The Experts below are selected from a list of 12282 Experts worldwide ranked by ideXlab platform
N Ishizuka - One of the best experts on this subject based on the ideXlab platform.
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i 2 two pion wave function and Scattering Phase Shift
Physical Review D, 2008Co-Authors: Kiyoshi Sasaki, N IshizukaAbstract:We calculate a two-pion wave function for the $I=2$ $S$-wave two-pion system with a finite Scattering momentum and estimate the interaction range between two pions, which allows us to examine the validity of a necessary condition for the finite size formula presented by Rummukainen and Gottlieb. We work in the quenched approximation employing the plaquette gauge action for gluons and the improved Wilson action for quarks at $1/a=1.63\text{ }\text{ }\mathrm{GeV}$ on the ${32}^{3}\ifmmode\times\else\texttimes\fi{}120$ lattice. The quark masses are chosen to give ${m}_{\ensuremath{\pi}}=0.420$, 0.488, and 0.587 GeV. We find that the energy dependence of the interaction range is small and the necessary condition is satisfied for our range of the quark mass and the Scattering momentum, $k\ensuremath{\le}0.16\text{ }\text{ }\mathrm{GeV}$. We also find that the Scattering Phase Shift can be obtained with a smaller statistical error from the two-pion wave function than from the two-pion time correlator.
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i 2pipi Scattering Phase Shift with two flavors of o a improved dynamical quarks
Physical Review D, 2004Co-Authors: Takeshi Yamazaki, S Aoki, M Fukugita, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, Kenichi Ishikawa, Masanori OkawaAbstract:We present a lattice QCD calculation of Phase Shift including the chiral and continuum extrapolations in two-flavor QCD. The calculation is carried out for $I=2$ $S$-wave $\ensuremath{\pi}\ensuremath{\pi}$ Scattering. The Phase Shift is evaluated for two momentum systems, the center of mass and laboratory systems, by using the finite-volume method proposed by L\"uscher in the center of mass system and its extension to general systems by Rummukainen and Gottlieb. The measurements are made at three different bare couplings $\ensuremath{\beta}=1.80$, 1.95 and 2.10 using a renormalization group improved gauge and a tadpole improved clover fermion action, and employing a set of configurations generated for hadron spectroscopy in our previous work. The illustrative values we obtain for the Phase Shift in the continuum limit are $\ensuremath{\delta}(\mathrm{deg}.)=\ensuremath{-}3.50(64)$, $\ensuremath{-}9.5(30)$ and $\ensuremath{-}16.9(64)$ for $\sqrt{s}(\mathrm{G}\mathrm{e}\mathrm{V})=0.4$, 0.6 and 0.8, which are consistent with experiments.
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i 2 pion pion Scattering Phase Shift in the continuum limit calculated with two flavor full qcd
Nuclear Physics B Proceedings Supplements, 2004Co-Authors: Takeshi Yamazaki, S Aoki, M Fukugita, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a calculation of the Scattering Phase Shift for the I = 2 S-wave pion-pion system in the continuum limit with two-flavor full QCD. Calculations are made at three lattice spacings, using the finite volume method of Luscher in the center of mass frame, and its extension to the laboratory frame.
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i 2 pion Scattering Phase Shift with wilson fermions
Nuclear Physics B Proceedings Supplements, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:Abstract We present results of Phase Shift for I = 2 S -wave ππ system with the Wilson fermions in the quenched approximation. The finite size method proposed by Lu¨scher is employed, and calculations are carried out atβ = 5.9 (a -1 = 1.934(16)GeV from m p ) on 24 3 × 60 , 32 3 × 0 , and 48 3 ×0 lattices.
