Joint High Energy Physics/Theory Seminars
HEP/theory seminar mailing list
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2010/2011
Organizers: Andriy Badin, Ashutosh Kotwal, Tom Mehen and Kate Scholberg
Held in Duke Physics Room 278 (old Room 246) (Unless otherwise noted)Regular time for Fall '10 semester: Mondays 3 pm. Currently all unlisted dates are open.
Regular times for Spring '11 semester: Friday 2:30 pm (preferred) and Monday 3 pm (alternate). Currently all dates not listed are open.
November 1: Andrew Laing, U. of Glasgow, 3 pm
The Neutrino Factory is the most powerful of the proposed facilities to search for CP violation in the lepton sector via neutrino oscillations. It would deliver a well known beam of nue and numubar from the decay of mu+ as well as nuebar and numu from mu- decay. Searching for "wrong-sign" muons indicative of the golden channel nue (nuebar) -> numu (numubar) appearance signal unrivalled sensitivity to the remaining unknown variables in the Pontecorvo-Maki-Nagawa-Sakata (PMNS) matrix can be achieved. This presentation will review the current status of design and optimisation of the neutrino factory facility and experiments with particular focus on the development of magnetised detectors and analyses to optimise the physics reach of the experiments which will be performed.
January 21: Jim Kneller, NCSU, 2:30 pm
The emission of neutrinos removes 99% of the energy released when the core of a massive star collapses to form a proto-neutron star and the number and size of the present neutrino detectors means we will detect tens to hundreds of thousands from the next supernova in the Galaxy. But while we have been (patiently) waiting a revolution has taken place in our understanding of how neutrinos evolve as the pass through the mantle of the supernova. In particular, the neutrino flavour composition of the signal is not fixed by the source - the neutrinosphere - but, instead, evolves due to a number of effects: neutrino collective effects close to the proto-neutron star, the dynamic MSW effect as the shockwave races through the star, and the turbulence effects both initial and that generated by the asphericity of the explosion. Each leaves characteristic fingerprints and by looking at how the flavour composition of the signal varies as a function of time and/or energy we can begin to tease out fundamental properties of the neutrino and simultaneously observe the explosion while it is still deep within the star. I will present an overview of the recent progress in this field and the telltale signatures we will be looking for when the signal (eventually) arrives.
February 4: Alex Himmel, Caltech, 2:30 pm
MINOS is a long-baseline neutrino oscillation experiment with two detectors 734 km apart exposed to the Fermilab NuMI neutrino beam. By comparing the energy spectrum and beam composition at the two sites neutrino oscillations at L/E~500 km/GeV can be measured with precision. We present measurements of the atmospheric mass splitting and mixing angle theta-23 for both neutrinos and antineutrinos using observations of charged current neutrino and antineutrino disappearance. The neutrino measurements are based on more than twice the data used in previous publications and the antineutrino measurements are based on a dedicated antineutrino beam run. This is the first precision measurement of antineutrino atmospheric oscillations using a pure sample of muon antineutrinos.
February 18: Reyco Henning, UNC Chapel Hill, 2:30 pm
Several models of physics beyond the current standard model predict the existence of axions and similar "Axion-like" (or Any) Light Particles (ALPs). It is possible for some of these particles to couple to electromagnetic fields and convert to detectable real photons. This phenomenon is exploited by experiments using resonant RF cavities, magnets or germanium detectors to search for solar or cosmological axions. Other experiments attempt to create and detect these particles by converting a photon traversing a magnetic field into an ALP and then reconverting the ALP into a photon in a separate magnet further downstream. A photon shield separates the two magnets and these experiments literally attempt to shine light through walls. Laser experiments in the optical and IR regime have already achieved significant sensitivities and experiments with X-rays have been proposed. In this talk I will review the state of the field, with emphasis on the experimental program, and then discuss the possibility of using the HIGS facility at TUNL to perform a novel search for these particles.
April 1: Alexey Petrov , Wayne State University, 2:30 pm
I discuss the flavor problem, concentrating on models with two Higgs doublets. I will derive two flavor basis independent constraints on Yukawa couplings that will give the observed mass hierarchy while keeping all Yukawa couplings of the same order. I briefly describe how these constraints can be realized in particular models, and discuss experimental constraints on those models in the near-decoupling limit.
April 8: Scott Willenbrock , University of Illinois, 2:30 pm
New physics could affect the top quark by modifiying its couplings to othe Standard Model particles. I discuss a modern approach, based on effective field theory, to including these modified couplings. I show how these couplings can be measured (or bounded) at the Tevatron and the LHC