2022 Fall Graduate Physics Colloquium Series: Evan Collins/Jonathan Samudio/William L.A. Burdett

DateSeptember 23, 2022
Time3:35 - 5:00 pm
LocationBaylor Sciences Building, Room E.125
2022 Fall Graduate Physics Colloquium Series

Evan Collins

A portrait of the Higgs boson by the CMS experiment ten years after the discovery

In July 2012, the ATLAS and CMS collaborations at the CERN Large Hadron Collider announced the observation of a Higgs boson at a mass of around 125 GeV. Ten years later, and with the data corresponding to the production of a 30-times larger number of Higgs bosons, we have learnt much more about the properties of the Higgs boson. The CMS experiment has observed the Higgs boson in numerous fermionic and bosonic decay channels, established its spin–parity quantum numbers, determined its mass and measured its production cross-sections in various modes. Here the CMS Collaboration reports the most up-to-date combination of results on the properties of the Higgs boson, including the most stringent limit on the cross section for the production of a pair of Higgs bosons, on the basis of data from proton–proton collisions at a centre-of-mass energy of 13 TeV. Within the uncertainties, all these observations are compatible with the predictions of the standard model of elementary particle physics. Much evidence points to the fact that the standard model is a low-energy approximation of a more comprehensive theory. Several of the standard model issues originate in the sector of Higgs boson physics. An order of magnitude larger number of Higgs bosons, expected to be examined over the next 15 years, will help deepen our understanding of this crucial sector.

Jonathan Samudio

Analysis improvements and Run 3 projections
for the production of a top quark pair with a
boosted Z or Higgs boson using effective field
theory in pp collisions at the LHC

The third data taking run of the LHC is underway, which will offer increased statistics to searches for new physics. In addition, new machine learning techniques have opened the door for significant
improvement in high energy physics analyses. A preliminary study of such improvements in a recently submitted analysis by the CMS
collaboration will be presented. The analysis focuses on probing effective field theory through the production of a top quark pair in
association with a Lorentz-boosted Z or Higgs boson. I will discuss the analysis and its methods and follow-up studies including the implementation of new machine learning techniques and projections
of Run 3 statistics.

William L.A. Burdett

Stability of 2-D Complex plasma Monolayers in Asymmetric Capacitively Coupled RF Discharges

2-D plasma crystals form from charged dust within a low-temperature plasma and serve as diagnostics of generic phenomena such as wave propagation. This presentation will discuss experiment showing the formation and stability of a 2-D crystal monolayer under certain pressures as well as the thresholds of the plasma parameters which lead to the crystal’s transition into a “fluid” state. In addition to the experiment, a self-consistent sheath model is used to calculate the RF sheath profile, microparticle charges, and microparticle resonant frequency as a function of power and background argon pressure.

Watch on Zoom at the following:

Meeting ID: 840 0820 1153

Passcode: 720767

For more information contact: Dr. Anzhong Wang 254-710-2276

PublisherDepartment of Physics
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