Contribution to a conference proceedings/Internal Report

PUBDB-2015-05821

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Lectures on new physics searches in $B\to D^{(*)}\tau\nu_\tau$

Fajfer, S. ; Nisandzic, I.

2014
Deutsches Elektronen-Synchrotron, DESY Hamburg

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Please use a persistent id in citations: doi:10.3204/DESY-PROC-2013-03/Fajfer

Report No.: DESY-PROC-2013-03

Abstract: The Standard model's predictions for the rates for $B\to D^{*} \tau\nu_\tau$ and $B\to D\tau\nu_\tau$ differ from the experimental results.The difference might be accounted by the presence of new physics.The understanding of the non-perturbative QCD dynamics in the mesontransitions is crucial in order to refine the searches for new physicseffects. We give short introduction to heavy quark effective theory(HQET) and then investigate the most general set of lowest dimensionaleffective operators leading to helicity suppressed modifications of$b\to c$ (semi)leptonic transitions. The contributions of these operatorsto $B\to D^{(*)} \tau \nu_\tau$ decay amplitudes can be found by determiningthe differential decay rate, longitudinal $D^*$ polarization fraction,$D^*- \tau$ opening angle asymmetry and the $\tau$ helicity asymmetry.We identify the size of possible new physics contributions constrainedby the present $ B\to D^{(*)} \tau \nu_\tau$ rate measurements andfind significant modifications are still possible in all these observables.Then we discuss few models of new physics scenarios which can contributein both decay modes.T = Lectures on new physics searches in $B\to D^{(*)}\tau\nu_\tau$

Keyword(s): new physics ; lectures ; B: semileptonic decay ; B: branching ratio ; decay: flavor changing ; neutral current: flavor changing ; quark: flavor: violation ; Heavy Quark Effective Theory ; quantum chromodynamics: nonperturbative ; tau: helicity ; helicity: asymmetry ; B --> D tau antineutrino/tau ; B --> D*(2010) tau antineutrino/tau

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Contributing Institute(s):

1. Bibliothek und Dokumentation (L)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

Experiment(s):

1. Facility (machine) HERA

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Linked articles:

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Proceedings/Internal Report Ali, A. (Editor)DESY* ; Bystritskiy, Y. (Editor) ; Ivanov, M. (Editor)
Proceedings, Helmholtz International School on Physics of Heavy Quarks and Hadrons (HQ2013)
2014Helmholtz International School on Physics of Heavy Quarks and Hadrons , HQ2013, DubnaDubna, Russia, 15 Jul 2013 - 28 Jul 20132013-07-152013-07-28 Hamburg : Deutsches Elektronen-Synchrotron, DESY (2014) [10.3204/DESY-PROC-2013-03]2014     Files BibTeX | EndNote: XML, Text | RIS

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