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We compare the ultrafast dynamics of the spin reorientation transition in the orthoferrite ${\mathrm{Sm}}_{0.7}{\mathrm{Er}}_{0.3}{\mathrm{FeO}}_{3}$ following two different pumping mechanisms. Intense few-cycle pulses in the midinfrared selectively excite either the $f\text{\ensuremath{-}}f$ electronic transition of ${\mathrm{Sm}}^{3+}$ or optical phonons. With phonon pumping, a finite time delay exists for the spin reorientation, reflecting the energy transfer between the lattice and $4f$ system. In contrast, an instantaneous response is found for resonant $f\text{\ensuremath{-}}f$ excitation. This suggests that $4f$ electronic pumping can directly alter the magnetic anisotropy due to the modification of $4f\text{\ensuremath{-}}3d$ exchange at femtosecond timescales, without involving lattice thermalization.

We have experimentally studied a magnetopiezoelectric effect (MPE), i.e., dynamic distortion caused by AC electric currents, in the antiferromagnetic conductor ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$ at low temperatures down to $77\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ using laser Doppler vibrometry. When AC electric currents are applied to ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$, dynamic displacement signals which increase in proportion to the current amplitude are clearly observed at $77\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, but their magnitude and temperature dependence strongly depend on Joule heating effects caused by the applied electric currents. Especially, poor thermal contact of ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$ samples to the sample holder produces second-harmonic displacement signals owing to thermal expansion due to the Joule heating, and tends to affect the temperature dependence of the MPE signals. In a measurement run without any heating effects, a sharp enhancement of the MPE signal is observed at the N\'eel temperature of ${\mathrm{CaMn}}_{2}{\mathrm{Bi}}_{2}$, which suggests that fluctuations of itinerant Mn moments near the N\'eel temperature play an important role in the MPE. We speculate that electric currents produce nonequilibrium antiferromagnetic moments via the antiferromagnetic Edelstein effect and the induced antiferromagnetic momemts enhance the MPE signal with the help of a large magnetovolume coupling near the N\'eel temperature. The MPE efficiency as a piezoelectric response reaches 300--$500\phantom{\rule{0.16em}{0ex}}\mathrm{pC}/\mathrm{N}$ at a maximum, which is comparable to high values of piezoelectric coefficients detected in the piezoelectric (ferroelectric) ceramics.

We approach the helium isotopes 6 He, 8 He, and 10 He by using the three-cluster model (core + 2 n ) from the viewpoint that these nuclei make a Borromean-nuclei series. In this report, we check our calculation code on 6 He (or 6 Li) and we study 8 He and 10 He with core excitation. To determine the parameters of potentials between core and n , we make use of the experimental data of the ground and the first excited states of 7 He and 9 He. We check the possible combinations of total J π 's of the ground and the first excited states of 7 He and 9 He for reproducing the ground state of 8 He, and 10 He. The state probabilities for 8 He are reported within our model.

Using the Okubo effective theory a realistic nucleon-nucleon potential is transformed into low-momentum effective one (LMNN). The feature of the LMNN potential is examined by calculating the triton binding energy, in order to see the dependence of the cutoff parameter Λ. Furthermore, the LMNN is expanded in a separable form. We compare the universal separable expansion method with a simple Legendre expansion. Through the calculation of the triton binding energies, the separability for the convergence of these ranks is evaluated. It is found that there is a tendency for the lower Λ of LMNN to gain better separability.

A realistic nucleon-nucleon potential is transformed into a low-momentum effective one (LMNN) using the Okubo theory. The separable potentials are converted from the LMNN with a universal separable expansion method and a simple Legendre expansion. Through the calculation of the triton binding energies, the separability for the convergence of these ranks is evaluated. It is found that there is a tendency for the lower momentum cutoff parameter $\Lambda$ of LMNN to gain good separability., Comment: 6 pages, 1 table

The finite range expansion method [Y. Koike, Prog. Theor. Phys. 87 (1992), 775], which gives well converged solutions of the three-body Faddeev equations, is extended to the three-body and two-two subsystems in order to solve the four-body Faddeev-Yakubovsky equations. A feasibility study is carried out to check the convergence in a four-nucleon system at 3.45 MeV below the four-body break-up threshold, which is in between the 2N-2N and 2N - N - N break-up thresholds. We obtain a converged phase shift and inelasticity parameter to 6 digits for 3N + N elastic scattering.

