| 1. |
- Battistoni, G, et al.
(författare)
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Search for a Lorentz invariance violation contribution in atmospheric neutrino oscillations using MACRO data
- 2005
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Ingår i: Physics Letters B. - : Elsevier. - 0370-2693 .- 1873-2445. ; 615:1-2, s. 14-18
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Tidskriftsartikel (refereegranskat)abstract
- The energy spectrum of neutrino-induced upward-going muons in MACRO has been analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of v(u) -> v(tau) transitions. The data disfavor these exotic possibilities even at a subdominant level, and stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter vertical bar Delta v vertical bar < 6 x 10(-24) at sin2 theta(v) = 0 and vertical bar Delta(v)vertical bar < 2.5-5 x 10(-26) at sin 2 theta(v) = +/- 1. These limits can also be re-interpreted as upper bounds on the parameters describing violation of the equivalence principle. (c) 2005 Elsevier B.V. All rights reserved.
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| 2. |
- Battistoni, G, et al.
(författare)
-
Search for exotic contributions to atmospheric neutrino oscillations
- 2005
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Ingår i: 29th International Cosmic Ray Conference. - Mumbai : Tata Institute of Fundamental Research. ; , s. 171-174
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The energy spectrum of neutrino-induced upward-going muons in MACRO was analysed in terms of relativity principles violating effects, keeping standard mass-induced atmospheric neutrino oscillations as the dominant source of v(mu) -> v(tau) transitions. The data disfavor these possibilities even at a sub-dominant level; stringent 90% C.L. limits are placed on the Lorentz invariance violation parameter vertical bar Delta v vertical bar < 6 x 10(-24) at sin 2 theta(v) = 0 and vertical bar Delta v vertical bar < 2.5 divided by 5 x 10(-26) at sin 2 theta(v) = +/- 1. The limits can be re-interpreted as bounds on the Equivalence Principle violation parameters.
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| 3. |
- Becherini, Yvonne, et al.
(författare)
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Time correlations of high energy muons in an underground detector
- 2005
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Ingår i: Astroparticle physics. - : Elsevier. - 0927-6505 .- 1873-2852. ; 23:3, s. 341-348
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Tidskriftsartikel (refereegranskat)abstract
- We present the result of a search for correlations in the arrival times of high energy muons collected from 1995 till 2000 with the streamer tube system of the complete MACRO detector at the underground Gran Sasso Lab. Large samples of single muons (8.6 million), double muons (0.46 million) and multiple muons with multiplicities from 3 to 6 (0.08 million) were selected. These samples were used to search for time correlations of cosmic ray particles coming from the whole upper hemisphere or from selected space cones. The results of our analyses confirm with high statistics a random arrival time distribution of high energy cosmic rays. (c) 2005 Elsevier B.V. All rights reserved.
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| 4. |
- Becherini, Yvonne, et al.
(författare)
-
Time variations in the deep underground muon flux measured by MACRO
- 2005
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Ingår i: 29th International Cosmic Ray Conference. - Mumbai : Tata Institute of Fundamental Research. ; , s. 157-160
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- More than 30 million high-energy muons collected with the MACRO detector at the underground Gran Sasso Laboratory have been used to search for flux variations of different nature. Two kinds of studies were carried out: search for periodical variations and for the occurrence of clusters of events. Different analysis methods, including Lomb-Scargle spectral analysis and scan statistics have been applied to the data.
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