Parallel Image Generation Using the Z-buffering Algorithm on a Medium Grained Distributed Memory Model Computer

Computer Scienc

SO(10) Yukawa Unification with mu < 0

We consider the low energy implications including particle spectroscopy of SO(10) inspired t-b-tau Yukawa coupling unification with mu < 0, where mu is the coefficient of the bilinear Higgs mixing term of the minimal supersymmetric standard model (MSSM). We imploy non-universal MSSM gaugino masses induced by SO(10) invariant dimension five operators, such that the total number of fundamental parameters is precisely the same as in Yukawa unified supersymmetric SO(10) models with universal gaugino masses and mu > 0. We find that t-b-tau Yukawa unification with mu < 0 is compatible with the current experimental bounds, including the WMAP bound on neutralino dark matter and the measured value of the muon anomalous magnetic moment. We present a variety of benchmark points which include relatively light squarks (~ TeV) of the first two families and an example in which the bottom and top squarks are lighter than the gluino. This is quite distinct from Yukawa unification with mu > 0 and universal gaugino masses in which the gluino is the lightest colored sparticle and the sqaurks of the first two families have masses in the multi-TeV range.Comment: 13 pages, 2 figures, 1 tabl

SUSY GUTs with Yukawa unification: a go/no-go study using FCNC processes

We address the viability of exact Yukawa unification in the context of general SUSY GUTs with universal soft-breaking sfermion and gaugino mass terms at the GUT scale. We find that this possibility is challenged, unless the squark spectrum is pushed well above the limits allowed by naturalness. This conclusion is assessed through a global fit using electroweak observables and quark flavour-changing neutral current (FCNC) processes. The problem is mostly the impossibility of accommodating simultaneously the bottom mass and the BR(B --> Xs gamma), after the stringent CDF upper bound on the decay Bs --> mu^+ mu^- is taken into account, and under the basic assumption that the b --> s gamma amplitude have like sign with respect to the Standard Model one, as indicated by the B --> Xs l^+ l^- data. With the same strategy, we also consider the possibility of relaxing Yukawa unification to b - tau Yukawa unification. We find that with small departures from the condition tan beta ~= 50, holding when Yukawa unification is exact, the mentioned tension is substantially relieved. We emphasize that in the region where fits are successful the lightest part of the SUSY spectrum is basically fixed by the requirements of b - tau unification and the applied FCNC constraints. As such, it is easily falsifiable once the LHC turns on.Comment: 10 pages, 1 figure, 5 tables. v3: A few textual modifications. Conclusions unchanged. Matches journal versio

Complete Cubic and Quartic Couplings of 16 and 16ˉ\bar {16} in SO(10) Unification

A recently derived basic theorem on the decomposition of SO(2N) vertices is used to obtain a complete analytic determination of all SO(10) invariant cubic superpotential couplings involving $16_{\pm}$ semispinors of SO(10) chirality $\pm$ and tensor representations. In addition to the superpotential couplings computed previously using the basic theorem involving the 10, 120 and $\bar{126}$ tensor representations we compute here couplings involving the 1, 45 and 210 dimensional tensor representations, i.e., we compute the $\bar{16}_{\mp}16_{\pm}1$,$\bar{16}_{\mp}16_{\pm}45$ and $\bar{16}_{\mp}16_{\pm}210$ Higgs couplings in the superpotential. A complete determination of dimension five operators in the superpotential arising from the mediation of the 1, 45 and 210 dimensional representations is also given. The vector couplings $\bar{16}_{\pm}16_{\pm}1$, $\bar{16}_{\pm}16_{\pm}45$ and $\bar{16}_{\pm}16_{\pm}210$ are also analyzed. The role of large tensor representations and the possible application of results derived here in model building are discussed.Comment: 21 pages, Latex. Revised version to appear in Nuclear Physics

