bluuebunny/crossref_metadata_2025 huggingface dataset:
BULK FIELDS IN DELOCALIZED DILATONIC p-BRANES
Authors: YOUM DONAM
Published: May 2003

We study localization properties of various bulk fields on a dilatonic p-brane which is delocalized along its transverse directions except one. We find that all the bosonic and fermionic bulk fields can be localized on the delocalized dilatonic p-brane in a strict sense, namely the Kaluza–Klein zero modes of the bulk fields are normalizable and are localized around the brane, for any values of the dilaton coupling parameter.
CONFRONTING HEAVY TAU NEUTRINOS WITH NEUTRINO OSCILLATIONS
Authors: LIU CHUN
Published: May 2003

If the tau neutrino is as heavy as 10 MeV which may have certain astrophysical implications, the neutrino mass pattern is studied so as to accommodate the new oscillation observations. It predicts that the electron neutrino has Marjorana mass around 0.05 eV. A supersymmetric model is described to realize the above scenario.
BRANE WORLD IN A TOPOLOGICAL BLACK HOLES IN ASYMPTOTICALLY FLAT SPACE–TIME
Authors: YOUM DONAM
Published: May 2003

We study static brane configurations in the bulk background of the topological black holes in asymptotically flat space–time and find that such configurations are possible even for flat black hole horizon, unlike the AdS black hole case. We construct the brane world model with an orbifold structure S1/Z2 in such bulk background and study massless bulk scalar field.
SKLYANIN BRACKET AND DEFORMATION OF THE CALOGERO–MOSER SYSTEM
Authors: DOLGUSHEV V. A.
Published: May 2003

A two-dimensional integrable system being a deformation of the rational Calogero–Moser system is constructed via the symplectic reduction, performed with respect to the Sklyanin algebra action. We explicitly resolve the respective classical equations of motion via the projection method and quantize the system.
PROJECTION OPERATORS AND D-BRANES IN PURELY CUBIC OPEN STRING FIELD THEORY
Authors: MATSUO YUTAKA
Published: May 2003

We study a matrix version of the purely cubic open string field theory as describing the expansion around the closed string vacuum. Any D-branes in the given closed string background can appear as classical solutions by using the identity projectors. Expansion around this solution gives the correct kinetic term for the open strings on the created D-branes while there are some subtleties in the unwanted degree of freedom.
SUPERCONFORMAL AND SUPER-BRS INVARIANCE OF THE N=1 SUPERSYMMETRIC WZW MODEL BASED ON LIE SUPERALGEBRA
Authors: MESREF L.
Published: May 2003

We study the superconformal and super-BRS invariance of the supersymmetric Wess–Zumino–Witten model based on Lie superalgebra. The computation of the critical super-dimension of this model is done using the Fujikawa regularization. Finally, we recover the well-known result which fixes the relative coupling constant α2=1 in a rigorous way.
A REMARK ON NONCONFORMAL NONSUPERSYMMETRIC THEORIES WITH VANISHING VACUUM ENERGY DENSITY
Authors: CORRADINI OLINDO , IGLESIAS ALBERTO , KAKUSHADZE ZURAB , LANGFELDER PETER
Published: May 2003

We discuss nonconformal nonsupersymmetric large-N gauge theories with vanishing vacuum energy density to all orders in perturbation theory. These gauge theories can be obtained via a field theory limit of type IIB D3-branes embedded in orbifolded space–times. We also discuss gravity in this setup.
A STATIONARY VACUUM SOLUTION DUAL TO THE KERR SOLUTION
Authors: YA. TURAKULOV Z. , DADHICH N.
Published: May 2003

We present a stationary axially symmetric two-parameter vacuum solution which could be considered as "dual" to the Kerr solution. It is obtained by removing the mass parameter from the function of the radial coordinate and introducing a dimensionless parameter in the function of the angle coordinate in the metric functions. It turns out that it is in fact the massless limit of the Kerr–NUT solution.
TUNING THE TADPOLE IMPROVED CLOVER WILSON ACTION ON COARSE ANISOTROPIC LATTICES
Authors: ZHANG JUNHUA , LIU CHUAN
Published: May 2003

Wilson quark action, with tadpole improved clover term added, is studied on coarse anisotropic lattices. The bare velocity of light parameter in this action is determined nonperturbatively using the pseudo-scalar and vector meson dispersion relations for various values of the gauge coupling β and bare quark mass parameter κ.
EQUATION OF STATE FOR HOT GLUON PLASMA WITH EFFECTIVE TWO LOOPS
Authors: WANG XIN , LI JIARONG , LIU JUEPING
Published: May 2003

We present analytical results for the equation of state for hot gluon plasma obtained with an effective perturbation based on hard thermal loops resummation theory. The effective two-loop results depend on Debye screening and finite width of gluons as physical parameters. Considering next-to-leading Debye mass and finite width effects, we find the equation of state to be in good agreement with recent lattice results for T≳2T c .
THE ANAPOLE MOMENT OF DIRAC NEUTRINOS IN LEFT–RIGHT SYMMETRIC MODEL AND IN MINIMAL SUPERSYMMETRIC MODEL
Authors: AYDIN C.
Published: May 2003

The static parity-violating coupling of Dirac neutrino to an external electromagnetic field is calculated in the SU (2) L × SU (2) R × U (1) left–right model and in the N=1 broken supergravity model (MSSM).
ON THE POSSIBILITY OF AN ASTRONOMICAL DETECTION OF CHROMATICITY EFFECTS IN MICROLENSING BY WORMHOLE-LIKE OBJECTS
Authors: TORRES DIEGO F. , EIROA ERNESTO F. , ROMERO GUSTAVO E.
Published: May 2003

