# Progress of Theoretical and Experimental Physics

Published by Oxford University Press (OUP)

Online ISSN: 2050-3911

Published by Oxford University Press (OUP)

Online ISSN: 2050-3911

Publications

We report a high-statistics measurement of the differential cross section of
the process gamma gamma --> K^0_S K^0_S in the range 1.05 GeV <= W <= 4.00 GeV,
where W is the center-of-mass energy of the colliding photons, using 972
fb^{-1} of data collected with the Belle detector at the KEKB asymmetric-energy
e^+ e^- collider operated at and near the Upsilon-resonance region. The
differential cross section is fit by parameterized S-, D_0-, D_2-, G_0- and
G_2-wave amplitudes. In the D_2 wave, the f_2(1270), a_2(1320) and f_2'(1525)
are dominant and a resonance, the f_2(2200), is also present. The f_0(1710) and
possibly the f_0(2500) are seen in the S wave. The mass, total width and
product of the two-photon partial decay width and decay branching fraction to
the K bar{K} state Gamma_{gamma gamma}B(K bar{K}) are extracted for the
f_2'(1525), f_0(1710), f_2(2200) and f_0(2500). The destructive interference
between the f_2(1270) and a_2(1320) is confirmed by measuring their relative
phase. The parameters of the charmonium states chi_{c0} and chi_{c2} are
updated. Possible contributions from the chi_{c0}(2P) and chi_{c2}(2P) states
are discussed. A new upper limit for the branching fraction of the P- and
CP-violating decay channel eta_c --> K^0_S K^0_S is reported. The detailed
behavior of the cross section is updated and compared with QCD-based
calculations.

…

With the use of two kinds of boson operators, a new boson representation of
the su(2)-algebra is proposed. The basic idea comes from the pseudo
su(1,1)-algebra recently given by the present authors. It forms a striking
contrast to the Schwinger boson representation of the su(2)-algebra which is
also based on two kinds of bosons. This representation may be suitable for
describing time-dependence of the system interacting with the external
environment in the framework of the thermo field dynamics formalism, i.e., the
phase space doubling. Further, several deformations related to the
su(2)-algebra in this boson representation are discussed. On the basis of these
deformed algebra, various types of time-evolution of a simple boson system are
investigated.

…

A pseudo su(1,1)-algebra is formulated as a possible deformation of the Cooper pair in the su(2)-algebraic many-fermion system. With the aid of this algebra, it is possible to describe the behavior of individual fermions
which are generated as the result of interaction with the external environment. The form presented in this paper is a generalization
of a certain simple case developed recently by the authors. The basic idea follows the su(1,1) algebra in the Schwinger boson representation for treating energy transfer between the harmonic oscillator and the external
environment. The Hamiltonian is given following the idea of phase space doubling in the thermo-field dynamics formalism, and
the time-dependent variational method is applied to this Hamiltonian. Its trial state is constructed in the frame deformed
from the BCS-Bogoliubov approach to superconductivity. Several numerical results are shown.

…

We report the measurement of differential cross sections for $\omega$ and
$\eta'$ photoproduction from protons at backward angles
($-1.0<\cos\Theta_{C.M}^{X}<-0.8$) using linearly polarized photons at
$E_{\gamma}=$$1.5-3.0$ GeV. Differential cross sections for $\omega$ mesons are
larger than the predicted $u$-channel contribution in the energy range
$2.0\leq\sqrt{s}\leq2.4$ GeV. The differential cross sections for $\omega$ and
$\eta'$ mesons become closer to the predicted $u$-channel contribution at
$\sqrt{s}>2.4$ GeV. A bump structure in the $\sqrt{s}$ dependence of the
differential cross sections for $\eta'$ mesons was observed at
$\sqrt{s}\sim$2.35 GeV.

…

We have observed a "$K^-pp$"-like structure in the $d(\pi^+,K^+)$ reaction at
1.69 GeV/$c$. In this reaction $\Lambda(1405)$ hyperon resonance is expected to
be produced as a doorway to form the $K^-pp$ through the $\Lambda^*p\rightarrow
K^-pp$ process. However, most of the produced $\Lambda(1405)$'s would escape
from deuteron without secondary reactions. Therefore, coincidence of
high-momentum ($>$ 250~MeV/$c$) proton(s) in large emission angles
($39^\circ<\theta_{lab.}<122^\circ$) was requested to enhance the
signal-to-background ratio. A broad enhancement in the proton coincidence
spectra are observed around the missing-mass of 2.27 GeV/$c^2$, which
corresponds to the $K^-pp$ binding energy of 95 $^{+18}_{-17}$ (stat.)
$^{+30}_{-21}$ (syst.) MeV and the width of 162 $^{+87}_{-45}$ (stat.)
$^{+66}_{-78}$ (syst.) MeV.

…

We have measured an inclusive missing-mass spectrum of the $d(\pi^+, K^+)$
reaction at the pion incident momentum of 1.69 GeV/$c$ at the laboratory
scattering angles between 2$^\circ$ and 16$^\circ$ with the missing-mass
resolution of 2.7 MeV/$c^2$ (FWHM). In this Letter, we first try to understand
the spectrum as a simple quasi-free picture based on several known elementary
cross sections, considering the neutron/proton Fermi motion in deuteron. While
gross spectrum structures are well understood in this picture, we have observed
two distinct deviations; one peculiar enhancement at 2.13 GeV/$c^2$ is due to
the $\Sigma N$ cusp, and the other notable feature is a shift of a broad bump
structure, mainly originating from hyperon resonance productions of
$\Lambda(1405)$ and $\Sigma(1385)^{+/0}$, by about 22.4 $\pm$ 0.6 MeV/$c^2$
toward the low-mass side.

