Refine your search:     
Report No.
 - 
Search Results: Records 1-20 displayed on this page of 38

Presentation/Publication Type

Initialising ...

Refine

Journal/Book Title

Initialising ...

Meeting title

Initialising ...

First Author

Initialising ...

Keyword

Initialising ...

Language

Initialising ...

Publication Year

Initialising ...

Held year of conference

Initialising ...

Save select records

Journal Articles

Casimir effect for fermions on the lattice

Nakayama, Katsumasa*; Suzuki, Kei

Proceedings of Science (Internet), 430, p.379_1 - 379_9, 2023/04

The conventional Casimir effect has been studied in the continuous spacetime, but to elucidate its counterpart in the lattice space is an important subject. Here, we discuss various types of Casimir effects for quantum fields on the lattice. By using a definition of the Casimir energy on the lattice, we show that the Casimir effect for the Wilson fermion is similar to that for the continuous Dirac fermion. We apply our definition to an effective Hamiltonian describing Dirac semimetals, such as Cd$$_3$$As$$_2$$ and Na$$_3$$Bi, and find an oscillatory behavior of the Casimir energy as a function of film thickness of semimetals. We also study contributions from Landau levels under magnetic fields and the Casimir effect for nonrelativistic particle fields on the lattice.

Journal Articles

Axial U(1) symmetry at high temperatures in $$N_f=2+1$$ lattice QCD with chiral fermions

Aoki, Sinya*; Aoki, Yasumichi*; Fukaya, Hidenori*; Hashimoto, Shoji*; Kanamori, Issaku*; Kaneko, Takashi*; Nakamura, Yoshifumi*; Rohrhofer, C.*; Suzuki, Kei

Proceedings of Science (Internet), 396, p.332_1 - 332_7, 2022/07

The axial U(1) anomaly in high-temperature QCD plays an important role to understand the phase diagram of QCD. The previous works by JLQCD Collaboration studied high-temperature QCD using 2-flavor dynamical chiral fermions such as the domain-wall fermion and reweighted overlap fermion. We extend our simulations to QCD with 2+1-flavor dynamical quarks, where the masses of the up, down, and strange quarks are near the physical point, and the temperatures are close to or higher than the pseudocritical temperature. In this talk, we will present the results for the Dirac spectrum, topological susceptibility, axial U(1) susceptibility, and hadronic collelators.

Journal Articles

What is chiral susceptibility probing?

Aoki, Sinya*; Aoki, Yasumichi*; Fukaya, Hidenori*; Hashimoto, Shoji*; Rohrhofer, C.*; Suzuki, Kei

Proceedings of Science (Internet), 396, p.050_1 - 050_9, 2022/07

In the early days of QCD, the axial $$U(1)$$ anomaly was considered as a trigger for the breaking of the $$SU(2)_Ltimes SU(2)_R$$ symmetry through topological excitations of gluon fields. However, it has been a challenge for lattice QCD to quantify the effect. In this work, we simulate QCD at high temperatures with chiral fermions. The exact chiral symmetry enables us to separate the contribution from the axial $$U(1)$$ breaking from others among the susceptibilities in the scalar and pseudoscalar channels. Our result in two-flavor QCD indicates that the chiral susceptibility, which is conventionally used as a probe for $$SU(2)_Ltimes SU(2)_R$$ breaking, is actually dominated by the axial $$U(1)$$ breaking at temperatures $$Tge 165$$ MeV.

Journal Articles

The phi meson in nuclear matter in a transport approach

Gubler, P.

Proceedings of Science (Internet), 380, p.215_1 - 215_5, 2022/05

Based on my recent research, I will explain about my numerical simulation of pA reactions (p: proton, A: nucleus), which are used to study the $$phi$$ meson in nuclear matter. I will particularly focus on the question of how the modification of the $$phi$$ meson spectral function in nuclear matter influences the experimentally observed di-lepton spectrum.

