Department of Physics
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Browsing Department of Physics by Content Type "Conference proceeding"
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- An analysis of nonoblique corrections to the Zb¯b vertexTakeuchi, Tatsu; Grant, Aaron K.; Rosner, Jonathan L. (1994)We present a model–independent analysis of the Zb¯b vertex, with the aim of constraining contributions of new physics to the left- and right–handed couplings of the b. We find that the left–handed coupling of the b is quite narrowly constrained by present data, but that the right–handed coupling is still largely unconstrained.
- Applied Antineutrino Physics 2015 -- Conference SummaryBowden, N. S.; Heeger, K. M.; Huber, Patrick; Mariani, Camillo; Vogelaar, R. Bruce (2016-02)This is a brief summary of the 11th Applied Antineutrino Physics 2015 workshop held at the Virginia Tech Arlington Research Facility from December 7-8, 2015.
- Center for Soft Matter and Biological Physics Symposium Scientific Program 2016(Virginia Tech. Center for Soft Matter and Biological Physics, 2016-05-19)A program from the symposium held on May 19, 2016, in Hahn North 130.
- Center for Soft Matter and Biological Physics Symposium Scientific Program 2017(Virginia Tech. Center for Soft Matter and Biological Physics, 2017-05-17)A program from the symposium held on May 17, 2017, in Hahn Hall North Atrium.
- Center for Soft Matter and Biological Physics Symposium Scientific Program 2018(Virginia Tech. Center for Soft Matter and Biological Physics, 2018-05-16)A program from the symposium held on May 16, 2018, in Hahn Hall North Auditorium.
- Center for Soft Matter and Biological Physics Symposium Scientific Program 2019(Virginia Tech. Center for Soft Matter and Biological Physics, 2019-05-22)A program from the symposium held on May 22, 2019, in Hahn Hall North Atrium.
- Center for Soft Matter and Biological Physics Virtual Symposium 2020 Scientific Program(Virginia Tech, 2020-05-20)A program for the symposium held online on May 20, 2020.
- Center for Soft Matter and Biological Physics Virtual Symposium 2021 Scientific Program(Virginia Tech, 2021-05-19)A program for the symposium held online on May 19, 2021.
- CHANDLER: A Technology for Surface-level Reactor Neutrino DetectionLink, Jonathan M. (2023-01-17)
- Constraining new physics with vertex correctionsTakeuchi, Tatsu; Lebedev, O.; Loinaz, William (1999)
- Constraints on New Physics from Matter Effects on Neutrino OscillationHonda, M.; Kao, Y.; Okamura, Naotoshi; Pronin, A.; Takeuchi, Tatsu (2006)
- Constraints on R-parity violation from precision electroweak measurementsTakeuchi, Tatsu; Lebedev, O.; Loinaz, William (World Scientific, 2001-01-01)
- Coupled two-species model for the pair contact process with diffusionDeng, S.; Li, W.; Täuber, Uwe C. (American Physical Society, 2020-10-22)The contact process with diffusion (PCPD) defined by the binary reactions B+B→B+B+B, B+B→∅ and diffusive particle spreading exhibits an unusual active to absorbing phase transition whose universality class has long been disputed. Multiple studies have indicated that an explicit account of particle pair degrees of freedom may be required to properly capture this system's effective long-time, large-scale behavior. We introduce a two-species representation for the PCPD in which single particles B and particle pairs A are dynamically coupled according to the stochastic reaction processes B+B→A, A→A+B, A→∅, and A→B+B, with each particle type diffusing independently. Mean-field analysis reveals that the phase transition of this model is driven by competition and balance between the two species. We employ Monte Carlo simulations in one, two, and three dimensions to demonstrate that this model consistently captures the pertinent features of the PCPD. In the inactive phase, A particles rapidly go extinct, effectively leaving the B species to undergo pure diffusion-limited pair annihilation kinetics B+B→∅. At criticality, both A and B densities decay with the same exponents (within numerical errors) as the corresponding order parameters of the original PCPD, and display mean-field scaling above the upper critical dimension dc=2. In one dimension, the critical exponents for the B species obtained from seed simulations also agree well with previously reported exponent value ranges. We demonstrate that the scaling properties of consecutive particle pairs in the PCPD are identical with that of the A species in the coupled model. This two-species picture resolves the conceptual difficulty for seed simulations in the original PCPD and naturally introduces multiple length scales and timescales to the system, which are also the origin of strong corrections to scaling. The extracted moment ratios from our simulations indicate that our model displays the same temporal crossover behavior as the PCPD, which further corroborates its full dynamical equivalence with our coupled model.
- Critical dynamics of anisotropic antiferromagnets in an external fieldNandi, Riya; Täuber, Uwe C. (American Physical Society, 2020-03-03)We numerically investigate the non-equilibrium critical dynamics in three-dimensional anisotropic antiferromagnets in the presence of an external magnetic field. The phase diagram of this system exhibits two critical lines that meet at a bicritical point. The non-conserved components of the staggered magnetization order parameter couple dynamically to the conserved component of the magnetization density along the direction of the external field. Employing a hybrid computational algorithm that combines reversible spin precession with relaxational Monte Carlo updates, we study the aging scaling dynamics for the model C critical line, identifying the critical initial slip, autocorrelation, and aging exponents for both the order parameter and conserved field, thus also verifying the dynamic critical exponent. We further probe the model F critical line by investigating the system size dependence of the characteristic spin wave frequencies near criticality, and measure the dynamic critical exponents for the order parameter including its aging scaling at the bicritical point.
