IBS-PNU Joint Workshop on Physics beyond the Standard Model

4 Dec 2019, 12:00 → 7 Dec 2019, 16:00 Asia/Seoul

Atlantis Room, B1 (Paradise Hotel Busan)

Deog Ki Hong (Pusan National University (KR))

The IBS-Busan Workshop on physics beyond standard model will be held during December 4-7, 2019 at the Paradise Hotel, Busan, Korea. The workshop is jointly organized by Center for Theoretical Physics of the Universe (CTPU) at IBS and High Energy Physics Group at Pusan National University (PNU). The purpose of this workshop is to bring together researchers for Physics beyond the Standard Model to present and discuss our current understanding and prospects for future progress.

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Information

• Workshop venue
- Paradise Hotel Busan
- More information: Paradise Hotel
- The workshop will be held in the Atlantis Room (Main Building B1).

• Accommodation
- Kolon Seacloud Hotel
- More information: Kolon Seacloud Hotel
- It takes just about 2 minutes on foot from the Kolon Seacloud Hotel to the workshop place.

• Registration deadline: November 15th, 2019
- Number of participants will be limited to 50.
- Accommodations will be provided to all invited participants and limited funds are available for some participants to support the accommodations if requested.

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Invited participants and speakers

• Gabriele Ferretti (Charmers U.)
• Koichi Hamaguchi (Tokyo U.)
• Francesco Sannino (CP3, SDU)
• Viljami Leino (Munich, Tech. U.)
• Joshua Ruderman (NYU)
• Changrim Ahn (Ewha U.)
• Kyu Jung Bae (Kyungpook Nat'l U.)
• Ki Young Choi (SKKU)
• Thomas Flacke (CTPU, IBS)
• Seok Kim  (Seoul Nat'l U.)
• Seyong Kim (Sejong U.)
• Yoonabi Kim (SKKU)
• Hyun Min Lee (Chung Ang U. /CERN)
• Hye-Sung Lee (KAIST)
• Kimyeong Lee (KIAS)
• Seung Joon Lee (Korea U.)
• Myeonghun Park (Seoul Tech U.)
• Seong Chan Park (Yonsei U.)
• Chang Sub Shin (CTPU, IBS)
• Sang Jin Sin (Hanyang U.)
• Jeonghyeon Song (Konkuk U.)
• Seokhoon Yun (KIAS)
• Ke-Pan Xie (Seoul Nat'l U.)
• Zeren Simon Wang (APCTP)

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Organizing Committee

• Kiwoon Choi (IBS-CTPU)
• Sanghyeon Chang (IBS-CTPU)
• Deog Ki Hong (PNU), Chair
• Kwang Sik Jeong (PNU)
• Jong-Wan Lee (PNU)
• Sang Hui Im (PNU)

 

For any information or assistance, please contact:

♦ Sang Hui Im
   imsanghui@pusan.ac.kr

 

Wednesday, 4 December

13:00 → 14:00 Registration

14:00 → 15:30 Afternoon session I

Convener: Kwang Sik Jeong (PNU)

14:00 Dark Axion Portal

Speaker: Hye-Sung Lee (KAIST)

Dark Axion Portal (Busan 2019).pdf

14:30 Searching for Dark Photons at the LHeC and FCC-he

Extensions of the Standard Model (SM) gauge group with a new $U(1)_X$ predict an additional gauge boson. Through kinetic mixing with the SM photons featured by a coupling $\epsilon$, the ensuing so-called dark photons $\gamma'$, which acquire mass as a result of the breaking of the gauge group $U(1)_X$, can interact with the SM field content. These massive dark photons can therefore decay to pairs of leptons, hadrons, or quarks, depending on their mass $m_{\gamma'}$. In this work, we discuss searches for dark photons in the mass range around and below one GeV at the LHeC and FCC-he colliders. The signal is given by the displaced decays of the long-lived dark photon into two charged fermions. We discuss the impact of conceivable irreducible (SM and machine-related) backgrounds and different signal efficiencies. Our estimates show that the LHeC and FCC-he can test a domain that is complementary to other present and planned experiments.

