Radiation astronomy/Hadrons

< Radiation astronomy

Hadrons are subatomic particles of a type including baryons and mesons that can take part in the strong interaction and may be useful in astronomy.

Hadrons

A hadron, like an atomic nucleus, is "a composite particle ... held together by the strong force ... Hadrons are categorized into two families: baryons (such as protons and neutrons[)] ... and mesons".[1]

Baryons

"A baryon is a composite subatomic particle [bound together by] the strong interaction, whereas leptons [are] not. The most familiar baryons are the protons and neutrons that make up most of the mass of the visible matter in the universe. Electrons (the other major component of the atom) are leptons. Each baryon has a corresponding antiparticle (antibaryon)".[2]

"Baryonic matter is matter composed mostly of baryons (by mass), which includes atoms of any sort (and thus includes nearly all matter that may be encountered or experienced in everyday life)."[2]

Neutrons

"Due to the very low energy of the colliding protons in the Sun, only states with no angular momentum (s-waves) contribute significantly. One can consider it as a head-on collision, so that angular momentum plays no role. Consequently, the total angular momentum is the sum of the spins, and the spins alone control the reaction. Because of Pauli's exclusion principle, the incoming protons must have opposite spins. On the other hand, in the only bound state of deuterium, the spins of the neutron and proton are aligned. Hence a spin flip must take place [...] The strength of the nuclear force which holds the neutron and the proton together depends on the spin of the particles. The force between an aligned proton and neutron is sufficient to give a bound state, but the interaction between two protons does not yield a bound state under any circumstances. Deuterium has only one bound state."[3]

The "force acting between the protons and the neutrons [is] the strong force".[3]

"A potential of 36 MeV is needed to get just one energy state."[3]

The width of a bound proton and neutron is "2.02 x 10-13 cm".[3]

"Another possibility [regarding neutron stars, called "baryon matter",] is that in the absence of gravity high-density baryonic matter is bound by purely strong forces. [...] nongravitationally bound bulk hadronic matter is consistent with nuclear physics data [...] and low-energy strong interaction data [...] The effective field theory approach has many successes in nuclear physics [...] suggesting that bulk hadronic matter is just as likely to be a correct description of matter at high densities as conventional, unbound hadronic matter."[4]

"The idea behind baryon matter is that a macroscopic state may exist in which a smaller effective baryon mass inside some region makes the state energetically favored over free particles. [...] This state will appear in the limit of large baryon number as an electrically neutral coherent bound state of neutrons, protons, and electrons in β-decay equilibrium."[4]

Protons

A "new type of neutron star model (Q stars) [is such that] high-density, electrically neutral baryonic matter is a coherent classical solution to an effective field theory of strong forces and is bound in the absence of gravity. [...] allows massive compact objects, [...] and has no macroscopic minimum mass."[4]

"Compact objects in astronomy are usually analyzed in terms of theoretical characteristics of neutron stars or black holes that are based upon calculations of equations of state for matter at very high densities. At such high densities, the effects of strong forces cannot be neglected. There are several conventional approaches to describing nuclear forces, all of which find that for a baryon number greater than ~250, a nucleus will become energetically unbound. High-density hadronic matter is not stable in these theories until there are enough baryons for gravitational binding to form a neutron star, typically with a minimum mass ≳ 0.1 M⊙ and maximum mass ≲ 3 M⊙."[4]

Mesons

A meson is a composite subatomic particle "bound together by the strong interaction."[5]

"Because mesons are composed of sub-particles, they have a physical size, with a radius roughly one femtometre, which is about 2/3 the size of a proton or neutron. All mesons are unstable, with the longest-lived lasting for only a few hundredths of a microsecond. Charged mesons decay (sometimes through intermediate particles) to form electrons and neutrinos. Uncharged mesons may decay to photons."[5]

"Mesons are not produced by radioactive decay, but appear in nature only as short-lived products of very high-energy interactions in matter ... In cosmic ray interactions, for example, such particles are ordinary protons and neutrons. Mesons are also frequently produced artificially in high-energy particle accelerators that collide protons, anti-protons, or other particles."[5]

"In nature, the importance of lighter mesons is that they are the associated quantum-field particles that transmit the nuclear force, in the same way that photons are the particles that transmit the electromagnetic force."[5]

"Each type of meson has a corresponding antiparticle (antimeson) in which quarks are replaced by their corresponding antiquarks and vice-versa."[5]

Mesons are subject to "both the weak and strong interactions. Mesons with net electric charge also participate in the electromagnetic interaction."[5]

"While no meson is stable, those of lower mass are nonetheless more stable than the most massive mesons, and are easier to observe and study in particle accelerators or in cosmic ray experiments. They are also typically less massive than baryons, meaning that they are more easily produced in experiments, and thus exhibit certain higher energy phenomena more readily than baryons composed of the same quarks would."[5]

Theoretical hadron astronomy

Def. a "strongly interacting particle [or a] particle which is affected by the strong nuclear force"[6] is called a hadron.

Neutrinos

"Atmospheric neutrinos can interact with the detector producing also hadrons. The most probable of these reactions is the single pion production [20][21]:"[7]

\nu_{\mu} + p \rightarrow \mu^- + \pi^+ + p^'.

