000292120 001__ 292120 000292120 005__ 20211110132738.0 000292120 0247_ $$2arXiv$$aarXiv:1402.2787 000292120 0247_ $$2datacite_doi$$a10.3204/DESY-PROC-2013-03/Koerner 000292120 0247_ $$2inspire$$ainspire:1281073 000292120 037__ $$aPUBDB-2015-05833 000292120 041__ $$aen 000292120 0881_ $$aMITP-14-004; arXiv:1402.2787 000292120 088__ $$2Other$$aMITP-14-004 000292120 088__ $$2arXiv$$aarXiv:1402.2787 000292120 1001_ $$0P:(DE-HGF)0$$aKörner, J. G.$$b0$$eCorresponding author 000292120 1112_ $$aHelmholtz International School on Physics of Heavy Quarks and Hadrons$$cDubna$$d2013-07-15 - 2013-07-28$$gHQ2013$$wRussia 000292120 245__ $$aHelicity Amplitudes and Angular Decay Distributions 000292120 260__ $$aHamburg$$bDeutsches Elektronen-Synchrotron, DESY$$c2014 000292120 300__ $$a169-184 000292120 3367_ $$033$$2EndNote$$aConference Paper 000292120 3367_ $$2DRIVER$$aconferenceObject 000292120 3367_ $$0PUB:(DE-HGF)8$$2PUB:(DE-HGF)$$aContribution to a conference proceedings$$bcontrib$$mcontrib$$s1450256848_27715 000292120 3367_ $$0PUB:(DE-HGF)15$$2PUB:(DE-HGF)$$aInternal Report$$mintrep 000292120 3367_ $$2BibTeX$$aINPROCEEDINGS 000292120 520__ $$aI discuss how to obtain angular decay distributions for sequentialcascade decays using helicity methods. The angular decay distributionsfollow from a reasonably simple master formula involving bilinearforms of helicity amplitudes and Wigner's $d$ functions. I discussin some detail the issue of gauge invariance for off-shell gauge bosons.As a technical exercise I calculate the linear relation between thehelicity amplitudes and the invariant amplitudes of semileptonic andrare baryon decays. I discuss two explicit examples of angular decaydistributions for (i) the decay $t\to b+W^+(\to \ell^+\nu_\ell)$ (whichleads to the notion of the helicity fractions of the $W^+$), and (ii)the sequential decay $\Lambda_b\to\Lambda(\to p\pi^-)+J/\psi(\to \ell^+\ell^-)$.T = Helicity Amplitudes and Angular Decay Distributions 000292120 536__ $$0G:(DE-HGF)POF3-899$$a899 - ohne Topic (POF3-899)$$cPOF3-899$$fPOF III$$x0 000292120 588__ $$aDataset connected to INSPIRE 000292120 650_7 $$2INSPIRE$$ahelicity: amplitude analysis 000292120 650_7 $$2INSPIRE$$abaryon: decay 000292120 650_7 $$2INSPIRE$$agauge boson: off-shell 000292120 650_7 $$2INSPIRE$$ainvariance: gauge 000292120 650_7 $$2INSPIRE$$acascade decay 000292120 693__ $$0EXP:(DE-H253)HERA(machine)-20150101$$1EXP:(DE-588)4159571-3$$5EXP:(DE-H253)HERA(machine)-20150101$$aHERA$$eFacility (machine) HERA$$x0 000292120 773__ $$a10.3204/DESY-PROC-2013-03/Koerner 000292120 7870_ $$0PUBDB-2015-05817$$aAli, Ahmed et.al.$$dDeutsches Elektronen-Synchrotron, DESY, Hamburg, 2014$$iIsPartOf$$rDESY-PROC-2013-03$$tProceedings, Helmholtz International School on Physics of Heavy Quarks and Hadrons (HQ2013) 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.pdf$$yOpenAccess 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.gif?subformat=icon$$xicon$$yOpenAccess 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.jpg?subformat=icon-1440$$xicon-1440$$yOpenAccess 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.jpg?subformat=icon-180$$xicon-180$$yOpenAccess 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.jpg?subformat=icon-640$$xicon-640$$yOpenAccess 000292120 8564_ $$uhttps://bib-pubdb1.desy.de/record/292120/files/Koerner.pdf?subformat=pdfa$$xpdfa$$yOpenAccess 000292120 909CO $$ooai:bib-pubdb1.desy.de:292120$$pdnbdelivery$$pdriver$$pVDB$$popen_access$$popenaire 000292120 9131_ $$0G:(DE-HGF)POF3-899$$1G:(DE-HGF)POF3-890$$2G:(DE-HGF)POF3-800$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$aDE-HGF$$bProgrammungebundene Forschung$$lohne Programm$$vohne Topic$$x0 000292120 915__ $$0StatID:(DE-HGF)0510$$2StatID$$aOpenAccess 000292120 9201_ $$0I:(DE-H253)L-20120731$$kL$$lBibliothek und Dokumentation$$x0 000292120 980__ $$acontrib 000292120 980__ $$aVDB 000292120 980__ $$aUNRESTRICTED 000292120 980__ $$aintrep 000292120 980__ $$aI:(DE-H253)L-20120731 000292120 9801_ $$aUNRESTRICTED 000292120 9801_ $$aFullTexts