Speaker: Zeren Simon Wang (APCTP)

ZSW_04.12.2019.pdf

15:00 Axion-photon-dark photon oscillation and its implication for 21 cm observation

We examine the resonant conversion of axion-like particle (ALP) or dark photon to the electromagnetic photon in the early Universe, which takes place due to the ALP-photon-dark photon oscillations in background dark photon gauge fields. It is noted that the corresponding conversion probability can have an unusual spectral feature which allows strong conversion at low frequency domain, but has negligible conversion at high frequencies above certain critical frequency which is determined by the ALP coupling to dark photon and the strength of background dark photon gauge field. We apply this scheme to heat up the 21 cm photons without affecting the Cosmic Microwave Background, which can explain the tentative absorption signal of 21 cm photons detected recently by the EDGES experiment.

Speaker: Seokhoon Yun (KIAS)

IBS-PNUworkshop_SH.Yun_04.12.19.key

15:30 → 16:00 Coffee break

16:00 → 18:00 Afternoon session II

Convener: Sang Hui Im (PNU)

16:00 Probing charged Higgs bosons using Top quark polarisation

We study the production and the decay of a heavy charged Higgs boson at the Large Hadron Collider (LHC) in gb fusion. The chiral structure of the $H^+ \bar{t} b$ coupling can trigger a particular spin state of the top quark produced in the decay of a Charged Higgs boson and therefore, is sensitive to the underlying mechanism of the electroweak symmetry breaking (EWSB). Taking two benchmark models (2HDM type-I and 2HDM type-Y) as an example, we show that observables sensitive to the top quark polarisation -- constructed of energies and angles of the top quark’s decay products -- can be used both as a discovery as well as a characterization tool. We discuss the resilience of these observables to the flavor scheme used in the calculations, and to the NLO QCD corrections.

Speaker: Adil Jueid (Konkuk University)

IBS-Busan-041219.pdf

16:30 Matter-antimatter asymmetry without loops

We propose a new mechanism for generating matter-antimatter asymmetry via the interference of tree-level diagrams only. We first derive a general result that a nonzero CP-asymmetry can be generated via at least two sets of interfering tree-level diagrams involving either 2→2 or 1→N(with N≥3) processes. We illustrate this point in a simple TeV-scale extension of the Standard Model with an inert Higgs doublet and right-handed neutrinos, along with an electroweak-triplet scalar field. The imaginary part needed for the required CP-asymmetry comes from the trilinear coupling of the inert-doublet with the triplet scalar. Small Majorana neutrino masses are generated by both scotogenic and type-II seesaw mechanisms. The real part of the neutral component of the inert-doublet serves as a cold dark matter candidate. The evolutions of the dark matter relic density and the baryon asymmetry are intimately related in this scenario.

Speaker: Arnab Dasgupta (Seoul National University of Science and Technology)

arnab_IBS-PNU_2019.key

17:00 Cosmological Relaxation from Dark Fermion Production

We consider the cosmological relaxation solution to the electroweak hierarchy problem using the fermion production as a dominant friction force. In our approach, neither super-Planckian field excursions nor a large number of e-folds arise, and scanning over thermal Higgs mass squared is avoided. The produced fermions from the relaxion source through the derivative coupling are SM-singlets, what we call dark fermions, and they can serve as the keV scale warm dark matter candidates.

Speaker: Ui Min (KAIST)

Ui Min_cosmological relaxation from dark fermion production.pdf

17:30 Probing sterile neutrino in meson decays with and without sequential neutrino decay

We present the most systematic approach to discover a sterile neutrino $N$ or constrain $\left| U_{\ell N} \right|^2$, the mixing between active neutrino $\nu_\ell$ (with $\ell=\mu,\tau$) and the sterile neutrino $N$, from $B \to D\ell N$ decays. Our constraint on $\left| U_{\mu N} \right|^2$ achievable from Belle II data is comparable with that from the much larger data set of upgraded LHCb, even much better for mass of sterile neutrino $m_N < 2$~GeV. We can also probe the Dirac and Majorana nature of $N$ by observing the sequential decay of $N$, including suppression factors associated with observation of a displaced
vertex and helicity flip, for Majorana $N$.

