KEK Theory Meeting on Particle Physics Phenomenology (KEK-PH2023)

Session

Short talks

Nov 7, 2023, 11:05 AM

Kobayashi Hall (KEK)

Conveners

Short talks: Hugues Beauchesne, William DeRocco

• Ryuichiro KITANO

Short talks: Keiichi Watanabe, Lukas Treuer

• Masato Yamanaka

Short talks: Keisho Hidaka, Lalu Zamakhsyari, Albertus Panuluh, Coh Miyao

• Yutaka SAKAMURA

Short talks: Jason Arakawa, Philip Lu, Kimiko Yamashita, Masato Yamanaka

• Wakutaka NAKANO (KEK)

Short talks: Takuya Agemura, Ahmed Hammad, Mihoko NOJIRI, Satsuki Nishimura

• Motoi ENDO

Short talks: Morimitsu Tanimoto, Yukimura Izawa, Ryosuke Suda, Tetsuo Shindou

• Hiroaki Sugiyama

Short talks: Xinru Wang, Yushi Mura, Chikako Idegawa, Pedro Pasquini

• Joe Sato

Short talks: Shuhei Ohzawa, Atsuya Niki, Ya-Juan Zheng

• Mihoko NOJIRI (KEK)

Short talks: Kensuke Akita , Natsumi Nagata, JUNSEOK LEE

• Andrea Mitridate

Short talks: Joe Sato, Shonosuke Takeshita, Keiya Ishiguro

• Masahiro Ibe

Short talks: Shuntaro Aoki, Hexu Zhang, Yuma Narita

• Kyohei Mukaida

Short talks: Shohei Okawa, Risshin Okabe, Shota Saito

• Natsumi Nagata

Short talks: Masashi Aiko, Kazunari Shima, Nodoka Yamanaka

• Shohei Okawa

Short talks: Kento Asai, Akifumi Chitose, Chuan-Ren Chen

• Dario Buttazzo

Short talks: Yuanyuan Wang, Takumi Kuwahara

• Ahmed Hammad

Short talks: Ryo Yokokura, Takafumi Kai

• Gregory Loges (KEK)

3. Hugues Beauchesne "Observability of the Higgs boson decay to a photon and a dark photon"

11/7/23, 11:05 AM

Many collider searches have attempted to detect the Higgs boson decaying to a photon and an invisible massless dark photon. For the branching ratio to this channel to be realistically observable at the LHC, there must exist new mediators that interact with both the standard model and the dark photon. In this talk, we present experimental and theoretical constraints on an extensive set of...

5. Keiichi Watanabe "Revisiting Froggatt-Nielsen Mechanism"

11/7/23, 11:05 AM

The Froggatt-Nielsen (FN) mechanism is a compelling explanation for the hierarchical structures observed in the Yukawa couplings of charged leptons and quark mixing angles. In this mechanism, the above structures are realized by imposing different U(1) charges for each generation of fermions under a new U(1) flavor symmetry. So far, several FN charge assignments have been proposed in the...

6. Lukas Treuer "Quantum Effects on Neutrino Parameters From a Flavored Gauge Boson"

11/7/23, 11:30 AM

Despite the longstanding assumption that neutrinos are massless, oscillation experiments have shown that they are, in fact, massive, and furthermore mix significantly. Constraints from other observations additionally indicate that these masses are very small compared to others in the Standard Model. A possible explanation is provided by the seesaw mechanism, wherein heavy intermediate...

41. William DeRocco "Exploring the dark side with high-cadence microlensing"

11/7/23, 11:30 AM

17. Jason Arakawa "Detection of Bosenovae with Quantum Sensors on Earth and in Space"

11/7/23, 4:10 PM

In a broad class of theories, the accumulation of ultralight dark matter (ULDM) with particles of mass $10^{-22}~\textrm{eV} < m_{\phi} < 1~\textrm{eV}$ leads to the formation of long-lived bound states known as boson stars. When the ULDM exhibits self-interactions, prodigious bursts of energy carried by relativistic bosons are released from collapsing boson stars in bosenova explosions. I...

