Tetra-Quark Resonances in Lattice QCD

We study $qq \bar q \bar q$-type four-quark (4Q) systems in SU(3)$_c$ anisotropic quenched lattice QCD, using the $O(a)$-improved Wilson (clover) fermion at $\beta=5.75$ on $12^3 \times 96$ with renormalized anisotropy $a_s/a_t=4$.For comparison, we first investigate the lowest $q\bar q$ scalar meson from the connected diagram and find its large mass of about 1.32GeV after chiral extrapolation, and thus the lowest $q\bar q$ scalar meson corresponds to $f_0(1370)$.We investigate the lowest 4Q state in the spatially periodic boundary condition, and find that it is just a two-pion scattering state, as is expected. To examine spatially-localized 4Q resonances, we use the Hybrid Boundary Condition (HBC) method, where anti-periodic and periodic boundary conditions are imposed on quarks and antiquarks, respectively. By applying HBC on a finite-volume lattice, the threshold of the two-meson scattering state is raised up, while the mass of a compact 4Q resonance is almost unchanged.In HBC, the lowest 4Q state appears slightly below the two-meson threshold. To clarify the nature of the 4Q system, we apply the Maximum Entropy Method (MEM) for the 4Q correlator and obtain the spectral function of the 4Q system.From the combination analysis of MEM with HBC, we finally conclude that the 4Q system appears as a two-pion scattering state and there is no spatially-localized 4Q resonance in the quark-mass region of $m_s< m_q <2m_s$

Multi-Quarks and Two-Baryon Interaction in Lattice QCD

We study multi-quark (3Q,4Q,5Q) systems in lattice QCD. We perform the detailed studies of multi-quark potentials in lattice QCD to clarify the inter-quark interaction in multi-quark systems. We find that all the multi-quark potentials are well described by the OGE Coulomb plus multi-Y-type linear potential, i.e., the multi-Y Ansatz. For multi-quark systems, we observe lattice QCD evidences of ``flip-flop'', i.e., flux-tube recombination. These lattice QCD studies give an important bridge between elementary particle physics and nuclear physics.Comment: A talk given at Particles and Nuclei International Conference(PANIC05), Santa Fe, NM, Oct. 24-28, 2005. 3 pages, 6 figure

Active learning and historical research on educational methods in fluid pressure in 150th anniversary of the Japanese school systems

Reconstructions of historically valuable teaching materials in Meiji Era We have been collecting students' physics notes and educational materials by nationwide searches to capture and record the real situation of Japanese education and to elucidate the characteristic formation process since the Meiji Era. Commemorating the 150th anniversary of the Japanese school system, we report what we have accumulated so far. In our recent exploratory research, we have been able to decipher physics lessons based on old textbooks in upper elementary schools, upper secondary schools, junior high schools, teacher’s schools, and preparatory departments. We have deciphered collections of teaching materials and students’ lecture notes based on the types of textbooks of A. Ganot’s used by Ogawa Masataka (Shizuoka Junior High School) and Sakai Sukeyasu (Mito Junior High School), and types of physics textbooks by B. Stewart, given by Sakurai Fusaki (Fifth Senior High School). Furthermore, we have analyzed Active Learning (AL) type physics education recorded by Matuoka’s physics-note (Saitama upper elementary school) based on the textbooks written by Gage. The innovative content of Japanese science education is deeply influenced by Europe and the United States, in particular those developed by Parker’s and G. P. Quackenbos’ and Stewart’s physics, and those that are deeply referring to Ganot’s Physics textbooks. We have attempted modern reconstruction of historically valuable materials using ICT-and AL in Fluid Dynamics. For example, we present case studies for improvement of a hands-on experiment on Pascal’s Principle, Figure 1, using home-made suction-cup &amp; vacuum-pump and wireless pressure sensors. AL on Pascal’s Principle by using Suction Cup and wireless ICT sensors We present on how to create simple experimental tools made at home by inexpensive goods from one-dollar stores, even during the COVID-19 pandemic. Modern reconstruction of AL on Pascal's Principle by using suitable experimental devises such as suction cup and vacuum pump, Figure 1. We show non-buoyancy-upward fluid forces for near-vacuum pressures in suction cup, based on the important boundary conditions, which will produce a simple experimental clarification of the Graf‘s “buoyance paradox” (Graf, 2004) in fluid pressure.  Here, the same pressure is achieved by a small hole which connects a suction cup to barometer and wireless sensor zone. The same is done with a thin silicon tube connecting the suction cup to the device zone. ACKNOWLEDGEMENT This work was supported by Grant-in-Aid for Scientific Research 21K02947, 21K02890 and 19H01711. REFERENCE Graf, F. H. (2004). Just What Did Archimedes Say About Buoyancy the Physics. Teacher, 42, 296