…

We address a question whether the recently observed Higgs mass $M_{H} = 126$
GeV, of the order of the weak scale $M_{W}$, is calculable as a finite value in
the scnenario of gauge-Higgs unification. In the scenario formulated on a flat
5-dimensional space-time, the Higgs mass is calculable, being protected under
the quantum correction by gauge invariance, though the predicted Higgs mass is
generally too small compared with $M_{W}$. In the 6-dimensional SU(3) model,
however, a suitable orbifolding is known to lead to a mass of the order of
$M_{W}$: $M_{H} = 2M_{W}$ at the tree level, which has some similarity to the
corresponding prediction by the MSSM, $M_{H}$ leq (cos beta) $M_{Z}$. We
demonstrate first by a general argument and secondly by explicit calculations
that, even though the quantum correction to the quartic self-coupling of the
Higgs field is UV-divergent, its deviation from that of $g^{2}$ is calculable,
and therefore two observables, $M_{H}^{2}$ and Delta equiv
$(M_{H}/2M_{W})^{2}-1$, are both calculable in the gauge-Higgs unification
scenario. The implication of the precise value 126 GeV to the compactification
scale and the bulk mass of the matter field in our model is also discussed.

…

In this paper, we analyse the hadronic decay of B to J a1(1260) in
pertubative QCD approach (pQCD), where a1(1260) is a axial-vector meson and
J{psi} is a vector meson.

…

A search for inelastic scattering of weakly interacting massive particles (WIMPs) on the isotope $^{129}$Xe was done in data taken with the single-phase liquid-xenon detector XMASS at the Kamioka Observatory. Using a restricted
volume containing 41 kg of liquid xenon at the very center of our detector, we observed no significant excess of events in
165.9 live days of data. Our background reduction allowed us to derive our limits without explicitly subtracting the remaining
events that are compatible with background expectations. As an example, we derive for a 50 GeV WIMP an upper limit of 3.2 pb
at the 90% confidence level for its inelastic cross section on $^{129}$Xe nuclei.

…

We propose to use the complex-range Gaussian basis functions, {r^l e^{-(1 \pm
i\omega)(r/r_n)^2}Y_{lm}(\hat{r}); r_n in a geometric progression}, in the
calculation of three-body resonances with the complex-scaling method (CSM) in
which use is often made of the real-range Gaussian basis functions, {r^l
e^{-(r/r_n)^2}Y_{lm}(\hat{r})}, that are suitable for describing the
short-distance structure and the asymptotic decaying behavior of few-body
systems. The former basis set is more powerful than the latter when describing
the resonant and nonresonant continuum states with highly oscillating amplitude
at large scaling angles \theta. We applied the new basis functions to the CSM
calculation of the 3\alpha resonances with J=0^+, 2^+ and 4^+ in 12C. The
eigenvalue distribution of the complex scaled Hamiltonian becomes more precise
and the maximum scaling angle becomes drastically larger (\theta_{max}=16 deg.
\arrow 36 deg.) than those given by the use of the real-range Gaussians. Owing
to these advantages, we were able to confirm the prediction by Kurokawa and
Kato [Phys. Rev. C 71, 021301 (2005)] on the appearance of the new broad 0^+_3
state; we show it as an explicit resonance pole isolated from the 3$\alpha$
continuum.

…

Recent CLAS data for the pi Sigma invariant mass distributions (line-shapes)
in the gamma p -> K^+ pi Sigma reaction are theoretically investigated. The
line-shapes have peaks associated with the Lambda(1405) excitation. Our model
consists of gauge invariant photo-production mechanisms, and the chiral unitary
model that gives the rescattering amplitudes where Lambda(1405) is contained.
It is found that, while the pi Sigma line-shape data in the Lambda(1405) region
are successfully reproduced by our model for all the charge states, the
production mechanism is not so simple that we need to introduce parameters
associated with short-range dynamics to fit the data. Our detailed analysis
suggests that the nonresonant background contribution is not negligible, and
its sizable effect shifts the Lambda(1405) peak position by several MeV. We
also analyze the data using a Breit-Wigner amplitudes instead of those from the
chiral unitary model. We find that the fitted Breit-Wigner parameters are
closer to the higher pole position for Lambda(1405) of the chiral unitary
model. This work sets a starting point for a fuller analysis in which
line-shape as well as K^+ angular distribution data are simultaneously analyzed
for extracting Lambda(1405) pole(s).

…

We study 6d N=(2,0) theory of type SU(N) compactified on Riemann surfaces
with finite area, including spheres with fewer than three punctures. The Higgs
branch, whose metric is inversely proportional to the total area of the Riemann
surface, is discussed in detail. We show that the zero-area limit, which gives
us a genuine 4d theory, can involve a Wigner-Inonu contraction of global
symmetries of the six-dimensional theory. We show how this explains why
subgroups of SU(N) can appear as the gauge group in the 4d limit. As a
by-product we suggest that half-BPS codimension-two defects in the
six-dimensional (2,0) theory have an operator product expansion whose operator
product coefficients are four-dimensional field theories.