We study the colour changes induced by blending in a wormhole-like microlensing scenario with extended sources. The results are compared with those obtained for limb darkening. We assess the possibility of an actual detection of the colour curve using the difference image analysis method.
SCALING IN γ*p TOTAL CROSS-SECTIONS, SATURATION AND THE GLUON DENSITY
Authors: SCHILDKNECHT DIETER , SURROW BERND , TENTYUKOV MIKHAIL
Published: May 2003

Including the new HERA data, the γ*p total cross-section is analyzed in the generalized vector dominance/color-dipole picture (GVD/CDP) that contains scaling in [Formula: see text], where Λ2(W2) is an increasing function of W2. At any Q2, for W2→∞, the cross-sections for virtual and real photons become identical, σγ*p (W2,Q2)/σγp (W2)→ 1. The gluon density deduced from the color-dipole cross-section fulfills the leading order DGLAP relationship. Evolution à la DGLAP breaks down for η≲0.1.
DALITZ PLOT SLOPE PARAMETERS FOR K →πππ DECAYS AND TWO-PARTICLE INTERFERENCE
Authors: MARTÍNEZ M. I. , HERRERA G.
Published: May 2003

We study the possible distortion of phase-space in the decays K→πππ, which may result from final state interference among the decay products. Such distortion may influence the values of slope parameters extracted from the Dalitz plot distribution of these decays. We comment on the consequences on the magnitude of violation of the |Δ I|=1/2 rule in these decays.
TOPOLOGICAL EFFECTS OF INSTANTON DUE TO DEFECTS
Authors: JIA DUOJE , DUAN YISHI
Published: May 2003

A new doublet variable is proposed to decompose non-Abelian gauge field for describing the topological effects of instantons due to the defects in appropriate phase of SU(2) Yang–Mills theory. It is shown that the instanton number can be directly related to the isospin defects of the doublet order parameter and contributed from topological charges of these defects. The θ-term in instanton action is found to be the delta-function form of the doublet and the Lagrangian of instantons in terms of new variables is also presented.
EXPERIMENTAL INVESTIGATIONS OF CHANGES IN β-DECAY RATE OF 60Co AND 137Cs
Authors: BAUROV YU. A. , KONRADOV A. A. , KUSHNIRUK V. F. , KUZNETSOV E. A. , SOBOLEV YU. G. , RYABOV YU. V. , SENKEVICH A. P. , ZADOROZSNY S. V.
Published: May 2003

Results of simultaneous measurements of β-decay rate with the aid of Ge(Li)-detectors performed at two laboratories 140 km apart (INR RAS, Troitsk, 60 Co , and JINR, Dubna, 137 Cs ) from 15 March 2000 to 10 April 2000 are presented. Regular deviations of the count rate of γ-quanta following the β-decay of ~0.7% (INR RAS, 60 Co ) and ~0.2% (JINR, 137 Cs ) from the statistical average, are observed. The analysis of extremum deviations of γ--quanta count rate shows that the set of directions of tangents to the Earth's parallels of latitude at the extremum points of trajectories of motion in the space of each laboratory clearly forms three separate compact subsets of directions which agree, for two laboratories, to an accuracy of ±10°. This phenomenon is shown not to be explained on the basis of traditional notion. A possible explanation is suggested based on the hypothesis that there exists a new anisotropic interaction caused by the cosmological vectorial potential Ag, a new fundamental constant having, according to the experiments carried out, the coordinate of right ascension α ≈ 285° in the second equatorial system. This is in agreement with earlier experiments.
NEGATIVE FRICTION OF DARBOUX COSMOLOGICAL FLUIDS
Authors: ROSU H. C.
Published: May 2003

Atmospheric free fall with quadratic resistance when considered from the point of view of the strictly isospectral construction of supersymmetric quantum mechanics is a powerful analogy for the class of Darboux cosmological fluids that we introduced in a previous work. Here, using this analogy, it is shown that the possible accelerating cosmological effects are due to the quadratic negative friction properties with which the Darboux fluids are endowed through the mathematical construction.
ANOMALY MATCHING IN GAUGE THEORIES AT FINITE MATTER DENSITY
Authors: HSU STEPHEN D. H. , SANNINO FRANCESCO , SCHWETZ MYCK
Published: May 2003

We investigate the application of 't Hooft's anomaly matching conditions to gauge theories at finite matter density. We show that the matching conditions constrain the low-energy quasiparticle spectrum associated with possible realizations of global symmetries.
THE BARYON FRACTIONS IN CLUSTERS OF GALAXIES
Authors: WU XIANG-PING
Published: May 2003

We report briefly the current status on the baryon fraction measurements in clusters of galaxies and their cosmological implications.
BRANE WORLD IN A TOPOLOGICAL BLACK HOLE BULK
Authors: BIRMINGHAM DANNY , RINALDI MASSIMILIANO
Published: May 2003

We consider a static brane in the background of a topological black hole in arbitrary dimensions. For hyperbolic horizons, we find a solution only when the black hole mass assumes its minimum negative value. In this case, the tension of the brane vanishes, and the brane position coincides with the location of the horizon. For an elliptic horizon, we show that the massless mode of Randall–Sundrum is recovered in the limit of large black hole mass.
A POSSIBLE WAY TO RELATE THE "COVARIANTIZATION" AND THE NEGATIVE DIMENSIONAL INTEGRATION METHOD IN THE LIGHT-CONE GAUGE
Authors: SUZUKI ALFREDO T. , BENTÍN RICARDO
Published: May 2003

Here we present a possible way to relate the method of covariantizing the gauge-dependent pole and the negative dimensional integration method for computing Feynman integrals pertinent to the light-cone gauge fields. Both techniques are applicable to the algebraic light-cone gauge and dispense with prescriptions to treat the characteristic poles.
POSSIBLE CONFINEMENT MECHANISMS FOR NONRELATIVISTIC PARTICLES ON A LINE
Authors: STICHEL P. C. , ZAKRZEWSKI W. J.
Published: May 2003