2. Keisho Hidaka "Impact of quark flavor violating SUSY on h(125) decays at future lepton colliders,"

11/7/23, 4:10 PM

We study the CP-even neutral Higgs boson decays $h \to c \bar{c}, b \bar{b}, b \bar{s}, \gamma \gamma, g g$ in the Minimal Supersymmetric Standard Model (MSSM) with general quark flavor violation (QFV) due to squark generation mixings, identifying the h as the Higgs boson with a mass of 125 GeV. We compute the widths of the h decays to $c \bar c, b \bar b, b \bar s (s \bar b)$ at full...

9. Lalu Zamakhsyari "Probing chirality structure in lepton-flavor-violating Higgs decay $h \to \tau\mu$ at the LHC"

11/7/23, 4:35 PM

A phenomenological study for determining the chirality structure in lepton-flavor-violating Higgs (hLFV) decays $h \to \tau\mu$ at the LHC is presented. We estimate the effects of the $\tau$ polarization in the analysis. We find that the sensitivity would be generically affected up to $ \pm4-6 \%$ in terms of the BR($h\to\tau\mu$) upper bound. We further study the benchmark scenarios, and...

18. Philip Lu "Regurgitated Dark Matter"

11/7/23, 4:35 PM

We present an alternative production mechanism to thermal freeze-out for WIMP dark matter. In this model, GeV mass particles are shepherded into false vacuum pockets during a first order phase transition and trapped by a large mass gap. They form compact remnants that collapse into light primordial black holes, which subsequently regurgitates the initial constituent particles through Hawking...

10. Albertus Panuluh "Renormalization group effects in the quark sector of universal seesaw model"

11/7/23, 5:00 PM

We study the quark sector of the universal seesaw model with SU(2)L × SU(2)R × U(1). This model aims to explain the mass hierarchy of the quark sector by introducing the corresponding vector-like quark (VLQ) for each ordinary quark with different hierarchical masses. We integrated out the VLQs one by one within the tree-level matching and also took into account the one-loop renormalization...

19. Kimiko Yamashita "Positivity Bounds on Higgs-Portal Dark Matter"

11/7/23, 5:00 PM

We consider the positivity bounds for WIMP scalar dark matter with effective Higgs-portal couplings up to dimension-8 operators. Taking the superposed states for Standard Model Higgs and scalar dark matter, we show that the part of the parameter space for the effective couplings, otherwise unconstrained by phenomenological bounds, is ruled out by the positivity bounds on the dimension-8...

12. Coh Miyao "Neutrino models based on the U$$(1)_{\mu-\tau}$$ gauge symmetry"

11/7/23, 5:25 PM

Recently precise experiments have suggested that there is a discrepancy between theoretical and experimental values of muon g-2 based on the Standard Model (SM). It is known that the $$U(1)_{¥mu-¥tau}$$ gauge model can solve this. There are also studies that describe neutrino physics in terms of this symmetry-based model. For example, an analytical method has been proposed to give predictions...

21. Masato Yamanaka "Revisit the relic density of Higgs-portal dark matter"

11/7/23, 5:25 PM

We revisit the relic density of Higgs portal dark matter (DM) with taking into account the Higgsplosion effect. We minimally extend the standard model by introducing a fermionic DM, and derive the Boltzmann equation with the DM annihilation channel of high-multiplicity final state. It is shown that the balance of Higgsplosion and Higgspersion effects derives a window function, and the final...

37. Morimitsu Tanimoto "Fermion mass hierarchy and CP violation in modular symmetry"

11/8/23, 10:00 AM

Modular symmetry of flavors presents new aspects for mass hierarchy and CP violation. I introduce the general discussions and then present examples. of flavor model. These works are collaborated with S. Petcov.

