全部 标题 作者
关键词 摘要

OALib Journal期刊
ISSN: 2333-9721
费用:99美元

查看量下载量

相关文章

更多...

Analytical Results Connecting Stellar Structure Parameters and Extended Reaction Rates

DOI: 10.1155/2014/656784

Full-Text   Cite this paper   Add to My Lib

Abstract:

Possible modification in the velocity distribution in the nonresonant reaction rates leads to an extended reaction rate probability integral. The closed form representation for these thermonuclear functions is used to obtain the stellar luminosity and neutrino emission rates. The composite parameter that determines the standard nuclear reaction rate through the Maxwell-Boltzmann energy distribution is extended to by the extended reaction rates through a more general distribution than the Maxwell-Boltzmann distribution. The new distribution is obtained by the pathway model introduced by Mathai (2005). Simple analytic models considered by various authors are utilized for evaluating stellar luminosity and neutrino emission rates and are obtained in generalized special functions such as Meijer's G-function and Fox's H-function. The standard and extended nonresonant thermonuclear functions are compared by plotting them. Behaviour of the new energy distribution, which is more general than the Maxwell-Boltzmann, is also studied. 1. Introduction The mystery behind the distant universe is explored so far by the understanding of the sun, the star near to us. It is the only star whose mass, radius, and luminosity are fairly accurately known. The structural change in the sun is due to the central thermonuclear reactor in it. Solar nuclear energy generation and solar neutrino emission are governed by chains of nuclear reactions in the gravitationally stabilized solar fusion reactor [1, 2]. Qualitative calculations of specific reaction rates require a large amount of experimental inputs and theoretical assumptions. By using the theories from nuclear physics and kinetic theory of gases one can determine the reaction rate for low-energy nonresonant thermonuclear reactions in nondegenerate plasma [3]. The formalization of the calculation of the reaction rate of interacting articles under cosmological or stellar conditions was presented by many authors [4, 5]. For the most common case, a nuclear reaction in which a particle of type strikes a particle of type producing a nucleus and a new particle is symbolically represented as where is the energy release given by , where denote the masses of the particles and denotes the velocity of light. The reaction rate of the interacting particles and is obtained by averaging the reaction cross section over the normalized density function of the relative velocity of the particles [5–7]. Let and denote the number densities of the particles and , respectively, and let be the reaction cross section where is the relative velocity of the

