15,625 research outputs found

    Ordinary atom-mirror atom bound states: A new window on the mirror world

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    Mirror symmetry is a plausible candidate for a fundamental symmetry of particle interactions which can be exactly conserved if a set of mirror particles exist. The properties of the mirror particles seem to provide an excellent candidate to explain the inferred dark matter of the Universe and might also be responsible for a variety of other puzzles in particle physics, astrophysics, meteoritics and planetary science. One such puzzle -- the orthopositronium lifetime problem -- can be explained if there is a small kinetic mixing of ordinary and mirror photons. We show that this kinetic mixing implies the existence of ordinary atom - mirror atom bound states with interesting terrestrial and astrophysical implications. We suggest that sensitive mass spectroscopic studies of ordinary samples containing heavy elements such as lead might reveal the presence of these bound states, as they would appear as anomalously heavy elements. In addition to the effects of single mirror atoms, collective effects from embedded fragments of mirror matter (such as mirror iron microparticles) are also possible. We speculate that such mirror matter fragments might explain a mysterious UV photon burst observed coming from a laser irradiated lead target in a recent experiment.Comment: about 8 pages, couple of change

    Quantum Information Paradox: Real or Fictitious?

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    One of the outstanding puzzles of theoretical physics is whether quantum information indeed gets lost in the case of Black Hole (BH) evaporation or accretion. Let us recall that Quantum Mechanics (QM) demands an upper limit on the acceleration of a test particle. On the other hand, it is pointed out here that, if a Schwarzschild BH would exist, the acceleration of the test particle would blow up at the event horizon in violation of QM. Thus the concept of an exact BH is in contradiction of QM and quantum gravity (QG). It is also reminded that the mass of a BH actually appears as an INTEGRATION CONSTANT of Einstein equations. And it has been shown that the value of this integration constant is actually zero. Thus even classically, there cannot be finite mass BHs though zero mass BH is allowed. It has been further shown that during continued gravitational collapse, radiation emanating from the contracting object gets trapped within it by the runaway gravitational field. As a consequence, the contracting body attains a quasi-static state where outward trapped radiation pressure gets balanced by inward gravitational pull and the ideal classical BH state is never formed in a finite proper time. In other words, continued gravitational collapse results in an "Eternally Collapsing Object" which is a ball of hot plasma and which is asymptotically approaching the true BH state with M=0 after radiating away its entire mass energy. And if we include QM, this contraction must halt at a radius suggested by highest QM acceleration. In any case no EH is ever formed and in reality, there is no quantum information paradox.Comment: 8 pages in Pramana Style, 6 in Revtex styl

    On arbitrary-level IIR and FIR filters

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    A recently published method for designing IIR (infinite-impulse-response) digital filters with multilevel magnitude responses is reinterpreted from a different viewpoint. On the basis of this interpretation, techniques for extending these results to the case of finite-impulse-response (FIR) filters are developed. An advantage of the authors' method is that, when the arbitrary-level filter is implemented, its power-complementary filter, which may be required in specific applications, is obtained simultaneously. Also, by means of a tuning factor (a parameter of the scaling matrix), it is possible to generate a whole family of arbitrary-level filters

    Lepton Masses in a Minimal Model with Triplet Higgs Bosons and S3S_3 Flavor Symmetry

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    Viable neutrino and charged lepton masses and mixings are obtained by imposing a S3×Z4×Z3S_3 \times Z_4 \times Z_3 flavor symmetry in a model with a few additional Higgs. We use two SU(2)LSU(2)_L triplet Higgs which are arranged as a doublet of S3S_3, and standard model singlet Higgs which are also put as doublets of S3S_3. We break the S3S_3 symmetry in this minimal model by giving vacuum expectation values (VEV) to the additional Higgs fields. Dictated by the minimum condition for the scalar potential, we obtain certain VEV alignments which allow us to maintain μτ\mu-\tau symmetry in the neutrino sector, while breaking it maximally for the charged leptons. This helps us to simultaneously explain the hierarchical charged lepton masses, and the neutrino masses and mixings. In particular, we obtain maximal θ23\theta_{23} and zero θ13\theta_{13}. We allow for a mild breaking of the μτ\mu-\tau symmetry for the neutrinos and study the phenomenology. We give predictions for θ13\theta_{13} and the CP violating Jarlskog invariant JCPJ_{CP}, as a function of the μτ\mu-\tau symmetry breaking parameter. We also discuss possible collider signatures and phenomenology associated with lepton flavor violating processes.Comment: 29 pages, 5 figures. Version to be appeared in PRD. Phenomenology of Lepton flavor violation and possible collider signatures of this model have been include

    Mirror matter in the solar system: New evidence for mirror matter from Eros

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    Mirror matter is an entirely new form of matter predicted to exist if mirror symmetry is a fundamental symmetry of nature. Mirror matter has the right broad properties to explain the inferred dark matter of the Universe and might also be responsible for a variety of other puzzles in particle physics, astrophysics, meteoritics and planetary science. It is known that mirror matter can interact with ordinary matter non-gravitationally via photon-mirror photon kinetic mixing. The strength of this possibly fundamental interaction depends on the (theoretically) free parameter ϵ\epsilon. We consider various proposed manifestations of mirror matter in our solar system examining in particular how the physics changes for different possible values of ϵ\epsilon. We find new evidence for mirror matter in the solar system coming from the observed sharp reduction in crater rates (for craters less than about 100 meters in diameter) on the asteroid 433 Eros. We also re-examine various existing ideas including the mirror matter explanation for the anomalous meteorite events, anomalous slow-down of Pioneer spacecraft etc

    Modulus stabilization of generalized Randall Sundrum model with bulk scalar field

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    We study the stabilization of inter-brane spacing modulus of generalized warped brane models with a nonzero brane cosmological constant. Employing Goldberger-Wise stabilization prescription of brane world models with a bulk scalar field, we show that the stabilized value of the modulus generally depends on the value of the brane cosmological constant. Our result further reveals that the stabilized modulus value corresponding to a vanishingly small cosmological constant can only resolve the gauge hierarchy problem simultaneously. This in turn vindicates the original Randall-Sundrum model where the 3-brane cosmological constant was chosen to be zero.Comment: 12 Pages, 1 figure, Revtex, Version to appear in Euro. Phys. Let

    A Note on Unintentional Adulterations in Ayurvedic Herbs

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    Medicinal plants constitute an effective source of traditional and modern medicine. Adulterations and substitutions are common in raw material trade of medicinal plants. In general, adulteration is considered as an intentional malpractice. However, in raw material trade unintentional adulteration also exists. This article explains some of the reasons for unintentional adulterations with examples and key characters to distinguish them

    Inter-Electrode Capacitances of Triode Valves and their Dependence on the Operating Condition

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