282852
Electroweak baryogenesis: Concrete in a SUSY model with a gauge singlet
SUSY models with a gauge singlet easily allow for a strong first order electroweak phase transition (EWPT) if the vevs of the singlet and Higgs fields are of comparable size. We discuss the profile of the stationary expanding bubble wall and CP-violation in the effective potential, in particular transitional CP-violation inside the bubble wall during the EWPT. The dispersion relations for charginos contain CP-violating terms in the WKB approximation. These enter as source terms in the Boltzmann equations for the (particle-antiparticle) chemical potentials and fuel the creation of a baryon asymmetry through the weak sphaleron in the hot phase. This is worked out for concrete parameters.
16265499
Bubble wall velocity in the minimal supersymmetric light stop scenario
We build on existing calculations of the wall velocity of the expanding bubbles of the broken symmetry phase in a first-order electroweak phase transition within the light stop scenario (LSS) of the MSSM. We carry out the analysis using the 2-loop thermal potential for values of the Higgs mass consistent with present experimental bounds. Our approach relies on describing the interaction between the bubble and the hot plasma by a single friction parameter, which we fix by matching to an existing 1-loop computation and extrapolate to our regime of interest. For a sufficiently strong phase transition (in which washout of the newly created baryon asymmetry is prevented) we obtain values of the wall velocity, vw≈0.05, far below the speed of sound in the medium, and not very much deviating from the previous 1-loop calculation. We find that the phase transition is about 10% stronger than suggested by simply evaluating the thermal potential at the critical temperature. We also comment on the relevance of our results to extended models, such as the NMSSM.
123226903
Neutrino oscillations and warped geometry.
It is shown how small Dirac and Majorana masses for neutrinos arise in five dimensional models with warped geometry. The atmospheric and solar neutrino anomalies can be satisfactorily resolved. Rare processes, such as proton decay, neutrinoless double beta decay and flavor violation, may provide valuable information on the higher dimensional theory.
15025301
Electroweak constraints on warped geometry in five dimensions and beyond
Here we consider the tree level corrections to electroweak (EW) observables from standard model (SM) particles propagating in generic warped extra dimensions. The scale of these corrections is found to be dominated by three parameters, the Kaluza-Klein (KK) mass scale, the relative coupling of the KK gauge fields to the Higgs and the relative coupling of the KK gauge fields to fermion zero modes. It is found that 5D spaces that resolve the hierarchy problem through warping typically have large gauge-Higgs coupling. It is also found in D> 5 where the additional dimensions are warped the relative gauge-Higgs coupling scales as a function of the warp factor. If the warp factor of the additional spaces is contracting towards the IR brane, both the relative gauge-Higgs coupling and resulting EW corrections will be large. Conversely EW constraints could be reduced by finding a space where the additional dimension’s warp factor is increasing towards the IR brane. We demonstrate that the Klebanov Strassler solution belongs to the former of these possibilities.
16466682
The supersymmetric standard model
This set of lectures introduces at an elementary level the supersymmetric Standard Model and discusses some of its phenomenological properties. ∗
121566694
Neutrino oscillations, rare decays and warped geometry
We discuss how the solar and atmospheric neutrino anomalies can be satisfactorily resolved via neutrino oscillations in a five-dimensional framework with warped geometry. In one particularly significant example, no new fields such as singlet (right-handed) neutrinos have to be introduced. We also consider rare processes including proton and neutrinoless double beta decays. The Kaluza–Klein excitations of the standard model particles are predicted to possess masses in the 10 TeV range.
113403181
New data acquisition system for the COMPASS experiment
The modern market offers low cost high performance FPGA integrated circuits equipped with dozens of multi gigabit serial links making them ideal devices for data transmission and data sorting applications. Therefore we have designed the new DAQ system that would perform the detector readout and event building in a custom made FPGA based hardware. The software part will provide the control and monitoring function. Currently, the prototypes of the new FPGA card are being tested and the control and monitoring software is being prepared for the tests with the real hardware.
14827287
FPGA based data acquisition system for COMPASS experiment
This paper presents the current data acquisition system (DAQ) of the COMPASS experiment at CERN and discusses development of a new DAQ. The aim of the new DAQ is to substitute software event building by structure composed of special FPGA cards that will do the event building. The software part of the new DAQ is robust multinode system with high emphasis on reliability. It is based on state machines and implemented in C++ with usage of the QT framework, the DIM library, and the IPBus technology. A prototype of the system has been developed and tested. The new DAQ software fulfills given requirements.
111119743
Upgrade of the COMPASS calorimetric trigger
In 2009 COMPASS performed a short measurement of neutral Primakoff reactions, characterised by highly energetic photons in one of the two electromagnetic calorimeters. A digital trigger was implemented in the existing readout electronics which calculates the energy released in the central region of the calorimeter. In 2012 a long measurement of these processes has been performed. In order to extend the kinematic range to lower energetic photons the trigger system has been upgraded in a way to be more selective to specific physics channels. The new ADC firmware preserves hit information and provides it to newly developed backplane trigger modules. There hits from all three thousand channels are processed and the trigger decision is made.