Ryan’s selected talks

A collection of slides for a selection of public talks given by Ryan Reece.

ATLAS talks

Here’s my selected list of public talks I have given on physics with the ATLAS experiment.

  1. ATLAS searches for heavy Higgs bosons and supersymmetry using tau decays
    on behalf of the ATLAS Collaboration
    2016/09/23, IHEP, Beijing, China
    A conference talk I gave at Tau2016: International Workshop on Tau Lepton Physics in Beijing, China. Weak scale supersymmetry, which is one of the best motivated and studied Standard Model extensions, predicts that every SM particle has a partner with different spin. Both supersymmetry and other extensions of the Standard Model predicts the existence of several Higgs bosons. This talk summarizes the searches for supersymmetric particles and for additional heavy Higgs bosons performed with the ATLAS experiments at the LHC, with emphasis on those targeting final states with tau leptons. The analyses discussed use datasets corresponding to approximately 13-15/fb of 13 TeV proton-proton collision data taken in the years 2015-2016.

  2. Searching for new physics in high-mass ditau events at ATLAS
    2013/10/15, University of California, Davis, CA, USA
    A seminar I gave at UC Davis, reporting on seachers for new physics in high-mass ditau events with ATLAS with the 2011 and 2012 datasets.

  3. Searching for new physics in high-mass ditau events at ATLAS
    on behalf of the ATLAS Collaboration
    2013/08/15, University of California, Santa Cruz, CA, USA
    A conference talk I gave at APS Meeting: Divison of Particles and Fields (DPF) 2013 reporting results from searching for new physics in high-mass ditau events in the ATLAS experiment with the 20/fb of proton-proton collision data collected in 2012.

  4. A search for new physics in high-mass ditau events in the ATLAS detector
    2013/06/12, University of Pennsylvania, Philadelphia, PA, USA
    This talk was my Ph.D. thesis defense. My graduate research as a student at the University of Pennsylvania, working with the ATLAS experiment at the Large Hadron Collider at CERN, was on the reconstruction and identification of hadronic tau decays, measuring the SM Z→ττ production cross section in proton-proton collisions at √s = 7 TeV, and searching for new physics in high-mass ditau events. You can download my thesis here or find it at CDS as CERN-THESIS-2013-075.

  5. Searching for new physics in high-mass ditau events at ATLAS
    2012/12/13, Yale University, New Haven, CT, USA, also 12/11, 11/26, and 11/20
    A seminar I gave at Yale University summarizing my efforts in tau lepton physics at ATLAS, including the first ATLAS cut-based tau identification, the Z → ττ cross section, and the first search for Z → ττ at ATLAS. I gave similar seminars at NYU, UT Austin, and (remotely to) Brookhaven National Lab.

  6. Hadronic tau decays in ATLAS
    2012/11/13, University of Chicago, Chicago, IL, USA
    A review of the tau object reconstructed and supported by ATLAS and its current status, given at the Chicago 2012 Workshop on LHC Physics, The University of Chicago.

  7. Searches for charged Higgs bosons, supersymmetry, and exotica with tau leptons with the ATLAS and CMS detectors at the LHC
    on behalf of the ATLAS and CMS Collaborations
    2012/09/20, Nagoya University, Nagoya, Japan
    A conference talk I gave reviewing the latest status of the ATLAS and CMS searches for charged Higgs bosons, supersymmetry, and exotica with tau leptons in the final state at Tau 2012: the 12th International Workshop on Tau Lepton Physics, Nagoya, Japan.

  8. Measurement of the W and Z boson cross sections in pp collisions at 7 TeV with the ATLAS detector
    on behalf of the ATLAS Collaboration
    2011/07/22, Grenoble, France
    A conference talk I gave at the 2011 International Europhysics Conference on High Energy Physics (EPS), in Grenoble, France, reviewing the W and Z boson cross section measurements, in electron, muon, and tau decays (the first ATLAS measurements with taus).

