Related papers: New physics effects in rare Z decays
The interpretation of the new effect of the superfluidity in reactions with small number of particles is discussed in a simple model where the exact solution is accessible. It is find that the fluctuations of observable with the gauge angle…
Rare decays are flavour changing neutral current processes that are loop-suppressed in the Standard Model (SM). New particles in SM extensions can therefore give significant contributions, modifying branching fractions and angular…
One of the most interesting puzzles in particle physics today is that new physics is expected at the TeV energy scale to solve the hierarchy problem, and stabilise the Higgs mass, but so far no unambiguous signal of new physics has been…
Fundamental particle physics is at a cross road. On the one hand the Standard Model successfully accounts for all experimental observations to date. On the other hand the ElectroWeak symmetry breaking mechanism is poorly understood and…
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon…
We consider a linearized, effective quantum theory of gravitation in which gravity weakens at energies higher than ~10^-3 eV in order to accommodate the apparent smallness of the cosmological constant. Such a theory predicts departures from…
Standard Model extensions often predict low-mass and very weakly interacting particles, such as the axion. A number of small-scale experiments at the intensity/precision frontier are actively searching for these elusive particles,…
Theoretical predictions for the top quark rare decays are reviewed within and beyond the standard model. Expectations at the CERN Large Hadron Collider are discussed.
Extending the sensitivity to New Physics beyond the anticipated reach of the LHC is a prime aim of future colliders. This paper summarises the potential of an e+e- linear collider, at and beyond 1 TeV, using a realistic simulation of the…
Gravity can become strong at the TeV scale in the theory of extra dimensions. An effective Lagrangian can be used to describe the gravitational interactions below a cut-off scale. In this work, we study the associated production of the…
Experimental analysis of data from particle collisions is typically expressed as statistical limits on a few benchmark models of particular, often historical, interest. The implications of the data for other theoretical models (current or…
In this paper we consider a general $SU(2)_L\otimes SU(2)_R$ invariant Lagrangian describing scalar, vector and axial-vector resonances. By expanding the WW and the ZZ scattering amplitude up to the fourth order in the external momenta we…
We parametrize phenomenologically possible new physics effects and calculate their influence on the invariant dilepton mass spectrum and the Dalitz plot for the decays $B \to K \ell^+ \ell^-$ and $B \to K^\ast \ell^+ \ell^-$. Especially the…
We show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there…
This article summarises the physics at future linear colliders. It will be shown that in all studied physics scenarios a 1 TeV linear collider in addition to the LHC will enhance our knowledge significantly and helps to reconstruct the…
The search and study of heavy Higgs bosons is an important part of the anticipated physics program of a high energy e+e- linear collider. This paper reviews the expected sensitivity of e+e- collisions from 0.5 up to 3 TeV in the study of…
Searches for new physics in the top quark sector are of great theoretical interest, yet some powerful avenues for discovery remain unexplored. We characterize the expected statistical power of the LHC dataset to constrain the single…
Experimental results obtained with the HERA collider and recent progress in their theoretical interpretation are reviewed. After a short introduction to HERA physics, deep inelastic scattering and photoproduction are discussed as (virtual)…
We present an overview of rare K, D and B decays. Particular attention is devoted to those flavour-changing neutral-current processes of K and B mesons that offer the possibility of new significant tests of the Standard Model. The…
Measurements at B factories have provided important constraints on new physics in several rare processes involving the B meson. New Physics, if present in the b quark sector may also affect the top sector. In an effective Lagrangian…