We introduce a new screening function which is useful for the few-body Coulomb scattering problem in ``screening and renormalization'' scheme. The new renormalization phase factor of the screening function is analytically shown. The Yukawa type of the screening potential has been used in several decades, we modify it to make more useful. As a concrete example, we compare the proton-proton scattering phase shifts calculated from these potentials. The numerical results document that high precision calculations of the renormalization are performed by the new screening function.

The field induced magnetic phase transitions of Cs 2 CuBr 4 were investigated by means of magnetization process and neutron scattering experiments. Cs 2 CuBr 4 should be characterized as S = 1/2 two-dimensional triangular antiferromagnet. Below the ordering temperature T N = 1.4 K, the Spin structure is the helical incommensurate structure almost within the triangular lattice plane. In the field direction within the triangular lattice plane, Cs 2 CuBr 4 exhibits the magnetization plateaux at one-third and two-thirds of the saturation magnetization. The spin structure in the one-third plateau phase is found to be almost collinear up-up-down structure which should be stabilized by quantum fluctuation as predicted by the theoretical studies.

We report the results of inelastic neutron scattering (INS) experiments on the S = 1 bond-alternating quasi-one-dimensional (1D) antiferromagnet Ni(C 9 D 24 N 4 )(NO 2 )ClO 4 under magnetic' fields below and above the critical field H c at which the energy gap closes. Normal field dependence of Zeeman split of the excited triplet state below H c has been observed, but the highest mode is unusually small and smears out with increasing field. This is probably explained by the highest branch buried in a magnon continuum, which was never observed in the S = 1 antiferromagnetic uniform chain. Above H c , we observed only one excitation branch, which is completely different from the Haldane material NDMAP [A. Zheludev et al., Phys. Rev. B 68 (2003), 134438] where three gapped branches were clearly observed.

Neutron inelastic scattering experiments have been performed on the paramagnetic heavy fermion compound CeRu 2 Si 2 in magnetic field along the crystal c -axis. Around the metamagnetic crossover field H m =7.7 T, the quasi-elastic excitation in the vicinity of the reciprocal lattice point (110) with an energy of 0.4 meV is significantly enhanced at T =0.4 K. The result indicates that the metamagnetic crossover in this compound is associated with a field-induced ferromagnetic correlation. The observation is consistent with the recent theoretical prediction by Satoh and Ohkawa based on quasi-particle band spectrum considerations.

A method for solving few-body scattering equations is proposed and examined. The solution of the scattering equations at complex energies is analytically continued to get scattering T-matrix with real positive energy. Numerical examples document that the method works well for two-nucleon scattering and three-nucleon scattering, if the set of complex energies is properly chosen., Comment: 6 pages, no figures, resubmitted to Prog. Theor. Phys

We performed the DC-magnetization and neutron scattering experiments under pressure {\it P} for a pressure-induced superconductor UGe$_2$. We found that the magnetic moment is enhanced at a characteristic temperature {\it T}$^{*}$ in the ferromagnetic state, where {\it T}$^{*}$ is smaller than a Curie temperature {\it T}$_{\rm C}$. This enhancement becomes remarkable in the vicinity of {\it P}$_{\rm C}^{*}$ = 1.20 GPa, where {\it T}$^{*}$ becomes 0 K and the superconducting transition temperature {\it T}$_{\rm SC}$ shows a maximum. The characteristic temperature {\it T}$^{*}$, which decreases with increasing pressure, also depends on the magnetic field., Comment: To be published in J.Phys.Soc.Jpn

In biomagnetic measurement in a magnetically moderately shielded room, the dominant environmental field noise is the line-frequency (50 Hz) noise. We have studied off-line processing to reduce the line-frquency noise that is included in the raw data measured with a multichannel SQUID magnetometer. Our method utilizes digital filtering and averaging to obtain exclusively the magnetic field unit vectors, which represent the spatial distribution of the noise field. The results for the magnetic field waveform, after subtraction of line-frequency noise components, indicated the effectiveness of our method in reducing the noise. Further, localization of a single equivalent current dipole in a simulation showed that the noise-reduced data decreased the error of the dipole location and increased the goodness-of-fit values.