27. Takuya Agemura "On Λ_QCD^2/m renormalons of pole mass and interquark potential"

11/8/23, 10:00 AM

Discovery of the cancellation of O(Λ_QCD) renormalons in the QCD potential and quark pole masses improved dramatically our understanding of the quark masses, and furthermore, enabled precise determination of the fundamental physical constants, such as alpha_s(Mz), m_b, m_c and Vcb. Here, we aim to extend our understanding to the cancellation of O(Λ_QCD^2) renormalons, whose nature has not been...

29. Ahmed Hammad "Classical/Quantum contrastive learning models for collider analyiss"

11/8/23, 10:25 AM

34. Yukimura Izawa "S4 flavor model with 3HDM"

11/8/23, 10:25 AM

The Standard Model fermions, quark leptons, have a generational structure with different masses (mass hierarchy) and mixing of generations (flavour mixing). The Standard Model only assigns parameters to these generational structures, but does not provide a theoretical explanation. In this study, we construct a flavour model that reproduces the generational structure of leptons using the S4...

31. Mihoko NOJIRI "Anatomy of Jet classification using deep learning"

11/8/23, 10:50 AM

State-of-the-art (SoTA) deep learning models have achieved tremendous improvements in jet classification performance while analyzing low-level inputs, but their decision-making processes have become increasingly opaque. We introduce an analysis model (AM) that combines several phenomenologically motivated neural networks to circumvent the interpretability issue while maintaining high...

20. Ryosuke Suda "Model building by Coset space dimensional reduction using eight-dimensional coset spaces"

11/8/23, 10:50 AM

We investigate the twelve-dimensional gauge-Higgs unification models with an eight-dimensional coset space. For each model, we apply the coset space dimensional reduction procedure and examine the particle contents of the resulting four-dimensional theory. Then, some twelve-dimensional SO(18) gauge theories lead to models of the SO(10)\times U(1) grand unified theory in four dimensions, where...

33. Satsuki Nishimura "Exploring the flavor structure of quarks and leptons with reinforcement learning"

11/8/23, 11:15 AM

We propose a method to explore the flavor structure of quarks and leptons with reinforcement learning, which is a type of machine learning. As a concrete model, we focus on the Froggatt-Nielsen model with U(1) flavor symmetry. By training neural networks on the U(1) charges of quarks and leptons, the agent finds 21 models to be consistent with experimentally measured masses and mixing angles...

40. Tetsuo Shindou "Low-scale leptogenesis and dark matter in a three-loop radiative seesaw model"

11/8/23, 11:15 AM

We show that three open questions in particle physics and cosmology: the origin of neutrino mass, the identity of dark matter, and the origin of the baryon asymmetry of the universe can be explained simultaneously in the three-loop seesaw model proposed by Krauss, Nasri, and Trodden. We discuss the difficulty of successful leptogenesis with three right-handed neutrinos, and we propose a...

42. Canceled

11/8/23, 4:10 PM

48. Xinru Wang "QCD preheating"

11/8/23, 4:10 PM

It is believed that QCD can not play major role to account for cosmological matter abundances observed in the Universe today including the baryon asymmetry of the Universe. However, in this talk, I would like to share a new picture of the thermal history called "QCD preheating". The dynamic motion of light quark condensate should have the potential to explosively produce the number densities...

45. Shuhei Ohzawa "Discrimination of Extended Higgs Sectors through Higher-Order Contributions to the Higgs Trilinear Coupling"

11/8/23, 4:35 PM

Since the nature of the Higgs boson remains undetermined, extended Higgs models with different Higgs potentials are proposed to explain phenomena beyond the Standard Model. In this presentation, we focus on the discrimination of extended Higgs models such as the Classical Scale Invariance model and the pseudo-Nambu-Goldstone model. By calculating the Higgs trilinear coupling at the 1-loop...

49. Yushi Mura "New theoretical constraints on the non-decoupling physics with the mass dependent beta function"

11/8/23, 4:35 PM

Electroweak baryogenesis is realized by the first order electroweak phase transition. In the extended Higgs models, it is caused by the relatively large scalar coupling constants. In such case, it is known that the Landau pole appears at a low scale, which is not compatible to the high energy experiments. By using the mass dependent beta function, in which threshold effects of the mass are...

