| 1. |
- Ohlsson, Tommy, 1973-, et al.
(author)
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Neutrino oscillations with three flavors in matter : Applications to neutrinos traversing the earth
- 2000
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In: Physics Letters B. - : Elsevier Science B.V.. - 0370-2693 .- 1873-2445. ; 474:1-2, s. 153-162
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Journal article (peer-reviewed)abstract
- Analytic formulas are presented for three flavor neutrino oscillations in matter in the plane wave approximation. We calculate in particular the time evolution operator in both mass and flavor bases. We also find the transition probabilities expressed as functions of the vacuum mass squared differences, the vacuum mixing angles, and the matter density parameter. The application of this to neutrino oscillations for both atmospheric and long baseline neutrinos in a mantle-core-mantle step function model of the Earth's matter density profile is discussed.
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| 2. |
- Jacobsson, Björn, et al.
(author)
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Effects of random matter density fluctuations on the neutrino oscillation transition probabilities in the Earth
- 2002
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In: Physics Letters B. - 0370-2693 .- 1873-2445. ; 532:04-mar, s. 259-266
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Journal article (peer-reviewed)abstract
- In this Letter, we investigate the effects of random fluctuations of the Earth matter density for long baselines on the neutrino oscillation transition probabilities. We especially identify relevant parameters characterizing the matter density noise and calculate their effects by averaging over statistical ensembles of a large number of matter density profiles. For energies and baselines appropriate to neutrino factories, absolute errors on the relevant appearance probabilities are at the level of \DeltaP(alphabeta)\ similar to 10(-4) (with perhaps \P-mue similar to 1% for neutrinos), whereby a modest improvement in understanding of the geophysical data should render such effects unimportant.
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| 3. |
- Ohlsson, Tommy, 1973-, et al.
(author)
-
Bilarge leptonic mixing from Abelian horizontal symmetries
- 2002
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In: Physics Letters B. - : Elsevier Science B.V.. - 0370-2693 .- 1873-2445. ; 537:02-jan, s. 95-102
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Journal article (peer-reviewed)abstract
- We construct and present a model for leptonic mixing based on higher-dimensional operators, using the Froggatt-Nielsen mechanism. and Abelian horizontal symmetries (flavor symmetries) of continuous and discrete type. Our model naturally yields bilarge leptonic mixing. coming from both the charged leptons and the neutrinos, and an inverted neutrino mass hierarchy spectrum. The obtained values of the parameters, i.e.. the leptonic mixing parameters and the neutrino mass squared differences, are all consistent with the atmospheric neutrino data and the Mikheyev-Smirnov-Wolfenstein large mixing angle solution for the solar neutrino problem.
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| 4. |
- Ohlsson, Tommy, 1973-
(author)
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Effects and influences on neutrino oscillations due to a thin density layer perturbation added to a matter density profile
- 2001
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In: Physics Letters B. - : Elsevier Science B.V.. - 0370-2693 .- 1873-2445. ; 522:04-mar, s. 280-286
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Journal article (peer-reviewed)abstract
- In this Letter, we show the effects on the transition probabilities for neutrino oscillations due to a thin constant density layer perturbation added to an arbitrary matter density profile, In the case of two neutrino flavors, we calculate the effects both analytically and numerically, whereas in the case of three neutrino flavors, we perform the studies purely numerically. As an realistic example we consider the effects of the Earth's atmosphere when added to the Earth's matter density profile on the neutrino oscillation transition probabilities for atmospheric neutrinos.
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| 5. |
- Ohlsson, Tommy, 1973-
(author)
-
Equivalence between Gaussian averaged neutrino oscillations and neutrino decoherence
- 2001
-
In: Physics Letters B. - : Elsevier B.V.. - 0370-2693 .- 1873-2445. ; 502:04-jan, s. 159-166
-
Journal article (peer-reviewed)abstract
- In this Letter, we show that a Gaussian averaged neutrino oscillation model is equivalent to a neutrino decoherence model. Without loss of generality, the analysis is performed with two neutrino flavors. We also estimate the damping (or decoherence) parameter for atmospheric neutrinos and compare it to earlier obtained results.
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| 6. |
- Ohlsson, Tommy, 1973-, et al.
(author)
-
Reconstruction of the Earth's matter density profile using a single neutrino baseline
- 2001
-
In: Physics Letters B. - : Elsevier Science B.V.. - 0370-2693 .- 1873-2445. ; 512:04-mar, s. 357-364
-
Journal article (peer-reviewed)abstract
- In this Letter, we show numerically that a symmetric Earth matter density profile can, in principle, be reconstructed from a single baseline energy spectrum up to a certain precision. For the numerical evaluations in the high-dimensional parameter space we use a genetic algorithm.
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| 7. |
- Angelopoulos, A., et al.
(author)
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K 0–KÌ„0 mass and decay-width differences : CPLEAR evaluation
- 1999
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In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 471:2, s. 332-338
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Journal article (peer-reviewed)abstract
- The CPT-violation parameters Re(δ) and Im(δ) determined recently by CPLEAR are used to evaluate the K0– mass and decay-width differences, as given by the difference between the diagonal elements of the neutral-kaon mixing matrix (M−iΓ/2). The results – GeV and GeV – are consistent with CPT invariance. The CPT invariance is also shown to hold within a few times 10−3–10−4 for many of the amplitudes describing neutral-kaon decays to different final states.
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| 8. |
- Apostolakis, A, et al.
(author)
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A determination of the CP violation parameter η+- from the decay of strangeness-tagged neutral kaons
- 1999
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In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 458:4, s. 545-552
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Journal article (peer-reviewed)abstract
- LEAR offered unique opportunities to study the symmetries which exist between matter and antimatter. At variance with other approaches at this facility, CPLEAR was an experiment devoted to the study of CP, T and CPT symmetries in the neutral-kaon system. A variety of measurements allowed us to determine with high precision the parameters which describe the time evolution of the neutral kaons and their antiparticles, including decay amplitudes, and the related symmetry properties. Limits concerning quantum-mechanical predictions (EPR, coherence of the wave function) or the equivalence principle of general relativity have been obtained. An account of the main features of the experiment and its performances is given here, together with the results achieved.
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| 9. |
- Apostolakis, A., et al.
(author)
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Measurement of the energy dependence of the form factor f+ in K 0 e3 decay
- 2000
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In: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 473:1, s. 186-192
-
Journal article (peer-reviewed)abstract
- Neutral-kaon decays to πeν were analysed to determine the q2 dependence of the K0e3 electroweak form factor f+. Based on 365612 events, this form factor was found to have a linear dependence on q2 with a slope λ+=0.0245±0.0012stat±0.0022syst.
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| 10. |
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