# Light Dark World International Forum 2016

chaired by ,
from to (Asia/Seoul)
at Daejeon, Korea ( CTPU seminar room )
Description

# Light Dark World 2016

July 11-15, 2016

IBS Center for Theoretical Physics of the Universe, Daejeon, Korea

Light Dark World 2016 is the inaugural meeting of the Light Dark World International Forum. It will be held on July 11-15, 2016 at the Center for Theoretical Physics of the Universe (CTPU) of the Institute for Basic Science (IBS), located at Daejeon in South Korea.

Light Dark World 2016 will bring together global experts from experiment and theory to discuss recent advances and develop new opportunities to study new light particles beyond the Standard Model, including light gauge boson, light scalar, light dark matter, axion, axion-like particle, and light sterile neutrinos.

http://indico.ibs.re.kr/e/LDW2016

[Notice]

• If you want to attend the forum dinner (Thursday evening), please pay KRW 20,000 at the CTPU admin office on your first day, unless you are a speaker.
• If you want to join the excursion (Friday afternoon), please pay KRW 20,000 at the CTPU admin office on your first day.

Material:
Poster
IBS CTPU admin office Email: mijin1024@ibs.re.kr Telephone: +82-42-878-8402
Go to day
• Monday, 11 July 2016
• 09:00 - 09:20 Registration and Coffee ( CTPU )
• 09:20 - 09:30 Welcome and Introduction: (session chair: Hye-Sung Lee)
• 09:20 Welcome and Introduction 10'  Speaker: Kiwoon Choi (IBS-CTPU) Material:
• 09:30 - 11:10 Morning Session 1: (session chair: Brian Batell)
• 09:30 New Direct Detection Probes of sub-GeV Dark Matter 50'  Speaker: Rouven Essig (Stony Brook) Material:
• 10:20 Implications of Naturalness for Searches for Light Dark Sectors 50'  Speaker: David Morrissey (TRIUMF) Material:
• 11:10 - 11:40 Coffee ( CTPU seminar room )
• 11:40 - 12:55 Morning Session 2: (session chair: Brian Batell)
• 11:40 Dark-sector searches from flavor-factory experiment 50'  Speaker: Youngjoon Kwon (Yonsei) Material:
• 12:30 New faces of dark matter: SIMP and its friends 25'  Speaker: Hyun Min Lee (Chuang-Ang) Material:
• 13:00 - 14:30 Lunch ( Cafeteria )
• 14:30 - 15:45 Afternoon Session: (session chair: Ketevi Assamagan)
• 14:30 New Electron Fixed Target Experiments to Search for Light Dark Matter 50'
This talk analyzes the present status of sub-GeV thermal dark matter annihilating
through Standard Model mixing. In these scenarios, the requirement that dark matter
be a thermal relic sets a sharp sensitivity target for terrestrial experiments, and
that one of the simplest and best-motivated interactions between the SM and light
dark matter the vector portal remains viable. Moreover, it is demonstrated that a small
set of future experiments that can decisively test these models. The talk will emphasize
electron beam fixed target experiments but will also survey other techniques.