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i 2 pion Scattering Phase Shift with wilson fermions
Physical Review D, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a lattice QCD calculation of the Scattering Phase Shift for the I52 S-wave two-pion system using the finite size method proposed by Luscher. We work in the quenched approximation employing the standard plaquette action at b55.9 for gluons and the Wilson fermion action for quarks. The Phase Shift is extracted from the energy eigenvalues of the two-pion system, which are obtained by a diagonalization of the pion four-point function evaluated for a set of relative spatial momenta. In order to change the momentum of the two-pion system, calculations are carried out on 24 3 360, 32 3 360, and 48 3 360 lattices. The Phase Shift is successfully calculated over the momentum range 0, p 2 ,0.3 GeV 2 .
S Aoki - One of the best experts on this subject based on the ideXlab platform.
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i 2 pi pi Scattering Phase Shift from the hal qcd method with the laph smearing
arXiv: High Energy Physics - Lattice, 2017Co-Authors: Daisuke Kawai, S Aoki, Takumi Doi, Yoichi Ikeda, Takashi Inoue, Takumi Iritani, Noriyoshi Ishii, Takaya Miyamoto, Hidekatsu Nemura, Kenji SasakiAbstract:Physical observables, such as the Scattering Phase Shifts and the binding energies, calculated from the non-local HAL QCD potential do not depend on the sink operators used to define the potential. This is called the scheme independence of the HAL QCD method. In practical applications, the derivative expansion of the non-local potential is employed, so that physical observables may receive some scheme dependence at given order of the expansion. In this paper, we compare the $I=2$ $\pi\pi$ Scattering Phase Shifts obtained in the point-sink scheme (the standard scheme in the HAL QCD method) and the smeared-sink scheme (the LapH smearing newly introduced in the HAL QCD method). Although potentials in different schemes have different forms as expected, we find that, for reasonably small smearing size, the resultant Scattering Phase Shifts agree with each other if the next-to-leading order (NLO) term is taken into account. We also find that the HAL QCD potential in the point-sink scheme has negligible NLO term for wide range of energies, which implies a good convergence of the derivative expansion in this case, while the potential in the smeared-sink scheme has non-negligible NLO contribution. Implication of this observation to the future studies of resonance channels (such as the $I=0$ and $1$ $\pi\pi$ Scatterings) with smeared all-to-all propagators is briefly discussed. All computations in this paper have been performed at the lattice spacing $a\simeq 0.12$ fm ($1/a \simeq 1.6$ GeV) on a $16^3\times 32$ lattice with the pion mass $m_\pi\simeq 870$ MeV.
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i 2pipi Scattering Phase Shift with two flavors of o a improved dynamical quarks
Physical Review D, 2004Co-Authors: Takeshi Yamazaki, S Aoki, M Fukugita, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, Kenichi Ishikawa, Masanori OkawaAbstract:We present a lattice QCD calculation of Phase Shift including the chiral and continuum extrapolations in two-flavor QCD. The calculation is carried out for $I=2$ $S$-wave $\ensuremath{\pi}\ensuremath{\pi}$ Scattering. The Phase Shift is evaluated for two momentum systems, the center of mass and laboratory systems, by using the finite-volume method proposed by L\"uscher in the center of mass system and its extension to general systems by Rummukainen and Gottlieb. The measurements are made at three different bare couplings $\ensuremath{\beta}=1.80$, 1.95 and 2.10 using a renormalization group improved gauge and a tadpole improved clover fermion action, and employing a set of configurations generated for hadron spectroscopy in our previous work. The illustrative values we obtain for the Phase Shift in the continuum limit are $\ensuremath{\delta}(\mathrm{deg}.)=\ensuremath{-}3.50(64)$, $\ensuremath{-}9.5(30)$ and $\ensuremath{-}16.9(64)$ for $\sqrt{s}(\mathrm{G}\mathrm{e}\mathrm{V})=0.4$, 0.6 and 0.8, which are consistent with experiments.
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i 2 pion pion Scattering Phase Shift in the continuum limit calculated with two flavor full qcd
Nuclear Physics B Proceedings Supplements, 2004Co-Authors: Takeshi Yamazaki, S Aoki, M Fukugita, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a calculation of the Scattering Phase Shift for the I = 2 S-wave pion-pion system in the continuum limit with two-flavor full QCD. Calculations are made at three lattice spacings, using the finite volume method of Luscher in the center of mass frame, and its extension to the laboratory frame.
