Joint Theory Seminar
Speaker:
Title:
Host:
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 4 hour 0 minutes before start
Description:
High Energy Seminar
Speaker: Albert de Roeck
Title: The SHiP Experiment: Search for Hidden Particles
Host: Robin
Room: 285
Abstract:
SHIP is a new general purpose fixed target facility, proposed at the CERN SPS accelerator. In five years, 2 × 10^20 protons of 400 GeV/c momentum will be dumped on a Molybdenum target. A dedicated and optimized detector downstream of the target will allow a search to be made for long-lived particles with masses below O(10) GeV/c2 foreseen in several extensions of the Standard Model. Examples are Heavy neutral leptons (massive sterile neutrinos), light scalars, dark photons and axion-like particles. Another dedicated detector will allow the study of active neutrino cross-sections and angular distributions. Some recent develoments and the timeline will be discussed.
User:
High-Energy Seminars
Time:
5:10am - 6:00am
Send Reminder:
Yes - 1 day 0 hour 0 minutes before start
Description:
Learn about recent progress on searches for long-lived particles, LHC and beyond.
Description:
Cinco de Mayo
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker: Jared Evans
Title: Simplified Models for Hidden Sector Freezeout
Host: Markus Luty
Room: 432
Abstract: As the hunt for the elusive dark matter progresses, an impressive series of null results has severely limited options for DM that freezes out via standard model interactions. A hidden sector containing the dark matter particle and an unstable mediator can freezeout independently of the sector's very weak connection to the standard model fields, opening opportunities for phenomenology. I will present two minimal simplified models for hidden sector freezeout (through the vector and scalar portal), discuss the existing constraints on these parameter spaces from a wide array of complementary experimental approaches, and address how the features of these models survive in extensions beyond the minimal case.
Description:
Mother's Day
User:
High-Energy Seminars
Time:
5:30am - 6:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:
Title:
Host:
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:Prashant Saraswat (Caltech)
Title: The Weak Gravity Conjecture, Effective Field Theory, and Inflation
Host: Verhaaren
Room: 432
Abstract: The Weak Gravity Conjecture (WGC) is a proposed constraint on theories with gauge fields and gravity, requiring the existence of light charged particles and/or imposing an upper bound on the field theory cutoff. If taken as a consistency requirement for effective field theories (EFTs), the WGC rules out possibilities for model-building including some models of cosmic inflation. Arguments for the WGC based on black hole properties appear at first to be universal in nature, independent of detailed UV physics. However, I will show how UV theories which satisfy the WGC may have low-energy EFT descriptions which badly violate it, while avoiding any pathologies in black hole physics. I'll argue that parametric violation of the WGC at low energies can be achieved only at the cost of non-minimal field content in the UV. I'll discuss the implications of these results for inflationary model-building and phenomenology. I also propose a new parametric constraint, much weaker than the WGC that should in fact apply to EFTs, motivated by black hole entropy bounds.
User:
High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 4 hour 0 minutes before start
Description:
High Energy Seminar
Speaker: Kaixuan Ni (UC San Diego)
Title: First Results from the XENON1T Dark Matter Search
Host: Emilija Pantic
Room: 285
Abstract: XENON1T, the world’s largest dual-phase xenon dark matter detector running at Gran Sasso Underground Laboratory in Italy, just released the first results from a blind analysis of 34.2 live days data acquired between November 2016 and January 2017. The XENON1T detector contains a total of 3200 kg of ultra-pure liquid xenon of which 2000 kg are active. Shielded by a water Cherenkov muon veto, constructed with ultra-low background materials and together with liquid xenon self-shielding, the experiment achieved a record low background in one tonne of target in the region of interest for dark matter search. I will present the techniques that realize such a low background, details on the calibration and background studies, and the first results which set the new world record limit on WIMP-nucleon scattering cross sections.
User:
High-Energy Seminars
Time:
6:30am - 7:30am
Send Reminder:
Yes - 3 days 4 hour 0 minutes before start
Description:
Joint Theory Seminar
Speaker:
Title:
Host:
Room: 432
Abstract:
User:
High-Energy Seminars
Time:
9:10am - 10:10am
Send Reminder:
Yes - 1 day 4 hour 0 minutes before start
Description:
High Energy Seminar
Speaker: Daniel Dwyer (LBNL)
Title: Evidence against sterile neutrinos from the Daya Bay Experiment
Host: Robert Svoboda
Room: 285
Abstract:
Prevailing models of antineutrino emission by nuclear reactors do not
agree with observations. This discrepancy has been considered
possible evidence for neutrino oscillation to non-interacting, or
sterile, neutrino states. Although the existence of sterile neutrinos
would have profound implications, a variety of measurements by the
Daya Bay Experiment disfavor sterile models. I will summarize these
observations with a particular focus on the latest result: a precise
measurement of the antineutrino flux versus reactor fuel burn-up.
I’ll wrap up with a provocative question: does any compelling evidence
for sterile neutrinos remain?