46. Atsuya Niki "Indirect search for the WIMP at \mu^+\mu^+ collider"

11/8/23, 5:00 PM

Weakly interacting massive particles (WIMPs) with electroweak charges, such as the wino and the Higgsino, are one of the most natural candidates of the dark matter in the universe. In this paper, we study the search for WIMPs at future multi-TeV $\mu^+\mu^+$ colliders. We examine the direct production search of WIMPs through the mono-muon channel and the indirect search through the quantum...

50. Chikako Idegawa "Electron electric dipole moment and electroweak baryogenesis in a complex scalar extension of the Standard Model"

11/8/23, 5:00 PM

In the Standard Model plus one complex scalar field, it is known that the signal of the new physics is suppressed when Higgs boson masses are degenerate. The introduction of higher dimensional operators is necessary to generate the CP symmetry violation associated with the realization of electroweak baryogenesis in this model. In this study, We analyze the contribution to the electron electric...

51. Pedro Pasquini "light BSM physics search using radiative emission of neutrino pair"

11/8/23, 5:25 PM

We propose a new possibility of using the coherently enhanced neutrino pair emission to probe BSM light-mediator interactions between electron and neutrinos. With typical momentum transfer at the atomic $\mathcal O(1\,{\rm eV})$ scale, this process is extremely sensitive for the mediator mass range $\mathcal O(10^{-3}∼10^4)$\,eV. The sensitivity on the product of couplings with electron ($g_e$...

47. Ya-Juan Zheng "CP-violating top-Higgs coupling in SMEFT"

11/8/23, 5:25 PM

We study the process $\mu^- \mu^+ \to \nu_\mu \bar{\nu}_\mu t \bar{t} H$.

39. Joe Sato "Asymmetric mediator in scotogenic model"

11/9/23, 10:40 AM

The scotogenic model is the Standard Model (SM) with Z2 symmetry and the addition of Z2 odd right-handed Majorana neutrinos and SU(2)L doublet scalar fields. We have extended the original scotogenic model by an additional Z2 odd singlet scalar field that plays a role in dark matter. In our model, the asymmetries of the lepton and Z2 odd doublet scalar are simultaneously produced through...

14. Kensuke Akita "Supernova 1987A limits on heavy neutral leptons and ${\rm U(1)}_{L_\mu-L_\tau}$ gauge bosons from the high-energy tail of neutrino fluxes"

11/9/23, 10:40 AM

Light hypothetical particles can be produced in the core of supernovae. Their subsequent decays to neutrinos can produce a flux component with higher energies than the standard flux. We discuss limits on light particles decaying to neutrinos flavor-dependently from supernovae using this flux modification. In particular, we will obtain limits on heavy neutral leptons (HNLs) and ${\rm...

15. Natsumi Nagata "Vortex Creep Heating vs. Dark Matter Heating in Neutron Stars,"

11/9/23, 11:05 AM

Dark matter particles captured in neutron stars deposit their energy as heat. This DM heating effect can be observed only if it dominates over other internal heating effects in NSs. In this work, as an example of such an internal heating source, we consider the frictional heating caused by the creep motion of neutron superfluid vortex lines in the NS crust. The luminosity of this heating...

22. Shonosuke Takeshita "W boson mass and grand unification via the type-II seesaw-like mechanism"

11/9/23, 11:05 AM

We propose an SU(5) GUT model extended with two additional pairs of 10 representation vector-like fermions. The CDF collaboration W boson mass anomaly is explained by using the VEV of a real SU(2)L triplet scalar coming from the 24 representation Higgs. The vector-like fermions are decomposed partly into vector-like quark doublets. Those vector-like quark doublets acquire mass from two...