…

We define supersymmetric Yang–Mills theory on an arbitrary 2D lattice (polygon decomposition) while preserving one supercharge.
When a smooth Riemann surface $\Sigma _g$ with genus $g$ emerges as an appropriate continuum limit of the generic lattice, the discretized theory becomes a topologically twisted
${{\mathcal N}}=(2,2)$ supersymmetric Yang–Mills theory on $\Sigma _g$. If we adopt the usual square lattice as a special case of the discretization, our formulation is identical with Sugino's
lattice model. Although the tuning of parameters is generally required while taking the continuum limit, the number of necessary
parameters is at most two because of the gauge symmetry and the supersymmetry. In particular, we do not need any fine-tuning
if we arrange the theory so as to possess an extra global $U(1)$ symmetry ($U(1)_{R}$ symmetry), which rotates the scalar fields.

…

It is known that the gauge field and its composite operators evolved by the Yang–Mills gradient flow are ultraviolet (UV)
finite without any multiplicative wave function renormalization. In this paper, we prove that the gradient flow in the 2D
$O(N)$ non-linear sigma model possesses a similar property: The flowed $N$-vector field and its composite operators are UV finite without multiplicative wave function renormalization. Our proof in
all orders of perturbation theory uses a $(2+1)$-dimensional field theoretical representation of the gradient flow, which possesses local gauge invariance without gauge field.
As an application of the UV finiteness of the gradient flow, we construct the energy–momentum tensor in the lattice formulation
of the $O(N)$ non-linear sigma model that automatically restores the correct normalization and the conservation law in the continuum limit.

…

The gradient flow equation in the two-dimensional $O(N)$ non-linear sigma
model with lattice regularization is solved in the leading order of the $1/N$
expansion. By using this solution, we analytically compute the thermal
expectation value of a lattice energy--momentum tensor defined through the
gradient flow. The expectation value reproduces thermodynamic quantities
obtained by the standard large~$N$ method. This analysis confirms that the
above lattice energy--momentum tensor restores the correct normalization
automatically in the continuum limit, in a system with a non-perturbative mass
gap.

…

We argue that 6d N=(2,0) theory on S^1 x S^3 x C_2 reduces to the 2d
q-deformed Yang-Mills on C_2 at finite area, as a small extension to the result
of Gadde, Rastelli, Razamat and Yan. This is done by computing the partition
function on S^1 x S^3 of 4d N=2 supersymmetric non-linear sigma model on
T^*G_C, which gives the propagator of the 2d Yang-Mills.

…

We study the parameter dependence of the internal structure of resonance
states by formulating Complex two-dimensional (2D) Matrix Model, where the two
dimensions represent two-levels of resonances. We calculate a critical value of
the parameter at which "nature transition" with character exchange occurs
between two resonance states, from the viewpoint of geometry on
complex-parameter space. Such critical value is useful to know the internal
structure of resonance states with variation of the parameter in the system. We
apply the model to analyze the internal structure of hadrons with variation of
the color number Nc from infinity to a realistic value 3. By regarding 1/Nc as
the variable parameter in our model, we calculate a critical color number of
nature transition between hadronic states in terms of quark-antiquark pair and
mesonic molecule as exotics from the geometry on complex-Nc plane. For the
large-Nc effective theory, we employ the chiral Lagrangian induced by
holographic QCD with D4/D8/D8-bar multi-D brane system in the type IIA
superstring theory.

…

The $X$(3872) formation from the $B$-decay and its decay into the two-meson
state are investigated by employing a coupled-channel two-meson model with the
$c{\bar c}$ state. This two-meson state consists of the $D^0{\bar D}^*{}^0$,
$D^+D^{*-}$, $J/\psi\rho$, and $J/\psi\omega$ channels. The energy-dependent
decay widths of the $\rho$ and $\omega$ mesons are taken into account. The
interaction between $D$ and ${\bar D}^*$ mesons are taken to be consistent with
a lack of the $B{\bar B}^*$ bound state. The $c{\bar c}$-$D{\bar D}^*$ coupling
is taken as a parameter to fit the $X$(3872) peak energy. The coupling between
the $D{\bar D}^*$ and $J/\psi\rho$ or the $D{\bar D}^*$ and $J/\psi\omega$
channels is determined with the help of a quark model.
It is found that the $J/\psi\rho$ and $J/\psi\omega$ peaks appear around the
$D^0{\bar D}^*{}^0$ threshold under the reasonable assumptions and that their
peaks are very narrow when they appear. It is also found that the large decay
width of the $\rho$ meson enhances the isospin $I=1$ component in the decay
spectra in the $X$(3872) energy region. The size of the $J/\psi\pi^3$ peak we
calculated is 1.29-2.38 times as large as that of the $J/\psi\pi^2$. The
isospin symmetry breaking in the present model comes from the difference in the
charged and neutral $D$ and $D^*$ meson masses, which seems to give a
sufficiently large isospin mixing. Also, the results suggest that one can judge
whether the $X$(3872) is a bound state by looking into the ratio of the partial
decay width of $X$(3872) in the $D^0{\bar D}^*{}^0$ channel to that in the
$J/\psi\rho$ channel. Moreover, the relative importance of the $c{\bar
c}$-$D{\bar D}^*$ coupling in the $X$(3872) can be evaluated from the ratio of
the transfer strength of the $D^+D^{*-}$ to that of the $D^0{\bar D}^*{}^0$ as
well as from the ratio of the $J/\psi\pi^3$ peak size to that of the
$J/\psi\pi^2$.