Neutron scattering experiments have been carried out for a heavy fermion superconductor URu 2 Si 2 . We found that the (1 0 0) magnetic Bragg peak intensity is reduced by 1–2% in magnitude below the superconducting transition temperature of 1.15 K. This is direct evidence of the interplay between magnetism and superconductivity in URu 2 Si 2 .

High resolution neutron scattering experiments have been carried out in order to study the interplay between magnetism and superconductivity in the heavy fermion superconductor ${\mathrm{UPd}}_{2}{\mathrm{Al}}_{3}$. We found direct evidence for a magnetic excitation gap associated with superconductivity. We observed $1%$ suppression of the antiferromagnetic Bragg intensities below the superconducting transition temperature ${T}_{c}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}1.9\mathrm{K}$. We also observed the increases of the spin wave excitation energy and its linewidth in the superconducting state. These results indicate a strong coupling between magnetism and superconductivity in this compound.

An accurate solution for the three-nucleon bound state is obtained within 1 keV in the binding energy and, on the whole, better than 1% in the wave function, using a new systematic and efficient method. The method is based on a recently developed separable expansion for any finite-range interaction, in which a rigorous separable series for the two-body t-matrix is obtained by expanding the wave function in terms of a complete set of basis functions inside the range of the potential. In order to treat a potential with a strong repulsive core, as in the case of the Argonne potential, we develop a two-potential formalism. The expansion starts with a few EST (Ernst, Shakin, and Thaler) terms in order to accelerate the convergence and continues with an orthogonal set of polynomials, avoiding the known difficulties of a pure EST expansion. Thus, several techniques are combined in the present extended separable expansion (ESE). In this way, the method opens a new systematic treatment for accurate few-body calculations resulting in a dramatic reduction in the CPU time required to solve few-body equations.

Neutron scattering experiments have been carried out in order to study the interplay between magnetism and superconductivity in a heavy fermion superconductor, UPd 2 Al 3 . We have observed 1% suppression of the (0 0 0.5) magnetic peak intensity below the superconducting transition temperature T c . This is direct evidence for the coupling of the magnetic order parameter with the superconducting one. Furthermore, we have observed a spin excitation gap associated with superconductivity. The gap energy Δ E g increases continuously from Δ E g = 0 to 0.4 meV with decreasing temperature from T c to 0.4 K. This gap energy corresponds to 2 k B T c , which is smaller than the superconducting gap expected from the BCS theory (3.5 k B T c ). These results are indicative of the strong interplay between magnetism and superconductivity.

We prove that the twist-3 chiral-odd parton distributions obey simple Gribov-Lipatov-Altarelli-Parisi evolution equations in the limit ${N}_{c}\ensuremath{\rightarrow}\ensuremath{\infty}$ and give analytic results for the corresponding anomalous dimensions. To this end we introduce an evolution equation for the corresponding three-particle twist-3 parton correlation functions and find an exact analytic solution. For large values of $n$ (operator dimension) we are further able to collect all corrections subleading in ${N}_{c}$, so our final results are valid to $O(({1/N}_{c}^{2})\mathrm{ln}(n)/n)$ accuracy.

The effects of iodine intercalation have been investigated for the Co-substituted Bi-2212 phase ${\mathrm{Bi}}_{2}$${\mathrm{Sr}}_{2}$Ca(${\mathrm{Cu}}_{1\mathrm{\ensuremath{-}}\mathit{z}}$${\mathrm{Co}}_{\mathit{z}}$${)}_{2}$${\mathrm{O}}_{8+\mathrm{\ensuremath{\delta}}}$ with different \ensuremath{\delta} values in the overdoped regime. Whereas in the pristine samples ${\mathit{T}}_{\mathit{c}}$ depends on z and \ensuremath{\delta}, in the intercalated ones ${\mathit{T}}_{\mathit{c}}$ is independent of \ensuremath{\delta}. This indicates that the hole concentration p in the Bi-2212 phase has an upper limit and becomes saturated by the transfer of holes from the intercalated iodine. ${\mathit{T}}_{\mathit{c}}$(z)/${\mathit{T}}_{\mathit{c}}$(z=0) of the intercalated samples differs from that of the pristine ones. This suggests that the intercalation of iodine decreases ${\mathit{T}}_{\mathit{c}}$ not only through an increase in p, but also through a structural change, probably the interlayer decoupling between adjacent blocks of the ${\mathrm{CuO}}_{2}$ planes. \textcopyright{} 1996 The American Physical Society.

