Speaker: Jiajie Ling, Brookhaven National Laboratory
Title: "Observation of electron-antineutrino disappearance at Daya Bay"
Abstract:
The Daya Bay Reactor Neutrino Experiment has measured a non-zero value
for the neutrino mixing angle theta13 with a significance of 5.2
standard deviations. Antineutrinos from six nuclear reactors were
detected in six antineutrino detectors deployed in two near and one far
underground experimental halls. With 55 days of data, 10416 (80376)
electron antineutrino candidates were detected at the far hall (near
halls). The ratio of the observed to expected number of antineutrinos
at the far hall is R=0.940 +- 0.011(stat) +- 0.004(syst). A rate-only
analysis finds sin^22theta13=0.092 +- 0.016(stat) +- 0.005(syst) in a
three-neutrino framework.
In this seminar we will discuss the first results of Daya Bay experiment.
Speaker: Kendall Mahn, Triumf
Title: "Results from the T2K long baseline neutrino experiment"
Abstract:
Neutrino oscillations have been observed and confirmed at two mass
splittings ($\Delta m^2$), which is consistent with three generations of
neutrinos and an unitary mixing (PMNS) matrix. Despite the rapid
progress in understanding neutrino oscillations in the last decade,
further study of the large mixing in the leptons (as compared to the
quark CKM matrix) may give additional insight into the nature of
neutrinos. If $\theta_{23}$ is maximal (2$\theta_{23}=90$ degrees)
and/or $\theta_{13}=0$, then the PMNS matrix has a symmetry, indicative
of underlying physics. If, however, $\theta_{13}$ is non-zero, and
sufficiently large, then a programme to study CP violation with
neutrinos is possible, such as the proposed LongBaseline Neutrino
experiment in the US (LBNE) or Hyper-Kamiokande experiment in Japan. In
this case, CP violation with light neutrinos
may have some relationship to the CP violation in the decay of a
hypothetical heavy neutrino partner and to the development of the early
universe.
The Tokai-To-Kamioka (T2K) long baseline neutrino experiment is designed
to precisely measure $\nu_{\mu}$ disappearance ($\Delta m^2_{23}$,
$\theta_{23}$) and search for $\nu_e$ appearance ($\theta_{13}$). A beam
of muon neutrinos is generated at the J-PARC facility in Tokai-mura,
Japan, and is sampled by two near detectors, ND280 and INGRID, before
reaching the Super-Kamiokande detector, 295km away. This talk will
report updated results from T2K on $\nu_{\mu}$ disappearance and $\nu_e$
appearance. Future prospects for T2K and long baseline neutrino physics
will also be discussed.
To view the archived presentation click here.
Speaker: Craig Dukes, Virginia University
Title: "Mu2e: Using Rare Particle Decays to Probe the Energy Frontier"
Abstract:
Although there is great excitement in particle physics these days, with the
inauguration of the Large Hadron Collider and the great discoveries we hope
it will bring, for the first time in some seventy years there are no plans
for any new accelerators to take us to the next energy regime. Hence, in
order to find out what may be lurking beyond what we can directly produce
in collisions at particle accelerators we will need to look for indirect signs
such as rare and forbidden particle decays. There is a long history of such
searches, a history that predates particle physics itself. I will show how
such searches can probe mass scales unobtainable by direct searches at any
conceivable particle accelerator and describe an experiment, Mu2e, that
intends to use a novel technique to search for new physics through lepton
flavor violation in muon decays with sensitivities a factor of 10,000 over
existing limits.
Speaker: Vladimir Vassiliev, University of California, Los Angeles
Title: "Cherenkov Telescope Array - next-generation ground-based gamma-ray observatory"
Abstract:
The Cherenkov Telescope Array (CTA) is proposed as a next-generation
ground-based gamma-ray observatory for very high energy astronomy
(>10 GeV) and is expected to start operation in the current decade.
CTA will consist of a hybrid array of several types of Cherenkov
telescopes, planning to (a) provide coverage from a few tens of GeV to
beyond 100 TeV, (b) increase sensitivity by an order of magnitude at
around 1 TeV (c) significantly improve angular resolution and enable
morphological studies of sources, (d) increase field of view which
together with large photon detection area facilitates unparalleled
research of transient phenomena at high energies, and (e) enhance the
all sky survey capability. In this talk I plan to briefly review the
status of research in two areas of astrophysics, indirect detection of
dark matter and intergalactic magnetic fields, which is currently being
conducted by VERITAS, H.E.S.S., MAGIC, and Fermi observatories. I will
then illustrate the physics potential of CTA to further advance these
studies and overview CTA technology and the status of the project
focusing on the development of novel Schwarzschild‐Couder Telescope
design which is being developed by the CTA-US members of the CTA
consortium.
Speaker: Alex Penson, Columbia University
Title: “Search for gravitons using merged jets from Z boson decays with the ATLAS experiment”
Abstract:
Merged' jets result from the hadronic decay of high pT Z bosons. They can be used to extend limits on gravitons which decay to a pair of Z bosons, especially in modern Randall-Sundrum models in which Standard Model particles propagate in the five dimensional bulk.