Speaker: Donghun Lee (Yonsei University)

Donghun Lee.pptx

Thursday, 5 December

09:00 → 12:00 Morning session

Convener: Kyu Jung Bae (Kyungpook National U)

09:00 Dark Matter Heating vs. Rotochemical Heating in Old Neutron Stars

Dark matter (DM) particles in the Universe accumulate in neutron stars (NSs) through their interactions with ordinary matter. It has been known that their annihilation inside the NS core causes late-time heating, with which the surface temperature becomes a constant value of 2000-3000 K for the NS age t > 10^6-10^7 years. This conclusion is, however, drawn based on the assumption that the beta equilibrium is maintained in NSs throughout their life, which turns out to be invalid for rotating pulsars. The slowdown in the pulsar rotation drives the NS matter out of beta equilibrium, and the resultant imbalance in chemical potentials induces late-time heating, dubbed as rotochemical heating. This effect can heat a NS up to 10^6 K for t > 10^6−10^7 years. In fact, recent observations found several old NSs whose surface temperature is much higher than the prediction of the standard cooling scenario and is consistent with the rotochemical heating. Motivated by these observations, we reevaluate the significance of the DM heating in NSs, including the effect of the rotochemical heating. We show that the signature of DM heating can still be detected in old ordinary pulsars, while it is concealed by the rotochemical heating for old millisecond pulsars. On the other hand, a discovery of a very cold NS can give a robust constraint on the DM heating, and thus on DM models.

Speaker: Koichi Hamaguchi (University of Tokyo)

201912_Busan_Koichi.key

10:00 Coffee break

10:30 Dark Matter Targets with Exponentially Small Couplings

Speaker: Joshua Ruderman (New York University)

Targets_Busan_Josh.key

11:30 Four-form relaxation of Higgs mass and cosmological constant

We consider the cosmological relaxation of the Higgs mass and the cosmological constant due to the four-form fluxes in four dimensions. We introduce non-minimal four-form couplings for reheating the Universe after the last membrane nucleation and propose some simple examples with a pseudo-scalar or a complex singlet scalar field. We also discuss the implications of the non-minimal four-form coupling to gravity for flattening the inflaton potential in chaotic inflation models with a pseudo-scalar field.

Speaker: Hyun Min Lee (Chung-Ang University and CERN)

Busan2019-hmlee.pdf

12:00 → 14:00 Lunch

14:00 → 15:30 Afternoon session I

Convener: Hyun Min Lee (Chung Ang Univ. and CERN)

14:00 Higgs inflation: updated

Higgs inflation is the best fitting model of cosmological inflation after the Planck data. I would like to discuss some recent discussions on fine-tuning, unitarity, violent preheating, and primordial black hole formation in Higgs inflation.

Speaker: Seong Chan Park (Yonsei University)

scp.pdf

14:30 Magnetogenesis from rotating scalar: à la scalar chiral magnetic effect

The chiral magnetic effect is a phenomenon that an electric current parallel to the magnetic fields is induced in the presence of the chiral asymmetry in the fermionic system. In this talk, I would like to point out that the electric current induced by the dynamics of a pseudo scalar field that anomalously couples to electromagnetic fields can be interpreted as a similar effect in the scalar system. Noting that the velocity of the pseudo scalar field, which is the phase of a complex scalar, represents that the system carries a global U(1) number asymmetry, we see that the induced current is proportional to the asymmetry and parallel to the magnetic field, which is the same to the chiral magnetic effect. The mechanism like the Affleck-Dine mechanism an asymmetry carried by the Affleck-Dine field can induce the electric current and give rise to the instability in the (electro)magnetic field if it is unbroken by the expectation value of the Affleck-Dine field. Cosmological consequences of this mechanism are investigated.

Speaker: Chang Sub Shin (IBS-CTPU)

IBS_Busan_CSShin_1205.pdf

15:00 Neutrino self-interaction in the signals from blazar TXS 0506+056

Even though conventional leptonic or lepto-hadronic models of blazar successfully explain the observed electromagnetic component of the flaring signal from the Blazar TXS 0506+056 in a large range of energy window 𝐸𝛾∈(10−1eV,102 GeV), the predicted neutrino flux is too small to be consistent with the IceCube observation at 𝐸𝜈∼300 TeV. We show that a sizable self-interaction of neutrinos with a light messenger resolves the discrepancy. Interestingly, the same physics can relieve the cosmological tension in 𝐻0 and 𝜎8.