…

In order to understand the structure of X(3872), the $c\bar {c}$ charmonium core state that couples to the $D^0 \bar {D}^{\ast 0}$ and $D^+ D^{\ast -}$ molecular states is studied. The strengths of the couplings between the charmonium state and the hadronic molecular states
are determined so as to reproduce the observed mass of X(3872). The attraction between D and $\bar {D}^{\ast }$ is determined so as to be consistent with the observed $Z_b^{\pm ,0}$(10 610) and $Z_b^{\pm ,0}$(10 650) masses. Isospin symmetry breaking is introduced by the mass differences between the neutral and charged D mesons. The structure of X(3872) that we have obtained is not just a $D^0 \bar {D}^{\ast 0}$ hadronic molecule but a charmonium–hadronic molecule hybrid state. It consists of about 6% $c\bar {c}$ charmonium, 69% isoscalar $D \bar {D}^\ast $ molecule, and 26% isovector $D \bar {D}^\ast $ molecule. This explains many of the observed properties of X(3872), such as isospin symmetry breaking, the production rate in the $p \bar {p}$ collision, the non-existence of the $\chi _{c1}(2P)$ peak predicted by the quark model, and the absence of charged X. The same picture can be applied to other heavy two-meson S-wave systems, where the states predicted by the quark model are not observed above the thresholds.

…

We calculate the widths of the hidden charm decay $J/\psi\omega$ of two
charmonium-like states $X(3915)$ and $Z(3930)$ for $\chi_{c0}^\prime(2P)$ and
$\chi_{c2}^\prime (2P)$ assignments, respectively. Our results indicate that
the decay width of $Z(3930)\to J/\psi\omega$ is $2\sim 3$ orders smaller than
that of $X(3915)\to J/\psi\omega$, which further explains why only one
structure $X(3915)$ has been observed in the $J/\psi\omega$ invariant mass
spectrum for the process $\gamma\gamma\to J/\psi\omega $.

…

An Abelian gauge theory with Chern-Simons term is investigated for a
four-component Dirac fermion in 1+2 dimensions. The Ball-Chiu (BC) vertex
function is employed to modify the rainbow-ladder approximation for the
Schwinger-Dyson (SD) equation. We numerically solve the SD equation and show
the gauge dependence for the resulting phase boundary for the parity and the
chiral symmetry.

…

In contrast to the non-relativistic approaches, three-dimensional (3D) mesh
calculations for the {\it relativistic} density functional theory have not been
realized because of the challenges of variational collapse and fermion
doubling. We overcome these difficulties by developing a novel method based on
the ideas of Wilson fermion as well as the variational principle for the
inverse Hamiltonian. We demonstrate the applicability of this method by
applying it to $^{16}$O, $^{24}$Mg, and $^{28}$Si nuclei, providing detailed
explanation on the formalism and verification of numerical implementation.

…

We conjecture that a new class of 3d N=2 theories are associated with a
quiver Q and a mutation sequence m on it. We define the cluster partition
function from the pair (Q, m), and this partition function coincides with the
S^3_b partition function of the associated 3d N=2 theory T[(Q,m)]. Our
formalism includes the case where 3d N=2 theories arise from the
compactification of the 6d (2,0) A_{N-1} theory on a large class of 3-manifolds
M, including complements of arbitrary links in S^3. In this case the quiver is
defined from a 2d ideal triangulation, the mutation sequence represents an
element of the mapping class group, and the 3-manifold is equipped with a
canonical ideal triangulation. Our partition function coincides with that of
the holomorphic part of the SL(N) Chern-Simons partition function on M; when
N=2 and M is hyperbolic, the partition function reproduces the gluing
conditions of ideal hyperbolic tetrahedra in the semiclassical limit.

…

We study N=2 supersymmetric gauge theories on squashed 3-sphere and S^1xS^2.
Recent studies have shown that the partition functions in a class of N=2
theories have factorized representations in terms of vortex and anti-vortex
partition functions by explicitly evaluating matrix integrals obtained by
Coulomb branch localization. We directly derive this structure by performing
Higgs branch localization. It turns out that more general N=2 theories have
this factorization property. We also discuss the factorization of
supersymmetric Wilson loop.

…

The coexistence of various low-lying deformed states in $^{42}$Ca and
$\alpha$--$^{38}$Ar correlations in those deformed states have been
investigated using deformed-basis antisymmetrized molecular dynamics. Wave
functions of the low-lying states are obtained via parity and angular momentum
projections and the generator coordinate method (GCM). Basis wave functions of
the GCM calculation are obtained via energy variations with constraints on the
quadrupole deformation parameter $\beta$ and the distance between $\alpha$ and
$^{38}$Ar clusters. The rotational band built on the $J^\pi = 0_2^+$ (1.84 MeV)
state as well as the $J^\pi = 0_3^+$ (3.30 MeV) state are both reproduced. The
coexistence of two additional $K^\pi = 0^+$ rotational bands is predicted; one
band is shown to be built on the $J^\pi = 0_3^+$ state. Members of the
ground-state band and the rotational band built on the $J^\pi = 0_3^+$ state
contain $\alpha$--$^{38}$Ar cluster structure components.

…

An exponentially large extra dimension can be naturally realized by the Casimir energy and the gaugino condensation in 5D supersymmetric theory. The model does not require any hierarchies among the 5D parameters. The key ingredient is an additional modulus other than the radion, which generically exists in 5D supergravity. SUSY is broken at the vacuum, which can be regarded as the Scherk-Schwarz SUSY breaking. We also analyze the mass spectrum and discuss some phenomenological aspects. © 2014 The Author(s) 2014. Published by Oxford University Press on behalf of the Physical Society of Japan.

