bluuebunny/crossref_metadata_2025 huggingface dataset:
ON PION COOLING IN THE SUPERNOVA CORE
Authors: DUTTA SUKANTA , GOYAL ASHOK , CHOUDHURY S. R.
Published: September 2003

We examine the cooling mechanism of a nascent neutron star core by the emission of wrong helicity neutrinos, when the core is at the verge of pion condensation. We study the dominant process [Formula: see text] due to neutrino magnetic moment in terms of the model-independent multipole amplitudes based on dispersion relation theory. This calculation gives a more realistic emission rate for neutrinos and hence an upper bound for neutrino magnetic moment
D-BRANE RECOIL MISLAYS INFORMATION
Authors: ELLIS JOHN , MAVROMATOS N. E. , NANOPOULOS D. V.
Published: September 2003

We discuss the scattering of a light closed-string state off a D-brane, taking into account quantum recoil effects on the latter, which are described by a pair of logarithmic operators. The light particle and D-brane subsystems may each be described by a world sheet with an external source due to the interaction between them. This perturbs each subsystem away from criticality, which is compensated by dressing with a Liouville field whose zero mode we interpret as time. The resulting evolution equations for the D-brane and the closed string are of Fokker–Planck and modified quantum Liouville type, respectively. The apparent entropy of each subsystem increases as a result of the interaction between them, which we interpret as the loss of information resulting from nonobservation of the other entangled subsystem. We speculate on the possible implications of these results for the propagation of closed strings through a dilute gas of virtual D-branes.
NESTED DOMAIN DEFECTS
Authors: MORRIS J. R.
Published: September 2003

An example of a supersymmetric model involving two interacting chiral superfields is presented here which allows for solutions describing stringlike "domain ribbon" defects embedded within a domain wall. It is energetically favorable for the fermions within the wall to populate the domain ribbons, and an explicit solution is found for the fermion zero modes. The Fermi gas within ribbons can allow them to stabilize in the form of small loops.
TRICRITICAL ISING MODEL NEAR CRITICALITY
Authors: GUIDA RICCARDO
Published: September 2003

The most relevant thermal perturbation of the continuous d=2 minimal conformal theory with c=7/10 (Tricritical Ising Model) is treated here. This model describes the scaling region of the ϕ6 universality class near the tricritical point. The problematic IR divergences of the naive perturbative expansion around conformal theories are dealt within the OPE approach developed at all orders by the authors. The main result is a description of the short distance behavior of correlators that is compared with existing long distance expansion (form factors approach) related to the integrability of the model.
NONSTATIC SPHERICALLY SYMMETRIC SPACE–TIME AND GLOBAL MONOPOLE
Authors: CHAKRABORTY SUBENOY , BISWAS LALIT
Published: September 2003

Under the assumption of functional separability of the metric coefficients, we have solved the Einstein equations for nonstatic spherically symmetric model. The energy–momentum tensor for the monopole configuration is taken in the form [Formula: see text]. Also the trajectories have been studied in different situations.
p-BRANES AS COMPOSITE ANTISYMMETRIC TENSOR FIELD THEORIES
Authors: CASTRO CARLOS
Published: September 2003

p′-brane solutions to rank p+1 composite antisymmetric tensor field theories of the kind developed by Guendelman, Nissimov and Pacheva are found when the dimensionality of space–time is D=(p+1)+(p′+1). These field theories possess an infinite-dimensional group of global Noether symmetries, that of volume-preserving diffeomorphisms of the target space of the scalar primitive field constituents. Crucial in the construction of p′ brane solutions are the duality transformations of the fields and the local gauge field theory formulation of extended objects given by Aurilia, Spallucci and Smailagic. Field equations are rotated into Bianchi identities after the duality transformation is performed and the Clebsch potentials associated with the Hamilton–Jacobi formulation of the p′ brane can be identified with the duals of the original scalar primitive constituents. Explicit examples are worked out the analog of S and T duality symmetry are discussed. Different types of Kalb–Ramond actions are given and a particular covariant action is presented which bears a direct relation to the light cone gauge p-brane action.
QUANTUM HALL QUARKS OR SHORT DISTANCE PHYSICS OF FRACTIONALLY QUANTIZED HALL FLUIDS
Authors: GREITER MARTIN
Published: September 2003

In order to obtain a local description of the short distance physics of fractionally quantized Hall states for realistic (e.g. Coulomb) interactions, I propose to view the zeros of the ground state wave function, as seen by an individual test electron from far away, as particles. I then present evidence in support of this interpretation, and argue that the electron effectively decomposes into quarklike constituent particles of fractional charge.
MINIMAL SUPERSYMMETRIC STANDARD MODEL HIGGS RATES AND BACKGROUNDS IN ATLAS
Authors: RICHTER-WAS ELŻBIETA , FROIDEVAUX DANIEL , GIANOTTI FABIOLA , POGGIOLI LUC , CAVALLI DONATELLA , RESCONI SILVIA
Published: September 2003

This study presents an overview of the potential of the ATLAS detector at LHC for the observation of the Higgs boson of the minimal supersymmetric Standard Model (MSSM). The expected rates, backgrounds and significances are discussed channel by channel using realistic assumptions for the detector performance. As final results, the ranges of the MSSM parameter space projected on the (mA, tan β) and (mh, tan β) planes, for which the expected significances for the discovery of the different channels exceed a 5σ value, are shown for the ATLAS detector alone and for combined results from the ATLAS and CMS detectors. It is concluded that the combined potential of the two LHC detectors should fully cover the Higgs sector of the MSSM parameter space. The sensitivity of the results to the upper limit of the allowed mass for the lightest Higgs boson is extensively discussed. The direct impact of the SUSY particle sector on such searches is neglected in this paper.
PREPOTENTIAL OF N=2 SUPERSYMMETRIC YANG–MILLS THEORIES IN THE WEAK COUPLING REGION
Authors: MASUDA TAKAHIRO , SUZUKI HISAO
Published: September 2003

