Upcoming Talks

September 9, 2016
General The Standard Model

The Standard Model of particle physics is oft referenced, but rarely explictly defined. In our standard introductory lecture, we come together to construct a general talk with the background in the parts of the standard model we are most interested in.

September 16, 2016
Alex Leder The Enigma Machine

The German Enigma Machine represented a giant leap forward in military message encoding. In order to decode messages sent around with these machine British codebreaker at Bletchley park had to develop novel techniques for how to decode these messages. This talk will provide a bit of an overview of how this was done and discuss not just how the decoding was performed but also how it was used to help shorten World War II.

September 23, 2016
Rey Torres A = 3 Nuclei: A Lab for Energy Sharing in Asymmetric Systems

In non-interacting Fermi systems with imbalanced number of two different Fermions, the average momentum per fermion is higher for the majority. Adding a strong short-range interaction between different fermions may invert the momentum sharing of the two components, making the minority move faster on average than the majority. This feature is due to the high momentum distribution being dominated by short distance pairs of different type Fermions. It is a common behavior that applies to systems ranging from ultra-cold atoms at neV energies to nucleons with MeV energies. In nuclei the nucleon-nucleon tensor force makes the neutron-proton short range correlated pair (np-SRC) the dominant component contributing to the high momentum of nucleons. In light neutron-rich nuclei such as 3H, the average momentum of a proton should be higher than that of a neutron. In 3He the average momentum of the neutron should exceed that of the protons. We plan to test the above prediction experimentally by probing both the majority and minority nucleon momentum distributions of asymmetric A = 3 nuclei. We will do this by measuring the quasi-elastic 3H(e,e'p) and 3He(e,e'p) reactions in high-Q2, xB>1 kinematics where the effects of FSI are minimized. The use of mirror nuclei allows using probing the properties of the proton in one nucleus and learning about the properties of the neutron in the other. The experiment will run in 2017 at Hall-A of Jefferson-Lab, using an incoming 4.3 GeV electron beam and High Resolution Spectrometers (HRS) to detect scattered electrons and knockout protons. We will extract reduced cross-sections and cross-sections which will be used as a direct benchmark to detailed nuclear calculations in a regime they have not been tested in before.

September 30, 2016
Stephanie Brandt Practice Oral Exam

A practice oral exam with a talk on sterile neutrinos followed by general questions.

October 7, 2016
Charles Epstein Planetary Defense: Protecting the Planet from Asteroids using Nukes

The Earth is vulnerable to the constant threat of a catastrophic asteroid impact. In the event of an impending impact, we have a few options to protect ourselves, one of which is a nuclear detonation. Additionally, our knowledge of small but deadly asteroids is very limited. The US Government and the international community are committed to investigating and investing in efforts to safeguard the planet in the event of an impending hit. In this talk, I will describe the threat posed by asteroids and the ways by which we can mitigate it, focusing on the efforts at Lawrence Livermore National Laboratory.

October 14, 2016
Yunjie Yang Event generator tuning using Bayesian optimization

Monte Carlo event generators have become indispensable tools that are widely used by modern particle and nuclear physics experiments. Such event generators typically contain a large number of parameters that need to “tuned” by comparing the output of the generator with experimental data. Generating enough events to make such a comparison is often a computationally expensive task. Bayesian optimization is known to be a powerful tool in solving problems where the function has no closed-form and is expensive to evaluate, e.g. tuning the hyperparameters of machine learning algorithms. We propose treating Monte Carlo event generator tuning as a black-box optimization problem to be addressed using the framework of Bayesian optimization. In this talk, I will first give a brief introduction to event generator tuning and cover some basics of Bayesian optimization. I will then present some of our results from tuning 20 parameters of the PYTHIA8 event generator using such a Bayesian optimization approach.