The gauge model of nonrelativistic particles on a line interacting with nonstandard gravitational fields5 is supplemented by the addition of a (non)-Abelian gauge interaction. Solving for the gauge fields we obtain equations, in closed form, for a classical two-particle system. The corresponding Schrödinger equation, obtained by the Moyal quantization procedure, is solved analytically. Its solutions exhibit two different confinement mechanisms — dependent on the sign of the coupling λ to the nonstandard gravitational fields. For λ >0 confinement is due to a rising potential, whereas for λ<0 it is due to the dynamical (geometric) bag formation. Numerical results for the corresponding energy spectra are given. For a particular relation between two coupling constants, the model fits into the scheme of supersymmetrical quantum mechanics.
WARM DARK MATTER MODEL OF GALAXY FORMATION
Authors: JING Y. P.
Published: May 2003

Cold Dark Matter (CDM) models of galaxy formation had been remarkably successful to explain a number of observations in the past decade. However, with both the theoretical modeling and the observations being improved, CDM models have been very recently shown to have excessive clustering on the sub-galactic scale. Here we discuss a solution, based on our high-resolution numerical simulations, to this outstanding problem by considering Warm Dark Matter (WDM). Our results show that the over-clustering problem on sub-galactic scales can be overcome by WDM models, and all the advantages of CDM models are preserved by WDM models. Therefore, the WDM model will become an interesting alternative to the well-studied CDM models.
ZERO-POINT ENERGY OF A DILUTE DIELECTRIC BALL IN THE MODE SUMMATION METHOD
Authors: LAMBIASE G. , SCARPETTA G. , NESTERENKO V. V.
Published: May 2003

In the (ε1-ε2)2-approximation the Casimir energy of a dilute dielectric ball is derived using a simple and clear method of the mode summation. The addition theorem for the Bessel functions enables one to present in a closed form the sum over the angular momentum before the integration over the imaginary frequencies. The linear in (ε1-ε2)2 contribution into the vacuum energy is removed by an appropriate subtraction. The role of the contact terms used in other approaches to this problem is elucidated.
QUINTESSENCE WITH A LOCALIZED SCALAR FIELD ON THE BRANE
Authors: MYUNG Y. S.
Published: May 2003

We study issues of the quintessence in the brane cosmology. The initial bulk space–time consists of two 5D topological anti-de Sitter black hole joined by the brane (moving domain wall). Here we do not introduce any conventional radiation and matter. Instead we include a localized scalar on the brane as a stress–energy tensor, and thus we find the quintessence which gives an accelerating universe. Importantly, we obtain a ρ2-term as well as a holographic matter term of α/a4 from the masses of the topological black holes. We discuss a possibility that in the early universe, ρ2-term makes a large kinetic term which induces a decelerating universe. This may provide a hint of avoiding from the perpetually accelerating universe of the present-day quintessence. If a holographic matter term exists, it will plays the role of a CFT-radiation in the early universe.
COSMOLOGICAL CONSTANT OF THE INFLATING BRANES IN THE RANDALL–SUNDRUM–ODA MODEL
Authors: MERSINI LAURA
Published: May 2003

We examine the issue of the cosmological constant in the many inflating branes scenario, extending on two recent models by I. Oda and Randall–Sundrum. The exact solution in a closed form is found in the slow-roll approximation for the branes. We show that each positive tension brane has an induced canonical cosmological constant and expansion rate that are decreasing functions of their position in the fifth dimension.

The reason is that the square of the effective expansion rate enters as a source term in the Einstein equations for the branes. Thus the brane has two scale factors depending on time and the fifth dimension respectively. A displacement of the brane along the fifth dimension would adjust its effective expansion rate in such a way that it compensates for its internal energy changes due to inflation and possible phase transitions.
CONDITIONS FOR COMPLEX SPECTRA IN A CLASS OF ${\mathcal P}{\mathcal T}$ SYMMETRIC POTENTIALS
Authors: LÉVAI GÉZA , ZNOJIL MILOSLAV
Published: May 2003

We study a wide class of solvable [Formula: see text] symmetric potentials in order to identify conditions under which these potentials have regular solutions with complex energy. Besides confirming previous findings for two potentials, most of our results are new. We demonstrate that the occurrence of conjugate energy pairs is a natural phenomenon for these potentials and that the present method can readily be extended to further potential classes.
A GRASSMANN REPRESENTATION OF THE HUBBLE PARAMETER
Authors: ROSU HARET C. , TORRES JOSE
Published: May 2003

The Riccati equation for the Hubble parameter H of barotropic FRW cosmologies in conformal time for κ ≠ 0 spatial geometries and in comoving time for the κ = 0 geometry, respectively, is generalized to odd Grassmannian time parameters. We obtain a system of simple differential equations for the four supercomponents (two of even type and two of odd type) of the Hubble superfield function ℋ that is explicitly solved. The second even Hubble component does not have an evolution governed by general relativity though there are effects of the latter upon it.
THE MYSTERIOUS ULTRAHIGH ENERGY COSMIC RAY CLUSTERING
Authors: ANCHORDOQUI LUIS A. , GOLDBERG HAIM , REUCROFT STEPHEN , SWAIN JOHN , ROMERO GUSTAVO E. , TORRES DIEGO F.
Published: May 2003

We examine the correlation between compact radio quasars (redshifts in the range z=0.3–2.2) and the arrival direction of ultrahigh energy cosmic rays forming clusters. Our Monte Carlo simulation reveals a statistically significant correlation on the AGASA sample: the chance probability of this effect being less than 1%. The implications of this result on the origin of ultrahigh energy cosmic rays are discussed.
BLACK HOLES AND CONFORMAL MECHANICS
Authors: MIGNEMI S.
Published: May 2003

We show how the motion of a charged particle near the horizon of an extreme Reissner–Nordström black hole can lead to different forms of conformal mechanics, depending on the choice of the time coordinate.
ON THE INTEGRABILITY OF CLASSICAL RUIJSENAARS–SCHNEIDER MODEL OF BC2 TYPE
Authors: INOZEMTSEV V. I. , SASAKI R.
Published: May 2003