The differential cross sections and the vector and tensor analyzing powers Ay, Ayy, Axx, and Axz for the d-p elastic scattering were measured at Edlab = 270 MeV over the c.m. angular range from 57° to 138°. The data are compared with a Faddeev calculation. A good description is obtained for all components of the analyzing powers, while a discrepancy of about 30% is found in the cross section around θc.m. = 120°.

We have investigated the spin dynamics of the nearly-ideal one-dimensional bond-alternating antiferromagnet Ni(333-tet)NO2ClO4 (alias NTENP) by inelastic neutron scattering. The measurements have been performed as a function of both the wave vector (components along and perpendicular to the chain axis around q=π) and the temperature. Our experimental results at low temperatures show unambiguously the existence of a gapped dispersive mode in the spin-excitation spectrum. The magnetic response at q=π is peaked at the energy Δ≈1.2 meV and displays a finite energy width 2Γ≈0.3 meV at 1.5 K . As expected for a mainly magnetic mode, the gap feature shows a strong temperature dependence and vanishes almost completely above 25 K .

We report the result of an inelastic neutron elastic scattering experiment on U3Pd20Si6. We found a crystalline electric field excitation around 23 meV, indicating localized character of the 5f electrons in U3Pd20Si6. We also observed a sharp peak at dE=2.8 meV in the magnetic excitation spectra at 7 K, below the antiferromagnetic transition temperature 19 K, which may be attributed to antiferromagnetic spin wave excitations.

Neutron scattering experiments were carried out for the new Haldane compounds Ni(C5H14N2)2N3(ClO4) (NDMAZ) and Ni(C5H14N2)2N3(PF6) (NDMAP) in the magnetic field up to 10 T in order to investigate the field-induced long-range ordering and the spin excitation. For NDMAZ, the triplet excited state (1.61, 1.76, and 3.2 meV) and field dependence of these levels were observed at Q=(0 0 0.5). From these data, the intra-chain coupling constant≈4.3 meV and the anisotropic parameters D≈0.76 meV and |E|≈0.038 meV were estimated. For NDMAP the gap was observed at about 0.48 and 0.64 meV at Q=(0 0 0.5). By applying the field of 5 T, the first excited state shifted below the resolution less than 0.13 meV. Above the critical field HC, the intensities of singlet–triplet excitation becomes very weak. This work is the first neutron scattering study on a Haldane system above the critical fields.

We propose a simple but rigorous formalism to solve the Lippmann·Schwinger equation, expand· ing the wave function inside the potential range. The solution gives us a separable t-matrix. The formalism can be applied to any finite range two-body interactions and is useful to solve few-body equations. The solution of the two-body Lippmann-Schwinger equation is important not only in the two-body problem alone but also in the few-body problems. It is well known that a t-matrix solution in a separable form is very useful in the few-body equations. l ) Here we propose a new formalism to solve the two-body Lippmann-Schwinger equation. The assumption is that the two-body interaction is of finite range, i.e., vanishes beyond the range R. We expand the wave function I¢) inside the potential range. Since the range is finite, it is easy to find a set of complete base functions for the expansion. The expansion is useful in the integral equation because it keeps the product Vl¢) unchanged. Then we get a set of linear equations each for the scatter­ ing problem and for the bound state problem. It will be shown that the solution of the scattering equation leads to a separable t-matrix. Thus the present formalism is very useful in the few-body equations. When it is applied to the two-body bound state problem, it easily gives the bound state wave function in the whole range, although the original expansion is limited inside the potential range. The resulting separable t-matrix in the present formalism can also be derived from a separable potential expansion method developed by Adhikari and his collabo­ rators. 2 ) Their method has been used in a recent nod scattering calculation by the present author3) adopting modified Malftiet-Tjon potential as the two-body interac-. tion. 4 ) It has been demonstrated that the phase shift and the absorption parameters of the nod scattering are obtained very accurately with low rank separable potentials. The result has been compared with those obtained from other methods. 4 ) It was found that the agreement between them are satisfactorily good. However, it is sometimes asked why a separable potential expansion works so well. The present formalism gives a simple but solid theoretical base for the nod scattering calculation done in Ref. 3). First we discuss the two-body scattering problem. Hereafter, we use the partial wave projected one-dimensional equation, for simplicity. But, it is not essential. We could also use a three-dimensional one. The scattering wave function j¢) satisfies the Lippmann-Schwinger equation

