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Bimaximal Mixing
Bimaximal mixing refers to a proposed form of the lepton mixing matrix. It is characterized by the \nu_3 neutrino being a ''bimaximal mixture'' of \nu_\mu and \nu_\tau and being completely decoupled from the \nu_e, i.e. a uniform mixture of \nu_\mu and \nu_\tau. The \nu_e is consequently a uniform mixture of \nu_1 and \nu_2. Other notable properties are the symmetries between the \nu_\mu and \nu_\tau flavours and \nu_1 and \nu_2 mass eigenstates and an absence of CP violation. The moduli squared of the matrix elements have to be: :\begin , U_, ^2 & , U_, ^2 & , U_, ^2 \\ , U_, ^2 & , U_, ^2 & , U_, ^2 \\ , U_, ^2 & , U_, ^2 & , U_, ^2 \end = \begin \frac & \frac & 0 \\ \frac & \frac & \frac \\ \frac & \frac & \frac \end. According to PDG convention, bimaximal mixing corresponds to \theta_=\theta_=45^\circ and \theta_=\delta_=0, which produces following matrix: :\begin U_ & U_ & U_ \\ U_ & U_ & U_ \\ U_ & U_ & U_ \end = \begin \frac & \frac & 0 \\ -\frac & \frac & \frac \\ \frac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepton Mixing Matrix
In particle physics, a lepton is an elementary particle of half-integer spin (spin ) that does not undergo strong interactions. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), and neutral leptons (better known as neutrinos). Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. The best known of all leptons is the electron. There are six types of leptons, known as '' flavours'', grouped in three ''generations''. The first-generation leptons, also called ''electronic leptons'', comprise the electron () and the electron neutrino (); the second are the ''muonic leptons'', comprising the muon () and the muon neutrino (); and the third are the ''tauonic leptons'', comprising the tau () and the tau neutrino (). Electrons have the least mass of all the charged leptons. The heavier ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribimaximal Mixing
Tribimaximal mixing is a specific postulated form for the Pontecorvo–Maki–Nakagawa–Sakata (PMNS) lepton mixing matrix ''U''. Tribimaximal mixing is defined by a particular choice of the matrix of moduli-squared of the elements of the PMNS matrix as follows: :\begin , U_, ^2 & , U_, ^2 & , U_, ^2 \\ , U_, ^2 & , U_, ^2 & , U_, ^2 \\ , U_, ^2 & , U_, ^2 & , U_, ^2 \end = \begin \frac & \frac & 0 \\ \frac & \frac & \frac \\ \frac & \frac & \frac \end. This mixing is historically interesting as it is quite close to reality when compared to other simple hypotheses where the squares of matrix elements take exact ratios, and also compared to the naive supposition that the matrix would be approximately diagonal like the CKM matrix. However the precision of modern experiments mean that such a simple form is excluded by experiment at a level of over 5σ, mainly due to the fact the tribimaximal scheme has a zero in the U_ element, but also (to a much lesser extent) because it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leptons
In particle physics, a lepton is an elementary particle of half-integer spin (spin ) that does not undergo strong interactions. Two main classes of leptons exist: charged leptons (also known as the electron-like leptons or muons), and neutral leptons (better known as neutrinos). Charged leptons can combine with other particles to form various composite particles such as atoms and positronium, while neutrinos rarely interact with anything, and are consequently rarely observed. The best known of all leptons is the electron. There are six types of leptons, known as '' flavours'', grouped in three ''generations''. The first-generation leptons, also called ''electronic leptons'', comprise the electron () and the electron neutrino (); the second are the ''muonic leptons'', comprising the muon () and the muon neutrino (); and the third are the ''tauonic leptons'', comprising the tau () and the tau neutrino (). Electrons have the least mass of all the charged leptons. The heavi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of High Energy Physics
The ''Journal of High Energy Physics'' is a monthly peer-reviewed open access scientific journal covering the field of high energy physics. It is published by Springer Science+Business Media on behalf of the International School for Advanced Studies. The journal is part of the SCOAP3 initiative. According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 5.810. References External links *Journal pageat International School for Advanced Studies The International School for Advanced Studies (Italian: ''Scuola Internazionale Superiore di Studi Avanzati''; SISSA) is an international, state-supported, post-graduate-education and research institute in Trieste, Italy. SISSA is active in th ... website English-language journals Monthly journals Physics journals Publications established in 1997 Springer Science+Business Media academic journals Academic journals associated with learned and professional societies Particle physics journals {{p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics Letters B
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics. ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Chooz
