Instead, to this point, lepton flavor conservation is an experimental fact. Lepton number. To fully conserve lepton numbers, two neutrinos must be emitted, a muon neutrino and an electron antineutrino. Tau neutrino. Observed reactions always conserve lepton numbers, while reactions which violate lepton number conservation are “forbidden” and are never observed. However, theory does not necessitate that lepton number always be conserved. • The anti-electron neutrino ($%")has an electron lepton number ""=-1. Lepton number However, this was not unexpected: 1953 Konopinski and Mahmoud introduced a notion of lepton number L that must be conserved in reactions: • electron, muon, neutrino have L = +1 • anti-electron, anti-muon, anti-neutrino have L = –1 This new ad hoc law would explain many facts: Summary. Muon neutrino. As such, electrons and neutrinos are leptons. We can see that the particles have lepton number +1 and the antiparticles have a lepton number -1. A class of fermion whose members participate in weak, electromagnetic, and gravitational interactions. • A muon ((") has a muon lepton number #)=+1. It has no net electric charge and a spin of ½. Neutrino oscillation is a quantum mechanical phenomenon whereby a neutrino created with a specific lepton family number ("lepton flavor": electron, muon, or tau) can later be measured to have a different lepton family number. Our results show the significance of muon and tau lepton number angular distributions, together with the traditional electron lepton number ones. Together with the muon it forms the second generation of leptons, hence the name muon neutrino. Most experiments involving neutrinos involve electron neutrinos which are much more common in our low-energy world, but some current neutrino detectors are sensitive to the other two as well. As described in the calculations of particles, leptons appear at the same magic numbers found in atomic elements. The lepton family number carried by the neutrino is defined by the left-handed current of the neutrino family. • The muon neutrino (%)) has a muon lepton number #)=+1. Tau neutrino. Along with +!e+ decays, two other rare muon processes provide the most stringent current Muon neutrino. • The anti-muon ((&) has a muon lepton number #)=-1. The same pattern is observed for the muon. The massive leptons are the electron, muon and tau, and each of them has an associated neutrino. The recent supernova simulations with muon production call for such an analysis, as they relax the standard νμ;τ ¼ ν¯μ;τ (two-flavor) assumption. From 1964 to 1967, it was established in similar experiments that when v μ collide with nuclei, μ-are created but μ + are not, that is, the muonic neutrino v μ and the muonic antineutrino v̀ μ are not identical, and an additional lepton number, L μ, which is conserved, must be introduced. A lepton is a type of fermion with a charge of 0 or -1 Electron Muon Tau Electron neutrino Muon neutrino Tau neutrino Electrons and neutrinos are stable, while the Tau and Muon are heavier and tend to decay quickly. Electron, Muon, and Tau Neutrinos. Two effective operators in the Standard Model are identified which lead to just such decays and no other processes. This process is experimental and the keywords may be updated as the learning algorithm improves. The lepton family number is defined through the weak basis of the SU(2) doublet, where the charged lepton mass matrix is real and diagonal. Lepton number is conserved because the electron has lepton number of +1 and a neutrino has lepton number … The electron was also the first particle to be discovered. The concept of lepton number is a slippery one if sterile neutrinos exist and mix in vacuum with ac-tive species. avors, each accompanied by a conserved lepton-avor number.2 In modern textbooks, we describe (negative) muon decay as !e e ; the electron neutrino and the muon neutrino are di erent objects. • The muon neutrino (#$) has a muon lepton number … All lepton numbers add up to zero after the decay, and they are zero before the decay, since the Xi-minus is a baryon. We show that lepton number violating muon decays, μ+→e++¯¯¯¯¯νe+¯¯¯¯νi (i=e,μ or τ), can consistently explain the neutrino anomaly reported by the LSND experiment. Conservation of the number of leptons of different flavors (for example, electron number or muon number) may sometimes be violated (as in neutrino oscillation). Helicity and lepton numbers of neutrino. For example, the neutrino scattering reaction A lepton number of 1 is assigned to both the electron and the neutrino and −1 to the antineutrino and the positron. In essence, lepton number can be cre-ated [17, 18] or destroyed [19, 20] by active-sterile neu-trino interconversion. has a muon lepton number "$=+1. Family lepton numbers are assigned to the three families of leptons, which are easily remembered by their flavors. Wave centers centers must be at the nodes of standing waves to be stable and the other geometric arrangements likely do not lead to this stability. This principle is known as conservation of lepton number. For this work we assume the neutrinos have Majorana mass. The electron and electron neutrino (and their antiparticles) are one set, the muon and muon neutrino are another, and the tau and tau neutrino make up the third. Leptons are a family of elemental particles that includes the electron, the muon, the tau, and their associated neutrinos.Like quarks, which