The numerical quality of the3H wave function obtained by the separable expansion method of Ernst, Shakin, and Thaler is examined. Separable approximations to the Paris potential with increasing accuracy are used in the1S0 and3S1-3D1 partial waves to calculate the binding energy, wave function, wave-function component percentages, and theS- andD-wave asymptotic normalization constants of3H. The results are compared with existing five-channel calculations obtained directly (without expansion) from the Paris potential to determine convergence. It is found that the results converge rapidly to the right values, indicating that the3H wave function thus obtained is of high quality and essentially indistinguishable from that obtained directly from the Paris interaction.

It is demonstrated numerically that a separable expansion of the two-body {ital t} matrix gives us an exact method of solving the Faddeev equation with a local potential. The method of a separable expansion adopted is simple and systematic. The result of the three-body calculation on the {ital n}-{ital d} scattering is stable at least in four significant figures with a lower truncation of the separable series.

The non-relativistic quark cluster model is employed to study two-baryon systems including hyperons such as Λ,Σ and Ξ. The quark confinement is described in terms of the flip-flop model. For a description of long- and medium-range parts of the baryon-baryon interaction, the exchanges of pseudoscalar mesons and a scalar meson σ are taken into account in the present calculation. Adjusting the parameters so as to fit the nucleon-nucleon scattering data, we obtain a strongly bound state di-hyperon which is about 60–120 MeV lower than the ΛΛ threshold.

Complex energy method is introduced to handle singularity of Green’s function in fourbody Faddeev-Yakubovsky equations. We find that it is applicable to finding resonance states. Finite range expansion method is introduced to reduce the size of matrices of the Faddeev-Yakubovsky equations. We think this is applicable even in the energy region above the four-body break-up threshold when we employ low-momentum NN interactions.

Strong interplay between antiferromagnetism and superconductivity in a heavy-fermion superconductor UPd2Al3 is studied by neutron scattering. The (0 0 0.5) antiferromagnetic Bragg intensity exhibits 1% reduction below the superconducting transition temperature TC. We found that the magnetic excitation gap of about 0.4 meV is associated with superconductivity. The spin-wave excitation shows an enhancement and anomalous decrease below TC. These results are indicative of the strong interplay between antiferromagnetism and superconductivity.

Inelastic neutron scattering experiments on the S = 1 quasi-one-dimensional bond-alternating antiferromagnet Ni(C9D24N4)(NO2)ClO4 have been performed under magnetic fields below and above a critical field Hc at which the energy gap closes. Normal field dependence of Zeeman splitting of the excited triplet modes below Hc has been observed, but the highest mode is unusually small and smears out with increasing field. This can be explained by an interaction with a low-lying two magnon continuum at q(parallel) = pi that is present in dimerized chains but absent in uniform ones. Above Hc, we find only one excited mode, in stark contrast with three massive excitations previously observed in the structurally similar Haldane-gap material NDMAP [A. Zheludev, Phys. Rev. B 68, 134438 (2003)].

The complex energy method [Prog. Theor. Phys. 109, 869L (2003)] is applied to the four body Faddeev‐Yakubovsky equations in the four nucleon system. We obtain a well converged solution in all energy regions below and above the four nucleon break‐up threshold.