  9. Likelihood functions for supersymmetric observables in frequentist analyses of the CMSSM and NUHM1
    2009/09/29, CERN, Meyrin, Switzerland
    Discussion of a paper by the same name that I lead as a graduate student for the Penn HEP Journal Club, mostly researchers in the ATLAS group. Most of the talk is a primer on the method of maximum likelihood and how one uses it to calculate confidence contours. While low profile, this talk is important to me because it marks the time that I started to understand the basics of the frequentist theory of statistical confidence intervals.

Philosophy of science talks

Here’s my selected list of public talks I have given on philosophy of science, in particular with focuses on philosophy of quantum mechanics, statistics, and machine learning.

  1. Machine learning and realism
    2017/03/16, Universität Bremen, Bremen, Germany
    This is a talk I gave at the Deutschen Physikalischen Gesellschaft (DPG), Bremen 2017 meeting, where I argue that philosophers should be interested in developments in machine learning because they offer provocative ways of framing classic philosophical questions concerning the problem of induction, realism, and natural kinds, among others. Drawing on examples of uses of machine learning in particle physics, we introduce and discuss the following questions: How does the theory of statistical hypothesis testing address the problem of induction? How can machine learning be used in statistical inference? How is clustering related to natural kinds? Can the scientific method be automated? And if so, what does that imply about the objectivity of science?

  2. ATLAS, data reduction, and epistemology
    2016/11/29, Höchstleistungsrechenzentrum Stuttgart (HLRS), Stuttgart, Germany
    This is a talk I was invited to give at a workshop on the philosophy of big data at HLRS, a high-performance computing laboratory in Stuttgart. I review broadly the data reduction issues for the ATLAS experiment, and how the theory of statistical confidence intervals is central to the epistemology of science.

  3. Fields over particles
    2016/07/20, Saig (Black Forest), Germany
    This is a talk I gave at the 4th International Summer School in Philosophy of Physics, in Saig, Germany. Despite being the most empirically successful scientific theory ever developed, quantum mechanics has yet to yield a consensus interpretation of its foundations. Much of the controversy in interpreting quantum mechanics concerns the issue of which ingredients of the theory are more fundamental and which are derivative. Before reconciling debates among possible interpretations of quantum mechanics, it would be helpful to clarify what are the ontological commitments of the theory—what is quantum mechanics about? Nonrelativistic quantum mechanics (NRQM), as it was first developed in the 1920s, is often taken to fundamentally describe the dynamics of particles, probabilistically related to a wave function, which provides seemingly non-particle, non-local, wave-like, interference phenomena observable in quantum systems, referred to as “wave-particle duality”. Since the development and maturing of Quantum Field Theory (QFT) in the following decades, many attitudes about the fundamentality of particles have shifted to view them as derivative, emergent excitations in a quantum field. In this talk, I review arguments for taking the field picture as more fundamental than the particle picture.

  4. How models are tested at the LHC
    2015/07/21, Saig (Black Forest), Germany
    This is a talk I gave at the 3rd International Summer School in Philosophy of Physics in Saig, Germany. The recent discovery at the LHC of a new particle so far consistent with the Higgs boson has brought a warranted confirmation of the Higgs mechanism for electroweak symmetry breaking, but there are still many mysteries about why the Standard Model is the way it is. I give an introduction to the ATLAS experiment and a high-level overview of how the collaboration reconstructs and identifies final-state particles, uses detailed simulations to assist in modeling, and processes the data in a world-wide computing grid. Physicists have often lead in developing statistical theory and methods. I try to facilitate an appreciation for hypothesis tests and statistical confidence intervals, and how they are used to justify scientific claims like searches for new physics at the LHC.

Other outreach talks

  1. Cosmic rays, physics, and relativity
    2014/07/11, University of California, Santa Cruz, CA, USA
    A talk I gave at an event for Quark Net, a scientific outreach program that brings the inspiration and science in particle physics to high school students and others. I review how cosmic ray muons, that the students had been building detectors to count, are important in the history of particle physics and are connected to deep questions about relativity and astrophysics.