Electroweak and Flavour Structure of a Warped Extra Dimension with Custodial Protection

We present the electroweak and flavour structure of a model with a warped extra dimension and the bulk gauge group SU(3) x SU(2)_L x SU(2)_R x P_LR x U(1)_X. The presence of SU(2)_R implies an unbroken custodial symmetry in the Higgs system allowing to eliminate large contributions to the T parameter, whereas the P_LR symmetry and the enlarged fermion representations provide a custodial symmetry for flavour diagonal and flavour changing couplings of the SM Z boson to left-handed down-type quarks. We diagonalise analytically the mass matrices of charged and neutral gauge bosons including the first KK modes. We present the mass matrices for quarks including heavy KK modes and discuss the neutral and charged currents involving light and heavy fields. We give the corresponding complete set of Feynman rules in the unitary gauge.Comment: 74 pages, 2 figures. clarifying comments and references added, version to be published in JHE

The Impact of a 4th Generation on Mixing and CP Violation in the Charm System

We study D0-D0 mixing in the presence of a fourth generation of quarks. In particular, we calculate the size of the allowed CP violation which is found at the observable level well beyond anything possible with CKM dynamics. We calculate the semileptonic asymmetry a_SL and the mixing induced CP asymmetry eta_fS_f which are correlated with each other. We also investigate the correlation of eta_fS_f with a number of prominent observables in other mesonic systems like epsilon'/epsilon, Br(K_L -> pi0 nu nu), Br(K+ -> pi+ nu nu), Br(B_s ->mu+ mu-), Br(B_d -> mu+ mu-) and finally S_psi phi in the B_s system. We identify a clear pattern of flavour and CP violation predicted by the SM4 model: While simultaneous large 4G effects in the K and D systems are possible, accompanying large NP effects in the B_d system are disfavoured. However this behaviour is not as pronounced as found for the LHT and RSc models. In contrast to this, sizeable CP violating effects in the B_s system are possible unless extreme effects in eta_fS_f are found, and Br(B_s ->mu+ mu-) can be strongly enhanced regardless of the situation in the D system. We find that, on the other hand, S_psi phi > 0.2 combined with the measured epsilon'/epsilon significantly diminishes 4G effects within the D system.Comment: 22 pages, 23 figures, v2 (references added

Inverse problems with inexact forward operator : iterative regularization and application in dynamic imaging

The classic regularization theory for solving inverse problems is built on the assumption that the forward operator perfectly represents the underlying physical model of the data acquisition. However, in many applications, for instance in microscopy or magnetic particle imaging, this is not the case. Another important example represent dynamic inverse problems, where changes of the searchedfor quantity during data collection can be interpreted as model uncertainties. In this article, we propose a regularization strategy for linear inverse problems with inexact forward operator based on sequential subspace optimization methods (SESOP). In order to account for local modelling errors, we suggest to combine SESOP with the Kaczmarz’ method. We study convergence and regularization properties of the proposed method and discuss several practical realizations. Relevance and performance of our approach are evaluated at simulated data from dynamic computerized tomography with various dynamic scenarios

spl(2,1) dynamical supersymmetry and suppression of ferromagnetism in flat band double-exchange models

The low energy spectrum of the ferromagnetic Kondo lattice model on a N-site complete graph extended with on-site repulsion is obtained from the underlying spl(2,1) algebra properties in the strong coupling limit. The ferromagnetic ground state is realized for 1 and N+1 electrons only. We identify the large density of states to be responsible for the suppression of the ferromagnetic state and argue that a similar situation is encountered in the Kagome, pyrochlore, and other lattices with flat bands in their one-particle density of states.Comment: 7 pages, 1 figur

Particle-Antiparticle Mixing, epsilon_K, Delta Gamma_q, A_SL^q, A_CP(B_d -> psi K_S), A_CP(B_s -> psi phi) and B -> X_{s,d} gamma in the Littlest Higgs Model with T-Parity

We calculate a number of observables related to particle-antiparticle mixing in the Littlest Higgs model with T-parity (LHT). The resulting effective Hamiltonian for Delta F=2 transitions agrees with the one of Hubisz et al., but our phenomenological analysis goes far beyond the one of these authors. In particular, we point out that the presence of mirror fermions with new flavour and CP-violating interactions allows to remove the possible Standard Model (SM) discrepancy between the CP asymmetry S_{psi K_S} and large values of |V_ub| and to obtain for the mass difference Delta M_s < (Delta M_s)_SM as suggested by the recent result by the CDF collaboration. We also identify a scenario in which simultaneously significant enhancements of the CP asymmetries S_{phi psi} and A_SL^q relative to the SM are possible, while satisfying all existing constraints, in particular from the B -> X_s gamma decay and A_CP(B -> X_s gamma) that are presented in the LHT model here for the first time. In another scenario the second, non-SM, value for the angle gamma=-(109+-6) from tree level decays, although unlikely, can be made consistent with all existing data with the help of mirror fermions. We present a number of correlations between the observables in question and study the implications of our results for the mass spectrum and the weak mixing matrix of mirror fermions. In the most interesting scenarios, the latter one turns out to have a hierarchical structure that differs significantly from the CKM one.Comment: 51 pages, 20 figures, 1 table. Extended discussion of the phases in the new mixing matrix V_Hd, some references added or updated, conclusions unchanged. Final version published in JHE

Phenomenology of a three-family model with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X