Lattice QCD Study for the Interquark Force in Three-Quark and Multi-Quark Systems

We study the three-quark and multi-quark potentials in SU(3) lattice QCD. From the accurate calculation for more than 300 different patterns of 3Q systems, the static ground-state 3Q potential $V_{\rm 3Q}^{\rm g.s.}$ is found to be well described by the Coulomb plus Y-type linear potential (Y-Ansatz) within 1%-level deviation. As a clear evidence for Y-Ansatz, Y-type flux-tube formation is actually observed on the lattice in maximally-Abelian projected QCD. For about 100 patterns of 3Q systems, we perform the accurate calculation for the 1st excited-state 3Q potential $V_{\rm 3Q}^{\rm e.s.}$ by diagonalizing the QCD Hamiltonian in the presence of three quarks, and find a large gluonic-excitation energy $\Delta E_{\rm 3Q} \equiv V_{\rm 3Q}^{\rm e.s.}-V_{\rm 3Q}^{\rm g.s.}$ of about 1 GeV, which gives a physical reason of the success of the quark model. $\Delta E_{\rm 3Q}$ is found to be reproduced by the ``inverse Mercedes Ansatz'', which indicates a complicated bulk excitation for the gluonic-excitation mode. We study also the tetra-quark and the penta-quark potentials in lattice QCD, and find that they are well described by the OGE Coulomb plus multi-Y type linear potential, which supports the flux-tube picture even for the multi-quarks. Finally, the narrow decay width of penta-quark baryons is discussed in terms of the QCD string theory.Comment: Invited talk at Int. Conference on Quark Confinement and the Hadron Spectrum 6, Sardinia, Italy, 21-25 Sep 200

Eye-tracking analysis of the educational effect of refutation text in reading science texts: Case of celestial movements and seasonal changes

Refutation text is focusing on learner’s naive concept in order to refute it and forming scientific concept. It has been reported that reading refutation text is more effective than reading expository text in changing naive concepts of learners. According to Broughton et al. (2010), those who read refutation text spent less time reading than those who read expository text and made fewer errors on the post-test. This may suggest the cognitive efficiency in reading refutation text. In previous studies, the educational effects of using expository text or refutation text were examined by comparing the percentage of correct answers to pre-test, post-test etc., to verify the effects. It has already been reported how learners' gaze allocation to sentences differs between expository text and refutation text (Ariasi et al., 2017). However, so far, few eye-tracking researches have been conducted. In this study, we used an eye-tracking device to conduct a qualitative investigation on how the eye movements and time differed between the group who read the refutation text and the group who read the expository text. The target of the survey is about 20 Japanese undergraduate and graduate students, and the survey period is scheduled for June to August 2022. As for the research questions, we created refutation text and expository text on the subjects of celestial movements and seasonal changes, referring to the research questions of previous research by Broughton et al. (2010). The survey method is as follows. (1) A paper-based pre-test was conducted. (2) Measure eye movements of subjects who read survey questions presented on a monitor. At this time, one group was shown only the refutation text, and the other group was shown only the expository text. In addition, to both groups, another same scientific text was displayed on the monitor in order to measure the personal reading speed. (3) A paper-based post-test was conducted. (4) After the measurement, we conducted a semi-structured interview, including to see which part of the sentences the learner paid attention to, and recorded the audio. At present, as a reproduction of the results of previous research, the group that read the refutation text spent less time reading the text, and when comparing the rate of increase in scores between the pre-test and the post-test, the group that read the refutation text had a tendency for the score to increase significantly. The analysis of the data obtained by eye tracking will be presented at the conference. ACKNOWLEDGMENT This work was supported by JSPS KAKENHI Grant Numbers JP21K02890. REFERENCES Broughton, S. H., Sinatra, G. M., &amp; Reynolds, R. E. (2010). The nature of the refutation text effect: An investigation of attention allocation. The Journal of Educational Research, 103(6), 407–423. Ariasi, N., Hyönä, J., Kaakinen, J. K., &amp; Mason, L. (2017). An eye‐movement analysis of the refutation effect in reading science text. Journal of Computer Assisted Learning, 33, 202－221. https://doi.org/10.1111/jcal.1215

