New Perspectives is a conference for, and by, young researchers in the Fermilab community. It provides a forum for graduate students, postdocs, visiting researchers, and all other young persons that contribute to the scientific program at Fermilab to present their work to an audience of peers.
New Perspectives has a rich history of providing the Fermilab community with a venue for young researchers to present their work. Oftentimes, the content of these talks wouldn’t appear at typical HEP conferences, because of its work-in-progress status or because its part of work that will not be published. However, it is exactly this type of work, frequently performed by the youngest members of our community, that forms the backbone of the research program at Fermilab. The New Perspectives Organizing Committee is deeply committed to presenting to the community a program that accurately reflects the breadth and depth of research being done by young researchers at Fermilab.
New Perspectives is organized by the Fermilab Student and Postdoc Association and serves as a preamble to the Fermilab Users Annual Meeting.
The muon system of the CMS experiment mostly uses gas-based detectors. These detectors will suffer during the planned upgrade of the LHC also called HL-LHC. Therefore the upgrade of the detector system and trigger components are needed to tackle the enormously challenging conditions posed by the HL-LHC. New detectors will be added to improve the performance in the critical forward region 1.6 < eta < 2.4 which employs Gas Electron Multiplier (GEM) technology aiming at suppressing background triggers while maintaining high trigger efficiency. Further enhancements are foreseen with a second GEM station and with two stations of new generation RPCs, having low resistivity electrodes. These detectors will combine tracking and triggering capabilities and can stand particle rates up to a few kHz/cm^2. We summarise the project plans, current status, and its physics benefits.
Traditional searches for supersymmetry at LHC collider experiments have returned null results thus far. The expected, characteristic signature of high missing energy (MET) final states has not been observed. Motivated by this, our analysis searches for "stealthier" SUSY where high MET signatures would not manifest. Two models considered here are Stealth and R-parity violating SUSY and evidence for said models is searched for through top squark pair production at the CMS experiment. Here the top squark decay leaves a final state that contains two top quarks and many light-flavored jets with no additional missing energy. The analysis uses a neural network employing gradient reversal in order to help discriminate signal events from background. The full Run2 data set is utilized and results are interpreted in the context of the above models.
A search is performed for a light pseudoscalar Higgs boson (a) motivated by the theoretical framework of two Higgs doublet plus singlet models (2HDM+S). This search uses the Full Run 2 LHC data collected at 13 TeV by the CMS experiment and analyzes the decay channel H->a a->mu mu tau tau, with H being either the 125 GeV state or a more massive Higgs boson. Final state taus have a boosted and collimated topology due to the large mass difference between the H and a. A novel algorithm for special final states with hadronically decaying taus is designed to increase the identification efficiency. This analysis also includes machine learning techniques for the fully hadronically decaying tau channel.
Event generation for the LHC takes a large amount of resources to reach the desired number of events. Additionally, with the next generation of supercomputers focusing on increasing the number of GPUs per CPU, it is necessary to develop an efficient way of generating events on GPUs. To this end, I will introduce a novel implementation of the Brends-Giele algorithm on GPUs and demonstrate the improved performance compared to traditional CPUs.
Over the last ten years, the popularity of Machine Learning (ML) has grown exponentially in all scientific fields, included particle physics. The amount of data and its complexity has grown as well, and the computing power required to perform inference can nowadays hardly be managed by the existing technology. Central Processing Units (CPUs) are generally affordable and ready to use but their ability to run Artificial Intelligence (AI) is very limited. In recent years, Graphics Processing Units (GPUs) have started to be used with very good results but they expensive, require a lot of power, and they are difficult to program since they were not invented for this task. Recently, Google has produced a brand new Edge Tensor Processing Unit (TPU) made explicitly to perform inference. It is cheap, it consumes less power than a GPU, and it comes with the portable size of a USB-key. A generic Liquid Argon Time-Projection Chamber (LArTPC) has been simulated and images produced by fictitious neutrino interactions have been used to benchmark the Edge TPU. Several popular Deep Learning (DL) models have been trained with those images using TensorFlow software and the performance of the Edge TPU during inference has been tested and compared with CPUs and GPUs. This work is a cooperation between Fermilab and the University of Cambridge.
The Deep Underground Neutrino Experiment (DUNE) is an international project for neutrino physics and proton-decay searches. As a long baseline neutrino oscillation experiment, it will be exposed to a megawatt muon neutrino beam produced at Fermilab, with a near detector complex onsite and a far detector complex further down the beamline ($\sim$13000 km) at the Sanford Underground Research Facility (South Dakota). This will allow to answer the question about CP-violation in the neutrino sector as well as precision measurements of the neutrino mixing parameters.