October 21, 2016
Lauren Yates The Mu2e Tracker

The Mu2e experiment is under construction and, when finished, will search for charged lepton flavor violation (CLFV) in the form of a muon converting into an electron without associated neutrinos. An observation of charged lepton flavor violation at a rate exceeding that predicted in the Standard Model would be clear evidence for new physics. The search at Mu2e will have significant new reach in this area, with a sensitivity four orders of magnitude better than any previous CLFV experiment. I will provide a general overview of Mu2e and will discuss the work that I did on the development of the tracker, which is the component of the detector that will provide the primary momentum measurement of possible conversion electrons.

October 28, 2016
John Hardin O(n) and U

We commonly deal with very big data, and we often need to do it fast. When we want to go really fast, analyzing how algorithmic complexity affects the various parts of our program can give us clues on where to start. This talk will give a brief overview of concepts affecting runtime and include some examples.

November 4, 2016
Efrain Segarra The OLIVIA Experiment – A “Trapless” Beta Decay Study

High precision measurements of nuclear decays are one of the most precise tools for probing physics beyond the standard model. These measurements at low energies indirectly probe physics at very high energies, rivaling that of the largest accelerators, while still remaining a relatively inexpensive research program. The OLIVIA experiment is a new experiment that will perform a kinematically-complete measurement of the 8Li beta decay in 3D. While most similar measurements use optical traps, OLIVIA is based on a TPC, coupled with scintillators. The proposed setup does not require trapping 8Li ions – significantly simplifying the measurement, but dramatically increasing the statistical accuracy. I will present the proposed experimental setup, our estimated sensitivity to constrain tensor currents in electroweak theory, and my work on energy reconstruction completed this summer.

November 11, 2016
Yi Jia A study of the nEXO detector to search for neutrinoless double beta decay

nEXO experiment is an update of EXO-200 in the future. It aims to search for neutrinoless double beta decay, thus determining if neutrino is Majorana fermion as predicted in theory. The study focuses on the detection of ionized electrons in nEXO detector, and explore how the strength of electric field in detector impacts the process of data analysis. With transform function from the design of electronics, the output waveform can be successfully transformed back to the input in simulation. In signal discrimination, the primary background is gamma with the same energy. By using the information about the charge waveform, position and time, we define input variables in TMVA to perform the event selection by BDTG method. High electric field can enhance the performance of signal discrimination and also benefit the energy resolution. The further study of these results can provide useful suggestions about some essential parameters including electric field, which can be very helpful in detector design.

November 18, 2016
Tom Boettcher Novel QCD at LHCb

Designed primarily to study decays of hadrons containing bottom quarks, LHCb’s unique geometry also makes it ideal for studying the structure of the proton at both high and low x. In this talk I’ll discuss searches for unobserved QCD phenomena in both of these kinematic regimes.

December 2, 2016
Brandon Allen Practice Oral Exam

A practice oral exam with a talk on muone g-2 followed by general questions.

December 9, 2016
Nick Buzinsky Simulations in Project 8

Neutrino flavor oscillations, as first demonstrated by SNO (2001), directly imply non-zero neutrino masses. Despite the large experimental effort put into neutrino oscillations to date, such experiments are sensitive only to mass differences, not their absolute values. Determining the absolute mass scale of the neutrino is a highly non-trivial problem requiring experimental precision into the sub-eV range. Project 8 uses a novel, radiometric approach for determining the mass scale of the neutrino. In this talk, we explore some of the efforts undertaken to improve the precision and the time-effectiveness of simulations, namely particle integration and synchrotron radiation modeling.

