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Title: Identity method reexamined

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Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review C
Additional Journal Information:
Journal Volume: 96; Journal Issue: 5; Related Information: CHORUS Timestamp: 2017-11-03 10:26:50; Journal ID: ISSN 2469-9985
American Physical Society
Country of Publication:
United States

Citation Formats

Pruneau, Claude A. Identity method reexamined. United States: N. p., 2017. Web. doi:10.1103/PhysRevC.96.054902.
Pruneau, Claude A. Identity method reexamined. United States. doi:10.1103/PhysRevC.96.054902.
Pruneau, Claude A. 2017. "Identity method reexamined". United States. doi:10.1103/PhysRevC.96.054902.
title = {Identity method reexamined},
author = {Pruneau, Claude A.},
abstractNote = {},
doi = {10.1103/PhysRevC.96.054902},
journal = {Physical Review C},
number = 5,
volume = 96,
place = {United States},
year = 2017,
month =

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 3, 2018
Publisher's Accepted Manuscript

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  • To test for linkage between a trait and a marker, one can consider identical marker alleles in related individuals, for instance, sibs. For recessive diseases, it has been shown that some information may be gained from the identity by descent (IBD) of the two alleles of an affected inbred individual at the marker locus. The aim of this paper is to extend the sib-pair method of linkage analysis to the situation of sib pairs sampled from consanguineous populations. This extension takes maximum advantage of the information provided by both the IBD pattern between sibs and allelic identity within each sibmore » of the pair. This is possible through the use of the condensed identity coefficients. Here, we propose a new test of linkage based on a {Chi}{sup 2}. We compare the performance of this test with that of the classical {Chi}{sup 2} test based on the distribution of sib pairs sharing 0, 1, or 2 alleles IBD. For sib pairs from first-cousin matings, the proposed test can better detect the role of a disease-susceptibility (DS) locus. Its power is shown to be greater than that of the classical test, especially for models where the DS allele may be common and incompletely penetrant; that is to say for situations that may be encountered in multifactorial diseases. A study of the impact of inbreeding on the expected proportions of sib pairs sharing 0, 1, or 2 alleles IBD is also performed here. Ignoring inbreeding, when in fact inbreeding exists, increases the rate of type I errors in tests of linkage. 21 refs., 8 figs., 9 tabs.« less
  • Scattering events of the type a + A $Yields$ A + a, where A is composed of (n - 1) particles all identical to a, are studied within the framework of the channel coupling array approach to many-body scattering. The n coupled equations describing the scattering derived under the assumption that the n particles forming the scattering system are distinguishable are shown to collapse to a single equation when particle identity is taken into account, and a particular choice of a channel coupling array which includes the important special case of channel permuting arrays is made. For this latter choice,more » which guarantees connectedness, only the exchange Born potential explicitly enters the integral equation for the transition operator or the differential equation for the scattering function. The present derivation provides a justification of equations used previously in e$sup -$ + H calculations. (AIP)« less
  • Event-by-event fluctuations of the chemical composition of the hadronic final state of relativistic heavy-ion collisions carry valuable information on the properties of strongly interacting matter produced in the collisions. However, in experiments incomplete particle identification distorts the observed fluctuation signals. The effect is quantitatively studied and a new technique for measuring chemical fluctuations, the identity method, is proposed. The method fully eliminates the effect of incomplete particle identification. The application of the identity method to experimental data is explained.
  • An incomplete particle identification distorts the observed event-by-event fluctuations of the hadron chemical composition in nucleus-nucleus collisions. A new experimental technique called the identity method was recently proposed. It eliminated the misidentification problem for one specific combination of the second moments in a system of two hadron species. In the present paper, this method is extended to calculate all the second moments in a system with an arbitrary number of hadron species. Special linear combinations of the second moments are introduced. These combinations are presented in terms of single-particle variables and can be found experimentally from the event-by-event averaging. Themore » mathematical problem is then reduced to solving a system of linear equations. The effect of incomplete particle identification is fully eliminated from the final results.« less
  • Event-by-event fluctuations of the chemical composition of the hadronic system produced in nuclear collisions are believed to be sensitive to properties of the transition between confined and deconfined strongly interacting matter. In this paper a new technique for the study of chemical fluctuation, the identity method, is introduced and its features are discussed. The method is tested using data on central PbPb collisions at 40 A GeV registered by the NA49 experiment at the CERN SPS.