Besides this, DUNE will use the near and far detectors to study a very vast science program. The four 17-kilotonne modules at 1.5 km underground conforming the far detector, based on liquid argon TPCs technology, aim to register a supernova burst signal and signatures of physics beyond the Standard Model, including baryon number non-conservation.
The advanced design of the three first modules of the far detector and its staged construction will allow DUNE to have a so called "module of opportunity" fourth detector for a plausible further extension of its capabilities.
In this talk, I will start with a description of the DUNE experiment. Then I will continue with a discussion about its physics program to end with a brief summary of the future possibilities for young researchers that it will open.
ProtoDUNE-SP is a Liquid Argon Time Projection Chamber(LArTPC) built at the CERN neutrino platform. It has two drift volumes with cathode plane at the center and an anode plane on either side of it. In ProtoDUNE-SP, space charge effect distorts the drift electric field and the drift velocity. Here we measure the drift velocity using tracks that cross both the anodes. Track start and end points are undistorted for such tracks. We further require the tracks to be confined to the central region of the TPC in order to minimize the spatial distortion in direction transverse to the drift direction. In addition, we remove any remaining transverse spatial distortion using a correction map we developed using anode-anode tracks. Drift distance for each point on the trajectory is determined using the wire numbers corresponding to the trajectory points. Drift velocity is then determined by taking the ratio of the change in drift distance to the change in drift time as a function of drift distance. Drift velocity variation of within 20% of the nominal value is observed using this method.
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a Gadolinium doped water Cherenkov detector located in the Booster Neutrino Beam at Fermilab with the primary goal of measuring the final state neutron multiplicity of neutrino-nucleus interactions. ANNIE will make use of pioneering photodetectors called Large Area Picosecond Photodetectors (LAPPDs) with less than 100 picosecond time resolution to enhance its reconstruction capabilities and demonstrate the feasibility of this technology as a new tool in high energy physics. After successfully taking commissioning beam and calibration data runs at the beginning of 2020, the future of ANNIE holds the exciting milestone of the first LAPPD deployment into the detector scheduled to happen this fall. Furthermore, additional future R&D efforts involving the use of the novel detection medium of water-based Liquid Scintillators will be highlighted in this talk.
ANNIE, the Accelerator Neutrino Neutron Interaction Experiment, is a 26-ton Gd-loaded water Cherenkov detector that aims to measure the momentum-transfer dependent final-state neutron multiplicity in neutrino-nucleus interactions. The improved understanding and modelling of these complex, many-bodied, interactions will reduce many of the more dominant systematics of current and next-generation long-baseline neutrino experiments. For ANNIE to achieve this goal, it is imperative to fully understand the detector’s neutron capture and detection capabilities. This talk will discuss the development, production and deployment of the AmBe neutron source and present the first neutron capture results in ANNIE.
The Short-Baseline Near Detector (SBND) will be a 112 ton liquid argon time projection chamber situated 110 m downstream of the Fermilab Booster Neutrino Beam target. SBND is the near detector of the Short-Baseline Neutrino programme which has been designed to test the eV-scale sterile neutrino hypothesis to high precision. Due to proximity of the detector to the beam target, SBND will observe millions of neutrino interactions and therefore be able to produce a range of high statistic inclusive and exclusive neutrino-argon cross section measurements. Alongside this, SBND will be capable of performing multiple searches for beyond the standard model physics such as searches for light Dark Matter. This talk will summarise the current status of SBND and the physics capabilities of the programme.
The ICARUS T600 LAr-TPC detector successfully ran for three years at the underground LNGS laboratories, performing a first sensitive search for LSND-like anomalous electron neutrino appearance in the CNGS beam. After a significant overhauling at CERN, the T600 detector has been placed in its experimental hall at Fermilab, where the cryogenic plant commissioning has been completed in April 2020 with the detector liquid argon filling. ICARUS is being put into operation to collect the first neutrino events from the Booster Neutrino Beam and NuMI off-axis beam. Searches for sterile neutrinos will then start in the framework of the SBN program, devoted to clarifying the open questions of the presently observed LSND-like neutrino anomalies.
