About

I am an Assistant Professor in the Department of Global Labor and Work at Cornell University’s School of Industrial & Labor Relations. I am also an affiliated scholar at the Workplace Justice Lab at Rutgers University’s School of Management and Labor Relations. My research interests center around work and labor, focusing on how the labor movement and governments are responding to emerging labor market forms such as the gig economy. My research is based on two years of ethnographic and survey work with two immigrant Workers’ Centers in New York City and by working as an app-based food delivery worker myself. In particular, I focus on the impacts of app-based employment for immigrant populations.

Research topics

• Physics
• Particle physics
• Nuclear physics
• Computer Science
• Optics
• Astrophysics
• Quantum mechanics
• Algorithm
• Mathematics
• Database
• Geology
• Operating system
• Engineering
• Statistics
• Biology
• Real-time computing
• Computer hardware
• Aerospace engineering
• Computational science
• Combinatorics
• Telecommunications
• Simulation

Selected publications

• Development of Robust Plastic Scintillator Bars for Fast-Neutron and Gamma-Ray Imaging in the NOVO Detector Array

  2025-11-01

  article

  Robust polyurethane-based plastic scintillator bars have been developed for simultaneous imaging of energetic neutron and gamma radiation in medical proton therapy facilities. The time and depth-of-interaction resolution obtained with dual-ended SiPM readout was determined and compared with that of corresponding detectors using organic glass scintillators (OGS). Though OGS performance is still out of reach, the tests confirmed the novel scintillator material represents a feasible alternative to OGS for imaging applications in harsh environments, distinguished by unrivaled mechanical robustness and stability.

  PublisherDOI

• The Novo Project - Hybrid Neutron/Gammaray Imaging for Range Verification in Proton Therapy

  2025-11-01

  article

  Proton therapy (PT) provides dose delivery with high spatial precision, allowing more conformal treatments and the minimization of adverse exposure to adjacent healthy tissues. However, PT is susceptible to uncertainties in the proton range which currently reduces treatment efficacy. To mitigate this, the NOVO collaboration is developing a real-time, multi-particle imaging system capable of simultaneous imaging of prompt gamma rays (PGs) and fast neutrons (FNs) emitted during treatment. This study presents the commissioning experiment of a prototype NOVO detector aimed at imaging a point-like source of accelerator-based neutrons. The array is composed of 14 interwoven organic scintillator bars using two novel scintillator materials - OGS and M600. Experiments were conducted at the Physikalisch-Technische Bundesanstalt in Braunschweig, Germany, where monoenergetic neutron fields from 1.2 MeV to 19 MeV were generated via accelerator-driven reactions. Images of the neutron source were reconstructed through the simple back-projection of double-scattered events, with the detector array position iterated using a two-axis motor table. The source position could be determined with a resolution of less than 5 mm for neutron fields above 14.8 MeV with 10,000 detected events. Further improvements to the array geometry and implementation of advanced reconstruction algorithms suggest detection of range shifts down to 1 mm is possible.

  PublisherDOI

• Imaging of a 14.8 MeV neutron source via a hybrid neutron/gamma ray camera for applications in particle therapy range verification

  2024-09-25

  article

  The highly localized nature of the dose deposition in proton therapy (PT) can be exploited for more conformal and less toxic treatments. However, this also makes PT highly sensitive to range uncertainties. To this end, the NOVO collaboration aims to develop a multi-particle imaging system for verifying the proton range in real time via the simultaneous imaging of secondary prompt gamma rays (PGs) and fast neutrons (FNs) emitted from patient tissues during treatment. In this work we present the first experimental imaging of a neutron source using a prototype NOVO detector - an interwoven array of 14 organic scintillator bars. Measurements were conducted at the Physikalisch-Technische Bundesanstalt Braunschweig, where a point-like source of 14.8 MeV neutron was produced from accelerator-induced $3 \mathrm{H}(\mathrm{d}, \mathrm{n}) 4 \mathrm{He}$ reactions. Images of the source were produced via simple back-projection of double-scattered neutrons with the detector array position shifted via its mounting to a 2 -axis motor table. The extracted centroids of the images reveal that source shifts of 1 cm are reliably identified, while shifts on the order of millimeters should be identifiable with sufficient statistics and more sophisticated imaging algorithms.

