NPAC (Nuclear/Particle/Astro/Cosmo) Forum

While the origins of the light (hydrogen, helium) and intermediate mass(carbon through iron) elements found in our solar system are well understood, we still don't know where roughly half of the elements heavier than iron were made. From the solar system abundance pattern of these nuclei, we can tell they were synthesized via rapid neutron captures in the r-process of nucleosynthesis. Exactly where the appropriate astrophysical conditions for the r-process exist, however, is still uncertain. Here we will discuss the two most popular potential astrophysical sites---core-collapse supernovae and neutron star mergers---and describe how progress in open issues in neutrino and nuclear physics may be the key to unlocking this longstanding mystery.

Host: 
Balantekin
Speaker: Rebecca Surman Notre Dame

 

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5310 Chamberlin Hall

In the last several decades neutrino oscillation experiments have given us a consistent picture of neutrino mass and mixing among three neutrino flavors. However, a series of longstanding and more recent anomalies hint at the existence of additional “sterile” neutrino flavors and complicates this simple picture. In order to improve on previous short baseline sterile neutrino searches, new detector technologies are required. Liquid Argon time projection chambers (LArTPCs) promise to have the sensitivity needed by current and next generation neutrino oscillation experiments looking for the appearance of electron-flavor neutrinos in a predominantly muon-flavored accelerator-based neutrino beam. MicroBooNE is the first of three LArTPC detectors planned for the newly re-established Short Baseline Neutrino program at Fermilab built to address the sterile neutrino hypothesis and to develop the technologies and expertise necessary to deploy a kiloton-scale LArTPC for future long baseline neutrino oscillation experiments. First data from the MicroBooNE experiment will be presented along with future prospects for LArTPC technology in the US.

Host: 
Baha Balantekin
Speaker: Matt Toups MIT

 

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5280 Chamberlin Hall

IceCube neutrino telescope recently discovered astrophysical neutrinos in the energy range from 10 TeV to 3 PeV. This discovery challenged existed theoretical models due to unexpected observation of soft 1/E^{2.5} neutrino spectrum. Together with limits from diffuse gamma-ray flux measured with Fermi LAT this excluded most of existed theoretical predictions. In my talk I'll discuss significance of the galactic component observation in the 4 years IceCube data. Also I'll review theoretical models, which can explain observed data both with Galactic and extra-galactic sources of neutrinos. Finally, I'll present model, which at the same time explain Ultra-High Energy Cosmic Ray protons, astrophysical neutrinos and diffuse gamma-ray background.

Host: 
Francis Halzen
Speaker: Dmitri Semikoz APC Paris

 

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5310 Chamberlin Hall

I will present the main elements of our independent studies of the high-energy events seen above 28TeV by IceCube, arXiv:1404.0017 and arXiv:1502.02649. I will cover the physics involved, and show the effect of modelling and assumptions on the conclusions one can reach about the flavor composition, spectrum, and background rates. I will compare our results and methodology with the official IceCube studies, and discuss future prospects.

Host: 
Carlos Arguelles Delgado
Speaker: Aaron Vincent Institute for Particle Physics Phenomenology , Durham University

 

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4274 Chamberlin Hall
Neutrinos created in one flavour state (electron, muon, and tau) can oscillate into a different one as they propagate. Such oscillations imply that states of a given flavour are really superpositions of three mass states, with the rate of oscillations depending on the difference in squared masses of these states. These differences have two characteristic scales, one measurable with solar neutrinos, and one with neutrinos from atmospheric and accelerator sources, so early experiments assumed mixing between only two flavours.

With larger and more precise detectors the full three-flavour structure can to begin to be probed. The mass ordering of the three states is accessible via neutrino interactions with matter as they propagate through the Earth, whilst the possibility that neutrino oscillations violate charge parity symmetry can be probed via electron neutrino appearance in a muon neutrino beam. In this talk I will discuss an update to the MINOS atmospheric neutrino analysis, and discuss CHIPS: an R&D experiment aiming to build a large water Cherenkov detector in a flooded mine pit in Northern Minnesota, which deployed a small prototype in the summer of 2014.
Host: 
Kael Hanson
Speaker: Andy Perch University College London

 

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5280 Chamberlin Hall
Speaker: Bryce Littlejohn Illinois Institute of Technology

 

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5310 Chamberlin Hall
Inclusive fluxes of muons and neutrinos in the atmosphere provide a continuous source of information about the spectrum and composition of cosmic rays interacting with air nuclei. Furthermore, measurements of the fluxes allow us to learn more about hadronic interactions in phase space regions not accessible at high-energy colliders. Using an accurate and flexible solution of the coupled cascade equations, called matrix-method, it is possible to study numerically the connection between atmospheric muon observations and measurements made at fixed-target or collider experiments. I will present the status of lepton
flux calculations using different interaction models and primary cosmic ray flux assumptions. Emphasis is put on the role of hadronic interactions by discussing the importance of different phase-space regions, particle species and interaction energies for the prediction of atmospheric lepton fluxes.
Host: 
Paolo Desiati
Speaker: Anatoli Fedynitch Karlsruhe

 

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5280 Chamberlin Hall
The first hints of new physics at the LHC may come in the form of extremely short-lived particles which decay instantly to particles in the standard model. These decays could appear as an excess of events in any number of channels. Until recently, searches for such an excess have often neglected decays through charm quarks, owing to the lack of an efficient charm jet identification algorithm.

I will introduce several supersymmetric models where decays through charm quarks are preferred. These searches motivated the development of a lifetime-based charm jet identification algorithm. After discussing this algorithm, I will present the results from two scalar quark searches, where charm jet identification played a central role in extending the previous experimental limits
Host: 
Stefan Westerhoff
Speaker: Dan Guest Yale University

 

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4274 Chamberlin

In this talk I shall narrate our plans of building a new underground laboratory facility in southern India called India-based neutrino observatory (INO). A 50 kilo-ton magnetised Iron CALorimeter (ICAL)is one of the first experiments proposed to be housed in this observatory for the study of neutrino properties like mass hierarchy, precision measurement of oscillation parameters etc. using the atmospheric neutrinos. The details of this ICAL project and its present status will also be covered in this talk.

Host: 
Justin Vandenbrouke
Speaker: Bannanje Sripathi Acharya Tata Institute

 

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5310 Chamberlin Hall

Work on VHE gamma-ray astronomy using the Atmospheric Cherenkov Technique started in India way back in 1969,soon after the discovery of pulsars. Over the years, steady improvements in telescope hardware have led to increase in the sensitivity and collection area as well as reduction in the energy threshold of the experiments. The latest in this series of experiments is the HiGRO project located at very high altitude (4.3km), at Hanle in the Ladakh region of Himalayas. In the first phase of this project 7 telescope array called HAGAR was installed the year 2008. It is an array of wavefront sampling non- imaging telescopes having a threshold energy of about 200 GeV for gamma-rays. This is the first ACT array operating at very high altitudes. A 21-m imaging telescope (called MACE), built by BARC group, will be commissioned at the same site adjascent to HAGAR array in this year. With MACE, the threshold energy of gamma-rays is expec to be about a few tens of GeV. Regular observations of galactic and extra galactic objects using HAGAR are going on since October 2008. I shall describe the status the HiGRO project at Hanle and the recent results obtained using the HAGAR array.

Host: 
Mike Duvernois
Speaker: Bannanje Sripathi Acharya Tata Institute

 

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Room and Building: 
5280 Chamberlin Hall

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