Speaker: Yongsoo Jho (Yonsei University)

YSJ_IBSPNU2019.pdf

15:30 → 16:00 Coffee break

16:00 → 18:00 Afternoon session II

Convener: Thomas Flacke (IBS-CTPU)

16:00 Towards the ultimate axion dark matter sensitivity in the 1-20 GHz frequency range

The IBS-CAPP has currently accomplished all its technical challenges towards achieving the ultimate sensitivity in axion dark matter: DFSZ level even for 10% axion dark matter content in the local halo. Early next year we are expecting to receive a low temperature superconducting (LTS), 12T magnet LTS-12T/320mm, based on Nb3Sn cable, from Oxford Instruments, which will enable us to cover the 1-8 GHz axion frequency range. For the rest of the frequency range of 8-20 GHz we need to finish the high temperature superconducting (HTS) 25T magnet being developed at BNL. I will present the current status and the rising competition from around the world for the various frequency ranges.

Speaker: Yannis Semertzidis (IBS-CAPP and KAIST)

YkS_BSM_Busan_2019_1105.pdf

YkS_BSM_Busan_2019_1105.pptx

16:30 Strong first order phase transition in composite Higgs models

We study the strong first order electroweak phase transition (SFOEWPT) with the SO(6)/SO(5) composite Higgs model, whose scalar sector contains one Higgs doublet and one real singlet. Six benchmark models are built with fermion embeddings in 1, 6, and 15 of SO(6). We show that SFOEWPT cannot be triggered under the minimal Higgs potential hypothesis, which assumes the scalar potential is dominated by the form factors from the lightest composite resonances. To get a SFOEWPT, the contributions from local operators induced by physics above the cutoff scale are needed. We take the 6 + 6 model as an example to investigate the gravitational waves prediction and the related collider phenomenology.

Speaker: Ke-Pan Xie (Seoul National University)

Ke-Pan_Busan.pdf

17:00 Recent (non-Rx) highlights from Belle

In this talk, we present recent highlights of physics results from Belle, other than R(D()), R_K(). We also show a recent status of the Belle II experiment.

Speaker: Yongjoon Kwon (Yonsei University)

IBS-Busan_Y.Kwon.pdf

Friday, 6 December

09:00 → 12:00 Morning session

Convener: Deog Ki Hong (PNU)

09:00 Recent developments in partial compositeness

I review attempts at constructing models of partial compositeness from strongly coupled gauge theories. A few minimality assumptions allow one to isolate a small number of prototypical models that can be studied on the lattice and probed at colliders. I review recent results in these
two areas, such as the spectrum from the lattice and two possible exotic signatures at colliders, namely light and weakly coupled additional ALPs and additional decays of top partners.

Speaker: Gabriele Ferretti (Chalmers University)

Ferretti_Busan19.pdf

10:00 Coffee break

10:30 The Lattice Study of SU(2) with Many Fermions

Depending on the number of Fermions a gauge theory can have a behavior ranging from asymptotic freedom to asymptotic safety. I show the behavior of SU(2) gauge theory with 4,6,8,24, and 48 fermions measured from lattice field theory simulations. We observe limits for the lower and upper edge of the conformal window and measure anomalous dimensions for mass and coupling. We also try to understand the behavior with very high number of fermions, possibly leading to second conformal window.

Speaker: Viljami Leino (Technical University of Munich)

VL_Busan_talk.pdf

11:30 Common exotic decays of vector-like top partners: Motivation, challenges, and opportunities for collider searches

Speaker: Thomas Flacke (IBS-CTPU)

FlackePNU.pdf

12:00 → 14:00 Lunch

14:00 → 15:30 Afternoon session I

Convener: Jong-Wan Lee (PNU)

14:00 A Natural Composite GUT

Speaker: Seung Joon Lee (Korea University)

14:30 Lattice NRQCD study of heavy quark and anti-quark annihilations in QGP and heavy dark matter annihilations in early universe

Speaker: Seyong Kim (Sejong University)

mini2019.pdf

15:00 Inert Doublet Model with U(1) symmetry

Speaker: Jeonghyeon Song (Konkuk University)

