Session X17: Particle Physics

$\nu_{e}$ Charged-Current Inclusive Cross Section Measurement and The Status of Flux Constraints Using $\nu-e$ Elastic Scattering in the NOvA Near Detector

The NOvA experiment is a long-baseline neutrino oscillation experiment designed to measure (a) the appearance of electron neutrino and antineutrino, and (b) the disappearance of muon neutrino and antineutrino. It consists of two segmented, liquid-scintillator detectors positioned 14 mrad off-axis from the Fermilab NuMI beam. In addition to the neutrino oscillation measurements, the NOvA Near Detector, located at Fermilab, provides an excellent opportunity for the measurement of neutrino interactions. In this talk, I present a measurement of the $\nu_{e}$ charged-current inclusive cross section between 1-3 GeV, and the status of flux constraints using $\nu-e$ elastic scattering.   

Measurment of the Charged Current Inclusive Anti-Neutrino to Neutrino Cross Section Ratio Using the $\pi^0$ Detector at T2K

Recent anti-neutrino data taken by the T2K experiment is used to measure the ratio of the cross sections for charged current interactions of muon type neutrinos relative to anti-neutrinos, $\frac{\sigma ( \overline{\nu}_\mu+nucleons \rightarrow \mu^+ + X)}{\sigma ( \nu_\mu+nucleons \rightarrow \mu^- + X )}$. Theoretical estimates for charged current quasi-elastic neutrino-quark scattering predict this ratio should be approximately $\frac{1}{3}$. This measurement used the $\pi^0$ detector (P$\emptyset$D) and a time projection chamber (TPC1) directly downstream at the off axis near detector (ND280) complex of the T2K experiment. Neutrino interactions occurring in the P$\emptyset$D with an exiting muon whose momentum is measured by TPC1 were selected. Preliminary results and studies of the event selection and relevant systematic uncertainties are presented.   

High-Energy Neutron Spectra and Flux Measurements Below Ground

High-energy neutrons are a ubiquitous and often poorly measured background. Below ground, these neutrons could potentially interfere with antineutrino based reactor monitoring experiments as well as other rare-event neutral particle detectors. We have designed and constructed a transportable fast neutron detection system for measuring neutron energy spectra and flux ranging from tens to hundreds of MeV. The spectrometer uses a multiplicity technique in order to have a higher effective area than traditional transportable high-energy neutron spectrometers. Transportability ensures a common detector-related systematic bias for future measurements. The spectrometer is composed of two Gd containing plastic scintillator detectors arranged around a lead spallation target. A high-energy neutron may interact in the lead producing many secondary neutrons. The detector records the correlated secondary neutron multiplicity. Over many events, the response can be used to infer the incident neutron energy spectrum and flux. As a validation of the detector response, surface measurements have been performed; results confirm agreement with previous experiments. Below ground measurements have been performed at 3 depths (380, 600, and 1450 m.w.e.); results from these measurements will be presented.   

Spectra of $\pi^+$ and $\pi^-$ from $\pi^+$-Carbon Interactions at 31 GeV/c with the NA61/SHINE Spectrometer

Tuning of secondary pion interactions will be important for the success of the next generation long baseline neutrino experiments. The interaction energy of 31 GeV/c is particularly useful for understanding secondary pion interactions in the LBNF and NuMI neutrino beamlines. $\pi^+$ and $\pi^-$ spectra have been obtained from interactions of 31 GeV/c $\pi^+$s with carbon from data taken in 2009 with the NA61/SHINE hadron spectrometer. dEdx and mass squared information from the TPC and Time of Flight systems were used to identify charged pions. The production and inelastic cross sections for this interaction will be measured from magnet off data taken in 2015 by NA61/SHINE. NA61/SHINE is poised to run with a more extensive data program to cover the important interactions for DUNE and the NuMI experiments over the next two years.   

Neutrino-Nucleon Interactions and Lattice QCD

We address techniques to make the theoretical underpinning of neutrino-nucleon scattering more robust. We see this foundation as a necessary step to disentangle fundamental physics (such as neutrino oscillation parameters) from nuclear effects. We address a reanalysis of old experiments with elementary targets, model-independent parametrizations of nucleon form factors based on analyticity, and lattice QCD calculations of the form factors.   

Search for electroweak production of a vector-like quark decaying to tH

Results of a search for a vector-like top-quark partner T of charge 2/3 produced through electroweak interaction in association with a bottom or top quark and decaying to a top quark and a Higgs boson are presented using data collected in pp collisions at sqrt(s)$=$13 TeV with the CMS detector. Depending on the coupling parameters for individual interactions, singly produced vector-like quarks might be enhanced compared to pair production at 13 TeV. The search uses boosted jet topologies to find Higgs boson candidates decaying to bottom quarks and fully hadronic top quark decays.   

A search for supersymmetry in events containing a leptonically decaying Z boson, jets and missing transverse momentum in sqrt(s) $=$ 13 TeV pp collisions with the ATLAS detector

A search for supersymmetric particles decaying to a Z boson, jets, and invisible particles is presented. The search is performed using 3.2 fb-1 of sqrt(s) $=$ 13 TeV proton-proton collisions recorded by the ATLAS detector at the Large Hadron Collider and investigates a three-sigma excess of events seen in 8 TeV collisions in 2012 in a similar final state. The results are interpreted using a simplified model in which gluinos are produced and subsequently decay via the second lightest neutralino to Z bosons and lightest supersymmetric particles.   

SUSY Spectrum Calculator Effects on Dark Matter Observables

Due to questions like the dark matter and hierarchy problem, searches for physics beyond the Standard Model (SM) have not only moved beyond the simplest extensions but the LHC has offered the first tantalizing hints of a new particle at 750 GeV. But as we move into new regimes beyond the minimal extensions to the SM, we need to ask ourselves how accurate are our existing simulations of theory therein? In my talk I will explore the effects of different supersymmetric, spectrum calculators (e.g. ISAJET and SPheno) on predictions for dark matter and Higgs sector observables.