Devices with low energy thresholds are one of the main pillars for the direct detection of dark matter, and tremendous progress has been made in the past few years in probing dark matter with sub-GeV masses. The SENSEI (Sub-Electron Noise Skipper Experimental Instrument) Collaboration has pioneered the silicon-based Skipper-Charge Coupled Device (CCD) technology capable of detecting electron recoils from dark matter interactions with sub-electron-noise precision and has already achieved world-leading sub-GeV dark matter results. Over the past year, SENSEI has been testing, characterizing, and taking science data with new Skipper-CCDs, which demonstrate the excellent performance and promise of this technology for sub-GeV dark matter searches. This talk will describe these developments and recent dark matter search results. The current status and future plans of SENSEI will also be discussed, including the status of installing at SNOLAB a detector consisting of about 100-grams of Skipper-CCDs.
The Northwestern EXperimental Underground Site at Fermilab (NEXUS@FNAL) is an underground cryogenic detector testing facility located in a clean room near the NOVA near detector. It currently features a vibration-isolated dry dilution refrigerator which operates down to 10 mK. The 300 meter water equivalent depth, combined with lead shielding around the refrigerator, is expected to lead to a background rate of <100 events/keV/kg/day. We present the current status of the NEXUS facility and overview of recent runs operating SuperCDMS R&D detectors. We also describe near and far term plans which include dark matter searches, qubit studies, neutrino detector development, and deployment of a neutron generator and backing array for neutron scattering experiments.
An overview of the most sensitive experiment to probe the QCD axion to date. In particular, it will focus on ADMX's recent success in reaching the so-called DFSZ sensitivity—a decade long goal sought by axion experimenters -- and its newest limits covering axion mass ranges of 2.66 to 3.31 μeV. Last but not least, a brief discussion of its recent technological advancements will follow.
DarkSide-20k is a next-generation dark matter detector at the Laboratori Nazionali del Gran Sasso in Italy. With a projected sensitivity of $7.4 \times 10^{−48}$ cm$^2$ for 1 TeV/$c^2$ WIMPs for a 10 year run, DarkSide-20k will be the most sensitive dark matter experiment ever built. I will highlight the innovative design features of the DarkSide-20k experiment, including custom cryogenic silicon photomultipliers and a novel sealed acrylic TPC. I will also discuss strategies for mitigating several important sources of intrinsic background.
As luminous tracers of the smallest halos, dwarf galaxies offer a unique window into the physics of dark matter (DM). The (lack of) a cutoff in the abundance of low-mass halos informs a variety of DM properties, which is crucial given the breadth of theoretical models that have gained popularity following the search for canonical WIMPs. In this talk, we describe recent advances in measuring and modeling small-scale structure tracers, focusing on the population of Milky Way (MW) satellite galaxies. In particular, we combine a state-of-the-art census of the MW satellite population with a rigorous model of the galaxy--halo connection in order to place the strongest astrophysical constraints to date on warm, interacting, and fuzzy DM. We discuss the implications of these constraints for specific DM candidates, including sterile neutrinos and ultra-light axions.
High Energy Physics is entering an exciting period with new insights into many of the fundamental mysteries of the universe, especially with developments in "big data" analyses. Continuous exploration of new, cutting-edge technologies and techniques is required to unravel these mysteries for scientific discovery. One of these mysteries lies also in neutrino physics and known as the short-baseline anomalies. The Short Baseline Neutrino (SBN) program aims to elucidate the nature of this anomaly with three detectors, SBND, MicroBooNE, and ICARUS. Analysis of neutrino data collected from these detectors involves a combination of complex fitting procedures and statistical correction techniques used to produce the sensitivity contours in a multi-dimensional parameter space. This prescription is known as the Feldman-Cousins unified approach which is very computationally expensive. This talk will focus on the development and deployment of new tools and algorithms that melds high-performance computing (HPC) and techniques for big data analysis to enable this computationally expensive physics studies to be completed on time scales that are not currently feasible.
We provide a technique called OASIS to reduce the number of simulated events required in a collider analysis to reach a target sensitivity. We achieve this by preferentially focusing the event generation in different regions of phase-space based on their utility to the analysis at hand (and appropriately weighting the events).
OASIS leads to a conservation of resources at all stages of the MC pipeline (including detector simulation) and opens a new avenue for resource-conservation that is complementary to approaches that seek to speed-up the simulation pipeline.
Quantum field theory (QFT) provides a framework to study phenomena in high-energy physics. However, its simulation in the strong interaction regime remains computationally challenging. Quantum computing could serve as an efficient tool to simulate QFT models in the future. In this talk, I will discuss a quantum algorithm to simulate the phi4 scalar model.
Tricritical Ising model (TIM) is a simple quantum spin chain model with a tricritical point separating a Ising phase transition line from a first-order transition line. We perform quantum simulation of the dynamical phase transition in TIM with Friedmann-Robertson-Walker metric. The results in principle could help us to understand the non-equilibrium dynamics in the early universe.