…

Supersymmetric gauge theories in five dimensions often exhibit less symmetry
than the ultraviolet fixed points from which they flow. The fixed points might
have larger flavor symmetry or they might even be secretly six-dimensional
theories on S^1. Here we provide a simple criterion when such symmetry
enhancement in the ultraviolet should occur, by a direct study of the fermionic
zero modes around one-instanton operators.

…

We describe a method to determine the anomaly polynomials of general 6d
$\mathcal{N}=(2,0)$ and $\mathcal{N}=(1,0)$ SCFTs, in terms of the anomaly
matching on their tensor branches. This method is almost purely field
theoretical, and can be applied to all known 6d SCFTs. We demonstrate our
method in many concrete examples, including $\mathcal{N}=(2,0)$ theories of
arbitrary type and the theories on M5 branes on ALE singularities, reproducing
the $N^3$ behavior. We check the results against the anomaly polynomials
computed M-theoretically via the anomaly inflow.

…

This is a status report on our endeavor to reveal the mechanism of
core-collapse supernovae (CCSNe) by large-scale numerical simulations.
Multi-dimensionality of the supernova engine, general relativistic
magnetohydrodynamics, energy and lepton number transport by neutrinos emitted
from the forming neutron star as well as nuclear interactions there, are all
believed to play crucial roles in repelling infalling matter and producing
energetic explosions. These ingredients are nonlinearly coupled with one
another in the dynamics of core-collapse, bounce, and shock expansion. Serious
quantitative studies of CCSNe hence make extensive numerical computations
mandatory. Since neutrinos are neither in thermal nor in chemical equilibrium
in general, their distributions in the phase space should be computed. This is
a six dimensional (6D) neutrino transport problem and quite a challenge even
for those with an access to the most advanced numerical resources such as the
"K computer". To tackle this problem, we have embarked on multi-front efforts.
In particular we report in this paper our recent progresses in the treatments
of multi-dimensional (multi-D) radiation-hydrodynamics. We are currently
proceeding on two different paths to the ultimate goal; in one approach we
employ an approximate but highly efficient scheme for neutrino transport and
treat 3D hydrodynamics and/or general relativity rigorously; some
neutrino-driven explosions will be presented and comparisons will be made
between 2D and 3D models quantitatively; in the second approach, on the other
hand, exact but so far Newtonian Boltzmann equations are solved in two and
three spatial dimensions; we will show some demonstrative test simulations. We
will also address the perspectives of exa-scale computations on the next
generation supercomputers.

…

We propose a new next-to-minimal supersymmetric standard model (NMSSM) which
is on a six-dimensional spacetime compactified on a $T^2/Z_3$ orbifold. In this
model, three gauge singlet fields $N, S_1$ and $S_2$ in addition to the minimal
supersymmetric standard model (MSSM) fields are introduced. These fields are
localized at some fixed points except for the singlet $N$ and the gauge fields.
The $\mu$ parameter is provided from the vacuum expectation value (vev) of $N$.
The $F$ terms get vevs simultaneously, and the gauginos mediate the
supersymmetry breaking to the MSSM sector. Both of these parameters are
strongly suppressed due to the profile of $N$. Thus these parameters induced
from those of the order of the so-called GUT scale can become close to the
electroweak scale without unnatural fine tuning.

…

We study the shell and alpha cluster structures in the ground and excited
states of 8Be in terms of the tensor-optimized shell model (TOSM). In TOSM, the
tensor correlation is optimized in the full space of 2p2h configurations
involving high-momentum components. The short-range correlation is treated with
the unitary correlation operator method (UCOM). We use the effective
interaction based on the bare nucleon-nucleon interaction AV8$^\prime$. The 8Be
states consist of two groups of ground band states and highly excited states
with the isospin T=0 and T=1. It is found that the tensor contributions of the
ground band states are stronger than the highly excited states and that the
kinetic energies and the central contributions of the ground band states are
almost twice the 4He values. These features suggest two-alpha clustering for
the ground band states in 8Be. We also estimate the correlation energy of the
$\alpha$ clustering using the alpha cluster model. In the highly excited
states, the calculated spectrum in TOSM reproduces the experimental level order
and the relative energies of each level. This agreement suggests that those
states can be interpreted as shell-like states. The level order is found to be
sensitive to the presence of the tensor force in comparison with the results
using the Minnesota effective interaction without the tensor force. It is also
found that the tensor contributions in the T=0 states are stronger than the T=1
states, which is consistent with the state dependence of the tensor force.

…

In the previous paper, we have shown that $R_1\equiv\frac{\Gamma_{n
\rightarrow \pi^0 + \nu^c}}{\Gamma_{p \rightarrow \pi^0 + e^c}}$ and
$R_2\equiv\frac{\Gamma_{p \rightarrow K^0 + \mu^c}}{\Gamma_{p \rightarrow \pi^0
+ e^c}}$ can identify the grand unification group $SU(5)$, $SO(10)$, or $E_6$
in typical anomalous $U(1)_A$ supersymmetric (SUSY) grand unified theory (GUT)
in which nucleon decay via dimension-6 operators becomes dominant. When $R_1 >
0.5$ the grand unification group is not $SU(5)$, while when $R_1 > 1$ the grand
unification group is $E_6$. Moreover, $R_2 > 0.3$ $E_6$ is implied. Main
ambiguities come from the diagonalizing matrices for quark and lepton mass
matrices in this calculation once we fix the vacuum expectation values of GUT
Higgs bosons. In this paper, we calculate $R_1$ and $R_2$ in $E_6\times
SU(2)_F$ SUSY GUT with anomalous $U(1)_A$ gauge symmetry, in which realistic
quark and lepton masses and mixings can be obtained though the flavor symmetry
$SU(2)_F$ constrains Yukawa couplings at the GUT scale. The ambiguities of
Yukawa couplings are expected to be reduced. We show that the predicted region
for $R_1$ and $R_2$ is more restricted than in the $E_6$ model without
$SU(2)_F$ as expected. Moreover, we re-examine the previous claim for the
identification of grand unification group with $100$ times more model points
($10^6$ model points), including $E_6 \times SU(2)_F$ model.

