminum layer was left. This makes the straws more sensitive to the muon beam since less material can interfere with the muon. Unfortunately, this also predicts that the straws will be more delicate which can affect the straws integrity when under tension. My experiment was to test how the leak rates will increase under tension by designing an apparatus to keep the straws under a constant tension and test how the leak rates changed when going from 0 grams tension to 800 grams of tension.

Graphs & Results

Measurement of Leak Properties of Mu2e/Mu2e-II Tensioned Straws

William Leija, Texas State University, Dr. Ken Heller, Ben Messerly, UMN School of Physics and Astronomy

The Standard Model is composed of 17 Fundamental Particles. All matter around us is composed of two basic types: Quarks & Leptons. Each group consists of six particles, which are related in pairs, or what is referred to as “generations”. The lightest and most stable particles make up the first generation, whereas the heavier and less-stable particles belong to the second and third generations. This is Currently the best theory to describe the most basic building blocks of the universe. Yet, it is an incomplete theory. Mu2e/Mu2e-II is attempting to observe CLFV (Charged Lepton Flavor Violation) which is not permitted in the standard model. This will hopefully be observed by a Muon changing into an electron. This process will happen with the Mu2e experiment: a proton beam hitting a tungsten target will produce pions which will decay into muons and are then pushed downstream through transportation solenoid. The transportation solenoid will eliminate additional particles based on charge and momentum. Muons will then be captured in the aluminum target and the converted electrons pass through the detector and are measured (looking for 105 Mev). Mu2e-II is using similar equipment & setup except the straws that make up the tracker will be less material and half the thickness. Why is it important that less material be used? When the electrons are detected, they will be reconstructed at the energy level they were at so by removing material, the less likely the remaining material will interfere will the electrons. Both reconstruction precision and reconstruction uncertainty are impacted by straw thickness and as a result impact the Mu2e rate of uncertainty

  1. The straws show promise in their performance under tension and as possible candidates for Mu2e-II

3) No continuation of my project is currently expected for myself since leak test chambers are not present at Texas State University.

NSF Award Number PHY-2049645

University of Minnesota, Physics & Astronomy

Dr. Ken Heller

Dr. Ben Messerly

Introduction

Conclusion

Acknowledgements

Step 1: Pre-Test the straws

  • Fully prep. & leak test potential straws
  • Passing Straws: Used for final testing
  • Failing Straws: Used for tension prototypes

Challenges:

  • Thinner/less material straws mean more delicate
  • Difficult to find straws that are passing

Step 2 : Tension Straws

  • Design and test potential designs for holding straws under tension
  • Tension apparatus must be able to hold straw at 800g tension

Challenges:

  • Most issues on this step

Step 3 : Test Daily

  • Leak test once a day
  • Ensure the straw is still under tension

Challenges:

  • Little to none

Group 1: brown, green, red - nice

Group 2: black - failure

Group 3: gray decreased - curious

Group 4: pink increased – alarming

School of Physics and Astronomy

This work was supported partially by the

Research Experiences for Undergraduates

(REU) Program of the

National Science Foundation

under Award Number

PHY-2049645