December 16, 2016
Zhaozhong Shi The Solenoidal Tracker at STAR

The Solenoidal Tracker at Relativistic Heavy-Ion Collider (STAR) Collaboration collects and analyzes experimental data from the Relativistic Heavy-Ion Collider at Brookhaven National Laboratory. The STAR detector consists of the Time Projection Chamber (TPC), the Time of Flight (TOF) Detector, and the Heavy Flavor Tracker (HFT). The STAR detector covers full azimuthal angle at mid-rapidity with excellent particle identification. In 2014, STAR Collaboration implemented the HFT detector. The HFT detector enables precision determination of event and decay vertices. The main goal of the HFT detector is to perform precision measurement of the production of charm hadron in high energy nuclear collisions. In the meantime, it also allows clean measurements of proton. We use event plane method to calculate the coefficient of second Fourier harmonic in the azimuth of K0 particles using the data from 2014 for Au + Au at center of mass energy sNN = 200GeV in STAR Collaboration. In addition, the author studies the number-of-quark scaling law from quark coalescence model for KS0 elliptic flow and confirms that KS0 is indeed created from quark-gluon plasma. The physics motivations and detail analyses will be presented in this talk.

February 10, 2017
Dylan Hsu Search for Dark Matter Production in Boosted Z Events with the CMS Detector

A search for new physics in events with a Z boson produced in association with large missing transverse momentum with the CMS experiment at the LHC is presented. This search is interpreted in a simplified model with a spin-1 dark matter mediator and in a model with a standard model Higgs-like scalar particle, each produced in association with the Z boson and decaying invisibly. The search is based on the summer 2016 data sample of proton-proton collisions at center-of-mass energy 13 TeV, corresponding to an integrated luminosity of 12.9/fb.

February 17, 2017
Constantin Weisser Kalman Filters - From Stocks to the Moon

Kalman filters are algorithms prominent in particle tracking, but also have wide ranging applications outside of particle physics. They aim to estimate the state of a system by combining noisy measurements and approximate evolution equations. Although their derivation is a mathematical jungle, I will try to give a big picture motivation of why they are so popular.

February 24, 2017
Zhaozhong Shi sPHENIX Calorimeter Test Beam at FNAL

sPHENIX is a new detector planned for the RHIC facility at BNL. sPHENIX will provide state-of-art capabilities for studies of the strongly interacting quark-gluon plasma using jet and heavy-flavor observables. The goal of sPHENIX is to understand the microscopic structure of the plasma and reveal how its strongly interacting nature arises from the underlying interactions of quarks and gluons described by quantum chromodynamics. sPHENIX is currently in CD-0 stage. We test the sPHENIX calorimeters at Fermilab Test Beam Facilities (FTBF). In this presentation, I wll talk about my involvement of the sPHENIX test beam at Fermilab during winter break and share my wonderful research and life experience at Fermilab.

March 3, 2017
Gabriel Collin How it's made: Neural networks

Neural networks form the basis of deep learning, that is now being used to drive cars, win Go, and perform physics analyses. But why and how do they work? In this talk I'll go over some simple examples to demystify the voodoo behind neural networks, as well as review some cutting edge applications in deep learning.

March 10, 2017
Tom Boettcher Dealing with the “H” in LHCb

Hadron colliders present numerous challenges and opportunities to B physicists. In this talk I’ll discuss why we’d do something as inconvenient as studying b hadron decays at the LHC. I’ll also discuss how LHCb triggers on these decays in such a harsh, messy environment.

March 17, 2017
John Hardin Kernel selection for multidimensional PDF estimation problems

KDE estimation in multiple dimensions presents a unique problem of kernel selection. As such, the interdimesional relative scale and correct kernel function must be derived experimentally. A systematic study of all reasonable possibilities (linear, quadratic, gaussian, etc) is presented along with there applicability to a variety of test cases and a gradient descent method of choosing scales. This data driven choice of parameters can improve pdf performance by entire percentage points.

March 24, 2017
Dan Abercrombie Calculating Criticality

I am going to continue the tradition of "Nuclear Week", which so far contains Prof. Bernstein's discussion of the Doomsday clock and the 8.711 lectures on Nuclear power. However, I have always found the talks consisting only of big numbers, used either to end the world or save our atmosphere, rather boring. Instead, I will demonstrate how to perform a back-of-the-envelope criticality calculation, derived from first principles that you already know. Using this method and publicly available data, I will show where this 6 kg of Plutonium figure comes from (besides experiment). I will also describe how various features of nuclear reactors modify this calculation to make the system more stable than a typical bomb (time permitting).