Liquid Argon Time Projection Chambers (LArTPCs) are the neutrino detectors of choice for novel oscillation experiments such as SBND, MicroBooNE, ICARUS, and DUNE because of their tracking, calorimetry, and particle identification capabilities. The Liquid Argon in a Testbeam (LArIAT) experiment was designed to measure new physical quantities as well as calibrate LArTPCs to the different particle species and interaction processes present in a neutrino experiment. LArIAT ran in a beam of charged particles (electrons, muons, pions, kaons, and protons) from 2015 to 2017 in Fermilab’s Test Beam Facility. Studies in LArIAT will produce novel physics results, including the first total hadronic cross section of kaons and pions in liquid argon and the behavior of antiprotons in argon, as well as new methods, such as using charge and light for the calorimetry of low-energy electrons. LArIAT continues to provide a deeper understanding of LArTPC technology and thus prepares us for the new horizons of DUNE.
Precise understanding of neutrino-nucleus interactions are required by the next generation of long baseline neutrino oscillation experiments to answer outstanding questions in neutrino physics. MINERvA is a neutrino scattering experiment at Fermilab that measures cross sections in various nuclear targets using a segmented scintillator based tracking detector and two types of calorimeters. MINERvA has published results using low energy data and medium energy data, for both neutrino and anti-neutrino muon NuMI beam modes. A brief description of the MINERvA experiment and highlights of recent results will be presented.
Planning for future long baseline neutrino oscillation experiments has revealed that neutrons produced by neutrino interactions could contribute significantly to the total uncertainty budget for DUNE with present models. Neutrino-produced neutrons that go undetected can skew energy reconstruction and cause events to be misclassified. The MINERvA experiment at Fermilab has demonstrated that plastic scintillator detectors can reconstruct an important fraction of the O(100 MeV) neutrons typical of the neutrino interactions expected at DUNE. This talk previews work to expand MINERvA's neutron reconstruction to neutrino interactions in iron and lead targets.
The sensitivity of future neutrino experiments to oscillation parameters and BSM physics is highly dependent on the reduction of theoretical nuclear modeling systematics within the quasielastic regime. The usage of highly phenomenological or even classical nuclear models of Fermi motion, as well as nontrivial and inconsistent reweighting schemes, only adds to these woes. Also, many neutrino generators lack robust validation schemes on widely available electron scattering data to (partially) confirm their models of neutrino-nucleus interactions. Using GENIE, we have begun the interpolation and implementation of a new quantum-mechanically derived, inherently two-body, total inclusive quasielastic lepton scattering cross section. This model makes available much of the two-body semifinal state kinematics information at the scattering vertex via nuclear responses and two-body response densities. Currently, the electron---He-4 cross section has been validated across the available world quasielastic data and shows excellent agreement. Work is continuing on a GENIE generator module for this cross section and will soon output full final state topologies for study within detector geometries. The nature of this generator will make comparative study of two-body final states in past and current lepton scattering experiments fully realizable. The framework created for this generator can be utilized by similar future cross section calculations for larger nuclei such as C-12 and Ar-40.
The main goal of the NOvA experiment is to study the neutrino oscillations phenomenon in the muon (anti)neutrino beam. For this purpose NOvA uses large segmented liquid scintillator detectors with similar structure.
Along with the main oscillation analyses, NOvA detectors allow perform additional physics studies, using the dedicated data-driven trigger system, capable of performing a low-latency preselection of the data with various signatures.
An overview of the NOvA experiment is presented, including the description of the oscillation analyses, data-driven triggering system for additional physics goals and supernova detection system.
In a neutrino interaction, hadrons are produced and traverse the nuclear medium before they are observed. However, while traversing the nucleus, hadrons can re-interact with nucleons resulting in final state interactions (FSI). In historical versions of the neutrino generator GENIE, FSI is modeled using an "effective" cascade model, hA, where possible final-state hadrons are fixed directly from hadron scattering data. However, for NOvA's 2020 analysis, we employ GENIE's semi-classical hN FSI model. In hN, hadrons steps through the nucleus via a nuclear density profile calculating step-by-step probabilities using a theory-based cross section model relating external pion scattering data to scattering amplitudes inside the nucleus. However, agreement to external pion scattering data is poor, motivating a tuning procedure of the relative pion probabilities in hN based on extant pion scattering data to produce NOvA's hN Central Value tune. The nominal hN model also does not have any reweightable uncertainties, so we create them utilizing similar work done by T2K to obtain uncorrelated uncertainties on our tuned Central Value. Finally, we train a Boosted Decision Tree to construct a reweighting scheme from the nominal value to our tuned Central Value, so as to avoid reproducing NOvA's full production with our Central Value tune. The result, from our uncorrelated uncertainties on the Central Value, is a 5-10% variation for true pion observables in a generated neutrino sample.
