Anti-neutrinos

Figure 6. Solutions of the gap equations and the charge neutrality condition (solid black line) in the /// vs //, plane. Two branches are shown states with diquark condensation on the upper right (A > 0) and normal quark matter states (A = 0) on the lower left. The plateau in between corresponds to a mixed phase. The lines for the /3-equilibium condition are also shown (solid and dashed straight lines) for different values of the (anti-)neutrino chemical potential. Matter under stellar conditions should fulfill both conditions and therefore for //,( = 0 a 2SC-normal quark matter mixed phase is preferable.

Energy release due to (anti)neutrino untrapping. The configurations for the quark stars are obtained by solving the Tolman-Oppenheimer-Volkoff equations for a set of central quark number densities nq for which the stars are stable. In Fig. 13 the configurations for different antineutrino chemical potentials are shown. The equations of state with trapped antineutrinos are softer and therefore this allows more compact configurations. The presence of antineutrinos tends to increase the mass for a given central density. 

J. P. Vigier, Charmed quark discovery in anti-neutrino nucleon scattering Lett. Nuovo Cimento 15(2) (Ser. 2), 41 48 (1976). 

The Urea process is essentially an electron capture followed by / -decay, with the emission of a neutrino and anti-neutrino pair, e.g. 

The synthesis of the light elements is sensitive to physical conditions in the early radiation-dominated era at temperatures T < 1 MeV, corresponding to an age r > 1 s. At these and higher temperatures, weak interactions rates Tweak > H were rapid compared to the expansion rate, and thus the weak interactions were in thermal equilibrium. In particular, the processes which interconvert neutrons and protons through scatterings with electrons (e ), positrons (e ), electron neutrinos (ve) and electron anti-neutrinos (v ), namely... 

If a nucleus has a NIZ ratio too high for stability, it is said to be neutron-rich. It will undergo radioactive decay in such a manner that the neutron to proton ratio decreases to approach more closely the stable value. In such a case the nucleus must decrease the value of N and increase the value of Z, which can be done by conversion of a neutron to a proton. When such a conversion occurs within a nucleus, 8 (or negatron) emission is the consequence, with creation and emission of a negative /3-particle designated by 8 or e (together with an anti-neutrino, here omitted for simplicity, see Ch. 4). For example ... 

All the particles in Table 10.1 have spin. Quantum mechanical calculations and experimental observations have shown that each particle has a fixed spin energy which is determined by the spin quantum number s s = h for leptons and nucleons). Particles of non-integral spin are csWeA fermions because they obey the statistical rules devised by Fermi and Dirac, which state that two such particles cannot exist in the same closed system (nucleus or electron shell) having all quantum numbers the same (referred to as the Pauli principle). Fermions can be created and destroyed only in conjunction with an anti-particle of the same class. For example if an electron is emitted in 3-decay it must be accompanied by the creation of an anti-neutrino. Conversely, if a positron — which is an anti-electron — is emitted in the ]3-decay, it is accompanied by the creation of a neutrino. 

Since the 19S0s it has become clear that neutrinos exist as several types. In j3 decay an "anti-neutrino" is formed, while a "neutrino" is emitted in 0 decay. Both these neutrinos are now referred to as electron neutrinos, and respectively. 

In all reactions the lepton number must be conserved the total number of leptons minus antileptons on each side of a decay or reaction process must be the same. A similar law is valid for the quarks. In the reaction above several quantum numbers are obeyed (i) the charge is the same on both side, (ii) the lepton number is zero on both sides (none = electron minus anti-neutrino), (iii) the quark number is conserved. The elementary reactions in Figure 10.4 can all be described in terms of lepton and quark transformations. 

In weak interactions, where neutrinos are involved, the symmetric property (i.e. the parity) is not conserved. This is related to the fact that the neutrino spin is 100% polarized anti-parallel to its momentum (helidty = — 1) since the neutrino mass fe nearly zero. (Helidty of the anti-neutrino is -fl however, i.e. its spin is... 

P. Alivisatos, et al., KamLAND, a Liquid Scintillator Anti-Neutrino Detector at the Kamioka Site, Preprint Stanford-HEP-98-03 Tohoku-RCNS-98-15 (Geneva Cem Library SCAN-9809050), at http //alice.cem.ch/search/complex uid=3470113 2649 freetextl=Alivisatos+P fieldl=wau, p. 60. 

A beta particle, (3 , is an electron in all respects it is identical to any other electron. Following on from Section 1.1, the sum of the masses of the "Ni plus the mass of the (3 , and i>, the anti-neutrino, are less than the mass of "Co. That mass difference drives the decay and appears as energy of the decay products. What happens during the decay process is that a neutron is converted to a proton within the nucleus. In that way the atomic number increases by one and the nuclide drops down the side of the valley to a more stable condition. A fact not often realized is that the neutron itself is radioactive when it is not bound within a nucleus. A free neutron has a half-life of only 10.2 min and decays by beta emission ... 

Fission Fragments Prompt Neutrons Prompt Gamma Rays Delayed Neutrons Isomeric Gamma Rays Fission Product Qeunmas Fission Product Betas Fission Product Anti-Neutrinos... 

The isomeric gamma rays occur 5 x 10 to 10 seconds after fission. All but the anti-neutrinos provide sensible heat. The total energy emission per fission Is seen to be 204.3 + 2.5 Mev vlth 194.O Mev of it appearing as sensible beat in the reactor. The se condary lanergy sources m the reactor are those associated vlth various neutron interactions. These energy sources are given in Table 9.1.2. specific energies depend on the reactor. 

Whereas a-partides are characterized by specific energies, the energies of emitted P-particles show a continuous distribution. This puzzled scientists for a long time, but was understood when it was realized that P-decay is accompanied by the emission of a neutrino or anti-neutrino and the energy that is released is distributed over the P-partide and the (anti)neutrino. Hence the various forms of P-decay can be described as follows ... 

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