…

We show that the sizable $D$-term contributions to the sfermion mass spectrum can be signatures of a certain grand unified theory (GUT), $E_6\times SU(2)_F\times U(1)_A$ GUT. Note that these $D$-term contributions destroy the degeneracy of sfermion masses among different generations in this model. This is different
from previous works, which have argued for the $D$-term contributions, which destroy the degeneracy of masses only between sfermions with different quantum charges, as a signature
of GUT with a larger rank unification group. Such $D$-terms are strongly constrained by the flavor-changing neutral current processes if the SUSY breaking scale is the weak scale.
However, in $E_6\times SU(2)_F\times U(1)_A$, a natural SUSY-type sfermion mass spectrum is obtained, and if the masses of ${{\bf{10}}}_3$ sfermions are larger than $O(1\,{\rm TeV})$ to realize the 126 GeV Higgs and the other sfermion masses are $O(10\,{\rm TeV})$, then a sizable $D$-term contribution is allowed. If these $D$-terms can be observed in future experiments, like the 100 TeV proton collider or muon collider, we may confirm the $E_6\times SU(2)_F\times U(1)_A$ GUT.

…

The WHOT-QCD Collaboration is pushing forward a series of lattice studies of
QCD at finite temperatures and densities using improved Wilson quarks. Because
Wilson-type quarks require more computational resources than the more widely
adopted staggered-type quarks, various theoretical and computational techniques
have to be developed and applied. In this paper, we introduce the fixed-scale
approach armed with the T-integration method, the Gaussian method based on the
cumulant expansion, and the histogram method combined with the reweighting
technique. Adopting these methods, we have carried out the first study of
finite-density QCD with Wilson-type quarks and the first calculation of the
equation of state with 2+1 flavors of Wilson-type quarks. We present results of
these studies and discuss perspectives towards a clarification of the
properties of 2+1 flavor QCD at the physical point, at finite temperatures and
densities.

…

It has recently been argued that atoms and molecules may become good targets
of determining neutrino parameters still undetermined, if atomic/molecular
process is enhanced by a new kind of coherence. We compute photon energy
spectrum rate arising from coherent radiative neutrino pair emission processes
of metastable excited states of I$_2$ and its iso-valent molecules, $|Av
\rangle \rightarrow |Xv' \rangle + \gamma + \nu_i\nu_j$ and $|A'v \rangle
\rightarrow |Xv' \rangle + \gamma + \nu_i\nu_j$ with $\gamma$ an IR photon and
$\nu_{i(j)}$ $i(j)-$th neutrino mass eigenstates, and show how fundamental
neutrino parameters may be determined. Energies of electronically excited
states of I$_2$, including the effect of spin-orbit couplings were calculated
by the multiconfigurational second order perturbation (CASPT2) method.
Summation over many vibrational levels of intermediate states is fully
incorporated. Unlike atomic candidate of a much larger energy difference such
as Xe, I$_2$ transitions from a vibrational level $A(v=0)$ to $X(v' = 24)$ give
an opportunity of determination of the mass type (Majorana vs Dirac
distinction) and determination of Majorana CPV (charge-conjugation parity
violating) phases, although the rate is much smaller.

…

We construct an action for the superconformal Chern-Simons theory with
non-Abelian gauge groups in three-dimensional N=3 projective superspace. We
propose a Lagrangian given by the product of the function of the tropical
multiplet, that represents the N=3 vector multiplet, and the O(-1,1) multiplet.
We show how the tropical multiplet is embedded into the O(-1,1) multiplet by
comparing our Lagrangian with the Chern- Simons Lagrangian in the N=2
superspace. We also discuss N=4 generalization of the action.

…

Massless matter fields and non-Abelian gauge fields are localized on domain
walls in a (4+1)-dimensional $U(N)_c$ gauge theory with $SU(N)_{L}\times
SU(N)_{R}\times U(1)_{A}$ flavor symmetry. We also introduce $SU(N)_{L+R}$
flavor gauge fields and a scalar-field-dependent gauge coupling, which provides
massless non-Abelian gauge fields localized on the wall. We find a chiral
Lagrangian interacting minimally with the non-Abelian gauge field together with
nonlinear interactions of moduli fields as the (3+1)-dimensional effective
field theory up to the second order of derivatives. Our result provides a step
towards a realistic model building of brane-world scenario using topological
solitons.

