scholarly journals The Results of MINOS and the Future with MINOS+

2016 ◽  
Vol 2016 ◽  
pp. 1-25 ◽  
Author(s):  
A. Timmons

The MINOS experiment took data from 2005 up until 2012. The MINOS experiment took data from 2005 up until 2012, continuing beyond that as the MINOS+ experiment. The experiment is a two-detector, on-axis, long-baseline experiment, sending neutrinos from Fermilab to the Soudan Underground Laboratory in northern Minnesota. By searching for the deficit of muon neutrinos at the Far Detector, MINOS/MINOS+ is sensitive to the atmospheric neutrino oscillation parametersΔm322andθ23. By using the full MINOS data set looking at bothνμdisappearance andνeappearance in both neutrino and antineutrino configurations at the NuMI beam along with atmospheric neutrino data recorded at the FD, MINOS has made the most precise measurement ofΔm322. Using a full three-flavour framework and searching forνeappearance, MINOS/MINOS+ gains sensitivity toθ13, the mass hierarchy, and the octant ofθ23. Exotic phenomenon is also explored with the MINOS detectors looking for nonstandard interactions and sterile neutrinos. The current MINOS+ era goals are to build on the previous MINOS results improving the precision on the three-flavour oscillation parameter measurements and strengthening the constraints placed on the sterile neutrino parameter space.

2012 ◽  
Vol 27 (21) ◽  
pp. 1250127 ◽  
Author(s):  
A. NICOLAIDIS

Theories with large extra dimensions may be tested using sterile neutrinos living in the bulk. A bulk neutrino can mix with a flavor neutrino localized in the brane leading to unconventional patterns of neutrino oscillations. A resonance phenomenon, strong mixing between the flavor and the sterile neutrino, allows one to determine the radius of the large extra dimension. If our brane is curved, then the sterile neutrino can take a shortcut through the bulk, leading to an apparent superluminal neutrino speed. The amount of "superluminality" is directly connected to parameters determining the shape of the brane. On the experimental side, we suggest that a long baseline neutrino beam from CERN to NESTOR neutrino telescope will help to clarify these important issues.


2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Jürgen Brunner

IceCube and ANTARES are the world-largest neutrino telescopes. They are successfully taking data, producing a wealth of scientific results. Whereas their main goal is the detection of cosmic neutrinos with energies in the TeV-PeV range, both have demonstrated their capability to measure neutrino oscillations by studying atmospheric neutrinos with energies of 10–50 GeV. After recalling the methods of these measurements and the first published results of these searches, the potential of existing, and planned low-energy extensions of IceCube and KM3Net are discussed. These new detectors will be able to improve the knowledge of the atmospheric neutrino oscillation parameters, and in particular they might help to understand the neutrino mass hierarchy. Such studies, which use atmospheric neutrinos, could be complemented by measurements in a long-baseline neutrino beam, which is discussed as a long-term future option.


2013 ◽  
Vol 28 (16) ◽  
pp. 1350067 ◽  
Author(s):  
JOSEPH BRAMANTE

If sterile neutrinos have a neutral coupling to standard model fermions, matter effect resonant transitions to sterile neutrinos and excess neutral-current events could manifest at long baseline experiments. Assuming a single sterile neutrino with a neutral coupling to fermionic matter, we re-examine bounds on sterile neutrino production at long baselines from the MINOS result Pνμ →νs < 0.22 (90% CL). We demonstrate that sterile neutrinos with a neutral vector coupling to fermionic matter could evade the MINOS limit, allowing a higher fraction of active to sterile neutrino conversion at long baselines. Scanning the parameter space of sterile neutrino matter effect fits of the LSND and MiniBooNe data, we show that in the case of a vector singlet coupling of sterile neutrinos to matter, some favored parametrizations of these fits would create neutral-current event excesses above standard model predictions at long baseline experiments (e.g. MINOS and OPERA).


2020 ◽  
Vol 80 (8) ◽  
Author(s):  
C. S. Kim ◽  
Youngjoon Kwon ◽  
Donghun Lee ◽  
Sechul Oh ◽  
Dibyakrupa Sahoo

Abstract We present, how a systematic study of $$B \rightarrow D\ell N$$B→DℓN ($$D \rightarrow K \ell N$$D→KℓN) decays with $$\ell =\mu ,\tau $$ℓ=μ,τ, at Belle II (BESIII) can provide unambiguous signature of a heavy neutrino N and/or constrain its mixing with active neutrinos $$\nu _\ell $$νℓ, which is parameterized by $$| U_{\ell N} |^2$$|UℓN|2. Our constraint on $$\vert U_{\mu N} \vert ^2$$|UμN|2 that can be achieved from the full Belle II data is comparable with what can be obtained from the much larger data set of the upgraded LHCb. Additionally, our method offers better constraint on $$\vert U_{\mu N} \vert ^2$$|UμN|2 for mass of sterile neutrino $$m_N < 2$$mN<2 GeV. We can also probe the Dirac and Majorana nature of N by observing the sequential decay of N, including suppression from observation of a displaced vertex as well as helicity flip, for Majorana N.


