1,931 research outputs found

    Novel Studies on the \eta' Effective Lagrangian

    Full text link
    The effective Lagrangian for \eta' incorporating the effect of the QCD \theta-angle has been developed previously. We revisit this Lagrangian and carry out its canonical quantization with particular attention to the test function spaces of constraints and the topology of the \eta'-field. In this way, we discover a new chirally symmetric coupling of this field to chiral multiplets which involves in particular fermions. This coupling violates P and T symmetries. In a subsequent paper, we will evaluate its contribution to the electric dipole moment (EDM) of fermions. Our motivation is to test whether the use of mixed states restores P and T invariance, so that EDM vanishes. This calculation will be shown to have striking new physical consequences.Comment: 14 pages, 1 figure; V2: NEW TITLE; revised version to be published in JHEP; references adde

    Non-thermal plasma technology for the abatement of NOx and SOx from the exhaust of marine diesel engine

    Get PDF
    Non-thermal plasma based technology is proposed to the abatement of NOx and SOx of the exhaust gas from marine diesel engine. Proposed technology uses electron gun and microwave energy to generate the plasma. Fundamentals of non-thermal plasma and chemistry are presented with a set of simulation results of the reduction of NOx and SO2 for a typical two stoke marine diesel exhaust engine which is supported by an experimental results obtained with microwave plasma. A new scheme is also proposed in this paper to generate required plasma for the treatment of NOx and SOx form high exhaust flow rate

    Dirac operator on the q-deformed Fuzzy sphere and Its spectrum

    Full text link
    The q-deformed fuzzy sphere SqF2(N)S_{qF}^2(N) is the algebra of (N+1)×(N+1)(N+1)\times(N+1) dim. matrices, covariant with respect to the adjoint action of \uq and in the limit q1q\to 1, it reduces to the fuzzy sphere SF2(N)S_{F}^2(N). We construct the Dirac operator on the q-deformed fuzzy sphere-SqF2(N)S_{qF}^{2}(N) using the spinor modules of \uq. We explicitly obtain the zero modes and also calculate the spectrum for this Dirac operator. Using this Dirac operator, we construct the \uq invariant action for the spinor fields on SqF2(N)S_{qF}^{2}(N) which are regularised and have only finite modes. We analyse the spectrum for both qq being root of unity and real, showing interesting features like its novel degeneracy. We also study various limits of the parameter space (q, N) and recover the known spectrum in both fuzzy and commutative sphere.Comment: 19 pages, 6 figures, more references adde

    Novel Edge States in Self-Dual Gravity

    Full text link
    In contrast to the Einstein-Hilbert action, the action for self-dual gravity contains vierbeins. They are eleminated at the level of observables by an SL(2,C)SL(2,\mathbb{C}) gauge condition implied by the action. We argue that despite this condition, new "edge" or superselected state vectors corresponding to maps of the spheres S2S^2_{\infty} at infinity to SL(2,C)SL(2, \mathbb{C}) arise. They are characterised by new quantum numbers and they lead to mixed states. For black holes, they arise both at the horizon and the spatial infinity and may be relevant for the black hole information paradox. Similar comments can be made about the Einstein-Palatini action which uses vierbeins.Comment: 15 pages, reference added, some minor notational changes - no changes in conclusio

    Reduction of NOx and PM in Marine Diesel Engine Exhaust Gas using Microwave Plasma

    Get PDF
    Abatement of NOx and particulate matters (PM) of marine diesel exhaust gas using microwave (MW) non-thermal plasma is presented in this paper. NOx mainly consist of NO and less concentration of NO2 in a typical two stoke marine diesel engine and microwave plasma generation can completely remove NO. MW was generated using two 2kW microwave sources and a saw tooth passive electrode. Passive electrode was used to generate high electric field region within microwave environment where high energetic electrons (1-3eV) are produced for the generation of non-thermal plasma (NTP). 2kW gen-set diesel exhaust gas was used to test our pilot-scale MW plasma reactor. The experimental results show that almost 100% removal of NO is possible for the exhaust gas flow rate of 60l/s. It was also shown that MW can significantly remove soot particles (PM, 10nm to 365nm) entrained in the exhaust gas of 200kW marine diesel engine with 40% engine load and gas flow rate of 130l/s. MW without generating plasma showed reduction up to 50% reduction of PM and with the plasma up to 90% reduction. The major challenge in these experiments was that igniting the desired plasma and sustaining it with passive electrodes for longer period (10s of minutes) as it required fine tuning of electrode position, which was influenced by many factors such as gas flow rate, geometry of reactor and MW power

    Non-Pauli Effects from Noncommutative Spacetimes

    Full text link
    Noncommutative spacetimes lead to nonlocal quantum field theories (qft's) where spin-statistics theorems cannot be proved. For this reason, and also backed by detailed arguments, it has been suggested that they get corrected on such spacetimes leading to small violations of the Pauli principle. In a recent paper \cite{Pauli}, Pauli-forbidden transitions from spacetime noncommutativity were calculated and confronted with experiments. Here we give details of the computation missing from this paper. The latter was based on a spacetime Bχn\mathcal{B}_{\chi\vec{n}} different from the Moyal plane. We argue that it quantizes time in units of χ\chi. Energy is then conserved only mod 2πχ\frac{2\pi}{\chi}. Issues related to superselection rules raised by non-Pauli effects are also discussed in a preliminary manner.Comment: 15 Pages, 1 Table, Full details and further developments of arXiv:1003.2250. This version is close to the one accepted by JHE

    Topology in Physics - A Perspective

    Full text link
    This article, written in honor of Fritz Rohrlich, briefly surveys the role of topology in physics.Comment: 16pp, 2 figures included (encapsulated postscript

    Localization in the Rindler Wedge

    Get PDF
    One of the striking features of QED is that charged particles create a coherent cloud of photons. The resultant coherent state vectors of photons generate a non-trivial representation of the localized algebra of observables that do not support a representation of the Lorentz group: Lorentz symmetry is spontaneously broken. We show in particular that Lorentz boost generators diverge in this representation, a result shown also in [1] (See also [2]). Localization of observables, for example in the Rindler wedge, uses Poincar\'e invariance in an essential way [3]. Hence in the presence of charged fields, the photon observables cannot be localized in the Rindler wedge. These observations may have a bearing on the black hole information loss paradox, as the physics in the exterior of the black hole has points of resemblance to that in the Rindler wedge.Comment: 11 page

    Lehmann-Symanzik-Zimmermann S-Matrix elements on the Moyal Plane

    Full text link
    Field theories on the Groenewold-Moyal(GM) plane are studied using the Lehmann-Symanzik-Zimmermann(LSZ) formalism. The example of real scalar fields is treated in detail. The S-matrix elements in this non-perturbative approach are shown to be equal to the interaction representation S-matrix elements. This is a new non-trivial result: in both cases, the S-operator is independent of the noncommutative deformation parameter θμν\theta_{\mu\nu} and the change in scattering amplitudes due to noncommutativity is just a time delay. This result is verified in two different ways. But the off-shell Green's functions do depend on θμν\theta_{\mu\nu}. In the course of this analysis, unitarity of the non-perturbative S-matrix is proved as well.Comment: 18 pages, minor corrections, To appear in Phys. Rev. D, 201
    corecore