"There is also a small loss due to inelastic hadronic interactions of the decay particles before they are stopped."[7]

The "optical properties of mixtures of PXE [phenyl-o-xylylethane] and derivatives of mineral oils are under investigation [3]."[7]

Strong interaction

"The strong interaction is observable in two areas: on a larger scale (about 1 to 3 femtometers (fm)), it is the force that binds protons and neutrons (nucleons) together to form the nucleus of an atom. On the smaller scale (less than about 0.8 fm, the radius of a nucleon), it is also the force ... that [forms and holds together] protons, neutrons and other hadron particles."[8]

"In the context of binding protons and neutrons together to form atoms, the strong interaction is called the nuclear force (or residual strong force). [T]he strong interaction ... obeys a quite different distance-dependent behavior between nucleons ... ."[8]

"Unlike [the] electromagnetic [and] weak [interactions], the strong force does not diminish in strength with increasing distance. After a limiting distance (about the size of a hadron) has been reached, it remains at a strength of about 10,000 newtons, no matter how much farther the distance between [hadrons].[9] The ... force between [hadrons] remains constant at any distance after [the hadrons] travel only a tiny distance from each other, and is equal to that need to raise one ton, which is 1000 kg x 9.8 N = ~ 10,000 N.[9]"[8]

"[T]he amount of work done against a force of 10,000 newtons (about the weight of a one-metric ton mass on the surface of the Earth) is enough to create particle-antiparticle pairs within a very short distance of an interaction."[8]

"The strong force is ... nearly absent between such hadrons (i.e., between baryons or mesons). In this case, only a residual force (described below) called the residual strong force acts between [these] hadrons, and this residual force diminishes rapidly with distance, and is thus very short-range (effectively a few femtometers)."[8]

Research

Hypothesis:

  1. Hadrons can be used in astronomy to discern information about their sources.

Control groups

This is an image of a Lewis rat. Credit: Charles River Laboratories.

The findings demonstrate a statistically systematic change from the status quo or the control group.

“In the design of experiments, treatments [or special properties or characteristics] are applied to [or observed in] experimental units in the treatment group(s).[10] In comparative experiments, members of the complementary group, the control group, receive either no treatment or a standard treatment.[11]"[12]

Proof of concept

Def. a “short and/or incomplete realization of a certain method or idea to demonstrate its feasibility"[13] is called a proof of concept.

Def. evidence that demonstrates that a concept is possible is called proof of concept.

The proof-of-concept structure consists of

  1. background,
  2. procedures,
  3. findings, and
  4. interpretation.[14]

See also

References

  1. ↑ "Hadron, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. July 11, 2013. Retrieved 2013-07-12.
  2. 1 2 "Baryon, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. May 3, 2013. Retrieved 2013-07-12.
  3. 1 2 3 4 Giora Shaviv (2013). Giora Shaviv. ed. Towards the Bottom of the Nuclear Binding Energy, In: The Synthesis of the Elements. Berlin: Springer-Verlag. pp. 169-94. doi:10.1007/978-3-642-28385-7_5. ISBN 978-3-642-28384-0. http://link.springer.com/chapter/10.1007/978-3-642-28385-7_5#page-1. Retrieved 2013-12-19.
  4. 1 2 3 4 Safi Bahcall, Bryan W. Lynn, and Stephen B. Selipsky (October 10, 1990). "New Models for Neutron Stars". The Astrophysical Journal 362 (10): 251-5. doi:10.1086/169261. http://adsabs.harvard.edu/abs/1990ApJ...362..251B. Retrieved 2014-01-11.
  5. 1 2 3 4 5 6 7 "Meson, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. June 16, 2013. Retrieved 2013-07-12.
  6. ↑ "hadron, In: Wiktionary". San Francisco, California: Wikimedia Foundation, Inc. 7 March 2015. Retrieved 2015-06-16.
  7. 1 2 3 T. Marrodán Undagoitia, F. von Feilitzsch, M. Göger-Neff, C. Grieb, K. A. Hochmuth, L. Oberauer, W. Potzel, and M. Wurm (1 October 2005). "Search for the proton decay p→ K+ ν in the large liquid scintillator low energy neutrino astronomy detector LENA". Physical Review D 72 (7): 075014. doi:10.1103/PhysRevD.72.075014. http://arxiv.org/pdf/hep-ph/0511230.pdf. Retrieved 2015-06-21.
  8. 1 2 3 4 5 "Strong interaction, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. May 27, 2012. Retrieved 2012-06-30.
  9. 1 2 Fritzsch, op. cite, p. 164.
  10. ↑ Klaus Hinkelmann, Oscar Kempthorne (2008). Design and Analysis of Experiments, Volume I: Introduction to Experimental Design (2nd ed.). Wiley. ISBN 978-0-471-72756-9. http://books.google.com/?id=T3wWj2kVYZgC&printsec=frontcover.
  11. ↑ R. A. Bailey (2008). Design of comparative experiments. Cambridge University Press. ISBN 978-0-521-68357-9. http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=9780521683579.
  12. ↑ "Treatment and control groups, In: Wikipedia". San Francisco, California: Wikimedia Foundation, Inc. May 18, 2012. Retrieved 2012-05-31.
  13. ↑ "proof of concept, In: Wiktionary". San Francisco, California: Wikimedia Foundation, Inc. November 10, 2012. Retrieved 2013-01-13.
  14. ↑ Ginger Lehrman and Ian B Hogue, Sarah Palmer, Cheryl Jennings, Celsa A Spina, Ann Wiegand, Alan L Landay, Robert W Coombs, Douglas D Richman, John W Mellors, John M Coffin, Ronald J Bosch, David M Margolis (August 13, 2005). "Depletion of latent HIV-1 infection in vivo: a proof-of-concept study". Lancet 366 (9485): 549-55. doi:10.1016/S0140-6736(05)67098-5. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1894952/. Retrieved 2012-05-09.

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