Measurement of the Michel parameters and the nu(tau) helicity in tau lepton decays

6533b858fe1ef96bd12b5b6a

RESEARCH PRODUCT

Measurement of the Michel parameters and the nu(tau) helicity in tau lepton decays

A Heister S Schael R Barate I De Bonis D Decamp C Goy Jp Lees E Merle Mn Minard B Pietrzyk S Bravo Mp Casado M Chmeissani Jm Crespo E Fernandez M Fernandez Bosman L Garrido E Grauges M Martinez G Merino R Miquel Lm Mir A Pacheco H Ruiz A Colaleo D Creanza M De Palma G Iaselli G Maggi M Maggi S Nuzzo A Ranieri G Raso F Ruggieri G Selvaggi L Silvestris P Tempesta A Tricomi G Zito X Huang J Lin Q Ouyang T Wang Y Xie R Xu S Xue J Zhang L Zhang W Zhao D Abbaneo P Azzurri G Boix O Buchmuller M Cattaneo F Cerutti B Clerbaux G Dissertori H Drevermann Rw Forty M Frank Tc Greening Jb Hansen J Harvey P Janot B Jost M Kado P Mato A Moutoussi F Ranjard L Rolandi D Schlatter O Schneider P Spagnolo W Tejessy F Teubert E Tournefier J Ward Z Ajaltouni F Badaud A Falvard P Gay P Henrard J Jousset B Michel S Monteil Jc Montret D Pallin P Perret F Podlyski Jd Hansen Jr Hansen Ph Hansen Bs Nilsson A Waananen A Kyriakis C Markou E Simopoulou A Vayaki K Zachariadou A Blondel G Bonneaud Jc Brient A Rouge M Rumpf M Swynghedauw M Verderi H Videau V Ciulli E Focardi G Parrini A Antonelli M Antonelli G Bencivenni G Bologna F Bossi P Campana G Capon V Chiarella P Laurelli G Mannocchi F Murtas Gp Murtas L Passalacqua M Pepe Altarelli Aw Halley Jg Lynch P Negus V O'shea C Raine As Thompson S Wasserbaech R Cavanaugh S Dhamotharan C Geweniger P Hanke G Hansper V Hepp Ee Kluge A Putzer J Sommer K Tittel S Werner M Wunsch R Beuselinck Dm Binnie W Cameron Pj Dornan M Girone N Marinelli Jk Sedgbeer Jc Thompson Vm Ghete P Girtler E Kneringer D Kuhn G Rudolph E Bouhova Thacker Ck Bowdery Aj Finch F Foster G Hughes Rwl Jones Mr Pearson Na Robertson I Giehl K Jakobs K Kleinknecht G Quast B Renk E Rohne Hg Sander H Wachsmuth C Zeitnitz A Bonissent J Carr P Coyle O Leroy P Payre D Rousseau M Talby M Aleppo F Ragusa A David H Dietl G Ganis K Huttmann G Lutjens C Mannert W Manner Hg Moser R Settles H Stenzel W Wiedenmann G Wolf J Boucrot O Callot M Davier L Duflot Jf Grivaz P Heusse A Jacholkowska J Lefrancois Jj Veillet I Videau C Yuan G Bagliesi T Boccali G Calderini L Foa A Giassi F Ligabue Alberto Maria Messineo F Palla G Sanguinetti A Sciaba G Sguazzoni R Tenchini A Venturi Pg Verdini Ga Blair G Cowan Mg Green T Medcalf A Misiejuk Ja Strong P Teixeira Dias Von Wimmersperg Toeller Jh Rw Clifft Tr Edgecock Pr Norton Ir Tomalin B Bloch Devaux P Colas S Emery W Kozanecki E Lancon Mc Lemaire E Locci P Perez J Rander Jf Renardy A Roussarie Jp Schuller J Schwindling A Trabelsi B Vallage N Konstantinidis Am Litke G Taylor Cn Booth S Cartwright F Combley M Lehto Lf Thompson K Affholderbach A Bohrer S Brandt C Grupen A Ngac G Prange U Sieler G Giannini J Rothberg Sr Armstrong K Cranmer P Elmer Dps Ferguson Y Gao S Gonzalez Oj Hayes H Hu S Jin J Kile Pa Mcnamara J Nielsen W Orejudos Yb Pan Y Saadi Ij Scott J Walsh Sl Wu X Wu G. Zobernig

subject

Physics Particle physics [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]Physics and Astronomy (miscellaneous)010308 nuclear & particles physics Electron–positron annihilation Hadron Parity (physics)Weak interaction 01 natural sciences Helicity 0103 physical sciences [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Michel parameters High Energy Physics::Experiment 010306 general physics Engineering (miscellaneous)Particle Physics - Experiment Lepton

description

A measurement of the Michel parameters and the average $\nu_\tau$ helicity in $\tau$ lepton decays is described. The data was collected with the ALEPH detector at LEP during the years 1991 to 1995. A total integrated luminosity of 155\,$\text{pb}^{-1}$ is analysed. The Michel parameters $\rho_l$, $\xi_l$, $(\xi\delta)_l$ ($l=e,\mu$), and $\eta_\mu$ are determined for the leptonic deca ys, and the chirality parameters $\xi_\pi$, $\xi_\rho$, and $\xi_{a_1}$ for the hadronic final states. Under the assumptions of $e$\bis $\mu$ universality and $\xi_\pi=\xi_\rho=\xi_{a_1}$, the values $\rho_l=0.742\pm 0.016, \eta_l=0.01 2\pm 0.026,\break (\xi\delta)_l=0.776\pm 0.051, \xi_l=0.986\pm 0.074$, and $\xi_h=0.992\pm 0.011$ are obtained. No significant deviation is observed from the Standard Model assumption of the \ vma{} structure of the charged weak interaction.

year	journal	country	edition	language
2001-01-01

10.1007/s100520100813 http://hdl.handle.net/11568/177823