Journal Articles

Gamma-ray observations at the coastal area of Japan Sea in winter seasons

Tsuchiya, Harufumi; Enoto, Teruaki*; Wada, Yuki*; Furuta, Yoshihiro; Nakazawa, Kazuhiro*; Yuasa, Takayuki*; Umemoto, Daigo*; Makishima, Kazuo*; GROWTH collaboration*

Proceedings of Science (Internet), 358, p.1163_1 - 1163_6, 2021/07

Journal Articles

The Energy spectrum of forward photons measured by the RHICf experiment in $$sqrt{s}$$ = 510 GeV proton-proton collisions

Sato, Kenta*; Tanida, Kiyoshi; 19 of others*

Proceedings of Science (Internet), 358, p.413_1 - 413_8, 2021/07

Journal Articles

Axial U(1) symmetry and mesonic correlators at high temperature in $$N_f=2$$ lattice QCD

Suzuki, Kei; Aoki, Sinya*; Aoki, Yasumichi*; Cossu, G.*; Fukaya, Hidenori*; Hashimoto, Shoji*; Rohrhofer, C.*

Proceedings of Science (Internet), 363, p.178_1 - 178_7, 2020/08

We investigate the high-temperature phase of QCD using lattice QCD simulations with $$N_f=2$$ dynamical M$"o$bius domain-wall fermions. On generated configurations, we study the axial $$U(1)$$ symmetry, overlap-Dirac spectra, screening masses from mesonic correlators, and topological susceptibility. We find that some of the observables are quite sensitive to lattice artifacts due to a small violation of the chiral symmetry. For those observables, we reweight the M$"o$bius domain-wall fermion determinant by that of the overlap fermion. We also check the volume dependence of observables. Our data near the chiral limit indicates a strong suppression of the axial $$U(1)$$ anomaly at temperatures $$geq$$ 220 MeV.

Journal Articles

Symmetries of the light hadron spectrum in high temperature QCD

Rohrhofer, C.*; Aoki, Yasumichi*; Cossu, G.*; Fukaya, Hidenori*; Gattringer, C.*; Glozman, L. Ya.*; Hashimoto, Shoji*; Lang, C. B.*; Suzuki, Kei

Proceedings of Science (Internet), 363, p.227_1 - 227_7, 2020/08

Properties of QCD matter change significantly around the chiral crossover temperature, and the effects on $$U(1)_A$$ and topological susceptibilities, as well as the meson spectrum have been studied with much care. Baryons and the effect of parity doubling in this temperature range have been analyzed previously by various other groups employing different setups. Here we construct suitable operators to investigate chiral and axial $$U(1)_A$$ symmetries in the baryon spectrum. Measurements for different volumes and quark-masses are done with two flavors of chirally symmetric domain-wall fermions at temperatures above the critical one. The possibility of emergent $$SU(4)$$ and $$SU(2)_{CS}$$ symmetries is discussed.

Journal Articles

Development of the neutron polarizer for the T-violation search using compound nuclei

Okudaira, Takuya; Oku, Takayuki; Sakai, Kenji; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke; Shinohara, Takenao; Kakurai, Kazuhisa*; Aizawa, Kazuya; Shimizu, Hirohiko*; et al.

Proceedings of Science (Internet), 356, p.029_1 - 029_5, 2019/12

The technology development section carries out the development of the neutron polarization device: $$^{3}$$He Spin Filter. It is often used for the fundamental physics region. In order to explain the matter-dominated universe, a time reversal violation is necessary and searches for new physics are conducted in the world. The T-violation search using a polarized neutron beam is planned at J-PARC. A large $$^{3}$$He spin filter is needed to polarize high energy neutrons for the experiment and is developed in JAEA. Recently, we developed the accurate measurement system to evaluate the polarization of $$^{3}$$He and a vacuum system to make the $$^{3}$$He spin filter, and large $$^{3}$$He spin filters for epi-thermal neutron was made using the system. The current status of the development of the $$^{3}$$He spin filter will be talked.