We show how to obtain the explicit form of the low energy quantum effect action for N=2 supersymmetric Yang–Mills theory in the weak coupling region from the underlying hyperelliptic Riemann surface. This is achieved by evaluating the integral representation of the fields explicitly. We calculate the leading instanton corrections for the group SU (Nc), SO (N) and SP (2N) and find that the one-instanton contribution of the prepotentials for these groups coincide with the one obtained recently by using the direct instanton calculation.
RENORMALIZATION CONSTANTS IN QUANTUM CHROMODYNAMICS
Authors: NISHIJIMA KAZUHIKO , DEMIZU IZURU
Published: September 2003

The gauge dependence of the renormalization constant of the quark field has been studied with the help of the renormalization group method. In the case of the color gauge field an exact evaluation of the renormalization constant is feasible because of the presence of a sum rule, but in the absence of the corresponding sum rule, only a qualitative evaluation is possible for the quark field.
THE SPIN CONTRIBUTION TO THE pp-TOTAL CROSS-SECTION AT HIGH ENERGY
Authors: ANDREEVA E. A. , STRIKHANOV M. N. , NURUSHEV S. B.
Published: September 2003

The experimental data on the pp-total cross-sections including the spin-dependent parts are analyzed with the goal to determine the contribution of spin interactions at high energies. Based on the Regge model with cuts, the energy dependencies of such contributions are estimated for two spin-dependent terms: (1) the total spin dependent term, σ1 and (2) the spin projection dependent term, σ2. The estimates show that their contributions to the unpolarized total cross section, σ0, decrease with energy from several % around 2 GeV/c to 10-2% around 200 GeV/c. The assumption σ1= -σ2 does not seem to be correct, while the hypothesis 3 σ1=-σ2 is more preferable, especially in the measured energy interval 2-6 GeV. There is a clear indication that the spin effects are sensitive to the pomeron intercept at - t=0 (GeV/c)2. In order to pin down such effects the spin dependent total cross-sections must be measured with precisions better than 10 μb at 200 GeV/c.
DEEP INELASTIC SCATTERING AT HERA
Authors: FOSTER B.
Published: September 2003

Results from the H1 and ZEUS experiments at HERA on deep inelastic scattering are reviewed. The data lead to a consistent picture of a steep rise in the F2 structure function and in the gluon density within the proton. Important new information on the partonic structure of diffraction is emerging from H1 and ZEUS. The spacelike region in which the weak and electromagnetic interactions become of equal strength is being explored for the first time. A possible excess of events at high x and Q2 compared to the expectations of the Standard Model has been observed in both experiments.
Z′ EFFECTS AND ANOMALOUS GAUGE COUPLINGS AT LC WITH POLARIZATION
Authors: PANKOV A. A. , PAVER N. , VERZEGNASSI C.
Published: September 2003

We show that the availability of longitudinally polarized electron beams at a 500 GeV linear collider would allow, from an analysis of the reaction e+e- → W+W-, to set stringent bounds on the couplings of a Z′ of the most general type. In addition, to some extent, it would be possible to disentangle observable effects of the Z′ from analogous ones due to competitor models with anomalous trilinear gauge couplings.
FREE-FIELD REPRESENTATION OF GROUP ELEMENT FOR SIMPLE QUANTUM GROUPS
Authors: MOROZOV ALEXEI , VINET LUC
Published: September 2003

A representation of the group element (also known as "universal [Formula: see text]-matrix") which satisfies Δ(g)=g⊗g, is given in the form [Formula: see text]where [Formula: see text], qi= q‖αi‖2/2 and Hi=2Hαi/ ‖αi‖2 and T±i are the generators of quantum group associated respectively with Cartan algebra and the simple roots. The "free fields" χ, ϕ, ψ form a Heisenberg-like algebra: [Formula: see text] We argue that the d G -parametric "manifold" which g spans in the operator-valued universal envelopping algebra, can also be invariant under the group multiplication g→ g′ · g′′. The universal ℛ-matrix with the property that ℛ(g⊗ I)(I⊗g)= (I⊗ g)(g⊗ I)ℛ is given by the usual formula [Formula: see text]
THE QUANTUM MECHANICS OF ISOLATED SYSTEMS
Authors: DEWITT BRYCE
Published: September 2003

No abstract.
EINSTEIN'S THEORY OF GRAVITATION AS A LAGRANGIAN THEORY FOR TENSOR FIELDS
Authors: MANOFF S.
Published: September 2003

Einstein's theory of gravitation (ETG) is considered as a Lagrangian theory of tensor fields over (pseudo) Riemannian spaces without torsion (Vn spaces, n=4) by means of the method of Lagrangians with covariant derivarives (MLCD). In a trivial manner Euler–Lagrange's equations as Einstein's equations are obtained. The corresponding energy–momentum tensors (EMT's) are found for the standard for the ETG Lagrangian invariant on the basis of the covariant Noether identities. The symmetric energy–momentum tensor of Hilbert appears as an element irrelevant to the whole scheme of the considered Lagrangian thoery of tensor fields over Vn spaces despite of the fact that it has some elements of the structure of the variational EMT of Euler–Lagrange. The notion of the active gravitational rest mast density is related to the variational EMT of Euler–Lagrange and on this basis to a certain extent to the EMT of Hilbert.
COMPARATIVE ANALYSIS OF HARD AND SOFT PROCESSES IN HIGH ENERGY HADRONIC COLLISIONS
Authors: LIU FENG , LIU FENG
Published: September 2003