  PublisherDOI

• A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery

  Nature · 2022 · 371 citations

  • Physics
  • Particle physics
  • Nuclear physics

  . Since then, more than 30 times as many Higgs bosons have been recorded by the ATLAS experiment, enabling much more precise measurements and new tests of the theory. Here, on the basis of this larger dataset, we combine an unprecedented number of production and decay processes of the Higgs boson to scrutinize its interactions with elementary particles. Interactions with gluons, photons, and W and Z bosons-the carriers of the strong, electromagnetic and weak forces-are studied in detail. Interactions with three third-generation matter particles (bottom (b) and top (t) quarks, and tau leptons (τ)) are well measured and indications of interactions with a second-generation particle (muons, μ) are emerging. These tests reveal that the Higgs boson discovered ten years ago is remarkably consistent with the predictions of the theory and provide stringent constraints on many models of new phenomena beyond the standard model.

  DOI

• Search for heavy Higgs bosons decaying into two tau leptons with the ATLAS detector using pp collisions at $\sqrt(s)$ = 13 TeV

  Proceedings of The European Physical Society Conference on High Energy Physics — PoS(EPS-HEP2021) · 2022 · 1 citations

  • Physics
  • Particle physics
  • Nuclear physics

  A search for heavy neutral Higgs bosons is performed using the LHC Run 2 data, corresponding to an integrated luminosity of 139 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV recorded by the ATLAS detector. The heavy resonance search is performed over the mass range 0.2-2.5~TeV for the $\tau^{+}\tau^{-}$ decay with at least one $\tau$-lepton decaying into handronic final states. The data is in good agreement with the standard model predictions. Results are interpreted in terms of several Minimum Supersymmetry Standard Model scenarios.

  DOI

• AtlFast3: The Next Generation of Fast Simulation in ATLAS

  Computing and Software for Big Science · 2022 · 106 citations

  • Computer Science
  • Computer Science
  • Computational science

  Abstract The ATLAS experiment at the Large Hadron Collider has a broad physics programme ranging from precision measurements to direct searches for new particles and new interactions, requiring ever larger and ever more accurate datasets of simulated Monte Carlo events. Detector simulation with Geant4 is accurate but requires significant CPU resources. Over the past decade, ATLAS has developed and utilized tools that replace the most CPU-intensive component of the simulation—the calorimeter shower simulation—with faster simulation methods. Here, AtlFast3, the next generation of high-accuracy fast simulation in ATLAS, is introduced. AtlFast3 combines parameterized approaches with machine-learning techniques and is deployed to meet current and future computing challenges, and simulation needs of the ATLAS experiment. With highly accurate performance and significantly improved modelling of substructure within jets, AtlFast3 can simulate large numbers of events for a wide range of physics processes.

  DOI

• Search for chargino–neutralino pair production in final states with three leptons and missing transverse momentum in $$\sqrt{s} = 13$$ TeV pp collisions with the ATLAS detector

  The European Physical Journal C · 2021 · 100 citations

  • Computer Science
  • Physics
  • Algorithm

  Abstract A search for chargino–neutralino pair production in three-lepton final states with missing transverse momentum is presented. The study is based on a dataset of $$\sqrt{s} = 13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:mrow> </mml:math> TeV pp collisions recorded with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mtext>fb</mml:mtext> <mml:mrow> <mml:mo>-</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> . No significant excess relative to the Standard Model predictions is found in data. The results are interpreted in simplified models of supersymmetry, and statistically combined with results from a previous ATLAS search for compressed spectra in two-lepton final states. Various scenarios for the production and decay of charginos ( $${\tilde{\chi }}^\pm _1$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>1</mml:mn> <mml:mo>±</mml:mo> </mml:msubsup> </mml:math> ) and neutralinos ( $${\tilde{\chi }}^0_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> ) are considered. For pure higgsino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>1</mml:mn> <mml:mo>±</mml:mo> </mml:msubsup> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mn>0</mml:mn> </mml:msubsup> </mml:mrow> </mml:math> pair-production scenarios, exclusion limits at 95% confidence level are set on $${\tilde{\chi }}^0_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> masses up to 210 GeV. Limits are also set for pure wino $${\tilde{\chi }}^\pm _1{\tilde{\chi }}^0_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>1</mml:mn> <mml:mo>±</mml:mo> </mml:msubsup> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mn>0</mml:mn> </mml:msubsup> </mml:mrow> </mml:math> pair production, on $${\tilde{\chi }}^0_2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msubsup> <mml:mrow> <mml:mover> <mml:mi>χ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:mrow> <mml:mn>2</mml:mn> <mml:mn>0</mml:mn> </mml:msubsup> </mml:math> masses up to 640 GeV for decays via on-shell W and Z bosons, up to 300 GeV for decays via off-shell W and Z bosons, and up to 190 GeV for decays via W and Standard Model Higgs bosons.