The DAMIC-M (Dark Matter in CCDs at Modane) is a near-future experiment that will succeed the DAMIC@SNOLAB experiment, in the search of low mass dark matter particles (<10 GeV) using scientific Charge-Coupled Devices (CCDs). It will consist of a tower of 50 of the most massive and radiopure CCDs with a total target mass of ~1 kg. By implementing the Skipper readout technique, which will allow for multiple non-destructive pixel charge measurements, it will achieve a single-electron energy resolution. To support this resolution, new fast and sensitive electronics are under development within the collaboration, advancing the efficiency and quality of the former acquisition system technology. Moreover, great effort is being made in material selection, detector shielding, and the mitigation of cosmogenic activation before the final installation in the low-background environment. Working on an experiment like this, going deep and trying to perfect every little detail offers a unique and amazing experience. I will present an overview of the progress toward the DAMIC-M experiment.
Many astrophysical observations point to the abundant existence of dark matter in the Universe. However, despite numerous experiments using different techniques, dark matter particles have yet to be directly observed. The Super Cryogenic Dark Matter Search experiment (SuperCDMS) uses silicon and germanium detectors operated at temperatures as low as 15 mK in the low-background environment at the SNOLAB underground laboratory (Sudbury, Canada) to probe dark matter interactions using phonon and ionization signals. The primary dark matter candidate for the SuperCDMS experiment are weakly interacting massive particles (WIMPs) with masses masses ≲ 10 GeV$/c^{2}$ which recoil from crystal nuclei. Single electron-hole pair resolution has been recently achieved using gram-sized R&D detectors operated at high voltage. By searching for dark matter-electron interactions, they have been used for searches of low-mass dark matter candidates such as dark photons and Light Dark Matter. Highlights of these results using extremely low thresholds and an overview of the SuperCDMS experiment will be presented.
The Scintillating Bubble Chamber (SBC) collaboration is in the process of building the first of a set of bubble chambers with 10 kg superheated liquid argon target masses. Superheated dark matter detectors containing freons such as C$_3$F$_8$ are well-studied and can be operated in thermodynamic states which make the detector intrinsically insensitive to electron recoils (ERs), but provide no event-by-event energy information for nuclear recoils (NRs) above the bubble nucleation-energy threshold. Noble liquids, especially argon and xenon, are well-studied scintillators, but are subject to ER backgrounds at low thresholds when searching for WIMPs or neutrinos. A prototype xenon-filled bubble chamber containing a 30 gram target mass has demonstrated that these two technologies can be combined, resulting in a bubble chamber with simultaneous scintillation (calorimetry) and bubble nucleation from neutron-induced NRs, while maintaining intrinsic insensitivity to ER bubble nucleation. We are now constructing our argon-filled R&D detector at Fermilab, where we will take calibration data with spontaneous fission and photoneutron sources, as well as gamma sources, to constrain the sensitivity of such a detector to NR and ER events at energy thresholds of O(100) eV, where the detector is projected to be sensitive to O(1-10) GeV/$c^2$ dark matter and reactor neutrino CE$\nu$NS. The detector can then be moved to a deep-underground site or nuclear reactor to take dark matter or neutrino data, respectively.
Recent measurement of coherent elastic neutrino-nucleus scattering (CEvNS) process by COHERENT collaboration has opened a new portal of exploring beyond the standard model physics. The primary uncertainty in CEvNS stems from underlying nuclear structure physics embedded in weak nuclear form factor. An accurate estimation of form factors is vital to the CEvNS program, since any experimentally measured deviation from the expected CEvNS event rate can either be attributed to new physics or to unconstrained nuclear physics. We present charge and weak nuclear form-factors and CEvNS cross section calculations on various nuclei using a microscopic many-body nuclear theory model based on Hartree-Fock approach with a Skyrme nuclear potential. We validate our charge form factor predictions against the elastic electron scattering data, and make predictions of weak form factors and CEvNS cross sections. Furthermore, we pay special attention to $^{40}$Ar nucleus and attempt to gauge the level of theoretical uncertainty pertaining the description of $^{40}$Ar form factor and its CEvNS cross section by comparing relative differences between different theoretical predictions.