Double Chooz was a short-baseline neutrino oscillation experiment in Chooz, France. Its goal was to measure or set a limit on the ''θ''13 mixing angle, a neutrino oscillation parameter responsible for changing electron neutrinos into other neutrinos. The experiment uses reactors of the Chooz Nuclear Power Plant as a neutrino source and measures the flux of neutrinos they receive. To accomplish this, Double Chooz has a set of two detectors situated 400 meters and 1050 meters from the reactors. Double Chooz was a successor to the Chooz experiment; one of its detectors occupies the same site as its predecessor. Until January 2015 all data has been collected using only the far detector. The near detector was completed in September 2014, after construction delays, and started taking data at the beginning of 2015. Both detectors stopped taking data in late December 2017. Detector design Double Chooz used two identical gadolinium-doped liquid scintillator detectors placed in vicinity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimaximal Mixing
Trimaximal mixing (also known as threefold maximal mixing ) refers to the highly symmetric, maximally CP-violating, 3 \times 3 fermion mixing configuration, characterised by a unitary matrix (U) having all its elements equal in modulus ( , U_, =1/\sqrt, a,i=1,2,3) as may be written, e.g.: : U= \begin \frac & \frac & \frac \\ \frac & \frac & \frac \\ \frac & \frac & \frac \end \Rightarrow (, U_, ^2)= \begin \frac & \frac & \frac \\ \frac & \frac & \frac \\ \frac & \frac & \frac \end where \omega=\exp(i2\pi/3) and \bar=\exp(-i2\pi/3) are the complex cube roots of unity. In the standard PDG convention, trimaximal mixing corresponds to: \theta_=\theta_=\pi/4, \theta_=\sin^(1/\sqrt) and \delta=\pi/2. The Jarlskog CP-violating parameter J takes its extremal value , J, =1/(6\sqrt). Originally proposed as a candidate lepton mixing matrix, and actively studied as such (and even as a candidate quark mixing matrix ), trimaximal mixing is now definitively ruled-out as a pheno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Golden-ratio Mixing
In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities. Expressed algebraically, for quantities a and b with a > b > 0, where the Greek letter phi ( or \phi) denotes the golden ratio. The constant \varphi satisfies the quadratic equation \varphi^2 = \varphi + 1 and is an irrational number with a value of The golden ratio was called the extreme and mean ratio by Euclid, and the divine proportion by Luca Pacioli, and also goes by several other names. Mathematicians have studied the golden ratio's properties since antiquity. It is the ratio of a regular pentagon's diagonal to its side and thus appears in the construction of the dodecahedron and icosahedron. A golden rectangle—that is, a rectangle with an aspect ratio of \varphi—may be cut into a square and a smaller rectangle with the same aspect ratio. The golden ratio has been used to analyze the proportions of natural objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Kamiokande
Super-Kamiokande (abbreviation of Super-Kamioka Neutrino Detection Experiment, also abbreviated to Super-K or SK; ja, スーパーカミオカンデ) is a neutrino observatory located under Mount Ikeno near the city of Hida, Gifu Prefecture, Japan. It is located underground in the Mozumi Mine in Hida's Kamioka area. The observatory was designed to detect high-energy neutrinos, to search for proton decay, study solar and atmospheric neutrinos, and keep watch for supernovae in the Milky Way Galaxy. It consists of a cylindrical stainless steel tank about in height and diameter holding 50,000 metric tons (55,000 US tons) of ultrapure water. Mounted on an inside superstructure are about 13,000 photomultiplier tubes that detect light from Cherenkov radiation. A neutrino interaction with the electrons or nuclei of water can produce an electron or positron that moves faster than the speed of light in water, which is slower than the speed of light in a vacuum. This creates a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrino
A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small ('' -ino'') that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles excluding massless particles. The weak force has a very short range, the gravitational interaction is extremely weak due to the very small mass of the neutrino, and neutrinos do not participate in the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected. Weak interactions create neutrinos in one of three leptonic flavors: electron neutrinos muon neutrinos (), or tau neutrinos (), in association with the corresponding charged lepton. Although neutrinos were long believed to be massless, it is now known that there are three discrete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electron
The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no known components or substructure. The electron's mass is approximately 1/1836 that of the proton. Quantum mechanical properties of the electron include an intrinsic angular momentum ( spin) of a half-integer value, expressed in units of the reduced Planck constant, . Being fermions, no two electrons can occupy the same quantum state, in accordance with the Pauli exclusion principle. Like all elementary particles, electrons exhibit properties of both particles and waves: They can collide with other particles and can be diffracted like light. The wave properties of electrons are easier to observe with experiments than those of other particles like neutrons and protons because electrons have a lower mass and hence a longer de Broglie wavele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
