Supersymmetric Baryogenesis in a Hybrid Inflation Model

We study baryogenesis in a hybrid inflation model which is embedded to the minimal supersymmetric model with right-handed neutrinos. Inflation is induced by a linear combination of the right-handed sneutrinos and its decay reheats the universe. The decay products are stored in conserved numbers, which are transported under the interactions in equilibrium as the temperature drops down. We find that at least a few percent of the initial lepton asymmetry is left under the strong wash-out due to the lighter right-handed (s)neutrinos. To account for the observed baryon number and the active neutrino masses after a successful inflation, the inflaton mass and the Majorana mass scale should be $10^{13}\,{\rm GeV}$ and ${\cal O}(10^{7}$-$10^{10})\,{\rm GeV}$, respectively.Comment: 19 pages, 2 figure

Near-Infrared Extinction in The Coalsack Globule 2

We have conducted J, H, and Ks imaging observations for the Coalsack Globule 2 with the SIRIUS infrared camera on the IRSF 1.4 m telescope at SAAO, and determined the color excess ratio, E(J-H)/E(H-Ks). The ratio is determined in the same photometric system as our previous study for the rho Oph and Cha clouds without any color transformation; this enables us to directly compare the near-infrared extinction laws among these regions. The current ratio E(J-H)/E(H-Ks) = 1.91 +- 0.01 for the extinction range 0.5 < E(J-H) <1.8 is significantly larger than the ratios for the rho Oph and Cha clouds (E(J-H)/E(H-Ks) = 1.60-1.69). This ratio corresponds to a large negative index alpha = 2.34 +- 0.01 when the wavelength dependence of extinction is approximated by a power law which might indicate little growth of dust grains, or larger abundance of dielectric non-absorbing components such as silicates, or both in this cloud. We also confirm that the color excess ratio for the Coalsack Globule 2 has a trend of increasing with decreasing optical depth, which is the same trend as the rho Oph and Cha clouds have.Comment: 13 pages, 5 figures, and 2 tables, Ap

Charged scalars confronting neutrino mass and muon g-2 anomaly

The present work introduces two possible extensions of the Standard Model Higgs sector. In the first case, the Zee-Babu type model for the generation of neutrino mass is augmented with a scalar triplet and additional singly charged scalar singlets. The second scenario, on the other hand, generalizes the Type-II seesaw model by replicating the number of the scalar triplets. A $\mathbb{Z}_3$ symmetry is imposed in case of both the scenarios, but, allowed to be violated by terms of mass dimension two and three for generating neutrino masses and mixings. We examine how the models so introduced can explain the experimental observation on the muon anomalous magnetic moment. We estimate the two-loop contribution to neutrino mass induced by the scalar triplet, in addition to what comes from the doubly charged singlet in the usual Zee-Babu framework, in the first model. On the other hand, the neutrino mass arises in the usual Type-II fashion in the second model. In addition, the role of the $\mathbb{Z}_3$ symmetry in suppressing lepton flavor violation is also elucidated.Comment: 4 tables, 14 captioned figure

The Distance to the Galactic Center Derived From Infrared Photometry of Bulge Red Clump Stars

On the basis of the near infrared observations of bulge red clump stars near the Galactic center, we have determined the galactocentric distance to be R_0 = 7.52 +- 0.10 (stat) +- 0.35 (sys) kpc. We observed the red clump stars at |l| < 1.0 deg and 0.7 deg < |b| < 1.0 deg with the IRSF 1.4 m telescope and the SIRIUS camera in the H and Ks bands. After extinction and population corrections, we obtained (m - M)_0 = 14.38 +- 0.03 (stat) +- 0.10 (sys). The statistical error is dominated by the uncertainty of the intrinsic local red clump stars' luminosity. The systematic error is estimated to be +- 0.10 including uncertainties in extinction and population correction, zero-point of photometry, and the fitting of the luminosity function of the red clump stars. Our result, R_0 = 7.52 kpc, is in excellent agreement with the distance determined geometrically with the star orbiting the massive black hole in the Galactic center. The recent result based on the spatial distribution of globular clusters is also consistent with our result. In addition, our study exhibits that the distance determination to the Galactic center with the red clump stars, even if the error of the population correction is taken into account, can achieve an uncertainty of about 5%, which is almost the same level as that in recent geometrical determinations.Comment: 14 pages, 4 figures, accepted by Ap

Response distribution of a single-degree-of-freedom linear system subjected to non-Gaussian random excitation by using cross-correlation function