I discuss quantum decoherence effects in neutrino oscillations. After a brief introduction to neutrino quantum decoherence, we turn our attention to reactor experiments and discuss how well these experiments could measure decoherence effects. In particular, I discuss results from the analysis of data from the current experiments RENO and Daya Bay, and discuss how well JUNO can improve these results.
The Fermilab Accelerator Division has a solid milestone for the next generation HEP facility. The proton accelerator and the NuMI target system are ready to operate 1-MW beam power to reveal neutrino properties. The Mu2e beam line has begun to be constructed which has a unique beam transport to discover the charged-lepton flavor violation (CLFV). Recently, IOTA demonstrated the concept of integrable optics which suppresses the space charge effect. The Fermilab has the advanced SRF technology which is used for PIP-II. Implementations of AI and robotics are ongoing projects. This talk will summarize those projects.
Electron Cooling is a process in which a heavier proton or ion beam is transversely and longitudinally cooled by a co-propagating electron beam. The cooling rate for this method of beam cooling is proportional to the transverse emittance of the cooling electron beam. Using magnetized electron beams to partition the Eigen emittances we can achieve much smaller emittances for higher efficiency cooling rates. Simulations and experiments are presented for partitioning high charge magnetized beams using the Fermilab Accelerator Science and Technology (FAST) facility.
In superconducting magnets, the irreversible transition of a portion of the coils to the resistive state is called “quench.” Having large stored energy, quenches can lead to damage of magnet components due to localized heating, high voltage, or large mechanical forces. Unfortunately, current quench protection systems can only detect the quench after it happens, giving magnet operators very short response time (a few ms). In this study, we propose a quench prediction system using an auto-encoder fully-connected deep neural network. When incrementally trained with expert features extracted from acoustic data in sensors around the magnet, the system can potentially forecast the quench seconds before it happens. This leads to better diagnostics and detection of magnet quenches, which eventually speed up magnet testing processes and prevent expensive parts from being damaged.
The determination of the neutrino flux from accelerator neutrino beams exhibits a challenge for the current and future short- and long-baseline neutrino experiments. These experiments provide the measurements of the neutrino oscillation parameters, the mass hierarchy, and the CP phase with high sensitivity. The current flux predictions for the on-axis and off-axis NuMI (Neutrinos at the Main Injector) neutrino detector locations depend on GEANT4 based beam simulation code called G4NuMI. The current simulation uses the new NuMI target, which has 1.5 mm spot size and it is expected to get 900-kW and even more in the upcoming years. In this work, for this new target system, we study the neutrino flux corresponding to the muon energy thresholds seen by the Muon Monitors for FTFP_BERT hadronic model and investigate the neutrino flux predictions at the on-axis and off-axis NuMI neutrino detector locations for FTFP_BERT and QGSP_BERT hadronic models by using G4NuMI beam simulation. We also present the application of the PPFX (Package to Predict the Flux) to the neutrino flux at the on-axis and off-axis NuMI detector locations for FTFP_BERT hadronic model. Finally, we investigate the neutrino spectrum at the NuMI neutrino detector locations that come from $\pi^{+}$ through the focusing components. All plots are based on G4NuMI with 50M protons on target (POT).
The Mu2e experiment at Fermilab will search for the charged-lepton flavor violating neutrino-less conversion of a negative muon into an electron in the field of an aluminum nucleus. The Mu2e detector is composed of a tracker, an electromagnetic calorimeter and an external active veto for cosmic rays. The calorimeter plays an important role in providing excellent particle identification capabilities, a fast online trigger filter while aiding the track reconstruction capabilities. The calorimeter requirements are to provide a large acceptance for 100 MeV electrons and reach: i) a time resolution better than 0.5 ns; ii) an energy resolution better than 10%; iii) a position resolution of 1 cm. The calorimeter consists of two disks, each one made of 674 pure CsI crystals readout by two large area 2 × 3 array of UV-extended SiPMs of 6 × 6 mm2 dimensions. We report here the tests done to finalize the calorimeter design and the status of production and construction. At the moment of writing, 85% of the crystals and all the SiPMs have been produced and characterized. The calorimeter engineering drawings have been completed and the large mechanical components are under fabrication. Analog and digital electronics have been prototyped and tested with irradiation dose so that the serial production is being organized. The calorimeter assembly phase is planned for end-2020.
Radiatiave muon capture (RMC) is a key background in searches for charge-changing lepton number violation at Mu2e ($\mu^-\rightarrow e^+$). In particular there are concerns that high energy positrons, whose progenitor is either a real- or virtual-photon, can bleed into the signal region for the charge-changing search.