April 7, 2017
Yunjie Yang Machine learning in hep-ex and nucl-ex: perspectives and applications

The use of machine learning techniques has become commonplace in our field of experimental particle and nuclear physics. However, skepticism and reservation among physicists towards such techniques are not uncommon either. I will first try to argue that, conceptually, these techniques are nothing foreign to us and the real barrier is probably just the languages we use to talk about them. Afterwards, I will show some interesting applications of machine learning techniques in our field, such as the auto-generation of jet images and anomaly detection in LHC superconducting magnets.

April 14, 2017
Lauren Yates Deep Learning in the MicroBooNE Experiment

Deep learning techniques are increasingly being used for data analysis tasks in high energy physics. In this talk, I will discuss the particular implementation of such techniques in a forthcoming analysis by the MicroBooNE collaboration. I will begin by introducing the MicroBooNE experiment and motivating our analysis, which is a search for a possible excess of low-energy electron neutrino events. I will provide an overview of the various steps in the analysis and the algorithms we are using at each step. Finally, I will discuss some of the ways we are planning to address the systematic uncertainties associated with deep learning.

April 21, 2017
Field Rogers Searching for Dark Matter with the General AntiParticle Spectrometer (GAPS)

Less than 5 percent of the Universe is composed of atoms and other particles that we understand, while the remainder composed of mysterious dark matter and dark energy. While dark matter has been detected in the astrophysical sense, we are interested in a particle physics understanding of dark matter. If certain dark matter particles annihilated in the Milky Way, we could detect the decay products and use them to learn about the dark matter that produced them. GAPS will search for dark matter signatures in cosmic rays using a novel technique for particle identification.

April 28, 2017
Jing Wang Heavy Flavor Production at CMS

Want to know who will win UCL 2017? Want to know if you should buy a PS4 or Nintendo Switch? Want to know the best place for ramen in Boston? Hmm.. I will not talk about any of them. Instead, I will discuss the measurement of open heavy flavor mesons in heavy ion collisions with CMS detector. I will focus on the background and results rather than the analysis techniques in details.

May 5, 2017
Joe Johnston The Ricochet Experiment

Coherent neutrino scattering is an expected neutrino interaction, but has never been detected due to the low recoil energies associated with the process. In this talk I will motivate the search and examine the technology that will allow the Ricochet experiment to detect coherent neutrino scattering. I will then discuss Bayesian Markov Chain Monte Carlo simulations and show how they can be applied to study the sensitivity of the Ricochet experiment. Finally, I will present recent results demonstrating the feasibility of performing the Ricochet experiment at the Double Chooz reactor.

May 12, 2017
Marjon Moulai Practice Oral Exam

A practice oral exam featuring a talk on J/psi production and general questions.

May 19, 2017
Yimin Wang Geocentrism v.s. Heliocentrism: The ultimate warfare between science and religion! Or is it?

The dispute between Geocentrism and Heliocentrism is believed as a representative aspect of the Renaissance era. It shows not only the progress of science philosophy but also the necessity of separating science from religious believes. However, Nicolaus Copernicus had his work Dē revolutionibus orbium coelestium published the day after his death. Giordano Bruno, a supporter for Heliocentrism, was executed in the Campo de' Fiori. These facts also imply that Catholic churches played a negative role in the proceeding of science. Was it actually the case that most people were blind-folded by Catholic believes and rest of them chose to remain in silence? Or are there more facts lying behind the whole story that cannot be summarized by merely the buzzword "science v.s. religion"?

May 26, 2017
Patrick Moran Fifth Forces and the DarkLight Experiment

A fifth force of nature sounds more like a deus ex machina in a science fiction plot than it does serious physics. However, there have been a number of theories and experimental anomalies, both past and present, that have pointed towards the existence of a force beyond the Standard Model. I will briefly overview the history of some of these searches and discuss current dark matter paradigms that predict a fifth force, with an overview of the DarkLight experiment.