According to the cone definition of the jet we propose a practical and effective algorithm to identify jets. Through comparison between the Monte Carlo samples with and without jet(s), the following observations are made. Contrary to what is expected, most of the jetty events do not have high multiplicity. The distributions of multiplicity and [Formula: see text] have long tails for the whole event sample because of (mini)jet production, but no such tail for a no-jet event subsample. The average transverse momentum per event [Formula: see text] and multiplicity n are positively correlated for the whole event sample, and negatively correlated for the jetty event subsample. Two ratios are introduced to describe the "degree of hardness" of each event and are found to be correlated positively with [Formula: see text], but negatively with multiplicity, indicating that [Formula: see text] is a better characteristic parameter to describe the evet hardness than multiplicity.
KOSZUL–TATE COHOMOLOGY FOR AN SP(2)-COVARIANT QUANTIZATION OF GAUGE THEORIES WITH LINEARLY DEPENDENT GENERATORS
Authors: TATARU LIVIU , TATAR RADU
Published: September 2003

The anti-BRST transformation, in its Sp(2)-symmetric version, for the general case of any stage-reducible gauge theories is implemented in the usual BV1,2 approach. This task is accomplished not by duplicating the gauge symmetries but rather by duplicating all fields and antifields of the theory and by imposing the acyclicity of the Koszul–Tate differential. In this way the Sp(2)-covariant quantization can be realized in the standard BV approach and its equivalence with BLT quantization9,10 can be proven by a special gauge fixing procedure.
ON SOME LOCAL PROPERTIES OF YANG–MILLS VACUUM
Authors: GUENDELMAN E. I. , NUDELMAN ALEKSEY
Published: September 2003

In this paper we use a noncovariant gauge which makes some of the YM features manifest which otherwise do not appear explicitly in the Landau gauge used by Nielsen and Olesen. We show, in fact, that the unstable mode which makes a large contribution to the vacuum energy is nonperturbative even classically.
TOWARDS THE CLASSIFICATION OF NONMARGINAL BOUND STATES OF M-BRANES AND THEIR CONSTRUCTION RULES
Authors: OHTA NOBUYOSHI , ZHOU JIAN-GE
Published: September 2003

We present a systematic analysis of possible bound states of M-brane solutions (including waves and monopoles) by using the solution generating technique of reduction fo M-brane to 10 dimensions, use of T-duality and then lifting back to 11 dimensions. We summarize a list of bound states for one- and two-charge cases including tilted brane solutions. Construction rules for these nonmarginal solutions are also discussed.
ORBITS OF EXCEPTIONAL GROUPS, DUALITY AND BPS STATES IN STRING THEORY
Authors: FERRARA SERGIO , GÜNAYDIN MURAT
Published: September 2003

We give an invariant classification of orbits of the fundamental representations of the exceptional groups E7(7) and E6(6) which classify BPS states in string and M theories toroidally compactified to d=4 and 5. The exceptional Jordan algebra and the exceptional Freudenthal triple system and their cubic and quartic invariants play a major role in this classification. The cubic and quartic invariants correspond to the black hole entropy in d=5 and d=4, respectively. The classification of BPS states preserving different numbers of supersymmetries is in close parallel to the classification of the little groups and the orbits of timelike, lightlike and spacelike vectors in Minkowski space. The orbits of BPS black holes in N=2 Maxwell–Einstein supergravity theories in d=4 and d=5 with symmetric space geometries are also classified including the exceptional N=2 theory, which has E7(-25) and E6(-26) as its symmetry in the respective dimensions.
ON THE REDUCED SU(N) GAUGE THEORY IN THE WEYL–WIGNER–MOYAL FORMALISM
Authors: GARCÍA-COMPEÁN HUGO , PLEBANSKI JERZY F. , QUIROZ-PÉREZ NORMA
Published: September 2003

Weyl–Wigner–Moyal formalism is used to describe the large N limit of reduced SU(N) quenching gauge theory. Moyal deformation of Schild–Eguchi action is obtained.
THERMAL PARTICLE CREATION IN A GENERAL CLASS OF COSMOLOGICAL SPACE–TIMES
Authors: MERSINI L.
Published: September 2003

A potential function depicting a general class of cosmological space–times containing three free parameters is used to analyze thermal particle creation. We investigate how sensitive the production rate depends on (1) the rise in the exponential expansion at early times; (2) the drop in the barrier at late times; and (3) near-thermal characteristics. This detailed calculation confirms the assertion by Parker that the crucial factor for thermal radiance is due to an exponential expansion and by Hu that near-thermal radiance can be characterized by the departure from exponential scaling.
e-e-97: A PROGRESS REPORT ON THE ELECTRON-ELECTRON COLLIDER FRONT
Authors: HEUSCH CLEMENS A.
Published: September 2003

Based on the easy availability of highly polarized electron beams, we revisit the need for an early realization of a TeV electron-electron collider. Most EWSB searches can be performed in unique ways at this facility, and the tunable "exotic" quantum numbers of the e-e- initial states can be used as powerful probes for a vairety of forays beyond the Standard Model. There are no accelerator. interaction region, or detector issues that would not compatibly function in the e+e- and e-e- configurations.
PARITY VIOLATING ASYMMETRIES AT FUTURE LEPTON COLLIDERS
Authors: CZARNECKI ANDRZEJ , MARCIANO WILLIAM J.
Published: September 2003