 Speaker: Gordan Krnjaic (Fermilab) Material:
• 15:20 Right-handed neutrino dark matter and the B-L gauge boson 25'  Speaker: Kunio Kaneta (IBS-CTPU) Material:
• 15:45 - 17:30 Coffee and Discussions  Location: CTPU
• Tuesday, 12 July 2016
• 09:00 - 09:30 Coffee and Discussions  Location: CTPU
• 09:30 - 11:10 Morning Session 1: (session chair: David Morrissey)
• 09:30 Cosmic Microwave Background Probes of Light Particles 50'  Speaker: Neelima Sehgal (Stony Brook) Material:
• 10:20 Phenomenology of light sterile neutrinos 50'  Speaker: Manfred Lindner (MPI Heidelberg) Material:
• 11:10 - 11:40 Coffee ( CTPU seminar room )
• 11:40 - 12:55 Morning Session 2: (session chair: David Morrissey)
• 11:40 Enhanced Production of Sterile Neutrinos at Accelerator Experiments 50'  Speaker: Brian Batell (Pittsburgh) Material:
• 12:30 Dark radiation with WIMPZILLA 25'  Speaker: Seongchan Park (Yonsei) Material:
• 13:00 - 14:30 Lunch ( Cafeteria )
• 14:30 - 15:45 Afternoon Session: (session chair: Sean Tulin)
• 14:30 Disappearance of dancing reactor neutrinos at RENO 50'
The RENO collaboration has observed energy and baseline distance dependent disappearance of reactor neutrinos that are emitted from the Hanbit nuclear power plant in South Korea. The experimental group has measured a neutrino squared-mass difference and the smallest neutrino mixing probability more precisely. Both of them are essential for understanding the unknown nature of neutrinos. The RENO measured value of the mass difference between the heaviest and lightest neutrinos is roughly a billionth of an electron mass. The experiment observes surprising spectral deviation from the prediction of reactor neutrino models. In this talk, we will present recent results of reactor neutrino oscillation at RENO.
 Speaker: Soo-Bong Kim (SNU) Material:
• 15:20 Interacting Dark Matter and Radiation in Cosmology 25'  Speaker: Tang Yong (KIAS) Material:
• 15:45 - 17:30 Coffee and Discussions  Location: CTPU
• Wednesday, 13 July 2016
• 09:00 - 09:30 Coffee and Discussions  Location: CTPU
• 09:30 - 11:10 Morning Session 1: (session chair: Ernest Ma)
• 09:30 The physics potential of the SHiP experiment at CERN 50'
SHIP is a new general purpose fixed target facility, whose Technical Proposal has been recently reviewed by the CERN SPS Committee, who recommended that the experiment proceeds further to a Comprehensive Design phase. In its initial phase, the 400GeV proton beam extracted from the SPS will be dumped on a heavy target with the aim of integrating $2\times 10^{20}$ pot in 5 years. A dedicated detector, based on a long vacuum tank followed by a spectrometer and particle identification detectors, will allow probing a variety of models with light long-lived exotic particles and masses below O(10) GeV/c$^2$. The main focus will be the physics of the so-called Hidden Portals, i.e. search for Dark Photons, Light scalars and pseudo-scalars, and Heavy Neutrinos. The sensitivity to Heavy Neutrinos will allow for the first time to probe, in the mass range between the kaon and the charm meson mass, a coupling range for which Baryogenesis and active neutrino masses could also be explained.
Another dedicated detector will allow the study of neutrino cross-sections and angular distributions. $\nu_\tau$ deep inelastic scattering cross sections will be measured with a statistics 1000 times larger than currently available, with the extraction of the $F_4$ and $F_5$ structure functions, never measured so far and allow for new tests of lepton non-universality with sensitivity to BSM physics. This second detector will also allow direct dark matter detection produced in the decay of the dark photons.

 Speaker: Walter Bonivento (INFN Cagliari) Material:
• 10:20 Role of dark Higgs boson in DM phenomenology 50'  Speaker: Pyungwon Ko (KIAS) Material:
• 11:10 - 11:40 Coffee ( CTPU seminar room )
• 11:40 - 12:55 Morning Session 2: (session chair: Ernest Ma)
• 11:40 Self-interacting dark matter and new light forces 50'  Speaker: Sean Tulin (York) Material:
• 12:30 A new constraint on millicharged dark matter from galaxy clusters 25'  Speaker: Toyokazu Sekiguchi (IBS-CTPU) Material:
• 13:00 - 14:30 Lunch ( Cafeteria )
• 14:30 - 15:20 Afternoon Session: (session chair: Hyun Min Lee)
• 14:30 Searches for axion and sterlile neutrino from the CUP (Center for Undergroud Physics), IBS 50'
The CUP at IBS has performed two experiments, KIMS (Korean Invisible Mass Search) at Yangyang Underground Laboratory and NEOS (Neutrino Experiment for Oscillation at Short baseline) in the tendon gallery of 3 GWth nuclear reactor at Yeounggwang.
In this talk, we will will present results for solar axion search from the KIMS and for sterile neutrino search from the NEOS.

 Speaker: Hyang Kyu Park (IBS CUP) Material:
• 15:20 - 17:30 Coffee and Discussions  Location: CTPU
• Thursday, 14 July 2016
• 09:00 - 09:30 Coffee and Discussions  Location: CTPU
• 09:30 - 11:10 Morning Session 1: (session chair: Alejandro Ibarra)
• 09:30 CP Violation, Fermion oscillations and Baryogenesis 50'
I discuss some recent work on oscillations of heavy neutral fermions, including neutral baryons. I discuss how to obtain sizable CP violation in such oscillations, and possible connections with baryogenesis and with dark matter.

 Speaker: Ann Nelson (Washington) Material:
• 10:20 Faking The Diphoton Excess (?) by Displaced Dark Photon Decays 50'
When passing identification cuts, a particle beyond SM can fake an SM object in a collider experiment. In this talk, I show how a light and meta-stable dark photon which decays into e+e- can fake an SM photon, either converted or unconverted, at the LHC. Using the recent hint of 750 GeV diphoton signal as an example, we discuss the distinct feature of the fake photon signal and how the signal can be imbedded into a larger class of theoretical explanation for the 750 GeV. I also discuss possible ways of distinguishing these dark photon decays from real photon events in the future.