  DOI

• arXiv : Search for exotic decays of the Higgs boson into long-lived particles in $pp$ collisions at $\sqrt{s} = 13$ TeV using displaced vertices in the ATLAS inner detector

  2021 · 1 citations

  • Physics
  • Particle physics
  • Nuclear physics

  A novel search for exotic decays of the Higgs boson into pairs of long-lived neutral particles, each decaying into a bottom quark pair, is performed using 139 fb$^{-1}$ of $\sqrt{s} = 13$ TeV proton-proton collision data collected with the ATLAS detector at the LHC. Events consistent with the production of a Higgs boson in association with a leptonically decaying $Z$ boson are analysed. Long-lived particle (LLP) decays are reconstructed from inner-detector tracks as displaced vertices with high mass and track multiplicity relative to Standard Model processes. The analysis selection requires the presence of at least two displaced vertices, effectively suppressing Standard Model backgrounds. The residual background contribution is estimated using a data-driven technique. No excess over Standard Model predictions is observed, and upper limits are set on the branching ratio of the Higgs boson to LLPs. Branching ratios above 10% are excluded at 95% confidence level for LLP mean proper lifetimes $c\tau$ as small as 4 mm and as large as 100 mm. For LLP masses below 40 GeV, these results represent the most stringent constraint in this lifetime regime.

• Muon reconstruction and identification efficiency in ATLAS using the full Run 2 pp collision data set at $$\sqrt{s}=13$$ TeV

  The European Physical Journal C · 2021 · 262 citations

  • Computer Science
  • Physics
  • Particle physics

  Abstract This article documents the muon reconstruction and identification efficiency obtained by the ATLAS experiment for 139 $$\hbox {fb}^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mtext>fb</mml:mtext><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> of pp collision data at $$\sqrt{s}=13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn></mml:mrow></mml:math> TeV collected between 2015 and 2018 during Run 2 of the LHC. The increased instantaneous luminosity delivered by the LHC over this period required a reoptimisation of the criteria for the identification of prompt muons. Improved and newly developed algorithms were deployed to preserve high muon identification efficiency with a low misidentification rate and good momentum resolution. The availability of large samples of $$Z\rightarrow \mu \mu $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>Z</mml:mi><mml:mo>→</mml:mo><mml:mi>μ</mml:mi><mml:mi>μ</mml:mi></mml:mrow></mml:math> and $$J/\psi \rightarrow \mu \mu $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>J</mml:mi><mml:mo>/</mml:mo><mml:mi>ψ</mml:mi><mml:mo>→</mml:mo><mml:mi>μ</mml:mi><mml:mi>μ</mml:mi></mml:mrow></mml:math> decays, and the minimisation of systematic uncertainties, allows the efficiencies of criteria for muon identification, primary vertex association, and isolation to be measured with an accuracy at the per-mille level in the bulk of the phase space, and up to the percent level in complex kinematic configurations. Excellent performance is achieved over a range of transverse momenta from 3 GeV to several hundred GeV, and across the full muon detector acceptance of $$|\eta |&lt;2.7$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>|</mml:mo><mml:mi>η</mml:mi><mml:mo>|</mml:mo><mml:mo>&lt;</mml:mo><mml:mn>2.7</mml:mn></mml:mrow></mml:math> .