Parity violating left–right scattering asymmetries at future high energy e+e- and e-e- colliders are examined. The utility of two polarized beams for precision measurements is pointed out. Sensitivity to "new" short–distance physics is briefly discussed. Electroweak radiative corrections due to the running of sin 2θW·(q2) are exhibited.
Z′ INVESTIGATIONS AT FUTURE LEPTON COLLIDERS
Authors: RIZZO THOMAS G.
Published: September 2003

In this talk I summarize the capability of future lepton colliders to indirectly discover a new Z′ and to determine its couplings to the fermions of the Standard Model. The physics associated with sitting on the Z′-pole is also briefly discussed. This analysis is based on the results presented in the Snowmass 1996 New Gauge Boson Working Group report.
PROBING EXOTIC HIGGS SECTORS IN ℓ-ℓ- COLLISIONS
Authors: GUNION JOHN F.
Published: September 2003

I review extended Higgs sectors and constraints thereon arising from ρ=1, gauge-coupling unification and b→sγ. The couplings and decays of the Higgs boson eigen-states are outlined for triplet representations. Direct experimental probes of exotic Higgs bosons are reviewed with a focus on the important role that would be played by an e-e- or μ-μ- collider.
SYSTEMATICS OF SLEPTON PRODUCTION IN e+e- and e-e- COLLISIONS
Authors: PESKIN MICHAEL E.
Published: September 2003

I present the basic formulae for slepton production in e+e- and e-e- collisions in an especially simple form, using a helicity basis. This parametrization introduces the useful neutralino functions to connect the neutralino eigenstates to observable cross sections.
CP-ODD PHASES IN SLEPTON PAIR PRODUCTION
Authors: THOMAS SCOTT
Published: September 2003

The effect of CP-odd supersymmetric phases on slepton pair production are considered. It is shown that CP-even observables in e+e- and e-e- collisions, such as the total selectron cross section, can depend on CP-odd supersymmetric phases through interference between different tree level amplitudes. Left handed selectron pair production in e-e- collisions is particularly sensitive to the relative phase between the bino and wino masses. This sensitivity is not limited to any kinematic regime and extends over all of neutralino parameter space. The relative phase between the bino and wino masses is a renormalization group invariant at one-loop, and therefore provides a clean probe for operators which violate gaugino universality at the messenger scale.
SUPERSYMMETRY AT LINEAR COLLIDERS: THE IMPORTANCE OF BEING e-e-
Authors: FENG JONATHAN L.
Published: September 2003

Advantages of the e-e- option at linear colliders for the study of supersymmetry are highlighted. The fermion number violating process [Formula: see text] provides unique opportunities for studies of slepton masses and flavor mixings. In particular, slepton mass measurements at the 100 MeV level through threshold scans of scalar pair production may be possible. Such measurements are over an order of magnitude better than those possible in e+e- mode, require far less integrated luminosity, and may lead to precise, model-independent measurements of tan β. Implications for studying gauginos and the importance of accurate beam polarimetry are also discussed.
HEAVY MAJORANA NEUTRINOS IN e-e- COLLISIONS
Authors: GREUB CHRISTOPH , MINKOWSKI PETER
Published: September 2003

We discuss the process e-e-→W-W- mediated by heavy Majorana neutrino exchange in the t- and u channel. In our model the cross section for this reaction is a function of the masses (mN) of the heavy Majorana neutrinos and mixing parameters (UeN) originating from mixing between the ordinary left-handed standard model neutrinos and additional singlet right-handed neutrino fields. Taking into account the standard model background and constraints from low energy measurements, we present discovery limits in the [Formula: see text] plane. We also discuss how to measure in principle the CP violating phases, i.e., the relative phases between the mixing parameters.
PHYSICS GOALS AND PARAMETERS OF PHOTON COLLIDERS
Authors: TELNOV VALERY
Published: September 2003

Linear colliders offer a unique possibility to study γγ and γe interactions at the energies 0.1–2 TeV. This option is now included in design reports of NLC, JLC and TESLA/SBLC. This paper includes: status of photon colliders, new possibilities in study of Higgs boson, ways to achieve high luminosities.
ELECTRON-ELECTRON LUMINOSITY IN THE NEXT LINEAR COLLIDER—A PRELIMINARY STUDY
Authors: ZIMMERMANN F. , THOMPSON K. A. , HELM R. H.
Published: September 2003

In this paper, we discuss some operational aspects of electron-electron collisions at the Next Linear Collider (NLC) and estimate the luminosity attainable in such a machine. We also consider the use of two future technologies which could simplify the operation and improve the luminosity in an e-e- collider: polarized rf guns and plasma lenses.
BACKGROUNDS AT AN e-e- LINEAR COLLIDER
Authors: MARKIEWICZ T. W. , MARUYAMA T.
Published: September 2003

Background sources at a 1 TeV Linear Collider are discussed along with ideas on how to limit their effect on the detector. With modest shielding and an adequate solenoidal field, we find that detector backgrounds are minimal and that the experimental environment should be similar to that which one normally associates with e+e- colliders.
COMPTON POLARIMETRY AT A 1 TEV LINEAR COLLIDER
Authors: WOODS M.
Published: September 2003

An electron beam polarization of 80% or greater will be a key feature of a 1 TeV Linear Collider. Accurate measurements of the beam polarization will therefore be needed. We discuss design considerations and capabilities for a Compton-scattering polarimeter located in the extraction line from the Interaction Point. Polarization measurements with 1% accuracy taken parasitic to collision data look feasible, but detailed simulations are needed. Polarimeter design issues are similar for both electron-positron and electron-electron collider modes, though beam disruption creates more difficulties for the electron-electron mode.
FINAL-FOCUS SYSTEM AND COLLISION SCHEMES FOR A 5-TeV W-BAND LINEAR COLLIDER
Authors: ZIMMERMANN F. , WHITTUM D. H.
Published: September 2003