We study an extension of the gauge group SU(3)_c X SU(2)_L X U(1)_Y of the standard model to the symmetry group SU(3)_c X SU(4)_L X U(1)_X (3-4-1 for short). This extension provides an interesting attempt to answer the question of family replication in the sense that models for the electroweak interaction can be constructed so that anomaly cancellation is achieved by an interplay between generations, all of them under the condition that the number of families must be divisible by the number of colours of SU(3)_c. This method of anomaly cancellation requires a family of quarks transforming differently from the other two, thus leading to tree-level flavour changing neutral currents (FCNC) transmitted by the two extra neutral gauge bosons $Z'$ and $Z''$ predicted by the model. In a version of the 3-4-1 extension, which does not contain particles with exotic electric charges, we study the fermion mass spectrum and some aspects of the phenomenology of the neutral gauge boson sector. In particular, we impose limits on the $Z-Z'$ mixing angle and on the mass scale of the corresponding physical new neutral gauge boson $Z_2$, and establish a lower bound on the mass of the additional new neutral gauge boson $Z'' \equiv Z_3$. For the analysis we use updated precision electroweak data at the Z-pole from the CERN LEP and SLAC Linear Collider, and atomic parity violation data. The mass scale of the additional new neutral gauge boson $Z_3$ is constrained by using updated experimental inputs from neutral meson mixing in the analysis of the sources of FCNC in the model. The data constrain the $Z-Z'$ mixing angle to a very small value of O(0.001), and the lower bounds on $M_{Z_2}$ and on $M_{Z_3}$ are found to be of O(1 TeV) and of O(7 TeV), repectively.Comment: 22 pages, 6 tables, 1 figure. To appear in J. Phys. G: Nuclear and Particle Physic

The Impact of Analog and Bang-Bang Steering Gear Control on Ship's Fuel Economy

The latest years have shown considerable efforts towards improving steering generated propulsion losses of ships by the introduction of various sophisticated control algorithms in the autopilots. However, little previous attention has been given to the steering gear control loop, although it is found to be at least equally important regarding steering performance and fuel economy. The paper presents a comprehensive survey of steering gear principles commonly used, including relevant details of three analog steering gear servo principles, which have outperformed conventional designs. Control system performance is evaluated from direct measurements of speed and fuel consumption, and results from several ships are given. The results presented should enhance the ability of ship owners and steering gear manufacturers to choose and design systems, which will minimize steering generated propulsion losse

Symmetries and Asymmetries of B -> K* mu+ mu- Decays in the Standard Model and Beyond

The rare decay B -> K* (-> K pi) mu+ mu- is regarded as one of the crucial channels for B physics as the polarization of the K* allows a precise angular reconstruction resulting in many observables that offer new important tests of the Standard Model and its extensions. These angular observables can be expressed in terms of CP-conserving and CP-violating quantities which we study in terms of the full form factors calculated from QCD sum rules on the light-cone, including QCD factorization corrections. We investigate all observables in the context of the Standard Model and various New Physics models, in particular the Littlest Higgs model with T-parity and various MSSM scenarios, identifying those observables with small to moderate dependence on hadronic quantities and large impact of New Physics. One important result of our studies is that new CP-violating phases will produce clean signals in CP-violating asymmetries. We also identify a number of correlations between various observables which will allow a clear distinction between different New Physics scenarios.Comment: 56 pages, 18 figures, 14 tables. v5: Missing factor in eqs. (3.31-32) and fig. 6 corrected. Minor misprints in eq. (2.10) and table A corrected. Conclusions unchange

Enrollment of adolescents and young adults onto SWOG cancer research network clinical trials: A comparative analysis by treatment site and era.

BackgroundFew adolescents and young adults (AYAs, 15-39 years old) enroll onto cancer clinical trials, which hinders research otherwise having the potential to improve outcomes in this unique population. Prior studies have reported that AYAs are more likely to receive cancer care in community settings. The National Cancer Institute (NCI) has led efforts to increase trial enrollment through its network of NCI-designated cancer centers (NCICC) combined with community outreach through its Community Clinical Oncology Program (CCOP; replaced by the NCI Community Oncology Research Program in 2014).MethodsUsing AYA proportional enrollment (the proportion of total enrollments who were AYAs) as the primary outcome, we examined enrollment of AYAs onto SWOG therapeutic trials at NCICC, CCOP, and non-NCICC/non-CCOP sites from 2004 to 2013 by type of site, study period (2004-08 vs 2009-13), and patient demographics.ResultsOverall, AYA proportional enrollment was 10.1%. AYA proportional enrollment decreased between 2004-2008 and 2009-2013 (13.1% vs 8.5%, P &lt; .001), and was higher at NCICCs than at CCOPs and non-NCICC/non-CCOPs (14.1% vs 8.3% and 9.2%, respectively; P &lt; .001). AYA proportional enrollment declined significantly at all three site types. Proportional enrollment of AYAs who were Black or Hispanic was significantly higher at NCICCs compared with CCOPs or non-NCICC/non-CCOPs (11.5% vs 8.8, P = .048 and 11.5% vs 8.6%, P = .03, respectively).ConclusionNot only did community sites enroll a lower proportion of AYAs onto cancer clinical trials, but AYA enrollment decreased in all study settings. Initiatives aimed at increasing AYA enrollment, particularly in the community setting with attention to minority status, are needed