Detailed Analysis of the Tetraquark Potential and Flip-Flop in SU(3) Lattice QCD

We perform the detailed study of the tetraquark (4Q) potential $V_{\rm 4Q}$ for various QQ-$\rm \bar{Q}\bar{Q}$ systems in SU(3) lattice QCD with $\beta=6.0$ and $16^3 \times 32$ at the quenched level. For about 200 different patterns of 4Q systems, $V_{\rm 4Q}$ is extracted from the 4Q Wilson loop in 300 gauge configurations, with the smearing method to enhance the ground-state component. We calculate $V_{\rm 4Q}$ for planar, twisted, asymmetric, and large-size 4Q configurations, respectively. Here, the calculation for large-size 4Q configurations is done by identifying $16^2 \times 32$ as the spatial size and 16 as the temporal one, and the long-distance confinement force is particularly analyzed in terms of the flux-tube picture. When QQ and $\rm \bar{Q}\bar{Q}$ are well separated, $V_{\rm 4Q}$ is found to be expressed as the sum of the one-gluon-exchange Coulomb term and multi-Y type linear term based on the flux-tube picture. When the nearest quark and antiquark pair is spatially close, the system is described as a "two-meson" state. We observe a flux-tube recombination called as "flip-flop" between the connected 4Q state and the "two-meson" state around the level-crossing point. This leads to infrared screening of the long-range color forces between (anti)quarks belonging to different mesons, and results in the absence of the color van der Waals force between two mesons.Comment: 17 pages, 23 figure

Effectiveness of using video analysis software in Introductory Physics

With the rapid development of science and technology, various IT-based teaching materials and effective teaching methods have been developed. One such method is to analyze physical phenomena by capturing video of experiments and analyzing the video. The authors have developed teaching materials to analyze various physical phenomena that are difficult to realize with conventional experimental methods using moving images. For example, the authors have developed teaching materials in which the collision of two objects is filmed from above and analyzed to learn about the law of conservation of momentum. Video analysis is considered useful in that it enables learners to understand physical phenomena by connecting the phenomena to graphs and equations while actually operating the video. In addition, it is also considered to promote exploration activities by allowing learners to take videos of physical phenomena of interest to them and analyze them. The teaching materials we have developed have been used in university classes and teacher training, but they were intended for a relatively small group of about 30 students, and were mainly used in situations where learners could immediately respond to any inadequacies in operation or content. On the other hand, with the trend to online learning due to COVID-19 starting in 2020, there are more and more opportunities for university students to take online classes, using computers at home or other locations, and the introduction of Computer-Based-Test as a new way of testing has been seriously considered in recent years. Under these circumstances, even if learners are stumped by operational problems, teachers are often unable to provide immediate support. It is also necessary to examine the extent to which the use of video analysis software is useful for understanding the content. Therefore, the purpose of the study that we are presenting, is to examine the effectiveness and challenges of a motion analysis assignment outside of class, for approximately 480 students taking calculus-based introductory physics in their first year of university, for two years in 2021 and 2022. After viewing the video analysis shown by the professor several times during the class, the students installed the video analysis software themselves and worked on the video analysis task. In 2021, 53% of the students reported that understanding the concepts just by watching the video analysis was very helpful and helpful on a 5-point Likert scale, while 63% reported that understanding the concepts was very helpful and helpful when they tried to do the video analysis on their own. The results will be presented along with the 2022 results. ACKNOWLEDGMENT This work was supported by JSPS KAKENHI Grant Numbers JP21K02890. REFERENCES Kobayashi, A. &amp; Okiharu, F. (2010). Active learning approaches by visualizing ICT devices with milliseconds resolution for deeper understanding in physics, AIP Conference Proceedings, 1263, 134-138. Laws, P. &amp; Pfister, H. (1998). Using digital video analysis in introductory mechanics projects, The Physics Teacher, 36,282-287. Logger Pro, https://www.vernier.com/

First Study for the Pentaquark Potential in SU(3) Lattice QCD

The static penta-quark (5Q) potential $V_{\rm 5Q}$ is studied in SU(3) lattice QCD with $16^3\times 32$ and $\beta$=6.0 at the quenched level. From the 5Q Wilson loop, $V_{\rm 5Q}$ is calculated in a gauge-invariant manner, with the smearing method to enhance the ground-state component. $V_{\rm 5Q}$ is well described by the OGE plus multi-Y Ansatz: a sum of the OGE Coulomb term and the multi-Y-type linear term proportional to the minimal total length of the flux-tube linking the five quarks. Comparing with ${\rm Q \bar Q}$ and 3Q potentials, we find a universality of the string tension, $\sigma_{\rm Q \bar Q} \simeq \sigma_{\rm 3Q} \simeq \sigma_{\rm 5Q}$, and the OGE result for Coulomb coefficients.Comment: 4 pages, 5 figure