The problem of finding the most general form of the classical integrable relativistic models of many-body interaction of the BCn type is considered. In the simplest nontrivial case of n=2, the extra integral of motion is presented in explicit form within the ansatz similar to the nonrelativistic Calogero–Moser models. The resulting Hamiltonian has been found by solving the set of two functional equations.
QUINTESSENCE AND THE FIRST DOPPLER PEAK
Authors: GONZALEZ-DIAZ PEDRO F.
Published: May 2003

By using a tracking quintessence model we obtain that the position of the first Doppler peak in the spectrum of CMB anisotropies only depends on the topology, of the universe, Ωk, for any value of the ratio ΩΛ/ΩM, so that such a dependence is perfectly valid in the range suggested by supernova observations. A prediction from the used quintessence model is also that all peaks at positions ℓn for n even are fully suppressed on that spectrum.
SPIN-3/2 FERMIONS IN TWISTOR FORMALISM
Authors: HAYASHI MITSUO J.
Published: May 2003

Consistency conditions for the local existence of massless spin-3/2 fields have been explored to find the facts that the field equations for massless helicity-3/2 particles are consistent if the space–time is Ricci-flat, and that in Minkowski space–time the space of conserved charges for the fields is its twistor space itself. After considering the twistorial methods to study such massless helicity-3/2 fields, we show in flat space–time that the charges of spin-3/2 fields, defined topologically by the first Chern number of their spin-lowered self-dual Maxwell fields, are given by their twistor space, and in curved space–time that the (anti-)self-duality of the space–time is the necessary condition. Since in N=1 supergravity torsions are the essential ingredients, we generalize our space–time to that with torsion (Einstein–Cartan theory), and investigate the consistency of existence of spin-3/2 fields in this theory. A simple solution to this consistency problem is found: The space–time has to be conformally (anti-)self-dual, left-(or right-) torsion-free. The integrability condition on α-surface shows that the (anti-)self-dual Weyl spinor can be described only by the covariant derivative of the right-(left-)handed torsion.
A TEST OF SU(15) AT HERA USING THE HELAS PROGRAM
Authors: KIM SUN MYONG
Published: May 2003

A possible SU(15) process at HERA is investigated. The process that we consider is [Formula: see text] through the exchange of new heavy gauge bosons X- and X-- which are predicted in SU(15). This process produces two easily observable like-sign muons in the final state. The cross-section of this process is calculated by using HELAS and VEGAS programs, and PDF-library functions. The cross-section turns out to be small to be observed in the near future.
NEUTRINO OSCILLATIONS AND LEPTON FLAVOR MIXING
Authors: KANG KYUNGSIK , KANG SIN KYU , KIM C. S. , KIM SUN MYONG
Published: May 2003

In view of the recent announcement on nonzero neutrino mass from Super-Kamiokande experiment, it would be very timely to investigate all the possible scenarios on masses and mixings of light neutrinos. Recently suggested mass matrix texture for the quark CKM mixing, which can be originated from the family permutation symmetry and its suitable breakings, is assumed for the neutrino mass matrix and determined by the four combinations of solar, atmospheric and LSND neutrino data and cosmological hot dark matter bound as input constraints. The charged-lepton mass matrix is assumed to be diagonal so that the neutrino mixing matrix can be identified directly as the lepton flavor mixing matrix and no CP invariance violation originates from the leptonic sector. The results favor hierarchical patterns for the neutrino masses, which follow from the case when the solar-atmospheric data is used.
O(αs) CORRECTIONS TO B→ Xse+e-DECAY IN THE 2HDM
Authors: YEGHIYAN G. K.
Published: May 2003

O(αs) QCD corrections to the inclusive B→Xse+e-decay are investigated within the two-Higgs doublet extension of the standard model (2HDM). The analysis is performed in the so-called off-resonance region; the dependence of the obtained results on the choice of the renormalization scale is examined in details. It is shown that O(αs) corrections can suppress the B→Xse+e-decay width up to 1.5–3 times (depending on the choice of the dilepton invariant mass s and the low-energy scale μ). As a result, in the experimentally allowed range of the parameter space, the relations between the B→Xse+e-branching ratio and the new physics parameters are strongly affected. It is also found that though the renormalization scale dependence of the B→Xse+e-branching is significantly reduced, higher order effects in the perturbation theory can still be non-negligible.
QUINTESSENCE AND BRANE WORLD SCENARIOS
Authors: MYUNG Y. S.
Published: May 2003

We discuss the possibility of quintessence in the dilatonic domain walls including the Randall–Sundrum brane world. We obtain the zero mode effective action for gravitating objects in the dilatonic domain wall. First we consider the four-dimensional (4D) gravity and the Brans–Dicke graviscalar with a potential. This can be further rewritten as a minimally coupled scalar with the Liouville-type potential in the Einstein frame. However this model fails to induce the quintessence on the dilatonic domain wall because the potential is negative. Second we consider the 4D gravity with the dilaton. In this case we also find a negative potential. Any negative potential gives us negative energy density and positive pressure, which does not lead to an accelerating universe. Consequently it turns out that the zero mode approach of the dilatonic domain wall cannot accommodate the quintessence in cosmology.
BRANS TYPE II–IV SOLUTIONS IN THE EINSTEIN FRAME AND PHYSICAL INTERPRETATION OF CONSTANTS IN THE SOLUTIONS
Authors: BHADRA A. , NANDI K. K.
Published: May 2003

We present new classes of non-singular static spherically symmetric solutions of Einstein minimally coupled scalar field (EMS) theory and investigate the nature of these solutions. It is shown that EMS class III and IV solutions are not independent. It appears that the EMS class IV solution can act as an alternative metric for describing physical models. An effort has been made to provide a physical interpretation of the constants that appear in the EMS class IV solution.
NON-ABELIAN SELF-DUALITY FROM SELF-INTERACTION
Authors: KHOUDEIR A.
Published: May 2003