Three-nucleons force (3NF) is studied actively on three-nucleon systems in these several years. We can expect its larger influence in four-nucleon systems due to a naive idea that there is only one combination to choose three particles in a three-body system, while there are four in a four-body system. This is an advantage to study 3NF on four-nucleon systems. On the other hand, recent investigations show that influence of 3NF appears larger in higher energy region. Therefore, it is beneficial to study reaction problems of four-nucleon systems at higher incident energies. However, nobody have succeeded to solve the four-body Faddeev-Yakubovsky (FY) equations above the four-body breakup threshold due to complexity of boundary con

The field induced magnetic phase transitions of Cs$_2$CuBr$_4$ were investigated by means of magnetization process and neutron scattering experiments. This system undergoes magnetic phase transition at Ne��l temperature $T_\mathrm{N}=1.4$ K at zero field, and exhibits the magnetization plateau at approximately one third of the saturation magnetization for the field directions $H\parallel b$ and $H\parallel c$. In the present study, additional symptom of the two-third magnetization plateau was found in the field derivative of the magnetization process. The magnetic structure was found to be incommensurate with the ordering vector $\boldsymbol{Q}=(0, 0.575, 0)$ at zero field. With increasing magnetic field parallel to the c-axis, the ordering vector increases continuously and is locked at $\boldsymbol{Q}=(0, 0.662, 0)$ in the plateau field range $13.1 \mathrm{T} < H < 14.4 \mathrm{T}$. This indicates that the collinear \textit{up-up-down} spin structure is stabilized by quantum fluctuation at the magnetization plateau., 6 pages, 4 Postscript figures, uses iopams.sty and IOPART.CLS

The hypernucleus Λ 9 Be is investigated using the α + Λ + α cluster model. The corresponding Faddeev equations are solved for different α − α and Λ − α interactions that describe both 8Be and Λ 5 He energy spectra. For the ground state Jπ = 1/2+ and excited states 3/2+ and 5/2+ we include the Coulomb repulsion between the α’s and calculate, in addition to the energy eigenvalues, the α− and Λ−particle mean radius, the rms charge radius, the electric quadrupole moment (Q), as well as the magnetic dipole. Structural differences between 9Be and Λ 9 Be lead to values of Q and μ that have opposite sign. Unlike previous theoretical work we find only two degenerate negative parity resonances 1/2− (3/2−) but, in addition, we get two degenerate positive parity resonances with Jπ = 7/2+ (9/2+) at higher energy which, together with the bound states, complete the positive parity rotational band.

The hypernucleus Λ 9 Be is investigated using the α + Λ + α cluster model. The corresponding Faddeev equations are solved for different α- α and Λ- α interactions that describe both 8Be and Λ 5 He energy spectra. For the ground state Inline Equation $${J^\pi } = {\frac{1}{2}^ + }$$ and excited states Inline Equation $${\frac{3}{2}^ + }and{\frac{5}{2}^ + }$$ we include the Coulomb repulsion between the a’s and calculate, in addition to the energy eigenvalues, the aia and Aiaparticle mean radius, the rms charge radius, the electric quadrupole moment (Q), as well as the magnetic dipole. Structural differences between 9Be and Λ 9 Be lead to values of Q and,u that have opposite sign. Unlike previous theoretical work we find only two degenerate negative parity resonances Inline Equation $${\tfrac{1}{2}^ - }({\tfrac{3}{2}^ - })$$ but, in addition, we get two degenerate positive parity resonances with Inline Equation $${J^\pi } = {\frac{7}{2}^ + }\left( {{{\frac{9}{2}}^ + }} \right)$$ at higher energy which, together with the bound states, complete the positive parity rotational band.

The magnetic structure of the localized-5f uranium intermetallic compound U3Pd20Si6 has been determined by means of a neutron diffraction experiment. Our data demonstrate that this compound has a collinear coupling of the sublattice ordering of the uranium spins on the 4a and 8c sites. We conclude that higher-order exchange and/or quadrupole interactions are necessary to stabilize this unique collinear structure. We discovered a new type of spin-flop transition against the uniaxial anisotropy induced by this collinear coupling.