Journal Articles

Performance evaluation of differential die-away system in an integrated active neutron NDA system for nuclear non-proliferation and nuclear security

Ozu, Akira; Maeda, Makoto; Komeda, Masao; Toh, Yosuke

Proceedings of 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2018) (Internet), 4 Pages, 2019/10

Journal Articles

A Submillimeter spatial resolution scintillation detector for time-of-flight neutron diffraction imaging

Nakamura, Tatsuya; Kawasaki, Takuro; To, Kentaro; Tsutsui, Noriaki; Ebine, Masumi; Birumachi, Atsushi; Sakasai, Kaoru

Proceedings of 2018 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2018) (Internet), 3 Pages, 2019/10

A two-dimensional scintillation neutron detector with a submillimeter spatial resolution was developed for pulsed neutron diffraction imaging at the J-PARC MLF. The detector comprised the thin, single ZnS/$$^{6}$$LiF scintillator screen coupled with the crossed wavelength-shifting fiber array for light collection. For a high spatial resolution, the wavelength shifting fibers with diameter of 0.1 mm were used them for assembling the detector. The prototype detector that has a neutron-sensitive area of 24 $$times$$ 24 mm$$^{2}$$ exhibited a spatial resolution of 0.20$$pm$$0.06 mm and 0.16$$pm$$0.06 mm for x and y directions, respectively. The detector had a detection efficiency of 7$$%$$ for thermal neutrons with a $$^{60}$$Co $$gamma$$-ray sensitivity in the order of 10$$^{-6}$$. In this paper detailed detector design is presented together with experimental results using the pulsed neutron beam.

Journal Articles

Towards understanding the $$phi$$ meson in nuclear matter with finite momentum

Gubler, P.

Proceedings of Science (Internet), 336, p.207_1 - 207_7, 2019/09

In this talk, results about the behavior of the $$phi$$ meson with non-zero momentum in nuclear matter will be presented and an outlook will be made on future theoretical and experimental developments related to this topic. Our findings are relevant for future experiments (such as E16) to be carried out at the J-PARC facility.

Journal Articles

Prospects for the spin structure study of hyperons using heavy quark decays at Belle II

Tanida, Kiyoshi

Proceedings of Science (Internet), 346, p.118_1 - 118_6, 2019/08

Journal Articles

Establishment of a novel detection system for measuring primary knock-on atoms

Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above $$sim$$0.2-0.3 MeV/nucleon for A=20$$sim$$30 amu; the PKA mass identification thresholds decrease to $$<$$0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.

Journal Articles

Development of differential die-away technique in an integrated active neutron NDA system for nuclear non-proliferation and nuclear security

Ozu, Akira; Maeda, Makoto; Komeda, Masao; Toh, Yosuke; Koizumi, Mitsuo; Seya, Michio

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 4 Pages, 2018/11

Journal Articles

Delayed gamma-ray spectroscopy inverse Monte Carlo analysis method for nuclear safeguards nondestructive assay applications

Rodriguez, D.; Rossi, F.; Seya, Michio; Koizumi, Mitsuo

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

Journal Articles

Development of radiation resistant monitoring camera system

Takeuchi, Tomoaki; Otsuka, Noriaki; Watanabe, Takashi*; Tanaka, Shigeo*; Ozawa, Osamu*; Komanome, Hirohisa*; Ueno, Shunji*; Tsuchiya, Kunihiko

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

no abstracts in English

Journal Articles

Evaluation of in-water wireless transmission system under the conditions simulated the severe accident

Otsuka, Noriaki; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Shibagaki, Taro*; Komanome, Hirohisa*

Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11

no abstracts in English

Journal Articles

Measurement of very forward particle production at RHIC with $$sqrt s=$$ 510 GeV proton-proton collisions

Sako, Takashi*; Tanida, Kiyoshi; 20 of others*

Proceedings of Science (Internet), 301, p.337_1 - 337_8, 2018/08

Journal Articles

Theoretical analysis on the $$K^{-3}$$He $$rightarrow Lambda pn$$ reaction for the $$bar{K} N N$$ bound-state search in the J-PARC E15 experiment

Sekihara, Takayasu; Oset, E.*; Ramos, A.*

Proceedings of Science (Internet), 310, p.199_1 - 199_5, 2018/03

38 (Records 1-20 displayed on this page)