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We study systematically derivation of the specific texture zeros, that is the nearest neighbor interaction (NNI) form of the quark mass matrices at the fixed point τ = ω in modular flavor symmetric models. We present models that the NNI forms of the quark mass matrices are simply realized at the fixed point τ = ω in the A 4 modular flavor symmetry by taking account multi-Higgs fields. Such texture zero structure originates from the ST charge of the residual symmetry Z 3 of SL (2,  Z ). The NNI form can be realized at the fixed point τ = ω in A 4 and S 4 modular flavor models with two pairs of Higgs fields when we assign properly modular weights to Yukawa couplings and A 4 and S 4 representations to three generations of quarks. We need four pairs of Higgs fields to realize the NNI form in A 5 modular flavor models.

A bstract We study A 4 × A 4 × A 4 modular symmetric flavor models to realize quark mass hierarchies and mixing angles without fine-tuning. Mass matrices are written in terms of modular forms. At modular fixed points τ = i∞ and ω , A 4 is broken to Z 3 residual symmetry. When the modulus τ is deviated from the fixed points, modular forms show hierarchies depending on their residual charges. Thus, we obtain hierarchical structures in mass matrices. Since we begin with A 4 × A 4 × A 4 , the residual symmetry is Z 3 × Z 3 × Z 3 which can generate sufficient hierarchies to realize quark mass ratios and absolute values of the CKM matrix |V CKM | without fine-tuning. Furthermore, CP violation is studied. We present necessary conditions for CP violation caused by the value of τ . We also show possibilities to realize observed values of the Jarlskog invariant J CP , quark mass ratios and CKM matrix |V CKM | simultaneously, if (10) adjustments in coefficients of Yukawa couplings are allowed or moduli values are non-universal.

A bstract We discuss how the moduli in modular flavor symmetric models dynamically select enhanced symmetry points at which the residual modular symmetry renders extra matter fields massless. The moduli dynamics non-perturbatively produces the extra matter particles, which gives (time-dependent) effective potential that traps the moduli to enhanced symmetry points. We show analytic estimates of particle production rate consistent with numerical results, and the dynamics of moduli based on the analytic estimates.

A bstract We study constructions and classifications of three-generation models based on magnetized T 4 and T 4 /Z 2 orbifold as candidates of the compact space. We focus on chiral fermion zero-mode wave functions in the extra dimensions. Freedoms of constant gauge fields, called Scherk-Schwarz phases are taken into account. We classify three-generation models in a systematic manner, clarifying the relationship between different models. The Higgs sector is also studied by analyzing possible assignments of the magnetic flux and Scherk-Schwarz phases, etc. to left- and right-handed fermions.

We study an approach to construct Siegel modular forms from Sp(6, Z ). Zero-mode wave functions on T 6 with magnetic flux background behave Siegel modular forms at the origin. Then T -symmetries partially break depending on the form of background magnetic flux. We study the background such that three T -symmetries T I , T II and T III as well as the S -symmetry remain. Consequently, we obtain Siegel modular forms with three moduli parameters ( ω 1 , ω 2 , ω 3 ), which are multiplets of finite modular groups. We show several examples. As one of examples, we study Siegel modular forms for$$\\widetilde{\\Delta }\\left(96\\right)$$in detail. Then, as a phenomenological applicantion, we study quark flavor models using Siegel modular forms for$$\\widetilde{\\Delta }\\left(96\\right)$$. Around the cusp, ω 1 = i∞ , the Siegel modular forms have hierarchical values depending on their T I -charges. We show the deviation of ω 1 from the cusp can generate large quark mass hierarchies without fine-tuning. Furthermore CP violation is induced by deviation of ω 2 from imaginary axis.

A bstract We revisit the modular weights in type IIB magnetized D-brane models. The simple analysis of wave function shows that the four-dimensional matter fields have the modular weight -1/2, but it may shift as one in type IIA intersecting D-brane models. For example, the localized gauge flux as well as the localized curvature can shift the modular weight in the magnetized D-brane models. Such corrections do not affect physical couplings such as physical Yukawa couplings. However, it leads to differences in supersymmetry breaking sfermion masses, which depend on the modular weights, although the A -term coefficients and the sum of sfermion masses squared seem to be the same between two models.

Carbonaceous (C-type) asteroids 1 are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites 2 , 3 and are essential for understanding planetary formation processes. However, their physical properties remain poorly known because carbonaceous chondrite meteoroids tend not to survive entry to Earth’s atmosphere. Here we report on global one-rotation thermographic images of the C-type asteroid 162173 Ryugu, taken by the thermal infrared imager (TIR) 4 onboard the spacecraft Hayabusa2 5 , indicating that the asteroid’s boulders and their surroundings have similar temperatures, with a derived thermal inertia of about 300 J m −2  s −0.5  K −1 (300 tiu). Contrary to predictions that the surface consists of regolith and dense boulders, this low thermal inertia suggests that the boulders are more porous than typical carbonaceous chondrites 6 and that their surroundings are covered with porous fragments more than 10 centimetres in diameter. Close-up thermal images confirm the presence of such porous fragments and the flat diurnal temperature profiles suggest a strong surface roughness effect 7 , 8 . We also observed in the close-up thermal images boulders that are colder during the day, with thermal inertia exceeding 600 tiu, corresponding to dense boulders similar to typical carbonaceous chondrites 6 . These results constrain the formation history of Ryugu: the asteroid must be a rubble pile formed from impact fragments of a parent body with microporosity 9 of approximately 30 to 50 per cent that experienced a low degree of consolidation. The dense boulders might have originated from the consolidated innermost region or they may have an exogenic origin. This high-porosity asteroid may link cosmic fluffy dust to dense celestial bodies 10 . Thermal imaging data obtained from the spacecraft Hayabusa2 reveal that the carbonaceous asteroid 162173 Ryugu is an object of unusually high porosity.