A 3-km long high-gradient W-band switched matrix linac may, in parallel channels, accelerate multiple electron and positron bunches to an energy of 2.5 TeV, with a tight control on the intra-bunch energy spread. In this report, we describe a final-focus system for such an accelerator, whose length is restrained by eliminating chromatic correction. The interaction point (IP) spot size is limited by synchrotron radiation in the last quadrupole (Oide effect). The energy loss due to beamstrahlung is optionally suppressed by combining bunches of opposite charge and colliding the neutral beams. We present two different high-luminosity multiple-collision schemes, which can provide a luminosity of up to 1035 cm -2 s -1, with only about 1 MW average beam power. In the first scheme, batches of equally-charged bunches are combined into superbunches which, possibly after charge compensation, are collided head-on with the opposing beam. In the second scheme, 25 charge-neutral electron-positron bunch pairs of one beam are each collided with 25 neutral bunch pairs of the other beam. These multiplexed collisions are facilitated by a crossing angle and by crab cavities upstream of the electron-positron combiner; however they also require focusing channels (e.g., a crystal) preserving IP beam size between the collision points, a difficult if not impossible construct. We describe the challenges posed by each approach.
THE UNIVERSE OF FLUCTUATIONS
Authors: SIDHARTH B. G.
Published: September 2003

We discuss the recent model of a Quantum Mechanical Black Hole (QMBH) which describes the most fundamental known particles, the leptons and approximately the quarks in terms of the Kerr–Newman Black Hole with a naked singularity shielded by Zitterbewegung effects. This goes beyond the Zitterbewegung and self interaction models of Barut and Bracken, Hestenes, Chacko and others and provides a unified picture which amongst other things gives a rationale for and an insight into:

(1) The apparently inexplicable reason why complex space–time transformations lead to the Kerr–Newman metric in General Relativity.

(2) The value of the fine structure constant.

(3) The ratio between electromagnetic and gravitational interaction strengths.

(4) The anomalous gyromagnetic ratio for the electron.

(5) Why the neutrino is left-handed.

(6) Why the charge is discrete.

In the spirit of Effective Field Theories, this model provides an alternative formalism for Quantum Theory and also for its combination with General Relativity.

Finally a mechanism for the formation of these QMBH or particles is explored within the framework of Stochastic Electrodynamics, QED and Quantum Statistical Mechanics. The cosmological implications are then examined. It turns out that a surprisingly large number of facts, including some which were hitherto inexplicable. follow as a consequence of the model. These include a theoretical deduction of the Mass, Radius and Age of the Universe, also the values of Hubble's constant and the Cosmological constant.
AN ACCURATE EXPONENTIALLY FITTED EXPLICIT FOUR-STEP METHOD FOR THE NUMERICAL SOLUTION OF THE RADIAL SCHRÖDINGER EQUATION
Authors: SIMOS T. E.
Published: September 2003

We present here an accurate exponentially fitted explicit four-step method for the numerical integration of the one-dimensional Schrödinger equation. The formula considered contains free parameters which are defined in order to integrate exponential functions. We note that this is the first explicit four-step exponentially fitted method in the literature. Numerical results also indicate that the new method is much more accurate than other well-known methods.
NONLOCAL EXTENDED CONFORMAL ALGEBRAS ASSOCIATED WITH MULTICONSTRAINT KP HIERARCHY AND THEIR FREE FIELD REALIZATIONS
Authors: SHAW JIIN-CHANG , TU MING-HSIEN
Published: September 2003

We study the conformal properties of the multiconstraint KP hierarchy and its non-standard partner by covariantizing their corresponding Lax operators. The associated second Hamiltonian structures turn out to be nonlocal extensions of Wn algebra by some integer or half-integer spin fields depending on the order of the Lax operators. In particular, we show that the complicated second Hamiltonian structure of the nonstandard multiconstraint KP hierarchy can be simplified by factorizing its Lax operator to multiplication form. We then diagonalize this simplified Poisson matrix and obtain the free field realizations of its associated nonlocal algebras.
FRACTIONAL-SPIN INTEGRALS OF MOTION FOR THE BOUNDARY SINE–GORDON MODEL AT THE FREE FERMION POINT
Authors: MEZINCESCU LUCA , NEPOMECHIE RAFAEL I.
Published: September 2003

We construct integrals of motion (IM) for the sine–Gordon model with boundary at the free fermion (β2=4π) which correctly determine the boundary S matrix. The algebra of these IM ("boundary quantum group" at q=1) is a one-parameter family of infinite-dimensional subalgebras of twisted [Formula: see text]. We also propose the structure of the fractional-spin IM away from the free fermion point (β2≠4π).
NEUTRINO CLOUDS
Authors: STEPHENSON G. J. , GOLDMAN T. , MCKELLAR B. H. J.
Published: September 2003

We consider the possibility that neutrinos (but no other light fermions) are coupled very weakly to an extremely light scalar boson. We first analyze the simple problem of one generation of neutrino and show that, for ranges of parameters that are allowed by existing data, such a system can have serious consequences for the evolution of stars and could impact precision laboratory measurements. We discuss the extension to more generations and show that the general conclusion remains viable. Finally, we note that, should such a scalar field be present, experiments give information about effective masses, not the masses that arise in unified field theories.
DERIVATION OF QUANTUM THEORIES: SYMMETRIES AND THE EXACT SOLUTION OF THE DERIVED SYSTEM
Authors: KHORRAMI M. , AGHAMOHAMMADI A. , ALIMOHAMMADI M.
Published: September 2003