…

We classify bions in the Grassmann $Gr_{N_{\rm F},N_{\rm C}}$ sigma model (including the ${\mathbb C}P^{N_{\rm F}-1}$ model) on ${\mathbb R}^{1}\times S^{1}$ with twisted boundary conditions. We formulate these models as $U(N_{\rm C})$ gauge theories with $N_{\rm F}$ flavors in the fundamental representations. These theories can be promoted to supersymmetric gauge theories and, further,
can be embedded into D-brane configurations in type-II superstring theories. We focus on specific configurations composed
of multiple fractional instantons, termed neutral bions and charged bions, which are identified as perturbative infrared renormalons
by Ünsal and his collaborators [G. V. Dunne and M. Ünsal, J. High Energy Phys. 1211, 170 (2012); G. V. Dunne and M. Ünsal, Phys. Rev. D 87, 025015 (2013)]. We show that D-brane configurations, as well as the moduli matrix, offer a very useful tool to classify
all possible bion configurations in these models. In contrast to the ${\mathbb C}P^{N_{\rm F}-1}$ model, there exist Bogomol’nyi–Prasad–Sommerfield (BPS) fractional instantons with topological charges greater than unity
(of order $N_{\rm C}$) that cannot be reduced to a composite of an instanton and fractional instantons. As a consequence, we find that the Grassmann
sigma model admits neutral bions made of BPS and anti-BPS fractional instantons, each of which has a topological charge greater
(less) than one (minus one), that are not decomposable into an instanton–anti-instanton pair and the rest. The ${\mathbb C}P^{N_{\rm F}-1}$ model is found to have no charged bions. In contrast, we find that the Grassmann sigma model admits charged bions, for which
we construct exact non-BPS solutions of the field equations.

…

We study the partition function of the N=6 supersymmetric U(N_1)_k x
U(N_2)_{-k} Chern-Simons-matter (CSM) theory, also known as the ABJ theory. For
this purpose, we first compute the partition function of the U(N_1) x U(N_2)
lens space matrix model exactly. The result can be expressed as a product of
q-deformed Barnes G-function and a generalization of multiple q-hypergeometric
function. The ABJ partition function is then obtained from the lens space
partition function by analytically continuing N_2 to -N_2. The answer is given
by min(N_1,N_2)-dimensional integrals and generalizes the "mirror description"
of the partition function of the ABJM theory, i.e. the N=6 supersymmetric
U(N)_k x U(N)_{-k} CSM theory. Our expression correctly reproduces perturbative
expansions and vanishes for |N_1-N_2|>k in line with the conjectured
supersymmetry breaking, and the Seiberg duality is explicitly checked for a
class of nontrivial examples.

…

We study supersymmetric Wilson loops in the ${\cal N} = 6$ supersymmetric
$U(N_1)_k\times U(N_2)_{-k}$ Chern-Simons-matter (CSM) theory, the ABJ theory,
at finite $N_1$, $N_2$ and $k$. This generalizes our previous study on the ABJ
partition function. First computing the Wilson loops in the $U(N_1) \times
U(N_2)$ lens space matrix model exactly, we perform an analytic continuation,
$N_2$ to $-N_2$, to obtain the Wilson loops in the ABJ theory that is given in
terms of a formal series and only valid in perturbation theory. Via a
Sommerfeld-Watson type transform, we provide a nonperturbative completion that
renders the formal series well-defined at all couplings. This is given by ${\rm
min}(N_1,N_2)$-dimensional integrals that generalize the "mirror description"
of the partition function of the ABJM theory. Using our results, we find the
maps between the Wilson loops in the original and Seiberg dual theories and
prove the duality. In our approach we can explicitly see how the perturbative
and nonperturbative contributions to the Wilson loops are exchanged under the
duality. The duality maps are further supported by a heuristic yet very useful
argument based on the brane configuration as well as an alternative derivation
based on that of Kapustin and Willett.

…

We consider states with large angular momentum to facilitate the study of the
M-theory regime of the AdS_4/CFT_3 correspondence. We study the duality between
M-theory in AdS_4xS^7/Z_k and the ABJM N=6 Chern-Simons-matter theory with
gauge group U(N)xU(N) and level k, taking N large and k of order 1. In this
regime the lack of an explicit formulation of M-theory in AdS_4xS^7/Z_k makes
the gravity side difficult, while the CFT is strongly coupled and the planar
approximation is not applicable. To overcome these difficulties, we focus on
states on the gravity side with large angular momentum J>>1 and identify the
dual operators in the CFT, thereby establishing the AdS/CFT dictionary in this
sector. Natural approximation schemes arise on both sides thanks to the
presence of the small parameter 1/J. On the AdS side, we use the matrix model
of M-theory on the maximally supersymmetric pp-wave background with matrices of
size J/k. A perturbative treatment of this matrix model provides a good
approximation to M-theory in AdS_4xS^7/Z_k when N^{1/3}<<J<<N^{1/2}. On the CFT
side, we study the theory on S^2xR with magnetic flux J/k. A Born-Oppenheimer
type expansion arises naturally for large J in spite of the theory being
strongly coupled. The energy spectra on the two sides agree at leading order.
This provides a non-trivial test of the AdS_4/CFT_3 correspondence including
near-BPS observables associated with membrane degrees of freedom, thus
verifying the duality beyond the previously studied sectors corresponding to
either BPS observables or the type IIA string regime.

…

Emission of muonium (μ^+e^-) atoms from a laser-processed aerogel surface into vacuum was studied for the first time. Laser ablation was used to create
hole-like regions with diameter of about 270 μm in a triangular pattern
with hole separation in the range of 300--500 μm. The emission probability
for the laser-processed aerogel sample is at least eight times higher than for
a uniform one.

