Light Dark World International Forum 2016

11 Jul 2016, 09:00 → 15 Jul 2016, 18:30 Asia/Seoul

CTPU seminar room (Daejeon, Korea)

Brian Batell (Pittsburgh), Hye-Sung Lee (IBS)

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

 

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[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.

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Poster LDW_2016_poster-2.pdf LDW_2016_poster.pdf

Monday, 11 July

09:00 Registration and Coffee

Welcome and Introduction: (session chair: Hye-Sung Lee)

1 Welcome and Introduction

Speaker: Kiwoon Choi (IBS-CTPU)

Slides IBS_introduction.pdf

Morning Session 1: (session chair: Brian Batell)

2 New Direct Detection Probes of sub-GeV Dark Matter

Speaker: Rouven Essig (Stony Brook)

Slides Rouven-Essig-Korea-LDW.final.pdf

3 Implications of Naturalness for Searches for Light Dark Sectors

Speaker: David Morrissey (TRIUMF)

Slides dmorri-ldw16.pdf

11:10 Coffee

Morning Session 2: (session chair: Brian Batell)

4 Dark-sector searches from flavor-factory experiment

Speaker: Youngjoon Kwon (Yonsei)

Slides LightDW_yjkwon.pdf

5 New faces of dark matter: SIMP and its friends

Speaker: Hyun Min Lee (Chuang-Ang)

Slides LDM2016-hmlee.pdf

13:00 Lunch

Afternoon Session: (session chair: Ketevi Assamagan)

6 New Electron Fixed Target Experiments to Search for Light Dark Matter

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)

Slides LightDarkWorld2016.pdf

7 Right-handed neutrino dark matter and the B-L gauge boson

Speaker: Kunio Kaneta (IBS-CTPU)

Slides kaneta_LDW2016.pdf

Coffee and Discussions

Tuesday, 12 July

Coffee and Discussions

Morning Session 1: (session chair: David Morrissey)

8 Cosmic Microwave Background Probes of Light Particles

Speaker: Neelima Sehgal (Stony Brook)

Slides LightDarkWorld2016.pdf

9 Phenomenology of light sterile neutrinos

Speaker: Manfred Lindner (MPI Heidelberg)

Slides lindner-daejeon16.pdf

11:10 Coffee

Morning Session 2: (session chair: David Morrissey)

10 Enhanced Production of Sterile Neutrinos at Accelerator Experiments

Speaker: Brian Batell (Pittsburgh)

Slides Batell-LDW2016.pdf

11 Dark radiation with WIMPZILLA

Speaker: Seongchan Park (Yonsei)

Slides scp.pdf

13:00 Lunch

Afternoon Session: (session chair: Sean Tulin)

12 Disappearance of dancing reactor neutrinos at RENO

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)

Slides LightDarkWorld-RENO-RENO50.pdf

13 Interacting Dark Matter and Radiation in Cosmology

Speaker: Tang Yong (KIAS)

Slides LDW_Tang.pdf

Coffee and Discussions

Wednesday, 13 July

Coffee and Discussions

Morning Session 1: (session chair: Ernest Ma)

14 The physics potential of the SHiP experiment at CERN

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)

Slides Korea.pdf

15 Role of dark Higgs boson in DM phenomenology

Speaker: Pyungwon Ko (KIAS)

Slides ibs-ctpu2016_pko.pdf

11:10 Coffee

Morning Session 2: (session chair: Ernest Ma)

16 Self-interacting dark matter and new light forces

Speaker: Sean Tulin (York)

Slides IBS_tulin_16.pdf

17 A new constraint on millicharged dark matter from galaxy clusters

Speaker: Toyokazu Sekiguchi (IBS-CTPU)

Slides Toyokazu_Sekiguchi.pdf

13:00 Lunch

Afternoon Session: (session chair: Hyun Min Lee)

18 Searches for axion and sterlile neutrino from the CUP (Center for Undergroud Physics), IBS

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)

Slides Light_Dark_World_hkpark.pdf

Coffee and Discussions

Thursday, 14 July

Coffee and Discussions

Morning Session 1: (session chair: Alejandro Ibarra)

19 CP Violation, Fermion oscillations and Baryogenesis

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)

Slides Nelson_korea.pdf

20 Faking The Diphoton Excess (?) by Displaced Dark Photon Decays

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)

Slides Fake_Photon_Tsai.pdf

11:10 Coffee

Morning Session 2: (session chair: Alejandro Ibarra)

21 The axion dark matter search at CAPP: a comprehensive approach, and the proton EDM experiment

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)

Slides YkS_Light_Dark_world_2016_0714.pptx

22 Relaxion from multiple axions

Speaker: Sang Hui Im (IBS-CTPU)

Slides LDW_shim.pdf

13:00 Lunch

Afternoon Session: (session chair: Hyun Min Lee)

23 Search for Dark Interactions at the LHC

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)

Slides DarkInteractions-Korea-Jul2016.pdf

Coffee and Discussions

18:00 Forum Dinner

Friday, 15 July

Coffee and Discussions

Morning Session 1: (session chair: Rouven Essig)

24 Light Dark Matter and Neutrinos

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)

Slides daejeon16.pdf

25 Searching for Light Dark Matter with Proton-Beam Fixed Target Experiments

Speaker: Patrick deNiverville (Victoria)

Slides ProtonFixedTargets.pdf

11:10 Coffee

Morning Session 2: (session chair: Rouven Essig)

26 Dark matter decay via the gravity portal

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 Lunch

Excursion