Pusan-191206.pdf

15:30 → 16:00 Coffee break

16:00 → 18:00 Afternoon session II

Convener: Seong Chan Park (Yonsei U)

16:00 Higgs precision with Deep Learning

Speaker: Myeonghun Park (Seoultech)

PARK_presentation.pdf

16:30 Neutrino Oscillations in Dark Matter

Speaker: Ki-Young Choi (Sungkyunkwan University)

DMANO_PNU_KYChoi.pdf

17:00 4D asymptotically safe quantum field theories (Skype)

Speaker: Francesco Sannino (CP3, University of Southern Denmark)

17:30 Searching for New Physics Signals from Timing Spectra at Neutrino Experiment

We propose a novel strategy to search for new physics signals in timing spectra, envisioning the situation in which new particles come from the decay of a heavier mother particle with a finite particle width. For example, the timing distribution of events induced by the dark matter particle scattering at the detector may populate in a relatively narrow range, forming a "resonance-like" shape. Due to this structural feature, the signal may be isolated from the backgrounds, in particular when the backgrounds are uniformly distributed in energy and time. We analyze the existing data for the CsI detector of the COHERENT experiment with a timing cut and an energy cut, and find an excess in the timing distribution which can be explained by dark matter. Our new approach can be generally utilized for searching for new physics such as light dark matter or non-standard neutrino interaction in coherent neutrino scattering experiments including CCM, COHERENT, and JSNS^2.

Speaker: Jong-Chul Park (Chungnam National University)

TimingSpectra_JCPark_Busan.pdf

18:00 → 20:00 Banquet

Saturday, 7 December

09:00 → 12:00 Morning session

Convener: Changrim Ahn (Ewha Womans U)

09:00 Why the quark mass is so small: the chiral symmetry and Heun's equation

We show that a holographic abelian Higgs model leads us to the Heun's equation, which is the same one derived for the bag model studied by Lichtenberg. The correspondence between two models resembles the AdS/CFT dictionary. The spectrum follows linear confinement for zero quark mass, while it is highly non-linear for finite quark mass. It can be traced back to the difference in the singularity class of equation of motion made by the quark mass. It suggests that the origin of the chiral symmetry is tied to the dynamics of color confinement.

Speaker: Sang-Jin Sin (Hanyang University)

2019.12.pusan.pdf

09:30 Higher Curvature Gravity and its implication

Einstein gravity may be coming from the leading linear term of the curvature in the low energy effective action. As the simplest extension of the Einstein gravity with the higher curvature term, we study the model with the Gauss-Bonnet term, which is the simplest term allowing the equation of motion to be at the 2nd order. The model wi analyze is the dilaton Einstein Gauss-Bonnet theory. We study the properties of this model, especially the black holes, and the cosmological implications in the early universe.

Speaker: Bum-Hoon Lee (Sogang University)

GravityGB1912Busan-v2.pdf

10:00 Coffee break

10:30 Black holes in holographic quantum gravity

Speaker: Seok Kim (Seoul National University)

busan_seok-kim.pdf

11:00 Complete Prepotential of 5d Superconformal Field Theories

Speaker: Kimyeong Lee (KIAS)

IBS-Busan_Kimyeong-Lee.pdf

11:30 Perturbative methods in holography vs. Supersymmetric Localization

We study supergravity BPS equations which correspond to mass- deformation of some representative AdS/CFT examples. The field theory of interest are N=4, D=4 super Yang-Mills, the ABJM model in D=3, and the Brandhuber-Oz fixed point in D=5. For these gauge theories the free energy with mass terms for matter multiplets is calculable in large-N limit using supersymmetric localization technique. We suggest a perturbative method to solve the supergravity equations. For the dual of mass-deformed ABJM model we reproduce the known exact solutions. For the mass-deformed Brandhuber-Oz theory our method gives the holographic free energy in analytic form. For N=1* deformations of N=4 super Yang-Mills, we calculated exactly some expansion coefficients, which were only known numerically before our work.

Speaker: Nakwoo Kim (Kyung Hee University)

nkimbusan2019.pdf

12:00 → 12:10 Closing