In this work I show positrons produced from off-shell photons can be related to the on-shell photon rate via a universal probability. This universal result is independent of the details of the virtual-photon amplitude and emerges as one approaches the end-point of the positron spectrum.
I will briefly comment on a possible asymmetry between electrons and positrons from internal conversion due to the Coulomb field of the target nucleus.
There is a long history of experiments measuring the anomalous magnetic moment of the muon, going back to the first tests of QED in the 1950's and 60's. The experimental method employed by the Fermilab Muon g-2 Experiment (E989) --- measuring the decay products from muons trapped in the uniform field of a storage ring --- is a direct descendent of the CERN-III measurement conducted in the 1970's. Here we briefly step through advancements in the theoretical and experimental precision of a_μ ≡ (g−2)/2 throughout the years to the present day. We then describe the most recent theoretical results and (updates to) experimental methods before looking to the future of the experiment.
The SpinQuest (Fermilab E1039) experiment will measure an azimuthal asymmetry in the Drell-Yan production of $\mu+$ $\mu-$ pairs from 120 GeV/c proton interactions with polarized nucleons to extract the Sivers function for $\bar{u}$ and $\bar{d}$. A nonzero asymmetry would be “smoking gun” evidence for orbital angular momentum of the light sea-quarks: predicted to be a major contributor to the proton’s spin. In our 10 minutes together, I will give an overview and share plans for the near future of this exciting experiment from the perspective of a young researcher.
The SpinQuest (Fermilab-E1039) experiment is designed to identify Drell-Yan production of μ+μ− pairs from 120 GeV/c proton interactions. In the next 10 minutes, I will present the exciting ideas for reusing and repurposing the E1039 spectrometer to detect sub-GeV dark-sector particles: a collection of particles that are not charged under the Standard Model forces, and only couple feebly to the SM. These particles can be produced in the high-intensity proton environment and, due to their long lifetime, their decay into muons may result in a meter-scale lab-frame displacement. I will discuss the status of the displaced-vertex trigger needed to identify the signal and the predicted physics reach of the upcoming dimuon run. I will also give a glimpse of future prospects for extending the reach to lower particle masses by also identifying dielectron decays.
The Rubin's Observatory Legacy Survey of Space and Time (LSST) is expected to observe the night sky during 10 years and retrieve information from 37 billion stars and galaxies, and up to 10 million of transient alerts producing over 20 TB of data a night. With this unprecedented level of statistics, LSST will face some analysis challenges. We will give an overview of the experiment, science goals, and challenges of LSST with emphasis on the study of dark energy.
Galaxy mergers can be used to probe galaxy evolution and to test cosmological models. Traditional high-redshift merger detection techniques, however, are resource-intensive. For instance, manual detection is both time-consuming and susceptible to human bias, while automated approaches require high-quality, space-based observations to obtain parameters such as the Sérsic index, Gini coefficient and visual separation between galaxies. Machine learning provides an alternative classification technique. Recent work used a convolutional neural network (CNN), a type of deep learning commonly applied to visual data, to identify high-redshift galaxy mergers in simulated images. The images include both “pristine” data (no added noise) and more realistic “noisy” data (added noise). We explore how these preliminary results can be improved using more complex network architectures such as ResNet and Inception. We also implement a domain-adversarial neural network (DANN) that can learn features from one domain (pristine images) that are relevant to another domain (noisy images). CNNs struggle with these multi-domain tasks; a conventional CNN trained on pristine images, for example, achieves an accuracy of only 53% on noisy data. In contrast, our DANN achieves an accuracy of 70% on noisy data. This suggests that domain adaptation algorithms may be a powerful tool for applying knowledge learned from large-scale simulations to real observations from astronomical surveys.
The cosmological standard model predicts that galaxies exist within a hierarchical paradigm, with large, luminous galaxies inhabiting massive dark matter halos and fainter dwarf galaxies inhabiting substructure in these halos. Long-term sky surveys including the Sloan Digital Sky Survey (SDSS) and Dark Energy Survey (DES) have resulted in the detection of many ultra-faint dwarf galaxies, offering important yet incomplete insight into the evolutionary history and structure of our own Milky Way galaxy. Here, I will introduce the DECam Local Volume Exploration (DELVE) Sky Survey, a 126-night multi-component survey on the 4-meter Blanco Telescope/ Dark Energy Camera at Cerro Tololo Inter-American Observatory (CTIO) in Chile. DELVE is intended to extend the region initially observed by DES in order to complete near-uniform observational coverage of the entire southern sky, allowing for analysis of the formation, distribution, and evolution of the Milky Way satellite population. The DELVE survey’s deep, widefield observing strategy is uniquely suited to probing galactic dark matter by detecting overdensities of old, metal-poor stars in the Local Volume’s stellar structure, which indicate the presence of a potential dwarf galaxy and thus dark matter substructure. I will highlight the recent discovery of the Centaurus I ultra-faint dwarf galaxy and the DELVE I halo star cluster, and describe ongoing efforts to search for new ultra-faint satellites of both the Milky Way and the Magellanic Clouds.