C-type asteroids 1 are considered to be primitive small Solar System bodies enriched in water and organics, providing clues to the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing 2 – 7 and on-asteroid measurements 8 , 9 with Hayabusa2 (ref.  10 ). However, the ground truth provided by laboratory analysis of returned samples is invaluable to determine the fine properties of asteroids and other planetary bodies. We report preliminary results of analyses on returned samples from Ryugu of the particle size distribution, density and porosity, spectral properties and textural properties, and the results of a search for Ca–Al-rich inclusions (CAIs) and chondrules. The bulk sample mainly consists of rugged and smooth particles of millimetre to submillimetre size, confirming that the physical and chemical properties were not altered during the return from the asteroid. The power index of its size distribution is shallower than that of the surface boulder observed on Ryugu 11 , indicating differences in the returned Ryugu samples. The average of the estimated bulk densities of Ryugu sample particles is 1,282 ± 231 kg m −3 , which is lower than that of meteorites 12 , suggesting a high microporosity down to the millimetre scale, extending centimetre-scale estimates from thermal measurements 5 , 9 . The extremely dark optical to near-infrared reflectance and spectral profile with weak absorptions at 2.7 and 3.4 μm imply a carbonaceous composition with indigenous aqueous alteration, matching the global average of Ryugu 3 , 4 and confirming that the sample is representative of the asteroid. Together with the absence of submillimetre CAIs and chondrules, these features indicate that Ryugu is most similar to CI chondrites but has lower albedo, higher porosity and more fragile characteristics. The Hayabusa2 spacecraft returned 5.4 g of material from the asteroid Ryugu. A first analysis of the samples found an estimated density of 1,282 ± 231 kg m −3 , considerably lower than even the most porous meteorites. Together with preliminary spectral analysis, these results indicate that Ryugu is similar to CI chondrites, but darker, more porous and more brittle.

We investigated the clinical features of bloodstream infections (BSIs) caused by Klebsiella pneumoniae harboring rmpA and molecular characteristics of the bacteria. We retrospectively investigated adult patients with K. pneumoniae BSI from January 2010 to March 2021 at Nagasaki University Hospital. A matched case–control study in a 1:3 ratio was conducted to clarify the clinical and bacterial characteristics of BSI caused by rmpA -positive K. pneumoniae compared with those caused by rmpA -negative isolates. Antimicrobial susceptibility testing and multilocus sequence typing (MLST) were performed for rmpA -positive isolates. The rmpA was detected in 36 (13.4%) of the 268 isolates. Of these 36 isolates, 31 (86.1%) harbored iucA and 35 (97.2%) each possessed peg-344 and iroB ; capsular types were identified as K1 in 9 (25.0%) and K2 in 10 isolates (27.8%). Contrarily, of the 108 rmpA -negative isolates, which were matched for case–control studies, 5 isolates (4.6%) harbored iucA and 1 (0.9%) each possessed peg-344 and iroB ; 2 (1.9%) and 3 isolates (2.8%) had K1 and K2 capsular types, respectively. Among the rmpA -positive isolates, ST23/K1 (eight isolates) was the most frequent, followed by ST412/non-K1/K2 (seven isolates), ST86/K2 (five isolates), and ST268/non-K1/K2 (four isolates). In a multivariate analysis using clinical factors, liver abscess positively correlated with rmpA -positive isolates, whereas biliary tract infection and use of anticancer drugs negatively correlated with rmpA -positive isolates in patients with K. pneumoniae BSI. Considering the correlation between rmpA -positive isolates and clinical features, rmpA can be used as a marker for understanding the pathophysiology of K. pneumoniae BSI.

A bstract We study the modular symmetry of zero-modes on T 1 2 × T 2 2 and orbifold compactifications with magnetic fluxes, M 1 , M 2 , where modulus parameters are identified. This identification breaks the modular symmetry of T 1 2 × T 2 2 , SL(2 , ℤ) 1 × SL(2 , ℤ) 2 to SL(2 , ℤ) ≡ Γ. Each of the wavefunctions on T 1 2 × T 2 2 and orbifolds behaves as the modular forms of weight 1 for the principal congruence subgroup Γ( N ), N being 2 times the least common multiple of M 1 and M 2 . Then, zero-modes transform each other under the modular symmetry as multiplets of double covering groups of Γ N such as the double cover of S 4 .