The non-Abelian self-dual action in three dimensions is derived using the self-interaction mechanism.
DOES DLCQ S-MATRIX HAVE A COVARIANT CONTINUUM LIMIT?
Authors: TANIGUCHI MASA-AKI , UEHARA SHOZO , YAMADA SATOSHI , YAMAWAKI KOICHI
Published: May 2003

We develop a systematic DLCQ perturbation theory and show that DLCQ S-matrix does not have a covariant continuum limit for processes with p+=0 exchange. This implies that the role of the zero mode is more subtle than ever considered in DLCQ and hence must also be treated with great care in nonperturbative approach. We also make a brief comment on DLCQ in string theory.
RELATIVISTIC COULOMB RESUMMATION IN QCD
Authors: MILTON KIMBALL A. , SOLOVTSOV IGOR L.
Published: May 2003

A relativistic Coulomb-like resummation factor in quantum chromodynamics is suggested, based on the solution of the quasipotential equation.
THE RELATION OF THERMAL FLUCTUATION AND INFORMATION-ENTROPY FOR ONE-DIMENSIONAL RINDLER OSCILLATOR
Authors: YU DAN , GUI YUAN-XING , YE XIN
Published: May 2003

Within the framework of thermo-field-dynamics (TFD), the information-entropies associated with the measurements of position and momentum for one-dimensional Rindler oscillator are derived, and the connection between its information-entropy and thermal fluctuation is obtained. A conclusion is drawn that the thermal fluctuation leads to the loss of information.
OSCILLATIONS OF FASTER THAN LIGHT MAJORANA NEUTRINOS: A CAUSAL FIELD THEORY
Authors: CHANG NGEE-PONG
Published: May 2003

In this paper, we carry out the canonical quantization of the field theory of an interacting tachyonic Majorana neutrino. We show how micro-causality is preserved in the physical scattering matrix elements between the in and out vacua.

The phenomenology of this radical proposal is nevertheless compatible with normal timelike oscillations.
CONSTRAINTS ON EXTRA DIMENSIONS FROM COSMOLOGICAL AND TERRESTRIAL MEASUREMENTS
Authors: MILTON KIMBALL A. , KANTOWSKI RONALD , KAO CHUNG , WANG YUN
Published: May 2003

If quantum fields exist in extra compact dimensions, they will give rise to a quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a cosmological constant. The fact that supernova and cosmic microwave background data indicate that the cosmological constant is of the same order as the critical mass density to close the universe supplies a lower bound on the size of the extra dimensions. Recent laboratory constraints on deviations from Newton's law place an upper limit. The allowed region is so small as to suggest that either extra compact dimensions do not exist, or their properties are about to be tightly constrained by experimental data.
UNDERSTANDING THE NATURE OF PROTON–AIR CROSS-SECTIONS AT VERY HIGH ENERGIES AND THE IMPLICATIONS
Authors: DE BHASKAR , BHATTACHARYYA S. , GUPTAROY P.
Published: May 2003

The purpose of this paper is to focus on the possible effective role of two relatively less-known models in analyzing comprehensively the very up-to-date data on proton–air inelastic cross-sections at high and ultra high energies. The standard versions of all the familiar simulation-based multiparticle production models, which nowadays normally claim front-ranking positions, address on the contrary, only a small part of the cross-section data for a very limited or sectional range of energy values. Against this background, the relevance and impact of the present study have finally been highlighted.
NONCOMMUTATIVITY IN LINEAR DILATON BACKGROUND
Authors: BHATTACHARYYA SANDIP , KUMAR ALOK , MAHAPATRA SWAPNA
Published: May 2003

We consider quantization of open string theories in linear dilaton and constant antisymmetric tensor backgrounds and discuss the noncommutativity of space–time coordinates arising in such theories, including their relationship with light-like noncommutativity as well as backgrounds with null isometries. It is argued that the results can also be understood using space–time equations of motion of the string modes. We then present N = 2 supersymmetric generalization of these theories and the associated noncommutative structure.
NEW PROGRESS IN STATIONARY D=N=4 SUPERGRAVITY
Authors: KECHKIN OLEG V.
Published: May 2003

A bosonic sector of the four-dimensional low-energy heterotic string theory with two Abelian gauge fields is considered in the stationary case. A new 4× 4 unitary null-curvature matrix representation of the theory is derived and the corresponding formulation based on the use of a new 2 × 2 Ernst type matrix complex potential is developed. The group of hidden symmetries is described and classified in the matrix-valued quasi general relativity form. A subgroup of charge symmetries is constructed and representation which transforms linearly under the action of this symmetry subgroup is established. Also the solution generation procedure based on the application of the total charge symmetry subgroup to the stationary Einstein–Maxwell theory is analyzed.
DOUBLE THREEFOLD DEGENERACIES FOR ACTIVE AND STERILE NEUTRINOS
Authors: MA ERNEST , RAJASEKARAN G.
Published: May 2003

We explore the possibility that the three active (doublet) neutrinos have nearly degenerate masses which are split only by the usual seesaw mechanism from three sterile (singlet) neutrinos in the presence of a softly broken A4 symmetry. We take the unconventional view that the sterile neutrinos may be light, i.e. less than 1 keV, and discuss some very interesting and novel phenomenology, including a connection between the LSND neutrino data and solar neutrino oscillations.
REMARKS ON INFLATION AND NONCOMMUTATIVE GEOMETRY
Authors: CHU CHONG-SUN , GREENE BRIAN R. , SHIU GARY
Published: May 2003