References

[1]  R. Davis Jr., “Nobel Lecture: a half-century with solar neutrinos,” Reviews of Modern Physics, vol. 75, no. 3, pp. 985–994, 2003.
[2]  H. J. Haubold and D. Kumar, “Extension of thermonuclear functions through the pathway model including Maxwell-Boltzmann and Tsallis distributions,” Astroparticle Physics, vol. 29, no. 1, pp. 70–76, 2008.
[3]  H. J. Haubold and R. W. John, “On the evaluation of an integral connected with the thermonuclear reaction rate in closed-form,” Astronomische Nachrichten, vol. 299, no. 5, pp. 225–232, 1978.
[4]  W. A. Fowler, G. R. Caughlan, and B. A. Zimmerman, “Thermonuclear rection rates,” Annual Review of Astronomy and Astrophysics, vol. 5, pp. 525–570, 1967.
[5]  A. M. Mathai and H. J. Haubold, Modern Problems in Nuclear and Neutrino Astrophysics, Akademie, Berlin, Germany, 1988.
[6]  H. J. Haubold and A. M. Mathai, “Analytic representations of modified non-resonant thermonuclear reaction rates,” Journal of Applied Mathematics and Physics, vol. 37, no. 5, pp. 685–695, 1986.
[7]  W. A. Fowler, “Experimental and theoretical nuclear astrophysics: the quest for the origin of the elements,” Reviews of Modern Physics, vol. 56, no. 2, pp. 149–179, 1984.
[8]  A. C. Phillips, The Physics of Stars, John Wiley & Sons, Chichester, UK, 2nd edition, 1999.
[9]  F. C. Adams, “Stars in other universes: stellar structure with different fundamental constants,” Journal of Cosmology and Astroparticle Physics, vol. 2008, no. 8, article 10, 2008.
[10]  M. Coraddu, G. Kaniadakis, A. Lavagno, M. Lissia, G. Mezzorani, and P. Quarati, “Thermal distributions in stellar plasmas, nuclear reactions and solar neutrinos,” Brazilian Journal of Physics, vol. 29, no. 1, pp. 153–168, 1999.
[11]  H. J. Haubold and A. M. Mathai, “On nuclear reaction rate theory,” Annalen der Physik, vol. 41, pp. 380–396, 1984.
[12]  M. Coraddu, M. Lissia, G. Mezzorani, and P. Quarati, “Super-Kamiokande hep neutrino best fit: a possible signal of non-Maxwellian solar plasma,” Physica A: Statistical Mechanics and Its Applications, vol. 326, no. 3-4, pp. 473–481, 2003.
[13]  A. Lavagno and P. Quarati, “Classical and quantum non-extensive statistics effects in nuclear many-body problems,” Chaos, Solitons and Fractals, vol. 13, no. 3, pp. 569–580, 2002.
[14]  A. Lavagno and P. Quarati, “Metastability of electron-nuclear astrophysical plasmas: motivations, signals and conditions,” Astrophysics and Space Science, vol. 305, no. 3, pp. 253–259, 2006.
[15]  M. Lissia and P. Quarati, “Nuclear astrophysical plasmas: ion distribution functions and fusion rates,” Europhysics News, vol. 36, no. 6, pp. 211–214, 2005.
[16]  C. Tsallis, “Possible generalization of Boltzmann-Gibbs statistics,” Journal of Statistical Physics, vol. 52, no. 1-2, pp. 479–487, 1988.
[17]  C. Tsallis, Introduction to Non-Extensive Statistical Mechanics, Springer, New York, NY, USA, 2009.
[18]  M. Gell-Mann and C. Tsallis, Eds., Nonextensive Entropy: Interdisciplinary Applications, Oxford University Press, New York, NY, USA, 2004.
[19]  A. M. Mathai and H. J. Haubold, “Pathway model, superstatistics, Tsallis statistics, and a generalized measure of entropy,” Physica A: Statistical Mechanics and Its Applications, vol. 375, no. 1, pp. 110–122, 2007.
[20]  R. K. Saxena, A. M. Mathai, and H. J. Haubold, “Astrophysical thermonuclear functions for Boltzmann-Gibbs statistics and Tsallis statistics,” Physica A: Statistical Mechanics and Its Applications, vol. 344, no. 3-4, pp. 649–656, 2004.
[21]  A. M. Mathai, “A pathway to matrix-variate gamma and normal densities,” Linear Algebra and Its Applications, vol. 396, no. 1–3, pp. 317–328, 2005.
[22]  A. M. Mathai and H. J. Haubold, “On generalized distributions and pathways,” Physics Letters A: General, Atomic and Solid State Physics, vol. 372, no. 12, pp. 2109–2113, 2008.
[23]  H. J. Haubold and D. Kumar, “Fusion yield: Guderley model and Tsallis statistics,” Journal of Plasma Physics, vol. 77, no. 1, pp. 1–14, 2011.
[24]  D. Kumar and H. J. Haubold, “On extended thermonuclear functions through pathway model,” Advances in Space Research, vol. 45, no. 5, pp. 698–708, 2010.
[25]  A. M. Mathai and R. K. Saxena, Generalized Hypergeometric Functions with Applications in Statistics and Physical Sciences, vol. 348 of Lecture Notes in Mathematics, Springer, New York, NY, USA, 1973.
[26]  A. M. Mathai, A Handbook of Generalized Special Functions for Statistics and Physical Sciences, Clarendo Press, Oxford, UK, 1993.
[27]  A. Erdélyi, Asymptotic Expansions, Dover, New York, NY, USA, 1956.
[28]  F. W. J. Olver, Asymptotics and Spcecial Functions, Academic Press, New York, NY, USA, 1974.
[29]  H. J. Haubold and A. M. Mathai, “Analytical results connecting stellar structure parameters and neutrino uxes,” Annalen der Physik, vol. 44, no. 2, pp. 103–116, 1987.

Full-Text

comments powered by Disqus

Contact Us

service@oalib.com

QQ:3279437679

WhatsApp +8615387084133