…

We investigate the initial state of the inflationary universe. In our recent publications, we have shown that requesting the
gauge invariance in the local observable universe guarantees the infrared (IR) regularity of loop corrections in a general single
clock inflation. Following this study, in this paper, we show that choosing the Euclidean vacuum ensures the gauge invariance in the local universe and hence the IR regularity of loop corrections. It has been suggested that loop corrections
to inflationary perturbations may yield secular growth, which can lead to the breakdown of the perturbative analysis in an
extremely long-term inflation. The absence of secular growth has been claimed by picking up only the IR contributions, which
we think is incomplete because the non-IR modes that are comparable to or smaller than the Hubble scale can potentially contribute
to the secular growth. We prove the absence of secular growth without neglecting these non-IR modes to a certain order in
the perturbative expansion. We also discuss how the regularity of the n-point function for the genuinely gauge-invariant variable constrains the initial states of the inflationary universe. These results apply in a fully general single-field
model of inflation.

…

Relativistic jets in active galactic nuclei, galactic microquasars, and gamma-ray bursts are widely considered to be magnetohydrodynamically
driven by black hole accretion systems, although the conversion mechanism from the Poynting into the particle kinetic energy
flux is still open. Recent detailed numerical and analytical studies of global structures of steady, axisymmetric magnetohydrodynamic
(MHD) flows with specific boundary conditions have not reproduced as rapid an energy conversion as required by observations.
In order to find more suitable boundary conditions, we focus on the flow along a poloidal magnetic field line just inside
the external boundary, without treating the transfield force balance in detail. We find some examples of the poloidal field
structure and corresponding external pressure profile for an efficient and rapid energy conversion as required by observations,
and that the rapid acceleration requires a rapid decrease of the external pressure above the accretion disk. We also clarify
the differences between the fast magnetosonic point of the MHD flow and the sonic point of the de Laval nozzle.

…

The Landau–Lifshitz equation is considered as an approximation of the Abraham–Lorentz–Dirac equation. It is derived from the
Abraham–Lorentz–Dirac equation by treating radiation reaction terms as a perturbation. However, while the Abraham–Lorentz–Dirac
equation has pathological solutions of pre-acceleration and runaway, the Landau–Lifshitz equation and its finite higher-order
extensions are free of these problems. So it seems mysterious that the properties of the solutions of these two equations
are so different. In this paper we show that the problems of pre-acceleration and runaway appear when one considers a series
of all-order perturbation which we call the Landau–Lifshitz series. We show that the Landau–Lifshitz series diverges in general.
Hence a resummation is necessary to obtain a well-defined solution from the Landau–Lifshitz series. This resummation leads
the pre-accelerating and the runaway solutions. The analysis focuses on the non-relativistic case, but we can extend the results
obtained here to the relativistic case, at least in one dimension.

…

KEKB has completed all of the technical milestones and has offered important insights into the flavor structure of elementary
particles, especially CP violation. The accelerator control system at KEKB and the injector linac was initiated by a combination
of scripting languages at the operation layer and EPICS (experimental physics and industrial control system) at the equipment
layer. During the project, many features were implemented to achieve extreme performance from the machine. In particular,
the online linkage to the accelerator simulation played an essential role. In order to further improve the reliability and
flexibility, two major concepts were additionally introduced later in the project, namely, channel access everywhere and dual-tier
controls. Based on the improved control system, a virtual accelerator concept was realized, allowing the single injector linac
to serve as three separate injectors to KEKB's high-energy ring, low-energy ring, and Photon Factory, respectively. These
control technologies are indispensable for future particle accelerators.

…

We review the basic dynamics and accretion of planetesimals by showing N-body
simulations. The orbits of planetesimals evolve through two-body gravitational
relaxation: viscous stirring increases the random velocity and dynamical
friction realizes the equiparation of the random energy. In the early stage of
planetesimal accretion the growth mode of planetesimals is runaway growth where
larger planetesimals grow faster than smaller ones. When a protoplanet
(runaway-growing planetesimal) exceeds a critical mass the growth mode shifts
to oligarchic growth where similar-sized protoplanets grow keeping a certain
orbital separation. The final stage of terrestrial planet formation is
collision among protoplanets known as giant impacts. We also summarize the
dynamical effects of disk gas on planets and the core accretion model for
formation of gas giants and discuss the diversity of planetary systems.

…

The Belle experiment, running at the KEKB e+e- asymmetric energy collider
during the first decade of the century, achieved its original objective of
measuring precisely differences between particles and anti-particles in the B
system. After collecting 1000 fb-1 of data at various Upsilon resonances, Belle
also obtained the many other physics results described in this article.

…

In the complex action theory whose path runs over not only past but also future, we study a normalized matrix element of an
operator $\hat {\mathcal O}$ defined in terms of the future state at the latest time $T_B$ and the past state at the earliest time $T_A$ with a proper inner product that makes normal a given Hamiltonian that is non-normal at first. We present a theorem that
states that, provided that the operator $\hat {\mathcal O}$ is $Q$-Hermitian, i.e., Hermitian with regard to the proper inner product, the normalized matrix element becomes real and time-develops
under a $Q$-Hermitian Hamiltonian for the past and future states selected such that the absolute value of the transition amplitude from
the past state to the future state is maximized. Furthermore, we give a possible procedure to formulate the $Q$-Hermitian Hamiltonian in terms of $Q$-Hermitian coordinate and momentum operators, and construct a conserved probability current density.

…

In this study we critically examine some important papers on weak measurement
and weak values. We find some insufficiency and mistakes in these papers, and
we demonstrate that the real parts of weak values provide the back-action to
the post-selection, which is caused by weak measurement. Two examples, a
counterfactual statement of Hardy's paradox and experiments that determine the
average trajectory of photons passing through double slits, are investigated
from our view point.

…

Top-cited authors

- Instituto Federal de Educação, Ciência e Tecnologia do Maranhão (IFMA), Brazil, São Luis