In this letter we discuss a certain class of Hidden Valley models where the dynamics in the hidden sector are close to a strongly coupled conformal fixed point. We show that these models can explain the excess in cosmic ray muon events with high muon multiplicities that has been reported from cosmic ray studies with the ALEPH and DELPHI detectors. We further point out that these models can also...

The Muon (g − 2) experiment, E821, at the Brookhaven AGS has the goal to measure the muon anomalous magnetic moment to a relative accuracy of ±3.5 × 10 −7. A su-perferric 14 m diameter storage ring has been constructed and an averaged magnetic field uniformity over the 90 mm diameter muon storage region of ± 1 part per million (ppm) has been achieved. A truncated double-cosine super-conducting ...

In the light of the recent measurement of the muon anmalous magnetic moment aμ by the Muon (g − 2) Collaboration, we examine the contribution to aμ from the exchange of flavor changing scalars. Assuming that the heavier generations have larger flavor changing couplings, we obtain a bound on μ−τ Yukawa coupling for a given scalar mass. Constraints on other flavor changing/conserving couplings ar...

Interest in the Muon Colliders is growing [1]. Electronpositron colliders beyond 2 TeV CM energy are likely to limited by background from beamstrahlung, and proton colliders beyond 20 TeV CM are likely to be limited by the sheer size of the multi-hundred km circumference. Being 200 times more massive than electrons, muons do not suffer from beamstrahlung limits. A 3 TeV muon collider is likely ...

We present simulation work performed at CERN and collaborating institutes concerning the muon front-end of a neutrino factory and a possible muon cooling experiment. The front-end in the CERN scheme of a neutrino factory has been revised, eliminating the 44 MHz cavities and starting directly with 88 MHz. Two options for a muon cooling experiment have been studied, one based on the 88 MHz CERN c...

The ee pair production in collisions of muon with atoms is considered to all orders in the parameter Zα. We obtain energy distribution of e and e as well as energy loss of muon passing through matter with heavy atoms. The found corrections to the Born contribution do not depend on the details of the target properties except of a simple factor. For the considered example of Pb target the muon en...

The phases of quantum interference effects in charged lepton production by neutrinos (neutrino oscillations) following pion decay at rest and in flight, muon decay and nuclear β−decay at rest as well as for ‘muon oscillations’ following pion decay at rest and in flight are calculated. The same phase is found for neutrino and muon oscillations following pion decay at rest. The results found disa...

A cosmic ray test system has been built to fully qualify the resistive plate chambers for the MUON system of the BESIII experiment. The setup has been designed to measure detector’s performance and to verify the stability and reliability of the MUON system. The same electronics, similar readout method and data analysis for BESIII MUON system have been used for this station. With this station, t...