16. JUNSEOK LEE "Nanohertz Gravitational Waves from Axion Domain Walls Coupled to QCD"

11/9/23, 11:30 AM

The recently reported data from NANOGrav, EPTA, PPTA, and CPTA suggest the presence of stochastic gravitational waves in the nHz range. Here, we demonstrate that these can be explained by axion domain walls coupled to QCD. In this scenario, temperature-dependent biases, induced by non-perturbative effects of QCD, act on axion domain walls, causing them to collapse and emit gravitational waves....

23. Keiya Ishiguro "Finite Landscape on toroidal orientifolds with h^{2, 1} = 1"

11/9/23, 11:30 AM

We present a finite Landscape of Type IIB flux compactifications on toroidal orientifolds with h^{2, 1} = 1. Due to the S-duality and a duality in the complex-structure modulus space, the flux Landscape where we consider SUSY Minkowski solutions becomes finite with a fixed D3-brane charge of the three-form fluxes. Thus, we can define the probability associated with the modulus VEVs. In the...

24. Shohei Okawa "Renormalization group effects in QCD axion phenomenology,"

11/9/23, 3:10 PM

We study the impact of renormalization group effects on QCD axion phenomenology. Focusing on the DFSZ model, we argue that the relevance of running effects for the axion couplings crucially depends on the scale where the heavier Higgs doublet, charged under the Peccei-Quinn symmetry, is integrated out. We study the impact of these effects on astrophysical and cosmological bounds as well as on...

28. Shuntaro Aoki "Inflationary Correlators with Dynamical Mass,"

11/9/23, 3:10 PM

Massive fields can leave an imprint on primordial correlation functions or inflationary correlators with specific oscillatory features, which is dubbed the cosmological collider sig- nal. In this work, we analytically investigate effects of a time-dependent mass of a scalar field on inflationary correlators, extending previous numerical studies and implementing techniques developed in the...

30. Hexu Zhang "Dynamical realization of the small field inflation black of Coleman-Weinberg type in the post supercooled universe,"

11/9/23, 3:35 PM

The small field inflation (SFI) of Coleman-Weinberg (CW) type suffers from precise tuning of the initial inflaton field value to be away from the true vacuum one. We propose a dynamical trapping mechanism to solve this problem: an ultra-supercooling caused by an almost scale-invariant CW potential traps the inflaton at the false vacuum, far away from the true vacuum dominantly created by...

25. Risshin Okabe "Axion detection via superfluid 3He ferromagnetic phase and quantum measurement techniques,"

11/9/23, 3:35 PM

We propose to use the nuclear spin excitation in the ferromagnetic A1 phase of the superfluid 3He for the axion dark matter detection. This approach is striking in that it is sensitive to the axion-nucleon coupling, one of the most important features of the QCD axion introduced to solve the strong CP problem. We also show that the combination of the squeezing of the final state with the...

26. Shota Saito "Cosmological axions challenge string theory"

11/9/23, 4:00 PM

Recent cosmological observations have pointed to the existence of ultralight axions. The introduction of at least three ultralight axions could mitigate the Hubble tension and S8 tensions and explain cosmic birefringence. Furthermore, dark energy and dark matter could also be ultralight axions. These multiple axions challenge string theory, especially the swampland conjecture, which is...

32. Yuma Narita "Hybrid inflation driven by the QCD axion"

11/9/23, 4:00 PM

When the inflaton is coupled to the gluon Chern-Simons term for successful reheating, mixing between the inflaton and the QCD axion is generally expected given the solution of the strong CP problem by the QCD axion. This is particularly natural if the inflaton is a different, heavier axion. We propose a scenario in which the QCD axion plays the role of the inflaton by mixing with heavy axions....

35. Kento Asai "New Constraint on Dark Photon at T2K Off-Axis Near Detector"

11/9/23, 4:45 PM

The T2K experiment is one of the most powerful long-baseline experiments to investigate neutrino oscillations. The off-axis near detector called ND280 is installed 280m downstream from the neutrino production target to measure the neutrino energy spectrum. In this paper, we study the capability of the ND280 detector to search for the dark photon produced through the meson rare decay and...