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i 2 pion Scattering Phase Shift with wilson fermions
Nuclear Physics B Proceedings Supplements, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:Abstract We present results of Phase Shift for I = 2 S -wave ππ system with the Wilson fermions in the quenched approximation. The finite size method proposed by Lu¨scher is employed, and calculations are carried out atβ = 5.9 (a -1 = 1.934(16)GeV from m p ) on 24 3 × 60 , 32 3 × 0 , and 48 3 ×0 lattices.
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i 2 pion Scattering Phase Shift with wilson fermions
Physical Review D, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a lattice QCD calculation of the Scattering Phase Shift for the I52 S-wave two-pion system using the finite size method proposed by Luscher. We work in the quenched approximation employing the standard plaquette action at b55.9 for gluons and the Wilson fermion action for quarks. The Phase Shift is extracted from the energy eigenvalues of the two-pion system, which are obtained by a diagonalization of the pion four-point function evaluated for a set of relative spatial momenta. In order to change the momentum of the two-pion system, calculations are carried out on 24 3 360, 32 3 360, and 48 3 360 lattices. The Phase Shift is successfully calculated over the momentum range 0, p 2 ,0.3 GeV 2 .
V Lesk - One of the best experts on this subject based on the ideXlab platform.
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i 2 pion pion Scattering Phase Shift in the continuum limit calculated with two flavor full qcd
Nuclear Physics B Proceedings Supplements, 2004Co-Authors: Takeshi Yamazaki, S Aoki, M Fukugita, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a calculation of the Scattering Phase Shift for the I = 2 S-wave pion-pion system in the continuum limit with two-flavor full QCD. Calculations are made at three lattice spacings, using the finite volume method of Luscher in the center of mass frame, and its extension to the laboratory frame.
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i 2 pion Scattering Phase Shift with wilson fermions
Nuclear Physics B Proceedings Supplements, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:Abstract We present results of Phase Shift for I = 2 S -wave ππ system with the Wilson fermions in the quenched approximation. The finite size method proposed by Lu¨scher is employed, and calculations are carried out atβ = 5.9 (a -1 = 1.934(16)GeV from m p ) on 24 3 × 60 , 32 3 × 0 , and 48 3 ×0 lattices.
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i 2 pion Scattering Phase Shift with wilson fermions
Physical Review D, 2003Co-Authors: S Aoki, M Fukugita, S Hashimoto, Ki Ishikawa, N Ishizuka, Y Iwasaki, K Kanaya, T Kaneko, Y Kuramashi, V LeskAbstract:We present a lattice QCD calculation of the Scattering Phase Shift for the I52 S-wave two-pion system using the finite size method proposed by Luscher. We work in the quenched approximation employing the standard plaquette action at b55.9 for gluons and the Wilson fermion action for quarks. The Phase Shift is extracted from the energy eigenvalues of the two-pion system, which are obtained by a diagonalization of the pion four-point function evaluated for a set of relative spatial momenta. In order to change the momentum of the two-pion system, calculations are carried out on 24 3 360, 32 3 360, and 48 3 360 lattices. The Phase Shift is successfully calculated over the momentum range 0, p 2 ,0.3 GeV 2 .
Jozef J Dudek - One of the best experts on this subject based on the ideXlab platform.
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isoscalar ππ Scattering and the σ meson resonance from qcd
Physical Review Letters, 2017Co-Authors: Raul A Briceno, Jozef J Dudek, Robert G Edwards, David J WilsonAbstract:We present for the first time a determination of the energy dependence of the isoscalar ππ elastic Scattering Phase Shift within a first-principles numerical lattice approach to QCD. Hadronic correlation functions are computed including all required quark propagation diagrams, and from these the discrete spectrum of states in the finite volume defined by the lattice boundary is extracted. From the volume dependence of the spectrum, we obtain the S-wave Phase Shift up to the KK[over ¯] threshold. Calculations are performed at two values of the u, d quark mass corresponding to m_{π}=236,391 MeV, and the resulting amplitudes are described in terms of a σ meson which evolves from a bound state below the ππ threshold at the heavier quark mass to a broad resonance at the lighter quark mass.