- The Effect of Topcolor Assisted Technicolor, and other models, on Neutrino OscillationHonda, M.; Kao, Y.; Okamura, Naotoshi; Pronin, A.; Takeuchi, Tatsu (2007)
- Experimental Neutrino PhysicsLink, Jonathan M. (2016-02-11)
- Experimental Neutrino Physics: Review and SummaryLink, Jonathan M. (2016-09-22)
- Field-theory approaches to nonequilibrium dynamicsTäuber, Uwe C. (Springer-Verlag Berlin, 2007-01-01)It is explained how field-theoretic methods and the dynamic renormalisation group (RG) can be applied to study the universal scaling properties of systems that either undergo a continuous phase transition or display generic scale invariance, both near and far from thermal equilibrium. Part 1 introduces the response functional field theory representation of (nonlinear) Langevin equations. The RG is employed to compute the scaling exponents for several universality classes governing the critical dynamics near second-order phase transitions in equilibrium. The effects of reversible mode-coupling terms, quenching from random initial conditions to the critical point, and violating the detailed balance constraints are briefly discussed. It is shown how the same formalism can be applied to nonequilibrium systems such as driven diffusive lattice gases. Part 2 describes how the master equation for stochastic particle reaction processes can be mapped onto a field theory action. The RG is then used to analyse simple diffusion-limited annihilation reactions as well as generic continuous transitions from active to inactive, absorbing states, which are characterised by the power laws of (critical) directed percolation. Certain other important universality classes are mentioned, and some open issues are listed.
- Hyper-Kamiokande Physics OpportunitiesKearns, E.; Hyper-Kamiokande Working Group (2013)We propose the Hyper-Kamiokande (Hyper-K) detector as a next generation underground water Cherenkov detector [1]. It will serve as a far detector of a long baseline neutrino oscillation experiment envisioned for the upgraded J-PARC beam, and as a detector capable of observing, far beyond the sensitivity of the Super-Kamiokande (Super-K) detector, proton decays, atmospheric neutrinos, and neutrinos from astro- physical origins. The current baseline design of Hyper-K is based on the highly suc- cessful Super-K detector, taking full advantage of a well-proven technology. Hyper-K consists of two cylindrical tanks lying side-by-side, the outer dimensions of each tank being 48(W) 54(H) 250(L) m3. The total (fiducial) mass of the detector is 0.99 (0.56) million metric tons, which is about 20 (25) times larger than that of Super-K. A proposed location for Hyper-K is about 8 km south of Super-K (and 295 km away from J-PARC) at an underground depth of 1,750 meters water equivalent (m.w.e.). The inner detector region of the Hyper-K detector is viewed by 99,000 20-inch PMTs, corresponding to the PMT density of 20% photo-cathode coverage (one half of that of Super-K). The Hyper-K project is envisioned to be completely open to the international community. The current working group contains members from Canada, Japan, Korea, Spain, Switzerland, Russia, the United Kingdom and the United States. The United States physics community has a long history of making contributions to the neutrino physics program in Japan. In Kamiokande, Super-Kamiokande, K2K and T2K, US physicists have played important roles building and operating beams, near detectors, and large underground water Cherenkov detectors. This set of three one- page whitepapers prepared for the US Snowmass process describes the opportunities for future physics discoveries at the Hyper-K facility with beam, atmospheric and astrophysical neutrinos.
- The K2K SciBar detectorNitta, K.; Aliu, E.; Andringa, S.; Aoki, S.; Choi, S.; Dore, U.; Espinal, X.; Gomez-Cadenas, J. J.; Gran, R.; Hasegawa, M.; Hayashi, K.; Hayashi, K.; Hayato, Y.; Hiraide, K.; Ichikawa, A. K.; Iinuma, M.; Jang, J. S.; Jeon, E. J.; Joo, K. K.; Jung, C. K.; Kato, I.; Kerr, D.; Kim, J. Y.; Kim, S. B.; Kobayashi, K.; Kohara, A.; Kubota, J.; Kudenko, Y.; Kuno, Y.; Lee, M. J.; Lessac-Chenin, E.; Lim, I. T.; Loverre, P. F.; Ludovici, L.; Maesaka, H.; Mariani, Camillo; McGrew, C.; Mineev, O.; Morita, T.; Murakami, T.; Nakanishi, Y.; Nakaya, T.; Nawang, S.; Nishikawa, K.; Pac, M. Y.; Rhee, E. J.; Rodriguez, A.; Sanchez, F.; Sasaki, T.; Shiraishi, K. K.; Suzuki, A.; Takahashi, T.; Takubo, Y.; Tanaka, M.; Terri, R.; Tornero-Lopez, A.; Ueda, S.; Wilkes, R. J.; Yamamoto, S.; Yokoyama, M.; Yoshida, M. (Elsevier, 2004-12-11)