2018 ◽  
Vol 46 ◽  
pp. 1860038 ◽  
Author(s):  
Erica Smith

The NOvA experiment is a long-baseline accelerator-based neutrino oscillation experiment. It uses the upgraded NuMI beam from Fermilab to measure electron-neutrino appearance and muon-neutrino disappearance between the Near Detector, located at Fermilab, and the Far Detector, located at Ash River, Minnesota. The NuMI beam has recently reached and surpassed the 700 kW power benchmark. NOvA’s primary physics goals include precision measurements of oscillation parameters, such as [Formula: see text] and the atmospheric mass-squared splitting, along with probes of the mass hierarchy and of the CP violating phase. This talk will present the latest NOvA results, based on a neutrino beam exposure equivalent to [Formula: see text] protons-on-target.


Universe ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 41
Author(s):  
Antonio Palazzo

Several anomalies observed in short-baseline neutrino experiments suggest the existence of new light sterile neutrino species. In this review, we describe the potential role of long-baseline experiments in the searches of sterile neutrino properties and, in particular, the new CP-violation phases that appear in the enlarged 3 + 1 scheme. We also assess the impact of light sterile states on the discovery potential of long-baseline experiments of important targets such as the standard 3-flavor CP violation, the neutrino mass hierarchy, and the octant of θ 23 .


2015 ◽  
Vol 30 (07) ◽  
pp. 1550017 ◽  
Author(s):  
Debajyoti Dutta ◽  
Kalpana Bora

In this work, we have explored the possibilities of improving CP violation (CPV) discovery potential of newly planned Long-Baseline Neutrino Experiment (LBNE), USA, by combining with data from reactors. The third mixing angle θ13 is now very precisely measured and this precise measurement of θ13 helps in the measurement of CPV. Here, CPV is studied with and without data from reactors. The impact of placing a neutrino data (ND) is also studied. It is found that CPV discovery potential of LBNE with ND increases when combined with data from reactors. With a far detector of 35 kt, it is possible to obtain 5σ sensitivity of CPV when run for 5 years in ν and 5 years in [Formula: see text] mode. When normal hierarchy is assumed, CPV sensitivity is maximum. CPV discovery is possible by combining 5 years neutrino data from LBNE with 3 years anti-neutrino data from reactors. This study reveals that CPV can also be discovered at 5σ cl in inverted mass hierarchy (IH) mode when appearance measurement of LBNE is combined with reactors.


2018 ◽  
Vol 191 ◽  
pp. 03003
Author(s):  
Igor Krasnov

Seesaw mechanism constrains from below mixing between active and sterile neutrinos for fixed sterile neutrino masses. Signal events associated with sterile neutrino decays inside a detector at fixed target experiment are suppressed by the mixing angle to the power of four. Therefore sensitivity of experiments such as SHiP and DUNE should take into account minimal possible values of the mixing angles. We extend the previous study of this subject [1] to a more general case of non-zero CP-violating phases in the neutrino sector. Namely, we provide numerical estimate of minimal value of mixing angles between active neutrinos and two sterile neutrinos with the third sterile neutrino playing no noticeable role in the mixing. Thus we obtain a sensitivity needed to fully explore the seesaw type I mechanism for sterile neutrinos with masses below 2 GeV, and one undetectable sterile neutrino that is relevant for the fixedtarget experiments. Remarkably, we observe a strong dependence of this result on the lightest active neutrino mass and the neutrino mass hierarchy, not only on the values of CP-violating phases themselves. All these effects sum up to push the limit of experimental confirmation of sterile-active neutrino mixing by several orders of magnitude below the results of [1] from 10-10 - 10-11 down to 10-12 and even to 10-20 in parts of parameter space; non-zero CP-violating phases are responsible for that.


2010 ◽  
Vol 25 (15) ◽  
pp. 1219-1231 ◽  
Author(s):  
ALEC HABIG

The MINOS long-baseline experiment is using the NuMI neutrino beam to make precise measurements of neutrino flavor oscillations in the "atmospheric" neutrino sector. MINOS observes the νμ disappearance oscillations seen in atmospheric neutrinos, tests possible disappearance to sterile ν by measuring the neutral current flux, and extends our reach towards the so far unseen θ13 by looking for νe appearance in this νμ beam. The magnetized MINOS detectors also allow tests of CPT conservation by discriminating between neutrinos and anti-neutrinos on an event-by-event basis. The intense, well-understood NuMI neutrino beam created at Fermilab is observed 735 km away at the Soudan Mine in Northeast Minnesota. High-statistics studies of the neutrino interactions themselves and the cosmic rays seen by the MINOS detectors have also been made. MINOS started taking beam data in May 2005 and is now nearing the end of its five-year run. This paper reviews results published based on the first several years of data.


2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Sebastian A. R. Ellis ◽  
Kevin J. Kelly ◽  
Shirley Weishi Li

Abstract The unitarity of the lepton mixing matrix is a critical assumption underlying the standard neutrino-mixing paradigm. However, many models seeking to explain the as-yet-unknown origin of neutrino masses predict deviations from unitarity in the mixing of the active neutrino states. Motivated by the prospect that future experiments may provide a precise measurement of the lepton mixing matrix, we revisit current constraints on unitarity violation from oscillation measurements and project how next-generation experiments will improve our current knowledge. With the next-generation data, the normalizations of all rows and columns of the lepton mixing matrix will be constrained to ≲10% precision, with the e-row best measured at ≲1% and the τ-row worst measured at ∼10% precision. The measurements of the mixing matrix elements themselves will be improved on average by a factor of 3. We highlight the complementarity of DUNE, T2HK, JUNO, and IceCube Upgrade for these improvements, as well as the importance of ντ appearance measurements and sterile neutrino searches for tests of leptonic unitarity.


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