Standard model of physics

Could that be so that the Universe was created with the preponderance of matter over antimatter We have no support for such hypothesis. Einstein remarked If that s the way God made the world then I don t want to have anything to do with Him [7]. Indeed, the contemporary Standard Model of Physics suggests that equal amounts of matter and antimatter were born during the Big-Bang. Where has the antimatter gone What causes the apparent asymmetry between matter and antimatter Obviously the antiparticles have been annihilated by particles - but apparently this process was not fully symmetric, since enough matter was left over for our Universe. We seem to be the result of an accident, caused by a a slight imperfection of Nature. 

Quite generally, however, all these experimental attempts to measure molecular parity violating effects depend on guidance from theory. In the initial stage, theory is needed to identify suitable molecular candidates with favourable properties for an experiment, while at a later stage, theory is needed to analyse and interpret the results of an experiment. In the fom th section, I will describe the methods currently available for the computation of molecular parity violating effects, but first I will outline briefly the way one has to go from the standard model of physics in order to arrive at the final working equations employed in these calculations. 

FROM THE STANDARD MODEL OF PHYSICS TO MOLECULAR PARITY VIOLATION... 

In this section, I will sketch the way from the electroweak sector of the current standard model of physics to the actual Hamiltonians employed in... 

The current standard model of physics is a result of the ongoing attempts to understand the structure of matter and its fundamental interaction. According to present knowledge, the elemental building blocks of matter consist of spin 1/2 fermions which interact with each other via the exchange of bosons. 

The standard model of physics is based on the direct product gauge group SU 3)c X SU 2)i, x f/(l)Y- SU(3)c is the non-Abelian gauge group of quantum chromodynamics (QCD) that describes the colour interaction between the quarks (hence the index C), while SU(2)l x U(1)y is the gauge group of the electroweak model [13-15]. Since the SU(3)c transformations of QCD commute with the 517(2)l x t/(l)Y transformations, the QCD part is not discussed here any further. 

The standard model of physics is based entirely on dimensionless point particles, and, whatever it may reveal about dark matter, it offers no explanation of the extension and structure of molecules. These elementary particles acquire their mass mathematically, on interaction with the hypothetical Higgs field, in a process of [2]... 

There are many different extensions of the standard model of particle physics which result in modifications of the early universe expansion rate (the time -temperature relation). For example, additional particles will increase the energy density (at fixed temperature), resulting in a faster expansion. In such situations it is convenient to relate the extra energy density to that which would have been contributed by an additional neutrino with the ordinary weak interactions [19]. Just prior to e annihilation, this may be written as... 

Rare event physics is playing a significant role in modern physics the rare event signals, if detected, would be an evidence for the need of a new physics, beyond the standard model of particle Physics, and would have far-reaching consequences in Cosmology. 

During the 1960s, L.M. Lederman, M. Schwartz, and J. Steinberger conducted the well-known two-neutnno experiment, which established a relationship between particles, muon and muon neutrinos, electron and electron neutrino, This later evolved into I he standard model of particle physics. The Nobel prize in physics was shared by these researchers in 1988. 

Horldesoii, T.., M. Rimdan, M. Dresden, and T..M. Firowiv Rise of the Standard Model Particles Physics in fhe 1960s and 1970s. Cambridge University Press, New Yoik, NY, 1997... 

The principal purpose here has been to demonstrate what sort of electroweak interaction physics may be required for the existence of an 0(3)b theory of quantum electrodynamics on the low-energy physical vacuum. This demonstrates that an extended standard model of electroweak interactions can support such a theory with the addition of new physics at high energy. 

In summary, the thermal history of the early Universe is very simple. It just assumes a global isotropic and uniform Universe. In its simplest version - no structure of any kind on scales larger than individual particles - the contents of the Universe are determined by "standard elmentary physics" i) ag lobal expansion governed by GR, ii) particles interactions governed by the "Standard Model" of Particle Physics, iii) distributions of particles governed by the laws of Statistical Physics. 

Nottingham, W.N. and Greenwood, D.A. (1998). Introduction to the Standard Model of Particle Physics (Cambridge University Press, New York). 

Much current theoretical work is devoted to finding a more fundamental and general underlying theory from which the standard model of particle physics could be deduced as the low energy limit. String theory and the inclusion of the gravitational interaction are central viewpoints, and in such theories particles may have structure and the CPT theorem may be violated. 

The Standard Model of particle physics describes all of the known building blocks of matter. Research the particles included in the Standard Model. Write a short report describing the known particles and those thought to exist but not detected experimentally. 

Suppose there is some new physics beyond the standard model of particle physics which leads to extra relativistic energy so that pr —> p R = pn + px, hereafter, for convenience of notation, the subscript R will be dropped. It is useful, and conventional, to account for this extra energy in terms of the equivalent number of extra neutrinos AN = px/ Pv (Steigman, Schramm, Gunn 1977 (SSG) see also Hoyle Tayler 1964, Peebles 1966, Shvartsman 1969). In the presence of this extra energy, prior to e annihilation... 

As discussed earlier, the stellar and Galactic chemical evolution uncertainties afflicting 3He are so large as to render the use of 3He to probe or test BBN problematic therefore, I will ignore 3He in the subsequent discussion. There are a variety of equally valid approaches to using D, 4He, and 7Li to test and constrain the standard models of cosmology and particle physics (SBBN). In the approach adopted here deuterium will be used to constrain the baryon density (r] or, equivalently, if>h 2 ) Within SBBN, this leads to predictions of Yp and [Li]p. Indeed, once the primordial deuterium abundance is chosen, r/ may be eliminated and both Yp and [Li] p predicted directly, thereby testing the consistency of SBBN. 

If further observational and associated theoretical work should confirm the current tension among the SBBN-predicted and observed primordial abundances of D, 4He, 7Li, what physics beyond the standard models of cosmology and particle physics has the potential to resolve the apparent conflicts Are those models which modify the early, radiation-dominated universe expansion rate consistent with observations of the CMB temperature fluctuation spectrum If neutrino degeneracy is invoked, is it consistent with the neutrino properties (masses and mixing angles) inferred from laboratory experiments as well as the solar and cosmic ray neutrino oscallation data ... 

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