Response probability density function of a single-degree-of-freedom linear system subjected to non-Gaussian random excitation is investigated. The excitation is assumed to be a zero-mean stationary stochastic process prescribed by both the non-Gaussian probability density and the power spectral density with bandwidth and dominant frequency parameters. In this study, bimodal and Laplace distributions are used as the non-Gaussian distribution of the excitation. Monte Carlo simulations are performed to obtain the stationary probability distributions of the displacement and velocity of the system. Then, we calculate the maximum absolute value of the real part of cross-correlation function between the excitation and the response, which is considered as an evaluation index of waveform similarity between the excitation and the response. It is shown that the response probability distributions vary with the maximum value. With the aid of this maximum value, the shapes of the probability distributions of the system response can be predicted roughly without Monte Carlo simulations

Impact of workplace smoke-free policy on secondhand smoke exposure from cigarettes and exposure to secondhand heated tobacco product aerosol during COVID-19 pandemic in Japan: the JACSIS 2020 study

[Objectives] Promoting smoke-free policies is a key intervention for reducing secondhand smoke (SHS) exposure. During the COVID-19 pandemic in Japan, many indoor smoking spaces in workplaces were closed. This study aimed to reveal the association between a workplace smoke-free policy and SHS exposure among non-smoking employees, distinguishing between SHS exposure from cigarettes and exposure to secondhand heated tobacco product (HTP) aerosol, which have recently become popular in Japan. [Design and setting] We used data from the Japan COVID-19 and Society Internet Survey conducted in August–September 2020. [Participants] Among the 25 482 eligible respondents, 8196 non-smoking employees were analysed. [Primary outcome measure] Multivariable logistic regression models were used to examine the impact of smoke-free policies in the workplace. [Results] Compared with complete smoking bans, the ORs and 95% CIs for workplace SHS exposure at least once a week from cigarettes were 2.06 (95% CI: 1.60 to 2.65) for partial bans with no longer available smoking spaces, 1.92 (95% CI: 1.63 to 2.25) for partial smoking bans with still available smoking spaces and 5.33 (95% CI: 4.10 to 6.93) for no smoking bans. The corresponding ORs and 95% CIs for exposure to secondhand HTP aerosol were 4.15 (95% CI: 3.22 to 5.34), 2.24 (95% CI: 1.86 to 2.71) and 3.88 (95% CI: 2.86 to 5.26), respectively. [Conclusions] The effect of partial bans was limited, and temporary closure of smoking spaces might contribute to increased exposure to secondhand HTP aerosol. Complete smoking bans in the workplace were reaffirmed to be the best way to reduce SHS exposure from cigarettes and exposure to secondhand HTP aerosol

Clustering of Emission-line Stars in the W5E HII region

We have made a new survey of emission-line stars in the W5E HII region to investigate the population of PMS stars near the OB stars by using the Wide Field Grism Spectrograph 2 (WFGS2). A total of 139 H-alpha emission stars were detected and their g'i'-photometry was performed. The spatial distribution of them shows three aggregates, i.e., two aggregates near the bright-rimmed clouds at the edge of W5E HII region (BRC 13 and BRC 14) and one near the exciting O7V star. The age and mass of each H-alpha star were estimated from the extinction corrected color-magnitude diagram and theoretical evolutionary tracks. We found, for the first time in this region, that the young stars near the exciting star are systematically older (4 Myr) than those near the edge of the HII region (1 Myr). This result supports that the formation of stars proceed sequentially from the center of HII region to the eastern bright rim. We further suggest a possibility that the birth of low mass stars near the exciting star of HII region precede the production of massive OB stars in the pre-existing molecular cloud.Comment: 16 pages, 7 figures, 3 tables, accepted for publication in PAS

Effect of Prefilmer Edge Thickness on Breakup Phenomena of Liquid Film in Prefilming Airblast Atomizer

[EN] This paper describes the investigation of the effect of a prefilmer edge thickness on the breakup phenomena of a liquid film in a prefilmer airblast atomizer. The breakup phenomena of the liquid film at five prefilmer edge thicknesses (160, 500, 1250, 2000, and 3000 μm) under various conditions was observed using a high-speed camera. The breakup length of the liquid film was calculated by an image processing technique developed in this study. In order to quantitatively evaluate the effect of the prefilmer edge thickness on the breakup frequency, the Fast Fourier Transformation (FFT) analysis was conducted based on the time evolution of the breakup length. The results indicated that the breakup length increase and the breakup frequency decreases by increasing prefilmer edge thickness due to a larger volume of a liquid accumulation attaching to the prefilmer edge. The FFT analysis showed that the increase in prefilmer edge thickness causes the transition of the maximal power spectrum to a lower frequency (i.e. less than 100 Hz) due to the increase in the liquid accumulation at the edge as well. Finally, a dimensionless correlation has been proposed for the breakup length of a liquid film.Okabe, T.; Katagata, N.; Sakaki, T.; Inamura, T.; Fumoto, K. (2017). Effect of Prefilmer Edge Thickness on Breakup Phenomena of Liquid Film in Prefilming Airblast Atomizer. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 154-161. https://doi.org/10.4995/ILASS2017.2017.4931OCS15416