Based on the technique of derivation of a theory, presented in out recent paper,1 we investigated the properties of the derived quantum system. We show that the derived quantum system possesses the (nonanomalous) symmetries of the original one, and prove that the exact Green functions of the derived theory are expressed in terms of the semiclassically approximated Green functions of the original theory.
ε-EXPANSION IN QUANTUM FIELD THEORY IN CURVED SPACE–TIME
Authors: BREVIK IVER H. , OCAMPO HERNÁN , ODINTSOV SERGEI
Published: September 2003

We discuss ε-expansion in curved space–time for asymptotically free and asymptotically nonfree theories. The existence of stable and unstable fixed points is investigated for fϕ4 theory and SU(2) gauge theory. It is shown that ε-expansion maybe compatible with aysmptotic freedom on special solutions of the RG equations in a special ase (supersymmetric theory). Using ε-expansion RG technique, the effective Lagrangian for covariantly constant gauge SU(2) field and effective potential for gauged NJL model are found in (4-ε)-dimensional curved space (in linear curvature approximation). The curvature-induced phase transitions from symmetric phase to asymmetric phase (chromomagnetic vacuum and chiral symmetry broken phase, respectively) are discussed for the above two models.
DYNAMICAL SUPERSYMMETRY BREAKING — WHY AND HOW
Authors: POPPITZ ERICH
Published: September 2003

This theoretical review is intended to give nontheorists a flavor of the ideas driving the current efforts to experimentally find supersymmetry. We discuss the main reasons behind the expectation that supersymmetry may be "just around the corner" and may be discovered in the near future. We use simple quantum-mechanical examples to illustrate the concept — and the power — of supersymmetry, the possible ways to break supersymmetry, and the dynamical generation of small scales. We then describe how this theoretical machinery helps shape our perception of what physics beyond the electroweak scale might be.
QUESTION ON D=26: STRING THEORY VERSUS QUANTUM GRAVITY
Authors: ABE MITSUO , NAKANISHI NOBORU
Published: September 2003

In the covariant-gauge two-dimensional quantum gravity, various derivations of the critical dimension D=26 of the bosonic string are critically reviewed, and their interrelations are clarified. It is shown that the string theory is not identical with the proper framework of the two-dimensional quantum gravity, but the former should be regarded as a particular aspect of the latter. The appearance of various anomalies is shown to be explainable in terms of a new type of anomaly in a unified way.
GENERALIZED BRST QUANTIZATION AND MASSIVE VECTOR FIELDS
Authors: MARNELIUS ROBERT , SOGAMI IKUO S.
Published: September 2003

A previously proposed generalized BRST quantization on inner product spaces for second class constraints is further developed through applications. This BRST method involves a conserved generalized BRST charge Q which is not nilpotent, Q2≠0, but which satisfies Q=δ+δ†, δ2=0, and by means of which physical states are obtained from the projection δ| ph >=δ†| ph >=0. A simple model is analyzed in detail from which some basic properties and necessary ingredients are extracted. The method is then applied to a massive vector field. An effective theory is derived which is close to that of the Stückelberg model. However, since the scalar field here is introduced in order to have inner product solutions, a massive Yang–Mills theory with polynomial interaction terms might be possible to cosntruct.
SEIBERG–WITTEN THEORY OF RANK TWO GAUGE GROUPS AND HYPERGEOMETRIC SERIES
Authors: MASUDA TAKAHIRO , SASAKI TORU , SUZUKI HISAO
Published: September 2003

In SU(2) Seiberg–Witten theory, it is known that the dual pair of fields are expressed by hypergeometric functions. As for the theory with SU(3) gauge symmetry without matters, it was shown that the dual pairs of fields can be expressed by means of the Appell function of type F4. These expressions are convenient for analyzing analytic properties of fields. We investigate the relation between the Seiberg–Witten theory of rank two gauge group without matters and hypergeometric series of two variables. It is shown that the relation between gauge theories and Appell functions can be observed for other classical gauge groups of rank two. For B2 and C2, the fields are written in terms of Appell functions of type H5. For D2, we can express fields by Appell functions of type F4 which can be decomposed to two hypergeometric functions, corresponding to the fact SO (4)~ SU (2)× SU (2). We also consider the integrable curve of type C2 and show how the fields are expressed by Appell functions. However in the case of exceptional group G2, our examination shows that they can be represented by the hypergeometric series which does not correspond to the Appell functions.
CAUSAL ANOMALIES IN KALUZA–KLEIN GRAVITY THEORIES
Authors: REBOUÇAS M. J. , TEIXEIRA A. F. F.
Published: September 2003

Causal anomalies in two Kaluza–Klein gravity theories are examined, particularly as to whether these theories permit solutions in which the causality principle is violated. It is found that similarly to general relativity the field equations of the space–time–mass Kaluza–Klein (STM-KK) gravity theory do not exclude violation of causality of Gödel type, whereas the induced matter Kaluza–Klein (IM-KK) gravity rules out noncausal Gödel-type models. The induced matter version of general relativity is shown to be an efficient therapy for causal anomalies that occurs in a wide class of noncausal geometries. Perfect fluid and dust Gödel-type solutions of the STM-KK field equations are studied. It is shown that every Gödel-type perfect fluid solution is isometric to the unique dust solution of the STM-KK field equations. The question as to whether 5D Gödel-type noncausal geometries induce any physically acceptable 4D energy–momentum tensor is also addressed.
DIFFERENTIAL CALCULUS ON FUZZY SPHERE AND SCALAR FIELD
Authors: CAROW-WATAMURA URSULA , WATAMURA SATOSHI
Published: September 2003

