Thesis Defense |
Events During the Week of April 28th through May 5th, 2024
Monday, April 29th, 2024
- No events scheduled
Tuesday, April 30th, 2024
- No events scheduled
Wednesday, May 1st, 2024
- No events scheduled
Thursday, May 2nd, 2024
- A SEARCH FOR A STABLE SIX-QUARK BOUND STATE IN P-P COLLISIONS AT √ S = 13 TEV IN PARKED 2018 DATA AT CMS AND A STUDY OF THE AGING OF CATHODE STRIP CHAMBERS IN HIGH RADIATION ENVIRONMENTS.
- Time: 9:30 am - 11:30 am
- Place: 5280 Chamberlin Hall
- Speaker: Wren Vetens, Physics PhD Graduate Student
- Abstract: A search for a Standard Model dibaryonic dark matter candidate being produced in 13 TeV proton-proton collisions and annihilating with a neutron in the beam-pipe of the CMS detector is described herein. The search is to conducted in over 230 billion collisions collected in 2018 by the CMS detector, targeting the strange neutral hadrons that would be produced in such an annihilation. A custom vertex reconstruction is used, and a multivariate discriminator is trained to distinguish between the signal and a combinatorial background. Additionally, results from a study of the aging of detector components in Cathode Strip Chambers in high radiation environments with reduced Carbon Tetrafluoride gas mixtures are also presented.
- Host: Kevin Black
Friday, May 3rd, 2024
- A Study of Magnetized Plasma Turbulence in the Nonrelativistic and Relativistic Regimes
- Time: 2:00 pm
- Place: Sterling 1313;
- Speaker: Cristian Vega, Physics Graduate Student
- Abstract: Turbulence is ubiquitous in space and astrophysical plasmas and is believed to play an important role in particle heating and nonthermal acceleration. These plasmas are commonly threaded by an external magnetic field imposed by the object they surround (e.g., planet, star), making magnetized plasma turbulence a problem of significant interest. In this thesis, we use numerical simulations to study two relatively unexplored regimes of magnetized plasma turbulence, viz., the sub-electron inertial scale in nonrelativistic low electron beta plasmas and both the magnetohydrodynamic and kinetic scales in relativistically hot plasmas. Phenomenology is used to model the energy distribution of turbulent fluctuations and particles.
In the nonrelativistic regime studied, energy dissipation is seen to be strongly intermittent, concentrating on electron-scale current sheets. A few of these current sheets exhibit signatures of electron-only reconnection.
The particle energy probability density function in the relativistic regime displays a nonthermal tail of ultrarelativistic particles that goes from power-law-like to log-normal as the guide field is increased. We propose that this can be understood in terms of the acceleration mechanism that dominates in each case. Also noteworthy is the observed intermittency in the spatial distribution of ultrarelativistic particles. - Host: Stas Boldyrev