Gravity of monopole and string and the gravitational constant in 3He-A

We discuss the effective metric produced in superfluid ³He-A by such topological objects as the radial disgyration and monopole. In relativistic theories these metrics are similar to that of the local string and global monopole, respectively. But in ³He-A they have a negative angle deficit, which corresponds to a negative mass of the topological objects. The effective gravitational constant in superfluid ³He-A, deduced from a comparison with relativistic theories, is G∼Δ⁻², where the gap amplitude Δ plays the part of the Planck energy. G depends on temperature roughly as (1−T ²/T _c ² )⁻² and corresponds to a screening of Newton’s constant. Pis’ma Zh. éksp. Teor. Fiz. 67, No. 9, 666–671 (10 May 1998) Published in English in the original Russian journal. Edited by Steve Torstveit.     

On the left-right asymmetry of the angular distribution of α particles from ternary nuclear fission by polarized neutrons

Some experimental possibilities of establishing the nature of the recently observed T-odd angular correlation in ternary fission of ²³³U by polarized neutrons are discussed. Specifically, investigation of the neutron energy dependence of the correlation coefficient in the ternary fission of ²³⁹Pu and ²³⁵U could shed light on the problem under discussion. Pis’ma Zh. éksp. Teor. Fiz. 70, No. 9, 561–564 (10 November 1999)     

Tests of CPT invariance for neutral flavored meson-antimeson mixing

We focus on two aspects of CPT invariance in neutral meson-antimeson () mixing: (1) tests of CPT invariance, using only the property of ”lack of vacuum regeneration”, which occurs as a part of the well-known Lee-Oehme-Yang (LOY) theory; (2) methods for extracting the CPT-violating mixing parameter through explicit calculations by fully using the LOY-type theory. In the latter context, we demonstrate the importance of the C-even state. In particular, by measuring the time dependence of opposite-sign dilepton events arising from decays of the C-even and C-odd states, may be disentangled from the parameters and characterizing violations of the rule. Furthermore, these two parameters may also be determined. The same is true if one uses like-sign dilepton events arising from only the C-even state. Received: 5 August 2002 / Published online: 25 October 2002 RID="a" ID="a" e-mail: guruv@phy.iitb.ac.in RID="b" ID="b" e-mail: grimus@thp.univie.ac.at     

Higgs production: CP studies in e^-e^- collisions

We review the production of scalar Higgs-like particles in high-energy electron–electron collisions, via the fusion of electroweak gauge bosons. The emphasis is on how to distinguish a CP-even from a CP-odd Higgs particle. Among the more significant differences, we find that in the CP-odd case, the Higgs spectrum is much harder, and the dependence of the total cross section on the product of the polarizations of the two beams much stronger, than in the CP-even case. We also briefly discuss parity violation, and the production of charged Higgs bosons. Received: 1 December 1998 / Revised version: 15 February 1999 / Published online: 18 June 1999     

Cosmological constant: a lesson from the effective gravity of topological weyl media

Topological matter with Weyl points, such as superfluid ³He-A, provide an explicit example where there is a direct connection between the properly determined vacuum energy and the cosmological constant of the effective gravity emerging in condensed matter. This is in contrast to the acoustic gravity emerging in Bose-Einstein condensates (S. Finazzi, S. Liberati, and L. Sindoni, Phys. Rev. Lett. 108, 071101 (2012); arXiv:1103.4841). The advantage of topological matter is that the relativistic fermions and gauge bosons emerging near the Weyl point obey the same effective metric and thus the effective gravity is more closely related to real gravity. We study this connection in the bi-metric gravity emerging in ³He-A, and its relation to the graviton masses, by comparison with a fully relativistic bi-metric theory of gravity. This shows that the parameter ??, which in ³He-A is the bi-metric generalization of the cosmological constant, coincides with the difference in the proper energy of the vacuum in two states (the nonequilibrium state without gravity and the equilibrium state in which gravity emerges) and is on the order of the characteristic Planck energy scale of the system. Although the cosmological constant ?? is huge, the cosmological term T _??? ^?? itself is naturally non-constant and vanishes in the equilibrium vacuum, as dictated by thermodynamics. This suggests that the equilibrium state of any system including the final state of the Universe is not gravitating.     

T-Odd correlation in K+ → π0l+νγ decays beyond the standard model

The T-odd correlation in the decays K ⁺ → π ⁰ l ⁺ νγ (l = e, μ) is investigated as a function of the parameters of the effective Lagrangian. It is shown that the T-odd correlation offers a good indicator of new physics in the vector and pseudovector sectors of the model under consideration. In the scalar and pseudoscalar sectors, investigation of the T-odd correlation gives no way to improve the current limits on the parameters of various extensions of the Standard Model. __________ Translated from Yadernaya Fizika, Vol. 67, No. 5, 2004, pp. 1025–1032. Original Russian Text Copyright ? 2004 by Braguta, Likhoded, Chalov.     