We briefly discuss some possible cosmological implications of noncommutative geometry. While the noncommutativity we consider does not affect gravity, it can play an important role in the dynamics of other fields that are present in the early universe. We point out the possibility that noncommutativity may cause inflation induced fluctuations to become non-Gaussian and anisotropic, and may modify the short distance dispersion relations.
EQUIVALENCE BETWEEN SPACE–TIME–MATTER AND BRANE-WORLD THEORIES
Authors: DE LEON J. PONCE
Published: May 2003

We study the relationship between space–time–matter (STM) and brane theories. These two theories look very different at first sight, and have different motivation for the introduction of a large extra dimension. However, we show that they are equivalent to each other. First we demonstrate that STM predicts local and nonlocal high-energy corrections to general relativity in 4D, which are identical to those predicted by brane-world models. Secondly, we point out that in brane models the usual matter in 4D is a consequence of the dependence of five-dimensional metrics on the extra coordinate. If the 5D bulk metric is independent of the extra dimension, then the brane is void of matter. Thus, in brane theory matter and geometry are unified, which is exactly the paradigm proposed in STM. Consequently, these two 5D theories share the same concepts and predict the same physics. This is important not only from a theoretical point of view, but also in practice. We propose to use a combination of both methods to alleviate the difficult task of finding solutions on the brane. We show an explicit example that illustrate the feasibility of our proposal.
SPONTANEOUS BREAKDOWN OF $\mathcal{PT}$ SYMMETRY IN THE SOLVABLE SQUARE-WELL MODEL
Authors: ZNOJIL MILOSLAV , LÉVAI GÉZA
Published: May 2003

Apparently, the energy levels merge and disappear in many [Formula: see text] symmetric models. This interpretation is incorrect: In square-well model we demonstrate how the doublets of states in question continue to exist at complex conjugate energies in the strongly non-Hermitian regime.
INCREASE OF THE HAWKING RADIATION FOR SPINOR PARTICLES FROM SCHWARZSCHILD BLACK HOLES BY DIRAC MONOPOLES
Authors: GONCHAROV YU. P. , FIRSOVA N. E.
Published: May 2003

An algorithm for numerical computation of the barrier transparency for the potentials surrounding Schwarzschild black holes is described for massless spinor particles. It is then applied to calculate all the configurations (including the contributions of twisted field configurations connected with Dirac monopoles) luminosity for the Hawking radiation from a Schwarzschild black hole. It is found that the contribution due to monopoles can be of order 22% of all the configurations luminosity.
COHERENT STATES FOR UNUSUAL POTENTIALS
Authors: MARTIN NIETO MICHAEL
Published: May 2003

The program to construct minimum-uncertainty coherent states for general potentials works transparently with solvable analytic potentials. However, when an analytic potential is not completely solvable, like for a double-well or the linear (gravitational) potential, there can be a conundrum. Motivated by supersymmetry concepts in higher dimensions, we show how these conundrums can be overcome.
QUANTUM STATE DENSITY AND CRITICAL TEMPERATURE IN M-THEORY
Authors: ABDALLA M. C. B. , PIMENTEL B. M. , BYTSENKO A. A.
Published: May 2003

We discuss the asymptotic properties of quantum states density for fundamental p-branes which can yield a microscopic interpretation of the thermodynamic quantities in M-theory. The matching of the BPS part of spectrum for superstring and supermembrane gives the possibility of getting membrane's results via string calculations. In the weak coupling limit of M-theory, the critical behavior coincides with the first-order phase transition in the standard string theory at temperature less than the Hagedorn's temperature T H . The critical temperature at large coupling constant is computed by considering M-theory on manifold with topology [Formula: see text]. Alternatively we argue that any finite temperature can be introduced in the framework of membrane thermodynamics.
NEGATIVE PROBABILITY AND UNCERTAINTY RELATIONS
Authors: CURTRIGHT THOMAS , ZACHOS COSMAS
Published: May 2003

A concise derivation of all uncertainty relations is given entirely within the context of phase-space quantization, without recourse to operator methods, to the direct use of Weyl's correspondence, or to marginal distributions of x and p.
NEUTRINO MASS MATRICES IN MODELS WITH HORIZONTAL SYMMETRIES
Authors: RAY ASIM K. , SARKAR UTPAL
Published: May 2003

We have studied the most general neutrino mass matrices in models with SU(2) and SU(3) horizontal symmetries. Without going into the details of the models it is possible to write down the effective operators, which predict the structure of the Majorana neutrino mass matrices. Unlike other extensions of the standard model, the structure is now independent of the effective Yukawa couplings and depends entirely on the Higgs which gives mass to the other fermions. In the case of SU(3) symmetries the lowest dimensional operators are forbidden requiring a low mass scale for lepton number violation.
ENTROPY OF THE THREE-DIMENSIONAL SCHWARZSCHILD–de SITTER BLACK HOLE
Authors: MYUNG Y. S.
Published: May 2003

We study the three-dimensional Schwarzschild–de Sitter ( SdS 3) black hole which corresponds essentially to a conical defect. We compute the mass of the SdS 3 black hole from the correct definition of the mass in asymptotically de Sitter space. Then we clarify the relation between the mass, entropy and temperature for this black hole without any ambiguity. We also establish the SdS 3/ CFT 2-correspondence for the entropy by applying the Cardy formula to a CFT with a central charge c = 3ℓ/2G3. Finally we discuss the entropy bounds for the SdS 3 black hole.
ENERGY AND MOMENTUM OF OSCILLATING NEUTRINOS
Authors: GIUNTI C.
Published: May 2003

It is shown that Lorentz invariance implies that in general flavor neutrinos in oscillation experiments are superpositions of massive neutrinos with different energies and different momenta. It is also shown that for each process in which neutrinos are produced, there is either a Lorentz frame in which all massive neutrinos have the same energy or a Lorentz frame in which all massive neutrinos have the same momentum. In the case of neutrinos produced in two-body decay processes, there is a Lorentz frame in which all massive neutrinos have the same energy.
NULL GEODESICS IN BRANE WORLD UNIVERSE
Authors: YOUM DONAM
Published: May 2003