  DOI

• Jet energy scale and resolution measured in proton–proton collisions at $$\sqrt{s}=13$$ TeV with the ATLAS detector

  The European Physical Journal C · 2021 · 248 citations

  • Physics
  • Nuclear physics
  • Particle physics

  Abstract Jet energy scale and resolution measurements with their associated uncertainties are reported for jets using 36–81 fb $$^{-1}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msup><mml:mrow/><mml:mrow><mml:mo>-</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup></mml:math> of proton–proton collision data with a centre-of-mass energy of $$\sqrt{s}=13$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt><mml:mo>=</mml:mo><mml:mn>13</mml:mn></mml:mrow></mml:math> $${\text {Te}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mtext>TeV</mml:mtext></mml:math> collected by the ATLAS detector at the LHC. Jets are reconstructed using two different input types: topo-clusters formed from energy deposits in calorimeter cells, as well as an algorithmic combination of charged-particle tracks with those topo-clusters, referred to as the ATLAS particle-flow reconstruction method. The anti- $$k_t$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>k</mml:mi><mml:mi>t</mml:mi></mml:msub></mml:math> jet algorithm with radius parameter $$R=0.4$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>R</mml:mi><mml:mo>=</mml:mo><mml:mn>0.4</mml:mn></mml:mrow></mml:math> is the primary jet definition used for both jet types. This result presents new jet energy scale and resolution measurements in the high pile-up conditions of late LHC Run 2 as well as a full calibration of particle-flow jets in ATLAS. Jets are initially calibrated using a sequence of simulation-based corrections. Next, several in situ techniques are employed to correct for differences between data and simulation and to measure the resolution of jets. The systematic uncertainties in the jet energy scale for central jets ( $$|\eta |&lt;1.2$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>|</mml:mo><mml:mi>η</mml:mi><mml:mo>|</mml:mo><mml:mo>&lt;</mml:mo><mml:mn>1.2</mml:mn></mml:mrow></mml:math> ) vary from 1% for a wide range of high- $$p_{{\text {T}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>p</mml:mi><mml:mtext>T</mml:mtext></mml:msub></mml:math> jets ( $$250&lt;p_{{\text {T}}} &lt;2000~{\text {Ge}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>250</mml:mn><mml:mo>&lt;</mml:mo><mml:msub><mml:mi>p</mml:mi><mml:mtext>T</mml:mtext></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>2000</mml:mn><mml:mspace/><mml:mtext>GeV</mml:mtext></mml:mrow></mml:math> ), to 5% at very low $$p_{{\text {T}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>p</mml:mi><mml:mtext>T</mml:mtext></mml:msub></mml:math> ( $$20~{\text {Ge}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>20</mml:mn><mml:mspace/><mml:mtext>GeV</mml:mtext></mml:mrow></mml:math> ) and 3.5% at very high $$p_{{\text {T}}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>p</mml:mi><mml:mtext>T</mml:mtext></mml:msub></mml:math> ( $$&gt;2.5~{\text {Te}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mo>&gt;</mml:mo><mml:mn>2.5</mml:mn><mml:mspace/><mml:mtext>TeV</mml:mtext></mml:mrow></mml:math> ). The relative jet energy resolution is measured and ranges from ( $$24 \pm 1.5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>24</mml:mn><mml:mo>±</mml:mo><mml:mn>1.5</mml:mn></mml:mrow></mml:math> )% at 20 $${\text {Ge}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mtext>GeV</mml:mtext></mml:math> to ( $$6 \pm 0.5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mn>6</mml:mn><mml:mo>±</mml:mo><mml:mn>0.5</mml:mn></mml:mrow></mml:math> )% at 300 $${\text {Ge}}{\text {V}}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mtext>GeV</mml:mtext></mml:math> .

  DOI

Frequent coauthors

• R. Wang

  Johannes Gutenberg University Mainz

  2882 shared

• T. Beau

  Consejo Nacional de Investigaciones Científicas y Técnicas

  2352 shared

• L. Roos

  Laboratoire de Physique Nucléaire et de Hautes Énergies

  2151 shared

• S. Trincaz-Duvoid

  Laboratoire de Physique Nucléaire et de Hautes Énergies

  2151 shared

• J. Ocariz

  Université Paris Cité

  2151 shared

• M. Ridel

  Université Paris Cité

  2148 shared

• R. Camacho Toro

  Laboratoire de Physique Nucléaire et de Hautes Énergies

  1937 shared

• L. Schoeffel

  CEA Paris-Saclay

  1863 shared