Generalized Canonical Ward Identities

In the framework of Faddeev-Senjanovic (FS) path-integral quantization, CP ¹ nonlinear σ model coupled to Non-Abelian Chern-Simons (CS) fields is quantized. Generalized canonical Ward identities (WI) are deduced from the invariance of the canonical effective action under gauge transformations, which are obtained from the generators of gauge transformations, including all first-class constraints, in Dirac’s sense. The generalized canonical WI has brief form and is equivalent to canonical WI under gauge transformations in Dirac’s sense. This project is supported by Foundation of National Natural Science (10671086), Foundation of Shandong Natural Science (Y2007A01) and National Laboratory for Superlattices and Microstructures (CHJG200605).     

CP-odd WWZ couplings induced by vector-like quarks

A minimal extension of the standard model includes extra quarks with charges 2/3 and/or , whose left-handed and right-handed components are both SU(2) singlets. This model predicts new interactions of the flavor-changing neutral current at the tree level, which also violate CP invariance. We study CP-odd anomalous couplings for the W, W, and Z gauge bosons induced by the new interactions at the one-loop level. These couplings become non-negligible only if both up-type and down-type extra quarks are incorporated. Their form factors are estimated to be maximally of order . Such magnitudes are larger than those predicted in the standard model, though smaller than those in certain other models. Received: 26 February 1999 / Published oinline: 12 August 1999     

On the effective lagrangian in spinor electrodynamics with added violation of Lorentz and <Emphasis Type="Italic">CPT</Emphasis>-symmetries

We consider quantum electrodynamics with additional coupling of spinor fields to the space-time independent axial vector violating both Lorentz and CPT-symmetries. The Fock-Schwinger proper-time method is used to calculate the one-loop effective action up to the second order in the axial vector and to all orders in the space-time independent electromagnetic field strength. We find that the Chern-Simons term is not radiatively induced and that the effective action is CPT-invariant in the given approximation. Received: 29 January 2003 / Published online: 24 March 2003 RID="a" ID="a" e-mail: sitenko@itp.unibe.ch RID="b" ID="b" e-mail: rulik@to.infn.it     

Abelian dyons in the maximal Abelian projection of SU(2) gluodynamics

Correlations of the topological charge Q, the electric current J ^e, and the magnetic current J ^m in SU(2) lattice gauge theory in the maximal Abelian projection are investigated. It is found that the correlator 〈〈QJ ^eJ^m〉〉 is nonzero for a wide range of values of the bare charge. It is shown that: (i) the Abelian monopoles in the maximal Abelian projection are dyons which carry fluctuating electric charge; (ii) the sign of the electric charge e(x) coincides with that of the product of the monopole charge m(x) and the topological charge density Q(x). Pis’ma Zh. éksp. Teor. Fiz. 69, No. 3, 161–165 (10 February 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.     

New version of the integrated method for measuring small effects in experiments on beams extracted from a nuclear reactor at the effect sign switching frequency above the fundamental frequencies of the reactor power fluctuation spectrum

The principles of construction and the results of testing of a system for measuring P-odd asymmetries in nuclear reactions with polarized cold neutrons by the integrated method of recording events at the neutron polarization switching frequency above the fundamental frequencies of the reactor power fluctuation spectrum are presented. It is shown experimentally that if the signal under investigation is characterized by the spectral density of power decreasing with increasing frequency, switching of the equipment at a higher frequency decreases the measuring error. The dependence of the error of measurements of P-odd asymmetry in the emission of γ quanta in the ¹⁰B(n, α)⁷Li* ⟹ γ ⟹ ⁷Li(g.s.) reaction on the neutron polarization switching frequency is derived. The system described here is implemented experimentally for the first time.     

<Emphasis Type="Italic">CPT</Emphasis> Symmetry and Quantum Mechanics Tests in the Neutral Kaon System at KLOE

The neutral kaon system offers a unique possibility to perform fundamental tests of CPT invariance, as well as of the basic principles of quantum mechanics. The most recent limits obtained by the KLOE experiment at the DAΦNE e ⁺ e ⁻ collider on several kinds of possible CPT violation and decoherence mechanisms, which in some cases might be justified in a quantum gravity framework, are reviewed. No deviation from the expectations of quantum mechanics and CPT symmetry is observed, while the precision of the measurements, in some cases, reaches the interesting Planck scale region. Finally, prospects for this kind of experimental studies at KLOE-2 are presented.     