The hypernucleus ${}_{\ensuremath{\Lambda}}^{9}\mathrm{Be}$ is investigated using the $\ensuremath{\alpha}+\ensuremath{\Lambda}+\ensuremath{\alpha}$ cluster model. The corresponding Faddeev equations are solved for different $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\alpha}$ and $\ensuremath{\Lambda}\ensuremath{-}\ensuremath{\alpha}$ interactions that describe both ${}^{8}\mathrm{Be}$ and ${}_{\ensuremath{\Lambda}}^{5}\mathrm{He}$ energy spectra. For the ground state ${J}^{\ensuremath{\pi}}={\frac{1}{2}}^{+}$ and excited states ${\frac{3}{2}}^{+}$ and ${\frac{5}{2}}^{+}$ we include the Coulomb repulsion between the $\ensuremath{\alpha}'\mathrm{s}$ and calculate, in addition to the energy eigenvalues, the Coulomb energy, the $\ensuremath{\alpha}$- and $\ensuremath{\Lambda}$-particle mean radius, the rms charge radius, the electric quadrupole moment $(Q),$ as well as the magnetic dipole $(\ensuremath{\mu})$ and octopole $({\ensuremath{\mu}}_{3})$ moments. To the best of our knowledge these observables have not yet been measured and, therefore, our calculation constitutes the first prediction. Structural differences between ${}^{9}\mathrm{Be}$ and ${}_{\ensuremath{\Lambda}}^{9}\mathrm{Be}$ lead to values of Q and $\ensuremath{\mu}$ that have opposite sign. Unlike previous theoretical work we find only two degenerate negative parity resonances ${\frac{1}{2}}^{\ensuremath{-}}({\frac{3}{2}}^{\ensuremath{-}})$ but, in addition, we get two degenerate positive parity resonances with ${J}^{\ensuremath{\pi}}={\frac{7}{2}}^{+}({\frac{9}{2}}^{+})$ at higher energy which, together with the bound states, complete the positive parity rotational band.

It is demonstrated that a clear convergent series for the three‐body observables is obtained with a new separable expansion method where several techniques are unified. In the method, we utilize both the separable expansions of EST and of Adhikari‐Sloan, splitting the original potential into two potentials with different ranges. The Adhikari‐Sloan method is re‐formulated in a simple manner to show the possibility of a separable expansion more clearly. The method is applied to the AV14 potential as an example. The binding energy with some other observables of triton are calculated. This work definitely shows that a separable expansion is both reliable and a very efficient method among all possible methods of ‘‘rigorous’’ three‐body calculations.

We analyse the recent precision measurements of the lepton-hadron deep inelastic scattering at CERN and SLAC to extract model independent constraints among the nucleon matrix elements of the twist-4 operators. We also study a parameterization of these matrix elements and point out the possibility that the matrix elements of the quark-gluon mixed operator has a negative value of the order of $- (400 \pm 100\ {\rm MeV})^2$ at 5 GeV$^2$ renormalization scale., Latex, 11 pages, 4 figures (available upon request), DOE/ER/40427-05-N93

Time-resolved Raman spectrum of the S1 state of biphenyl was first reported by Kato et al. [1]. Several vibrational frequencies were determined and assigned, and a twisted S1 tructure was suggested on the basis of a vibrational analysis [2]. However, the broad feature in the 1300 ~ 1600 cm−1 region in the S1 Raman spectrum was left unassigned.

Our previous study of the magnetic susceptibility, χ, on zero-field and field cooling and magnetization-hysteresis-loop (MHL) for La2-xSrxCuO4 (LSCO) single crystals with x = 0.178 – 0.261 has suggested that a microscopic phase separation into superconducting (SC) and normal-state regions takes place in the overdoped regime of LSCO. In order to clarify the onset hole-concentration where the microscopic phase separation appears, we have carried out χ measurements on zero-field and field cooling and MHL measurements for LSCO single crystals with x = 0.125 and 0.147. From the χ measurements in a low magnetic field on field cooling, absolute values of χ at 2 K, |χ2k|, in x = 0.125 and 0.147 have been found to be smaller than that of x = 0.178, which can be understood in terms of the vortex-pinning effect around twin boundaries in a crystal. Neither two-step SC transition in χ vs- T in a moderate field on zero-field cooling nor second magnetization peak in MHL has been observed in x = 0.125, while both characteristics have been observed in x = 0.147. These results imply no enhancement of the vortex pinning in a moderate field-range and therefore suggest the existence of a homogeneous superconducting state in x = 0.125. Accordingly, it is concluded that the onset hole-concentration of the microscopic phase separation is located between x = 0.125 and 0.147.

We have performed neutron-scattering experiments in order to study the tiny magnetic moment in a heavy-fermion superconductor URu2Si2. The (1 0 0) magnetic Bragg peak intensity is found to be reduced by about 2% in magnitude below the superconducting transition temperature of about 1 K. This result indicates the interplay between magnetism and superconductivity in URu2Si2.