make up the protons and neutrons in the atomic nucleus, the lepton is a fermion, meaning it has a quantum spin of ½.Other fundamental particles with different spins are called bosons and mediate force interactions between the fermions. A lepton is an elementary, half-integer spin (spin 1 ⁄ 2) particle that does not undergo strong interactions. A lepton is a particle not affected by the strong nuclear forces, but is only subjected to the weak forces. In order for both electron lepton number and muon lepton number to be conserved, then the other particles must be an electron anti-neutrino and a muon neutrino. For example in electron capture one electron goes in and a neutrino goes out. Lepton Number Conservation. A lepton number L_e, L_\mu, L_\tau of +1 is given to each generation of lepton, and -1 to each flavor of antilepton. Abstract: We develop the consequences of introducing a purely leptonic, lepton number violating non-standard interaction (NSI) and standard model neutrino mixing with a fourth, sterile neutrino in the analysis of short-baseline, neutrino experiments. Muon number and tau number operate analogously with the other two lepton families. We can see that the particles have lepton number +1 and the antiparticles have a lepton number -1. in the presence of three neutrino flavors. We focus on the muon decay at rest (DAR) result from the Liquid Scintillation Neutrino Experiment (LSND) and the Karlsruhe and … The lepton family number is defined through the weak b The water-based detectors Kamiokande II and IMB detected 11 and 8 antineutrinos (lepton number = −1) of thermal origin, respectively, while the scintillator-based Baksan detector found 5 neutrinos (lepton number = +1) of either thermal or electron-capture origin, in a burst less than 13 seconds long. The muon neutrino is a subatomic lepton elementary particle which has the symbol ν μ. The next neutrino that is found is the muon neutrino with a particle count of 8. The scale of new physics Λ must be relatively low, Λ≤500 GeV. Lepton numbers are just ways to see what types of leptons are going to come out of a reaction given some particle goes in. But it is pointless to include the word "electron" in the question because the answer would be same no matter if you were talking about the anti-particle of any neutrino (be it a electron, muon or tauon type). There are three different lepton number s: the electron-lepton number $$L_e$$, the muon-lepton number $$L_{\mu}$$, and the tau-lepton number $$L_{\tau}$$.In any interaction, each of these quantities must be conserved separately. Let's take an example decay. Together with the muon it forms the second generation of leptons, hence the name muon neutrino. Unless, the question specified that it is the lepton number for an electron type anti-neutrino. Lepton number conservation states that the sum of lepton numbers before and after the interaction must be the same. It has no net electric charge and a spin of ½. One important thing about leptons, then, is that electron number, muon number, and tau number are always conserved when a massive lepton decays into smaller ones. However, the decay of the muon into an electron produces a distribution of electron energies, showing that it is at least a three-body decay. Subatomic particle - Subatomic particle - Charged leptons (electron, muon, tau): Probably the most-familiar subatomic particle is the electron, the component of atoms that makes interatomic bonding and chemical reactions—and hence life—possible. Quark Sector Heavy Neutrino Muon Capture Neutral Lepton Lepton Number Conservation These keywords were added by machine and not by the authors. • A muon (&!) lepton (lĕp´tŏn´) [Gr.,=light (i.e., lightweight)], class of elementary particles [1] that includes the electron [2] and its antiparticle [3], the muon [4] and its antiparticle, the tau and its antiparticle, and the neutrino [5] and antineutrino associated with each of these particles. Mixing between light and heavy neutrinos can induce lepton-flavor and total-lepton-number violation in the light sector, even if the light neutrino masses are zero or extremely small, because the states actually produced in weak processes are generally nonorthogonal. The current observational bounds There are 6 types of lepton. Every lepton has a corresponding antilepton. The muon neutrino is a subatomic lepton elementary particle which has the symbol ν μ. The same pattern is observed for the muon. The reaction is thus μ--> e-+ ν e + ν μ. (b) The proton has lepton number zero, the electron has electron lepton number 1, the anti-electron neutrino has electron lepton number -1, the muon neutrino has muon lepton number 1, and its antiparticle has muon lepton number -1. and lepton number-driven medium enhancement [3, 16]. Likewise, a decaying negative muon results in the creation of a muon neutrino, while a decaying positive muon results in the creation of a muon antineutrino. Lepton number conservation, like electric charge conservation, plays an important role in understanding reactions involving leptons. Then, not only is the total lepton number conserved, but so are the electron number and muon number. Lepton Decay. We revisit the time evolution of the lepton family number for a SU(2) doublet consisting of a neutrino and a charged lepton.  ) has an electron antineutrino has no net electric charge conservation, an. 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