Test of CPT symmetry in cascade decays

Cascade mixing provides an place for elegant study of – mixing. We use this idea to study the CPT violation caused by – mixing. An approximation method is adopted to treat the two complex – mixing parameters and . A procedure to extract the parameters and is suggested. The feasibility of exploring CPT violation and determining and in the future B-factories and LHC-B is discussed. Received: 14 July 1999 / Revised version: 12 February 2000 / Published online: 14 April 2000     

Effect of an electric field on the surface tension of a liquid at low temperatures

An external electric field changes the dispersion law of waves on the surface of a liquid. Besides the usual capillary term (∝k ³, k is the wave number) and gravitational term (∝k), a term quadratic in the wave vector appears in the expression for the square of the frequency in a homogeneous field. These excitations are associated with the variation of the coefficient of surface tension of the liquid at low temperatures. In the case of a large field tangent to the surface, the correction is proportional to T ^8/3, unlike the T ^7/3 correction in the absence of a field. Zh. éksp. Teor. Fiz. 111, 1369–1372 (April 1997)     

Metal-insulator crossover in high T c cuprates: A gauge field approach

A metal-insulator crossover appears in the experimental data for in-plane resistivity of underdoped cuprates and a range of superconducting cuprates in the presence of a strong magnetic field suppressing superconductivity. We propose an explanation for this phenomenon based on a gauge field theory approach to the t-J model. In this approach, based on a formal spin-charge separation, the low energy effective action describes gapful spinons (with a theoretically derived doping dependence of the gap m _s ² ∼ δ| ln δ|) and holons with finite Fermi surface (ɛF ∼ tδ) interacting via a gauge field whose basic effect on the spinons is to bind them into overdamped spin waves, shifting their gap by a damping term linear in T, which causes the metal-insulator crossover. The presence of a magnetic field perpendicular to the plane acts by increasing the damping, in turn producing a big positive transverse in-plane magnetoresistance at low T, as experimentally observed.     

QED effective action in a constant electromagnetic field under conditions of possible Lorentz invariance violation in the Dirac equation

This paper is devoted to the calculation of corrections to QED effective action associated with the axial-vector condensate b ^μ, which violate the Lorentz invariance. It was shown that the linear in b ^μ contribution to the 1-loop effective action (Chern-Simons term) is absent in the case of a constant electromagnetic field. The contribution, which is quadratic in b ^μ, was calculated for the cases of both constant magnetic and electric fields. Asymptotic estimates of the quadratic in b ^μ term for strong and weak field strengths were obtained.     

Effective monopole potential for SU(2) lattice gluodynamics in the spatial maximal Abelian gauge

We investigate the dual superconductor hypothesis in finite-temperature SU(2) lattice gluodynamics in the spatial maximal Abelian gauge. This gauge is more physical than the ordinary maximal Abelian gauge due to absence of nonlocalities in the temporal direction. We show numerically that in the spatial maximal Abelian gauge the probability distribution of the Abelian monopole field is consistent with the dual superconductor mechanism of confinement: the Abelian condensate vanishes in the deconfinement phase and is nonzero in the confinement phase. Pis’ma Zh. éksp. Teor. Fiz. 69, No. 3, 166–170 (10 February 1999) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Renormalization of a gauge theory in a nonlinear gauge

We discuss renormalization of an O(3) gauge model with the gauge fixing term given by ℒ_g.f.=-1/ζ|(∂_μ-igA ₃ ^μ )W ^+μ|²-(1/2α)(∂A ³)². We utilize earlier results on the general theory of renormalization of gauge theories in quadratic gauges to prove multiplicative renormalizability of the theory together with a subtractive renormalization of gauge fixing and ghost terms. We show that this model has a double BRS invariance and that it is preserved under renormalization.     

From effective BCS action to vortex dynamics

The topological term in the effective action for the electrically neutral BCS system is discussed. It is applied for the calculation of the transverse force acting on a vortex in the limit of a smooth vortex core and vanishing interlevel distance in the vortex core. The controversy between the topological terms in the articles by I. J. R. Aitchison et al., Phys. Rev. B 51, 6531 (1995) and A. van Otterlo et al., cond-mat/9703124 is resolved. Pis’ma Zh. éksp. Teor. Fiz. 65, No. 8, 641–646 (25 April 1997) Published in English in the original Russian journal. Edited by Steve Torstveit.     

Gauge theory onR×S 3 topology

A model for gauge theories over a compact Lie group is described using R × S³ as background space. The U(1) and SU(2) gauge theories are considered as particular examples, and a comparison with other results is given. Our results differ from those of Carmeli and MalinFound. Phys. 16, 791 (1986);17, 193 (1987)] by a supplementary term in the curvature tensor due to the noncommutativity of derivatives used on R × S³ space. Some observations about supersymmetry and gravity on R × S³ space are also given.