56. Masashi Aiko "Higgs Probes of axion-like particles"

11/9/23, 4:45 PM

We study axion-like particle contributions to the Higgs boson decays. The particle is assumed to couple with the standard model electroweak gauge bosons. Although direct productions of axion-like particles have often been discussed, we investigate indirect contributions to the Higgs boson decays into fermions, photons, W W, and Z Z bosons at the one-loop level. We found that the corrections...

36. Akifumi Chitose "Cosmic strings and monopoles from hidden symmetry"

11/9/23, 5:10 PM

Cosmic strings and monopoles may arise from hidden symmetries. Their interactions and potential observational signatures will be discussed.

43. Kazunari Shima "Phenomenological aspect of Nonlinear Supersymmetric General Relativity(NLSGR)ity"

11/9/23, 5:10 PM

The brief review of NLSGR, the phenomenological meanings, higher-spin SUSY, and superHiggs mechanism, etc are presented.ussed.

38. Chuan-Ren Chen "Impacts of ALP on the constraints of dark photon"

11/9/23, 5:35 PM

We revisit the constraints for the dark photon with the existence of an axion-like particle. We focus on the constraints from the laboratories, including beam dump and colliders. We found that the stringent bounds on the larger mass will be released.

44. Nodoka Yamanaka "Unphysical topological charge of nonabelian gauge theory"

11/9/23, 5:35 PM

We show that the topological charge of nonabelian gauge theory is not observable, which immediately leads to the resolution of the Strong CP problem. We then inspect the phenomenological consequences to particle physics physics. The most notable implication is the prohibition of the 't Hooft vertex and the sphaleron induced baryogenesis.

7. Ryo Yokokura "Generalized chiral instabilities, linking numbers, and non-invertible symmetries"

11/10/23, 10:35 AM

We demonstrate a universal mechanism of a class of instabilities in infrared regions for massless Abelian p-form gauge theories with topological interactions, which we call generalized chiral instabilities. Such instabilities occur in the presence of initial electric fields for the p-form gauge fields. We show that the dynamically generated magnetic fields tend to decrease the initial electric...

11. Yuanyuan Wang "Disappearance of the first-order chiral phase transition in QCD: cosmological implications for dark QCD,"

11/10/23, 10:35 AM

The first-order nature of the chiral phase transition in QCD-like theories can play crucial roles in addressing a dark side of the Universe, where the created out-of equilibrium is essential to serve as cosmological and astrophysical probes such as gravitational wave productions, which have extensively been explored. We find that such a first order feature may not hold when ordinary or dark...

8. Takafumi Kai "Flavor, CP and Metaplectic Modular Symmetries in Type IIB Chiral Flux Vacua"

11/10/23, 11:00 AM

We examine symmetries of chiral four-dimensional vacua of Type IIB flux compactifications with vanishing superpotential W=0. We find that the N=1 supersymmetric MSSM-like and Pati-Salam vacua possess enhanced discrete symmetries in the effective action below the mass scale of stabilized complex structure moduli and dilaton. Furthermore, a generation number of quarks/leptons is small on these...

13. Takumi Kuwahara "Dark Hadrons at LHC lifetime frontier"

11/10/23, 11:00 AM

The LHC lifetime frontier will probe a dark sector in the near future, and the visible decay searches at fixed-target experiments have been exploring the dark sector. Dark strong dynamics provides rich structure in the dark sector: dark baryons and dark mesons. Dark photons are also introduced to alleviate cosmological problems. Meanwhile, dark photons make dark hadrons long-lived in...

4. Masashi Aiko "Higgs Probes of axion-like particles"

We study axion-like particle contributions to the Higgs boson decays. The particle is assumed to couple with the standard model electroweak gauge bosons. Although direct productions of axion-like particles have often been discussed, we investigate indirect contributions to the Higgs boson decays into fermions, photons, W W, and Z Z bosons at the one-loop level. We found that the corrections...