Session A03: Particle Physics

MicroBooNE: Status & Prospects

MicroBooNE is a 170 ton Liquid Argon Time Projection Chamber (LArTPC) experiment that is currently taking data with the Booster Neutrino Beam at Fermilab. The two main physics goals of MicroBooNE are addressing the low-energy electromagnetic anomaly observed by the MiniBooNE experiment and measuring low-energy (~1 GeV) neutrino-argon cross-sections. MicroBooNE is also leading the way for an extensive Short-Baseline Neutrino (SBN) physics program at Fermilab to definitively address the sterile neutrino question where there are existing hints. This talk will describe the status of the MicroBooNE experiment and highlight some recent results along with future prospects.   

A Low Energy Track Reconstruction Algorithm to be Applied to the MiniBooNE Low Energy Excess Search in MicroBooNE

The MicroBooNE experiment is an 85 ton Liquid Argon Time Projection Chamber (LArTPC) located on the Booster Neutrino Beam at Fermi National Accelerator Laboratory.  A primary goal of the experiment is to investigate the low energy excess of electron neutrino like events observed by the MiniBooNE experiment.  I will present a brief overview of MicroBooNE and its searches for the low energy excess.  I will focus on the track reconstruction algorithm, to which I contributed by calibrating the response to protons and minimum ionizing particles.    

Studies of Photon Probability Distributions in the Belle II Particle Identification System

The Belle II experiment studies collisions of subatomic particles to better understand laws of nature. Interactions are observed by multiple detectors, and particle identification is provided by the imaging Time-of-Propagation detector, comprised of 16 modules with two 1.25m long quartz radiator bars. Charged particles passing through quartz with a relativistic velocity greater than light in that medium emit Cherenkov photons at angles characteristic for their mass. These photons can be internally reflected in the quartz before being detected by a series of multi-channel plate photomultiplier tubes. The charged particle can be identified by its photons. We compute the probability distribution functions of photons detected by channels and simulate each photon with GEANT4. We compare the probability distribution functions and GEANT4 simulations at select locations within the bar to determine any regions with systematic discrepancies. It was found that entry points closest to the readout plane yielded greater disagreement between probability distribution functions and simulations.   

A Search for the Neutrinoless Conversion of Negative Muons into Positrons with the Mu2e Experiment

The primary physics goal of the Mu2e Experiment is to search for Charged Lepton Flavor Violation (CLFV) in the process of a coherent neutrinoless  $\mu^{-} N \rightarrow e^{-} N$  transition.   This process is allowed under the Standard Model albeit at unobservable rates.   Another interesting process that  Mu2e  will search for is the neutrinoless conversion of stopped negative muons into positrons.  This process violates both lepton flavor and lepton number.   Observation of either process would be an unambiguous indication of New Physics.  In addition, the observation of  $\mu^{-} N \rightarrow e^{+} N’$ would be proof that  neutrinos are Majorana particles. We discuss the status and prospects of this search.   

Searches For Higgs-like Charged Bosons at Colliders

The ratio of branching fractions R(D*) = BR(B to D* tau nu)/BR(B to D* lepton nu)
and R(D) = BR(B to D tau nu)/BR(B to D lepton nu) are measured using a data sample
of 426/fb electron-positron collisions with the BABAR detector at SLAC's PEP-II collider. 
The combined ratios of R(D*) and R(D) exceed the Standard Model prediction at a level of
3.4 sigma. Combining with other measurements from Belle, LHCb, and predicted Belle II
the disagreement with the Standard Model prediction will be presented. 

Search for Rare Higgs Decays

Rare decays of the Higgs boson to mesons are a promising laboratory to study couplings to lighter quarks and physics beyond the standard model. A search for decays of the Higgs and the Z boson to pairs of J/ψ and Y resonances with subsequent decays of the mesons into muon pairs is performed with the Compact Muon Solenoid detector at the Large Hadron Collider (LHC). A data sample of proton-proton collisions collected in 2017 at a center-of-mass energy of 13 TeV is used. I will present results of this search and implications for future searches of beyond standard model signatures at high luminosity.