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isoscalar ππ Scattering and the σ meson resonance from qcd
2016Co-Authors: Raul A Briceno, Jozef J Dudek, Robert G Edwards, David J WilsonAbstract:We present for the first time a determination of the energy dependence of the isoscalar ππ elastic Scattering Phase-Shift within a first-principles numerical lattice approach to QCD. Hadronic correlation functions are computed including all required quark propagation diagrams, and from these the discrete spectrum of states in the finite volume defined by the lattice boundary is extracted. From the volume dependence of the spectrum we obtain the S-wave Phase-Shift up to the KK threshold. Calculations are performed at two values of the u, d quark mass corresponding to mπ = 236, 391 MeV and the resulting amplitudes are described in terms of a σ meson which evolves from a bound-state below ππ threshold at the heavier quark mass, to a broad resonance at the lighter quark mass.
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energy dependence of the rho resonance in pi pi elastic Scattering from lattice qcd
Physical Review D, 2013Co-Authors: Jozef J Dudek, Robert G Edwards, Christopher E ThomasAbstract:We determine the energy-dependent amplitude for elastic {pi} {pi} P-wave Scattering in isospin-1 by computing part of the discrete energy spectrum of QCD in finite cubic boxes. We observe a rapidly rising Phase Shift that can be well described by a single {rho} Resonance. The spectrum is obtained from hadron correlators computed using lattice QCD with light quark masses corresponding to m{sub {pi}}~400 MeV. Variational analyses are performed with large bases of hadron interpolating fields including, as well as fermion bilinears that resemble q{anti q} Constructions, also operators that look like pairs of pions with definite relative and total momentum. We compute the spectrum for a range of center-of-mass momenta and in various irreducible representations of the relevant symmetry group. Hence we determine more than thirty values of the isospin-1 P-wave Scattering Phase Shift in the elastic region, mapping out its energy dependence in unprecedented detail.
Sasa Prelovsek - One of the best experts on this subject based on the ideXlab platform.
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Scattering Phase Shifts for two particles of different mass and nonzero total momentum in lattice qcd
Physical Review D, 2012Co-Authors: Luka Leskovec, Sasa PrelovsekAbstract:We derive the relation between the Scattering Phase Shift and the two-particle energy in the finite box, which is relevant for extracting the strong Phase Shifts in lattice QCD. We consider elastic Scattering of two particles with different mass and with non-zero total momentum in the lattice frame. This is a generalization of the Luscher formula, which considers zero total momentum, and the generalization of Rummukainen-Gottlieb's formula, which considers degenerate particles with non-zero total momentum. We focus on the most relevant total momenta in practice, i.e. P=(2\pi/L) e_z and P=(2\pi/L) (e_x+e_y) including their multiples and permutations. We find that the P-wave Phase Shift can be reliably extracted from the two-particle energy if the Phase Shifts for l>=2 can be neglected, and we present the corresponding relations. The reliable extraction of S-wave Phase Shift is much more challenging since delta(l=0) is always accompanied by delta(l=1) in the Phase Shift relations, and we propose strategies for estimating delta(l=0). We also propose the quark-antiquark and meson-meson interpolators that transform according the considered irreducible representations.
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Scattering Phase Shift and resonance properties on the lattice an introduction
arXiv: High Energy Physics - Phenomenology, 2011Co-Authors: Sasa Prelovsek, C B Lang, Daniel MohlerAbstract:We describe the method for extracting the elastic Scattering Phase Shift from a lattice simulation at an introductory level, for non-lattice practitioners. We consider the Scattering in a resonant channel, where the resulting Phase Shift delta(s) allows the lattice determination of the mass and the width of the resonance from a Breit-Wigner type fit. We present the method for the example of P-wave pi-pi Scattering in the rho meson channel.