We study null bulk geodesic motion in the brane world cosmology in the RS2 scenario and in the static universe in the bulk of the charged topological AdS black hole. We obtain equations describing the null bulk geodesic motion as observed in one lower dimension. We find that the null geodesic motion in the bulk of the brane world cosmology in the RS2 scenario is observed to be under the additional influence of extra non-gravitational force by the observer on the three-brane, if the brane universe does not possess the Z2 symmetry. As for the null geodesic motion in the static universe in the bulk of the charged AdS black hole, the extra force is realized even when the brane universe has the Z2 symmetry.
EVIDENCE FOR NEUTRINOLESS DOUBLE BETA DECAY
Authors: KLAPDOR-KLEINGROTHAUS H. V. , DIETZ A. , HARNEY H. L. , KRIVOSHEINA I. V.
Published: May 2003

The data of the Heidelberg–Moscow double beta decay experiment for the measuring period August 1990–May 2000 (54.9813 kg y or 723.44 molyears), published recently, are analyzed using the potential of the Bayesian method for low counting rates. First evidence for neutrinoless double beta decay is observed giving first evidence for lepton number violation. The evidence for this decay mode is 97% (2.2σ) with the Bayesian method, and 99.8% c.l. (3.1σ) with the method recommended by the Particle Data Group. The half-life of the process is found with the Bayesian method to be [Formula: see text] (95% c.l.) with a best value of 1.5 × 1025 y . The deduced value of the effective neutrino mass is, with the nuclear matrix elements from Ref. 1,  = (0.11–0.56) eV (95% c.l.), with a best value of 0.39 eV. Uncertainties in the nuclear matrix elements may widen the range given for the effective neutrino mass by at most a factor 2. Our observation which at the same time means evidence that the neutrino is a Majorana particle, will be of fundamental importance for neutrino physics.
HIGH EXTENSIONS OF CONFORMAL SYMMETRY
Authors: EL KINANI E. H.
Published: May 2003

We discuss the extensions of the standard conformal symmetry obtained by generalizing the conformal transformations to the multicomplex plane MCn. The structure of its W-extension is also given. At the end, we propose the model of bosonic closed extended object invariant under multiconformal symmetry.
ROTATION INTRINSIC SPIN COUPLING: THE PARALLELISM DESCRIPTION
Authors: ZHANG C. M. , BEESHAM A.
Published: May 2003

For the Dirac particle in the rotational system, the rotation induced inertia effect is analogously treated as the modification of the "spin connection" on the Dirac equation in the flat space–time, which is determined by the equivalent tetrad. From the point of view of parallelism description of space–time, the obtained torsion axial-vector is just the rotational angular velocity, which is included in the "spin connection". Furthermore the axial-vector spin coupling induced spin precession is just the rotation-spin (1/2) interaction predicted by Mashhoon. Our derivation treatment is straightforward and simplified in the geometrical meaning and physical concept, however the obtained conclusions are consistent with that of the other previous work.
THREE-FLAVOR SYMMETRY OF HADRONS CONSISTENT WITH THE OKUBO–ZWEIG–IIZUKA RULE
Authors: KIRCHBACH M.
Published: May 2003

It is argued that the only three-flavor symmetry which is consistent with the Okubo–Zweig–Iizuka (OZI) rule, and is therefore dictated by the gluon gauge dynamics, is the heavy c quark limit of a certain U(4) F subgroup (called S OZI here) and defined as S OZI = lim mc→Λc SU (2)ud ⊗ SU (2)cd ⊗ U (1) with the two SU(2) groups acting in turn onto the first and second quark generations rather than Gell-Mann's eightfold SU(3) F. Within this scheme, the presence of non-strange quarkonium components in the wave function of the physical η and f1(1285) mesons appears necessarily through the violation of the OZI rule for the pseudoscalar and axial vector mesons by the anomalous axial U(1) A baryon number current and not by a primordial octet flavor symmetry. The physical observable which selects the S OZI over the SU(3) F scheme is the non-isotriplet part of the neutral axial current. In the case of the S OZI symmetry, the only non-isotriplet neutral axial current having a well-defined chiral limit is purely strange, while within the SU(3) F framework it is the octet axial current which is supposed to be partially conserved. Accordingly, while in the latter case the tree level ηN coupling is of significant strength, it almost vanishes in the former, in agreement with data, thus confirming the relevance of the S OZI symmetry.
ON TIME DISLOCATION SOLUTION OF EINSTEIN FIELD EQUATIONS
Authors: ANDRADE L. C. GARCIA DE
Published: May 2003

The theory considered here is not Einstein general relativity, but is a Poincaré type gauge theory of gravity, therefore the Birkhoff theorem is not applied and the external solution is not vacuum spherically symmetric and tachyons may exist outside the core defect.
CHARGE PICK-UP PHENOMENA IN U+Al INTERACTION
Authors: BASU BASUDHARA , BHATTACHARYYA D. P.
Published: May 2003

927 MeV/N U-projectile from LBL BEVALAC irradiated a stack consisting of CR-39(DOP) plastics and Al target at an angle of 30° to study the large fragmentation phenomena and charge pick-up reactions. The last one from the exposed plates has been etched for an hour in 6.25N NaOH solution at 70°C. Etch pit diameters of about 8,352 nuclei detected in the processed plastic have been measured. Attention has been paid to the observed charge pick-up cross-section that seems to be reduced due to the fission of newly formed nuclei after the charge pick-up events.
LIGHT QUARK ORBITAL RADIUS OF A HEAVY QUARK–LIGHT QUARK SYSTEM IN AN S-STATE
Authors: AVILA M. A.
Published: May 2003

