KARMEN: Neutrino Physics at ISIS

Drexlin, G.; Gemmeke, H.; Giorginis, G.; Grandegger, W.; Kleinfeller, J.; Maschuw, R.; Plischke, P.; Raupp, F.; Schmidt, Friedrich; Wochele, J.; Zeitnitz, B.; Finckh, E.; Kretschmer, W.; Vötisch, D.; Edgington, J.A.; Gorringe, T. P.; Booth, N. E.; Dodd, A.C.

doi:10.1007/978-3-642-73679-7_14

Cited by 5 publications

(6 citation statements)

References 5 publications

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“…The SuperKamiokande atmospheric data [1] strongly indicate that there is a large nonvanishing mixing of the muon neutrino. The same experiment and several others [2] also indicate presence of neutrino mixing of the electron neutrinos coming from the Sun, and there is further [3], though not nearly as strong [4], evidence of other neutrino mixing phenomena.…”

Section: Introductionsupporting

confidence: 64%

Nonabelian discrete symmetries, fermion mass textures and large neutrino mixing

Frampton

Rašin

2000

Physics Letters B

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Nonabelian discrete groups are an attractive tool to describe fermion masses and mixings. They have nonsinglet representations which seem particularly suitable for distinguishing the lighter generations from the heavier ones. Also, they do not suffer from the extra constraints a continuous group must obey, e.g. limits on extra particles. Some of the simplest groups are the nonabelian discrete subgroups of SO(3) and SU(2), the so called dihedral groups D n and dicyclic groups Q 2n , which both have only singlet and doublet representations. After studying which vacuum expectation value (VEV) directions of representations of dihedral and dicyclic groups preserve which subgroups, we construct a simple model based on the group Q 6 × Q 6 . The model reproduces the masses and mixings of all quarks and leptons, including neutrinos. It has a large mixing angle in the µ − τ neutrino sector, in accordance with the recent SuperKamiokande results, while keeping a small quark mixing in the bottom -charm sector. The reason is similar to the one found in the literature based on the SU(5) group: the large left handed mixing angle in the lepton sector corresponds to the large unphysical right handed in the down quark sector. The large mixing is also responsible for the different hierarchies of the two heaviest families in the up and down sector, and can be summarized as the order of magnitude relation: ms m b ∼ tan(θ µτ ) mc mt .

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Section: Introductionsupporting

confidence: 64%

Nonabelian discrete symmetries, fermion mass textures and large neutrino mixing

Frampton

Rašin

2000

Physics Letters B

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“…in the cross section are strongly peaked with respect to E D and we interpret the conditions (2.14) that the rest of the cross section is flat with respect to E D if varied over intervals several orders of magnitude larger than Γ. This is a reasonable assumption because in the LSND and KARMEN experiments the stopped muons have momenta of the order 0.01 MeV [11,12], and thus σ S will be in the same range. Assuming atomic dimensions of the spread of the detector particle wave function, we find σ D ∼ 10 −3 MeV.…”

Section: The Cross Sectionmentioning

confidence: 60%

“…One can see that at ρ = 0.5 the function g is around 0.9 which means that g 12 starts to deviate appreciably from 1 when ρ becomes greater than about 0.5. In the case of the LSND and KARMEN experiments, using Γ ≃ 3 × 10 −16 MeV for the decay width of the muon and the typical numbers σ S ≃ 0.01 MeV [11,12], ∆m 2 ≃ 1 eV 2 and E ν ≃ 30 MeV, we obtain ρ 12 ≃ 0.5×10 −2 . From this estimate we conclude that with the above input numbers the correction to the transition probability is negligible for the LSND and KARMEN experiments because 1−g 12 ∼ 10 −5 (see remark after definition of g (3.3)).…”

Section: The Case Of a Gaussian Muon Wave Packetmentioning

confidence: 94%

Neutrino oscillations and the effect of the finite lifetime of the neutrino source

1999

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We consider a neutrino source at rest and discuss a condition for the existence of neutrino oscillations which derives from the finite lifetime τ S of the neutrino source particle. This condition is present if the neutrino source is a free particle such that its wave function is non-stationary. For a Gaussian wave function and with some simplifying assumptions, we study the modification of the usual oscillation probability stemming from τ S . In the present accelerator experiments the effect of τ S can be neglected. We discuss some experimental situations where the source lifetime becomes relevant in the oscillation formula.14.60.Pq, 03.65.-w Typeset using REVT E X

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“…KARMEN continues to see an interesting anomaly in the time distribution of ν e and ν µ [25,26]. Tentatively, the KARMEN collaboration interprets this anomaly as an indication of a new neutral particle with its mass and lifetime (electromagnetic decay) as follows: 2 KARMEN Particle X: m x = 33.9 MeV , τ x > 0.3 µs .…”

Section: Karmen Anomaly: a Hint Of A Non-relativistic Mass Eigenstmentioning

confidence: 99%