We find that there is an alternative possibility to define the chirality operator on the fuzzy sphere, due to the ambiguity of the operator ordering. Adopting this new chirality operator and the corresponding Dirac operator, we define Connes' spectral triple on the fuzzy sphere and the differential calculus. The differential calculus based on this new spectral triple is simplified considerably. Using this formulation the action of the scalar field is derived.
EXOTIC REPRESENTATIONS OF THE ISOTROPIC HARMONIC OSCILLATOR
Authors: BOYA LUIS J. , CHISOLM ERIC , MAHAJAN S. M. , SUDARSHAN E. C. G.
Published: September 2003

We contruct and study a continuous family of representations of the N-dimensional isotropic harmonic oscillator (N≥2) which are not unitarily equivalent to the standard one. We explain why such representations exist and we investigate their simpler properties: the spectrum of the Hamiltonian (which contains nonstandard values), the form of the energy eigenfunctions, and their behavior under the ladder operators. Various symmetry and dynamical groups (e.g. the rotation group) which are valid on the standard representation are not implemented on the new ones. We comment very briefly on the prospects of observing these representations experimentally.
STRUCTURE FUNCTIONS OF THE NUCLEON AND THEIR INTERPRETATION
Authors: COOPER-SARKAR A. M. , DEVENISH R. C. E. , DE ROECK A.
Published: September 2003

The current status of measurements of the nucleon structure functions and their understanding is reviewed. The fixed target experiments E665, CCFR and NMC and the HERA experiments H1 and ZEUS are discussed in some detail. The extraction of parton momentum distribution functions from global fits is described, with particular attention paid to much improved information on the gluon momentum distribution. The status of αsmeasurements from deep inelastic data is reviewed. Models and nonperturbative approaches for the parton input distributions are outlined. The impact on the phenomenology of QCD of the data at very low values of the Bjorken x variable is discussed in detail. Recent advances in the understanding of the transition from deep inelastic scattering to photoproduction are summarized. Some brief comments are made on the recent HERA measurements of the ep NC and CC cross-sections at very high Q2.
FIELD THEORY APPROACH TO $K^0-\overline{K^0}$ AND $B^0-\overline{B^0}$ SYSTEMS
Authors: BEUTHE M. , PESTIEAU J. , LÓPEZ CASTRO G.
Published: September 2003

Quantum field theory provides a consistent framework to deal with unstable particles. We present here an approach based on field theory to describe the production and decay of unstable [Formula: see text] and [Formula: see text] mixed systems. The formalism is applied to compute the time evolution amplitudes of K0 and [Formula: see text] studied in DAPHNE and CPLEAR experiments. We also introduce a new set of parameters that describe CP violation in K→ππ decays without recourse to isospin decomposition of the decay amplitudes.
THE NONLINEAR SUPERPOSITION PRINCIPLE AND THE WEI-NORMAN METHOD
Authors: CARIÑENA J. F. , MARMO G. , NASARRE J.
Published: September 2003

Group theoretical methods are used to study some properties of the Riccati equation, which is the only differential equation admitting a nonlinear superposition principle. The Wei–Norman method is applied to obtain the associated differential equation in the group SL(2, ℝ). The superposition principle for first order differential equation systems and Lie–Scheffers theorem are also analyzed from this group theoretical perspective. Finally, the theory is applied in the solution of second order differential equations like time independent Schrödinger equation.
BRST-CO-BRST QUANTIZATION OF REPARAMETRIZATION-INVARIANT THEORIES
Authors: FÜLÖP GÉZA
Published: September 2003

We study some reparametrization-invariant theories in the context of the BRST-co-BRST quantization method. The method imposes restrictions on the possible gauge-fixing conditions and leads to well-defined inner product states through a gauge regularization procedure. Two explicit examples are treated in detail.
QUASITOPOLOGICAL FIELD THEORIES IN TWO DIMENSIONS AS SOLUBLE MODELS
Authors: CARNEIRO DA CUNHA BRUNO G. , TEOTONIO-SOBRINHO PAULO
Published: September 2003

We study a class of lattice field theories in two dimensions that includes Yang–Mills and generalized Yang–Mills theories as particular examples. Given a two-dimensional orientable surface of genus g, the partition function Z is defined for a triangulation consisting of n triangles of size ∊. The reason these models are called quasitopological is that Z depends on g, n and ∊ but not on the details of the triangulation. They are also soluble in the sense that the computation of their partition functions for a two-dimensional lattice can be reduced to a soluble one-dimensional problem. We show that the continuum limit is well defined if the model approaches a topological field theory in the zero area limit, i.e. ∊→0 with finite n. We also show that the universality classes of such quasitopological lattice field theories can be easily classified.
GENERATING ISOSPECTRAL HAMILTONIANS FROM A MODIFIED CRUM–DARBOUX TRANSFORMATION
Authors: BAGCHI B. , GANGULY A.
Published: September 2003

Using supersymmetry as a tool we set up a procedure to generate a sequence of pairwise isospectral potentials from a modified Crum–Darboux transformation. We show that such a transformation gives rise to shifted superpotentials much similar to what we encounter in a modified factorization scheme. We also explore some solvable systems to illustrate the applicability of our scheme.
AN ANALYSIS OF THE REPRESENTATIONS OF THE MAPPING CLASS GROUP OF A MULTIGEON THREE-MANIFOLD
Authors: SORKIN RAFAEL D. , SURYA SUMATI
Published: September 2003