Relic radiation left over from the explosive beginning of the Universe provides a wealth of information about how our Universe began and evolved over billions of years. One of the most remote observatories on Earth, located at the South Pole, is designed to study this radiation, known as the cosmic microwave background (CMB). In this talk, I will discuss the science of the CMB and how we build and deploy powerful microwave sensitive telescopes to study it.
MicroBooNE is a neutrino experiment based at Fermilab that utilizes a liquid argon time projection chamber (LArTPC) located on-axis in the Booster Neutrino Beam (BNB). It has been collecting data since October 2015 and is now the longest-running LArTPC detector to date with more than half a million neutrino interactions recorded. One of the experiment’s main goals is a search for the excess of electron-neutrino-like events seen by the MiniBooNE experiment, located near MicroBooNE in the BNB. I will describe the status of our searches for electron-like and photon-like signals within the MicroBooNE detector that could explain the MiniBooNE anomaly. In addition, MicroBooNE is pursing a broad and rich research program including detector physics, neutrino-argon interaction cross sections, and technical development efforts. This work will provide an important foundation for future LArTPC experiments such as DUNE. I will highlight exciting recent results and provide an outlook on future efforts.
MicroBooNE is a Liquid Argon Time Projection Chamber which has been taking neutrino data at Fermilab's Booster Neutrino Beamline since October 2015. One of its primary goals is to investigate the “Low Energy Excess” of neutrino events observed by the MiniBooNE experiment, for which candidate interpretations include an underestimation of neutrino neutral current (NC) resonant $\Delta$ production with subsequent radiative decay or another anomalous source of single photon production in neutrino interactions. NC $\Delta$ radiative decay could be a sizable contribution to the “Low Energy Excess”. This talk will present the status of the analysis developed to search for NC $\Delta$ radiative events in MicroBooNE, consisting of a boosted decision tree based event selection with a NC neutral pion background constraint.
MicroBooNE, the longest running liquid argon time projection chamber (LArTPC), is the first of several detectors in Fermilab’s leading-edge LArTPC program working toward stringent measurements of neutrino oscillation parameters. At energy scales relevant to accelerator-based experiments, charged current (CC) interactions producing an electron and at least one proton (1eNp) in the final state are a dominant contribution to $\nu_{e}$ event rates. To date, no experimental verification of the CC1eNp cross section on argon currently exists, though such a measurement is crucial for next-generation LArTPCs to reach discovery precision in the $\nu_{e}$ appearance channel. While MicroBooNE’s primary physics analyses utilize the on-axis Booster Neutrino Beam, a significant neutrino flux is also received from a higher energy, off-axis beam called NuMI. The greater $\nu_{e}$ to $\nu_{\mu}$ ratio of the NuMI beam provides a unique opportunity for MicroBooNE to perform world-leading measurements of $\nu_{e}$ cross sections. This work presents a selection of NuMI events as progress toward the first differential measurement of CC1eNp interactions in argon, demonstrating our ability to successfully measure & reconstruct electron neutrinos in MicroBooNE.
Current and future generation neutrino oscillation experiments aim towards a high-precision measurement of the oscillation parameters and that requires an unprecedented
understanding of neutrino-nucleus scattering. Charged-current quasi-elastic (CCQE) scattering
is the process in which the neutrino produces a charged lepton and removes
a single intact nucleon from the nucleus without producing any additional particles.
For existing and forthcoming accelerator--based neutrino experiments, CCQE interactions are either the dominant process or part of the signal.
MicroBooNE is the first liquid argon time projection chamber (LArTPC) commissioned as part of the Short Baseline Neutrino (SBN)
program at Fermilab and its excellent particle reconstruction capabilities allow the detection of neutrino interactions using exclusive final states,
which will play a crucial role in the success of future kiloton LArTPC detectors such as DUNE.
This talk will present the first measurement on argon of exclusive $\nu_{\mu}$ CCQE--like flux integrated
total and differential cros sections using single proton knock--out interactions recorded by the MicroBooNE LArTPC detector with 4$\pi$ acceptance and a 300 MeV/c proton threshold.