Radial probability density function of a heavy quark–light quark [Formula: see text] system in an S-state is analyzed numerically. It is found that the maximum of this function at r=a0 and the light quark energy (Eq) are related through the relation Eq=Z/a0, where Z=c0/c, c is the strength of the color Coulomb potential and c0=0.446. Z<1 can be thought of as due to a color anti-screening effect. The respective expectation value for r in this state is [Formula: see text]. These results are valid for c in the range c0≤ c≤0.7 and a light quark mass in the range 0≤ m≤ 300 MeV. As a result of these patterns of regularity, bounds on the mass of the heavy quarks are imposed. These give mc=1.3±0.33 GeV and mb=4.6±0.3 GeV. It is also shown that Eq is not directly an "inertia" parameter, as it has been called by the heavy quark effective theory, but a physical quantity that needs to be measured. The relations found in the present work coincide with the maximum value that the slope of the Isgur–Wise function at zero recoil can take, in either way [Formula: see text] or [Formula: see text].
MODULI STABILIZATION IN HETEROTIC M-THEORY
Authors: CHOI KIWOON , KIM HANG BAE , KIM HYUNG DO
Published: May 2003

We examine the stabilization of the two typical moduli, the length ρ of the 11th segment and the volume V of the internal six-manifold, in compactified heterotic M-theory. It is shown that, under certain conditions, the phenomenologically favored vacuum expectation values of ρ and V can be obtained by the combined effects of multi-gaugino condensations on the hidden wall and the membrane instantons wrapping the three-cycle of the internal six-manifold.
SPECTROSCOPY OF DOUBLY CHARMED BARYONS: $\Xi_{cc}^+$ AND $\Xi_{cc}^{++}$
Authors: GERSHTEIN S. S. , KISELEV V. V. , LIKHODED A. K. , ONISHCHENKO A. I.
Published: May 2003

Using the quark–diquark approximation in the framework of Buchmüller–Tye potential model, we investigate the spectroscopy of doubly charmed baryons:[Formula: see text] and [Formula: see text]. Our results include the masses, parameters of radial wave functions of states with different excitations of both diquark and light quark–diquark system. We calculate the values of fine and hyperfine splittings of these levels and discuss some new features, related to the identity of heavy quarks, in the dynamics of hadronic and radiative transitions between the states of these baryons.
COMMENTS ON HAMILTONIAN FORMALISM OF AdS/CFT CORRESPONDENCE
Authors: NAKATSU TOSHIO , YOKOI NAOTO
Published: May 2003

As a toy model to search for Hamiltonian formalism of the AdS/CFT correspondence, we examine a Hamiltonian formulation of the AdS2/CFT1 correspondence emphasizing unitary representation theory of the symmetry. In the course of a canonical quantization of the bulk scalars, a particular isomorphism between the unitary irreducible representations in the bulk and boundary theories is found. This isomorphism defines the correspondence of field operators. It states that field operators of the bulk theory are field operators of the boundary theory by taking their boundary values in a specific way. The Euclidean continuation provides an operator formulation on the hyperbolic coordinates system. The associated Fock vacuum of the bulk theory is located at the boundary, thereby identified with the boundary CFT vacuum. The correspondence is interpreted as a simple mapping of the field operators acting on this unique vacuum. Generalization to higher dimensions is speculated.
B- MESON DECAYS INTO $D^0_1+P^-(V^-)$ IN HQET
Authors: MOHANTA RUKMANI , GIRI ANJAN K.
Published: May 2003

The two-body nonleptonic weak decays [Formula: see text], where [Formula: see text] is a narrow p-wave charm resonance, are investigated using the generalized factorization hypothesis along with the HQET. The estimated decay rates for these processes agree reasonably well with the current experimental values.
ON THE RELATION OF THE GRAVITINO MASS AND THE GUT PARAMETERS
Authors: TKACH V. I. , ROSALES J. J. , TORRES J.
Published: May 2003

In this letter we consider the local supersymmetry breaking and the broken SU(5) symmetry permissible by a dilaton vacuum configuration in supergravity theories. We establish the relation between the parameters of spontaneous breaking of supersymmetry and GUT theory.
ON THE EXCEPTIONAL GAUGED WZW THEORIES
Authors: GHEZELBASH AMIR MASOUD
Published: May 2003

We consider two different versions of gauged WZW theories with the exceptional groups and gauged with any of their null subgroups. By constructing suitable automorphism, we establish the equivalence of these two theories. On the other hand our automorphism, relates the two dual irreducible Riemannian globally symmetric spaces with different characters based on the corresponding exceptional Lie groups.
FURTHER COMMENTS ON A VANISHING SINGLET AXIAL VECTOR CHARGE
Authors: CHENG T. P. , KOCHELEV N. I. , VENTO VICENTE
Published: May 2003

The recent suggestion of a vanishing flavor-singlet axial-charge of nucleon due to a nontrivial vacuum structure is further amplified. A perturbative QCD discussion, applicable for the heavy quark contributions, relates it to the physics of the decoupling theorem. It is also shown that [Formula: see text] leads to a negative η′-meson-quark coupling, which has been found to be compatible with the chiral quark model phenomenology.
SUPERCONFORMAL FIELD THEORY WITH BOUNDARY: SPIN MODEL
Authors: APIKYAN S. A. , SAHAKYAN D. A.
Published: May 2003

The GSO projected superconformal field theory (spin model) with boundary is studied. Boundary states, one-point structure constants, and "bootstrap" equations for the boundary–bulk structure constants are derived.
HADRON SPIN-FLIP AMPLITUDE AND SLOPE OF DIFFERENTIAL CROSS-SECTIONS
Authors: SELYUGIN O. V.
Published: May 2003

A possibility to obtain restrictions of the magnitude of the elastic spin-flip hadron scattering amplitude from accurately measured experimental data on the differential cross-sections of elastic hadron–hadron scattering is shown. Appropriate estimations confirm the previous analysis of experimental data at [Formula: see text] GeV and a probable contribution of the hadron spin-flip amplitude.