Conveners
Wednesday after lunch: LHC
- Soeren Andre Prell (Iowa State University)
The tau lepton is the only one kinematically allowed to decay into hadrons and a tau neutrino. Semi-leptonic tau decays (indicated as hadronic decays) occur about the 65% of times in a combination of charged and neutral hadrons, and a tau neutrino. The remaining times, tau leptons decay into a lighter charged lepton which can be identified and reconstructed by detectors, and two neutrinos,...
In the Standard Model (SM) lepton flavour numbers are exactly conserved. The observation of neutrino oscillations, however, proves that neutrinos are massive particles and allows for Lepton Flavour Violating (LFV) processes. Nevertheless, these processes are predicted with very low branching ratios and are sensitive to new physics effects, which could manifest as an enhancement in the decay...
Detailed measurements of Higgs boson properties can be performed using its decays into fermions, providing in particular a key window into the nature of the Yukawa interactions. This talk presents the latest measurements by the ATLAS experiment of Higgs boson properties in its delays into pairs of tau leptons, using the full Run 2 pp collision dataset collected at 13 TeV. They include in...
Many theories beyond the Standard Model predict new phenomena, such as leptoquarks, vector like leptons, Z', W' bosons, KK gravitons, supersymmetry, new scalars or heavy leptons, in final states with isolated, high-pT taus. Searches for new physics with such signatures, produced either resonantly or non-resonantly, are performed using the ATLAS experiment at the LHC. The most recent 13 TeV pp...
Relativistic heavy-ion beams at the LHC are accompanied by a large flux of equivalent photons, leading to photon-induced processes. In this talk, the observation of tau-lepton pair production in ultraperipheral lead-lead collisions recorded by the ATLAS experiment at the LHC in 2018 is reported. The measurement is used to constrain the tau lepton's anomalous magnetic dipole moment.
The measurement of the anomalous magnetic moment of leptons $a_l$ provides a sensitive test of QED and allows one to test for the existence of New Physics (NP) beyond the Standard Model. Since the NP effect is expected to scale with $m_l^2$, the tauon with its heavy mass promises to be the most suitable lepton for such a test. However, due to its short lifetime, the spin precessing methods...
