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CCAPP Seminar Heidi Wu and Francesco Capozzi - see titles and abstracts below

September 19, 2017
11:30AM - 12:30PM
4138 Physics Research Building

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Add to Calendar 2017-09-19 11:30:00 2017-09-19 12:30:00 CCAPP Seminar Heidi Wu and Francesco Capozzi - see titles and abstracts below Heidi Wu:Title: Sample variance in the local measurements of the Hubble constantThe Hubble constant H0 has recently been measured to percent-level precision, but two of the key results are in tension.  The local measurements using distance ladder have indicated H0 ~ 73 km/s/Mpc, while the global measurements using cosmic microwave background have indicated H0 ~ 67 km/s/Mpc.  In this talk, I will first review the methods and results of both local and global measurements, as well as previous attempts to alleviate this tension.  I will then present our efforts of using simulations to quantify the sample variance in the local measurements of H0.  Taking into account the inhomogeneous selection of type Ia supernovae, we find that this tension cannot be alleviated by sample variance or local density fluctuations.   I will conclude with future experiments that may resolve this tension.Francesco Capozzi:Title: “DUNE as the Next-Generation Solar Neutrino Experiment”Abstract: “Solar neutrinos reveal crucial information on neutrino properties and the interior of the Sun.However, it is not clear which experiment will significantly improve current observations in the near future.We show that DUNE, intended for other purposes, is extremely promising for this role. A combination of charged-current and elastic scattering events constrains the neutrino oscillation parameters θ12, Δm^2_21 and the 8B flux at an unprecedented level. DUNE can also make the first detection of hep neutrinos, with a 10\% precision on its normalization. A solar neutrino program in DUNE would reinvigorate this field and enrich DUNE scientific objectives. I will discuss both theoretical and experimental efforts needed to ensure the success of such a program." 4138 Physics Research Building Department of Physics physics@osu.edu America/New_York public

Heidi Wu:

Title: Sample variance in the local measurements of the Hubble constant

The Hubble constant H0 has recently been measured to percent-level precision, but two of the key results are in tension.  The local measurements using distance ladder have indicated H0 ~ 73 km/s/Mpc, while the global measurements using cosmic microwave background have indicated H0 ~ 67 km/s/Mpc.  In this talk, I will first review the methods and results of both local and global measurements, as well as previous attempts to alleviate this tension.  I will then present our efforts of using simulations to quantify the sample variance in the local measurements of H0.  Taking into account the inhomogeneous selection of type Ia supernovae, we find that this tension cannot be alleviated by sample variance or local density fluctuations.   I will conclude with future experiments that may resolve this tension.

Francesco Capozzi:

Title: “DUNE as the Next-Generation Solar Neutrino Experiment”

Abstract: “Solar neutrinos reveal crucial information on neutrino properties and the interior of the Sun.However, it is not clear which experiment will significantly improve current observations in the near future.We show that DUNE, intended for other purposes, is extremely promising for this role. A combination of charged-current and elastic scattering events constrains the neutrino oscillation parameters θ12, Δm^2_21 and the 8B flux at an unprecedented level. DUNE can also make the first detection of hep neutrinos, with a 10\% precision on its normalization. A solar neutrino program in DUNE would reinvigorate this field and enrich DUNE scientific objectives. I will discuss both theoretical and experimental efforts needed to ensure the success of such a program."