 Speaker: Yuhsin Tsai (Maryland) Material:
• 11:10 - 11:40 Coffee ( CTPU seminar room )
• 11:40 - 12:55 Morning Session 2: (session chair: Alejandro Ibarra)
• 11:40 The axion dark matter search at CAPP: a comprehensive approach, and the proton EDM experiment 50'
Axions are the result of a dynamic field, similar to Higgs field, invented to solve the so-called Strong CP-problem, i.e., why the electric dipole moment (EDM) of the neutron and proton has not been observed so far even though the theory of QCD requires otherwise.  Axions as dark matter can be thought of as an oscillatory field interacting extremely weakly with normal matter other than gravitationally.  The oscillation frequency is unknown, it can be anywhere between f = 200MHz to 200GHz and it’s expected to be a very narrow line, about df/f=10^-6.  A very strong magnetic field can be used to convert part of that field into a very weak electric field oscillating at the same frequency as the axion field.  In the coming years we plan to develop our experimental sensitivity to either observe or refute the axions as a viable dark matter candidate.  That approach includes the development of ultra strong magnets, high quality resonators in the presence of strong B-fields, new resonator geometries with high volume, low noise cryo-amplifiers and new techniques of detecting axions.

Another related subject, through the strong CP-problem, is the search for the EDM of the proton, improving the present sensitivity by more than three orders of magnitude.  Usually the study of EDM involves the application of strong electric fields and neutral systems were thought to be easier to work with at first.  Recently it became clear that charged particles in all-electric storage rings can be used instead, for sensitive EDM searches by using techniques similar to the muon g-2 experiment.  The high sensitivity study of the proton EDM is possible due to the high intensity polarized proton beams readily available today, making possible to reach beyond 10^3 TeV in New Physics mass scale.  
 Speaker: Yannis Semertzidis (IBS CAPP, KAIST) Material:
• 12:30 Relaxion from multiple axions 25'  Speaker: Sang Hui Im (IBS-CTPU) Material:
• 13:00 - 14:30 Lunch ( Cafeteria )
• 14:30 - 15:20 Afternoon Session: (session chair: Hyun Min Lee)
• 14:30 Search for Dark Interactions at the LHC 50'
Hidden sector or dark sector states appear in many extensions to the Standard Model, to provide a candidate for the dark matter in the universe or to explain astrophysical observations of positron excesses. A hidden or dark sector can be introduced with an additional $U(1)_d$ dark gauge symmetry. The presence of the dark sector could be inferred either from deviations from the SM-predicted rates of Drell-Yan (DY) events or from Higgs boson decays through exotic intermediate states. The discovery of the Higgs boson during Run 1 of the Large Hadron Collider opens a new and rich experimental program that includes the search for exotic decays H —> Z Zdark —> 4l and H —> Zdark Zdark -> 4l, where Zdark is a dark vector boson.

In this talk, we will review the status of current searches for dark sector states at the LHC and the prospects for LHC Run 2.

 Speaker: Ketevi Assamagan (BNL) Material:
• 15:20 - 17:30 Coffee and Discussions  Location: CTPU
• 18:00 - 20:00 Forum Dinner ( Gyejeolbapsang (TimeWorld) )
• Friday, 15 July 2016
• 09:00 - 09:30 Coffee and Discussions  Location: CTPU
• 09:30 - 11:10 Morning Session 1: (session chair: Rouven Essig)
• 09:30 Light Dark Matter and Neutrinos 50'
The possible connection between neutrinos and light dark matter
is explored.  There are a number of interesting scenarios, including
(I) the scattering of light dark matter off neutrinos in the Universe,
(II) the radiative generation of neutrino masses from warm dark matter,
and (III) the emergence of warm dark matter in left-right symmetry.
 Speaker: Ernest Ma (Riverside) Material:
• 10:20 Searching for Light Dark Matter with Proton-Beam Fixed Target Experiments 50'  Speaker: Patrick deNiverville (Victoria) Material:
• 11:10 - 11:40 Coffee ( CTPU seminar room )
• 11:40 - 12:30 Morning Session 2: (session chair: Rouven Essig)
• 11:40 Dark matter decay via the gravity portal 50'
We consider the Standard Model extended with a dark matter particle in curved spacetime, motivated by the fact that the only current evidence for dark matter is through its gravitational interactions, and we investigate the impact on the dark matter stability of terms in the Lagrangian linear in the dark matter field and proportional to the Ricci scalar. We show that this "gravity portal" induces decay even if the dark matter particle only has gravitational interactions, and that the decay branching ratios into Standard Model particles only depend on one free parameter: the dark matter mass. We study in detail the case of a light singlet scalar and discuss the prospects to observe its gravitationally induced decay.

 Speaker: Alejandro Ibarra (TU Munich)
• 12:30 - 13:30 Lunch ( Cafeteria )
• 13:30 - 18:00 Excursion  Location: Gonju City