It is known that the distinct unitary irreducible representations (UIR's) of the mapping class group G of a three-manifold ℳ give rise to distinct quantum sectors ("θ sectors") in quantum theories of gravity based on a product space–time of the form ℝ×ℳ. In this paper, we study the UIR's of G in an effort to understand the physical implications of these quantum sectors. The mapping class group of a three-manifold which is the connected sum of ℝ3 with a finite number of irreducible primes is a semidirect product group. Following Mackey's theory of induced representations, we provide an analysis of the structure of the general finite-dimensional UIR of such a group. In the picture of quantized primes as particles (topological geons), this general group-theoretic analysis enables one to draw several qualitative conclusions about the geons' behavior in different quantum sectors, without requiring an explicit knowledge of the UIR's corresponding to the individual primes. An important general result is that the classification of the UIR's of the so-called particle subgroup (equivalently, the UIR's of G in which the slide diffeomorphisms are represented trivially) is reduced to the problem of finding the UIR's of the internal diffeomorphism groups of the individual primes. Moreover, this reduction is entirely consistent with the geon picture, in which the UIR of the internal group of a prime determines the species of the corresponding quantum geon, and the remaining freedom in the overall UIR of G expresses the possibility of choosing an arbitrary statistics (Bose, Fermi or para) for the geons of each species. For UIR's which represent the slides nontrivially, we do not provide a complete classification, but we find some new types of efforts due to the slides, including quantum breaking of internal symmetry and of particle indistinguishability. In connection with the latter, a novel kind of statistics arises which is determined by representations of proper subgroups of the permutation group, rather than of the group as a whole. Finally, we observe that for a generic three-manifold there will be an infinity of inequivalent UIR's and hence an infinity of "consistent" theories, when topology change is neglected.
GRAVITATIONAL COUPLING FUNCTION IN SCALAR–TENSOR THEORIES
Authors: MODAK B. , KAMILYA S.
Published: September 2003

We present the gravitational coupling function ω(φ) in scalar tensor gravity theories as allowed by the Nöther symmetry. Some exact cosmological solutions have been presented in the scalar tensor gravity theories including cosmological constant using the above coupling function ω(φ) in the spatially flat homogeneous and isotropic background. The solutions are exponentially expanding in the asymptotic region and these inflationary solutions has the so-called graceful exit problem.
STATUS AND PERSPECTIVES OF DOUBLE BETA DECAY — WINDOW TO NEW PHYSICS BEYOND THE STANDARD MODEL OF PARTICLE PHYSICS
Authors: KLAPDOR-KLEINGROTHAUS H. V.
Published: September 2003

Nuclear double beta decay provides an extraordinarily broad potential to search for beyond Standard Model physics, probing already now the TeV scale, on which new physics should manifest itself. These possibilities are reviewed here.

First, the results of present generation experiments are presented. The most sensitive one of them — the Heidelberg–Moscow experiment in the Gran Sasso — probes the electron mass now in the sub eV region and will reach a limit of ~ 0.1 eV in a few years. Basing to a large extent on the theoretical work of the Heidelberg Double Beta Group in the last two years, results are obtained also for SUSY models (R-parity breaking, sneutrino mass), leptoquarks (leptoquark–Higgs coupling), compositeness, right-handed W boson mass and others. These results are comfortably competitive to corresponding results from high-energy accelerators like TEVATRON, HERA, etc.

Second, future perspectives of ββ research are discussed. A new Heidelberg experimental proposal (GENIUS) is presented which would allow one to increase the sensitivity for Majorana neutrino masses from the present level of at best 0.1 eV down to 0.01 or even 0.001 eV. Its physical potential would be a breakthrough into the multi-TeV range for many beyond standard models. Its sensitivity for neutrino oscillation parameters would be higher than that for all present terrestrial neutrino oscillation experiments and of those planned for the future. It could probe directly the atmospheric neutrino problem and even the large angle solution of the solar neutrino problem. It would further, already in a first step, using only 100 kg of natural Ge detectors, cover almost the full MSSM parameter space for prediction of neutralinos as cold dark matter, making the experiment competitive to LHC in the search for supersymmetry.
A SPECTROMETER TO STUDY ELASTIC AND DIFFRACTIVE PHYSICS AT LHC
Authors: ARNEODO M. , MASELLI S. , PERONI C.
Published: September 2003

The possibility to study elastic and diffractive physics in pp collisions at LHC is discussed. For this purpose we have considered detectors close to the beam in conjunction with the magnetic elements of the accelerator to provide a high precision spectrometer for very forward final state protons. The geometrical acceptance is given and the momentum resolution is calculated for different spatial resolution detectors.
2 + 1 EINSTEIN GRAVITY AS A DEFORMED CHERN-SIMONS THEORY
Authors: BIMONTE G. , MUSTO R. , VITALE P. , STERN A.
Published: September 2003

The usual description of (2+1)-dimensional Einstein gravity as a Chern–Simons (CS) theory is extended to a one parameter family of descriptions of 2+1 Einstein gravity. This is done by replacing the Poincaré gauge group symmetry by a q-deformed Poincaré gauge group symmetry, with the former symmetry recovered when q → 1. As a result, we obtain a one parameter family of Hamiltonian formulations for 2+1 gravity. Although formulated in terms of noncommuting dreibeins and spin-connection fields, our expression for the action and our field equations, appropriately ordered, are identical in form to the ordinary ones. Moreover, starting with a properly defined metric tensor, the usual metric theory can be built; the Christoffel symbols and space–time curvature having the usual expressions in terms of the metric tensor, and being represented by c-numbers. In this article, we also couple the theory to particle sources, and find that these sources carry exotic angular momentum. Finally, problems related to the introduction of a cosmological constant are discussed.