Physics with tau leptons

2007 ◽  
pp. i-i ◽  
Author(s):  
A. Stahl
Keyword(s):  
Tau Leptons

scholarly journals EVENTS WITH ISOLATED CHARGED LEPTONS AND LARGE MISSING TRANSVERSE MOMENTUM AT HERA

2004 ◽  
Vol 19 (25) ◽  
pp. 1881-1902 ◽  
Author(s):  
TANCREDI CARLI ◽  
DOMINIK DANNHEIM ◽  
LORENZO BELLAGAMBA
Keyword(s):  
Transverse Momentum ◽  
Zeus Collaboration ◽  
Tau Leptons ◽  
High Luminosity ◽  
Final State ◽  
Missing Transverse Momentum ◽  
State Formula ◽  
Charged Leptons ◽  
Good Agreement ◽  
Event Topology

Striking events with isolated charged leptons, large missing transverse momentum and large transverse momentum of the hadronic final state [Formula: see text] were observed at the electron proton collider HERA in a data sample corresponding to an integrated luminosity of about 130 pb-1. The H1 collaboration observed 11 events with isolated electrons or muons and with [Formula: see text]. Only 3.4±0.6 events were expected from Standard Model (SM) processes. Six of these events have [Formula: see text], while 1.3±0.3 events were expected. The ZEUS collaboration observed good agreement with the SM. However, ZEUS found two events with a similar event topology, but tau leptons instead of electrons or muons in the final state. Only 0.2±0.05 events were expected from SM processes. For various hypotheses, the compatibility of the experimental results was investigated with respect to the SM and with respect to possible explanations beyond the SM. Prospects for the high-luminosity HERA-II data taking period are given.

scholarly journals On spin asymmetry in muon and tau decays

2018 ◽  
Vol 33 (32) ◽  
pp. 1850191
Author(s):  
A. B. Arbuzov ◽  
T. V. Kopylova ◽  
I. K. Sklyarov
Keyword(s):  
Charged Lepton ◽  
Spin Asymmetry ◽  
Second Order ◽  
Tau Leptons ◽  
Mass Ratio ◽  
Fermi Model ◽  
Tau Decays ◽  
Standard Formula ◽  
Leading Logarithm ◽  
Michel Parameters

The angular asymmetry in decays of polarized muons and tau leptons is discussed. Both the standard [Formula: see text] Fermi model and the general parametrization via Michel parameters are considered. Numerical importance of contributions suppressed by charged lepton mass ratio is underlined. Contribution of the second order QED correction is estimated in the leading logarithm approximation.

scholarly journals Physics of tau leptons

1996 ◽  
Vol 274 (5-6) ◽  
pp. 287-374 ◽  
Author(s):  
S Gentile
Keyword(s):  
Tau Leptons

scholarly journals Study of the Drell-Yan process with the pair-production of polarized tau leptons in collisions of polarized proton beams

2019 ◽  
Vol 222 ◽  
pp. 03021
Author(s):  
A. Aleshko ◽  
E. Boos ◽  
V. Bunichev
Keyword(s):  
Parton Distribution ◽  
Polarization State ◽  
Distribution Functions ◽  
Hadronic Decay ◽  
New Method ◽  
Tau Leptons ◽  
Parton Distribution Functions ◽  
Accuracy Of Measurements ◽  
Polarized Proton

The new method for studying polarized parton distribution functions via the Drell-Yan process with tau production is proposed. The hadronic decay of tau to single charged pi-meson and neutrino is utilised for determination of the polarization state of the tau-lepton. The key feature of our approach is that we do not sum over the polarizations states of tau, but preserve this information through energies ofpions produced in corresponding decays. The new method in addition to existing ones should improve the accuracy of measurements of polarized structure functions of hadrons. In the current work, the feasibility of such an approach is assessed through numerical simulations.

scholarly journals ON THE SPIN CORRELATIONS OF MUONS AND TAU LEPTONS GENERATED IN THE ANNIHILATION PROCESSES e+e- → μ+μ-, e+e- → τ+τ-

2014 ◽  
Vol 35 ◽  
pp. 1460452
Author(s):  
VALERY V. LYUBOSHITZ ◽  
VLADIMIR L. LYUBOSHITZ
Keyword(s):  
Angular Correlation ◽  
Tau Leptons ◽  
Triplet States ◽  
Strongly Correlated ◽  
Electromagnetic Process ◽  
Correlation Tensor ◽  
Spin Correlations ◽  
Helicity Amplitudes ◽  
Unpolarized Electron ◽  
The One

Using the technique of helicity amplitudes, the electromagnetic process e+e- → μ+μ-(τ+τ-) is theoretically studied in the one-photon approximation. The structure of the triplet states of the final (μ+μ-) system is analyzed. It is shown that in the case of unpolarized electron and positron the final muons are also unpolarized, but their spins are strongly correlated. Explicit expressions for the components of the correlation tensor of the (μ+μ-) system are derived. The formula for the angular correlation at the decays of final muons μ+ and μ- is obtained. It is demonstrated that spin correlations of muons in the considered process have the purely quantum character, since one of the Bell-type incoherence inequalities for the correlation tensor components is always violated.

Sign in / Sign up

Export Citation Format

Share Document