Quality of life in patients with multiple myeloma and malignant lymphoma undergoing autologous progenitor stem cell transplantation: The effect of selected psychosocial and health aspects on quality of life: A retrospective analysis

BackgroundQuality of life (QoL) is defined as “a patient's subjective evaluation of his life situation”. QoL evaluation is carried out by means of generic and specific questionnaires. Generic QoL questionnaires generally evaluate a patient's overall condition regardless of his disease. Specific QoL questionnaires are designed to evaluate a patient's overall condition for a particular type of disease.AimThe study analyses the effect of selected psychosocial and health aspects on quality of life in patients with multiple myeloma and malignant lymphoma undergoing autologous progenitor stem cell transplantation.Materials/MethodsThe total number of respondents undergoing transplantation between 2001 and 2003 was 56:32 respondents (18 male and 14 female) with multiple myeloma, and 24 respondents (11 male and 13 female) with malignant lymphoma. The average age of patients with multiple myeloma was 60 years and the average age of patients with malignant lymphoma was 44.5 years. The Czech version of the international generic European Quality of Life Questionnaire, Version EQ-5D, was used. The effect of selected psychosocial and health aspects (age, sex, level of education, marital status, number of associated diseases, smoking abuse, religion, type of disease and time since the transplantation) on quality of life in patients was determined by means of analysis of variance.ResultsThe above-mentioned aspects proved statistically significant dependence of quality of life on age, smoking abuse in patients with multiple myeloma and on type of disease. EQ-5D score (dimensions of quality of life) and EQ-5D VAS (subjective health condition) significantly decrease with increasing age in both groups of patients and with smoking abuse in patients with multiple myeloma, and are significantly higher in patients with malignant lymphoma. The effect of other aspects on quality of life was not proven as statistically significant. The quality of life in patients with multiple myeloma undergoing autologous progenitor stem cell transplantation is at a lower level (mean EQ-5D score 68.9%, mean EQ-5D VAS 66.6%) than in patients with malignant lymphoma after the transplantation (mean EQ-5D score 82.7%, mean EQ-5D VAS 76.7%) at the Department of Clinical Haematology of the Department of Medicine of Charles University Hospital in Hradec Kralove, Czech Republic.ConclusionThe global quality of life in our patients with multiple myeloma and malignant lymphoma undergoing autologous progenitor stem cell transplantation is at a good level

Testing Yukawa-unified SUSY during year 1 of LHC: the role of multiple b-jets, dileptons and missing E_T

We examine the prospects for testing SO(10) Yukawa-unified supersymmetric models during the first year of LHC running at \sqrt{s}= 7 TeV, assuming integrated luminosity values of 0.1 to 1 fb^-1. We consider two cases: the Higgs splitting (HS) and the D-term splitting (DR3) models. Each generically predicts light gluinos and heavy squarks, with an inverted scalar mass hierarchy. We hence expect large rates for gluino pair production followed by decays to final states with large b-jet multiplicity. For 0.2 fb^-1 of integrated luminosity, we find a 5 sigma discovery reach of m(gluino) ~ 400 GeV even if missing transverse energy, E_T^miss, is not a viable cut variable, by examining the multi-b-jet final state. A corroborating signal should stand out in the opposite-sign (OS) dimuon channel in the case of the HS model; the DR3 model will require higher integrated luminosity to yield a signal in the OS dimuon channel. This region may also be probed by the Tevatron with 5-10 fb^-1 of data, if a corresponding search in the multi-b+ E_T^miss channel is performed. With higher integrated luminosities of ~1 fb^-1, using E_T^miss plus a large multiplicity of b-jets, LHC should be able to discover Yukawa-unified SUSY with m(gluino) up to about 630 GeV. Thus, the year 1 LHC reach for Yukawa-unified SUSY should be enough to either claim a discovery of the gluino, or to very nearly rule out this class of models, since higher values of m(gluino) lead to rather poor Yukawa unification.Comment: 32 pages including 31 EPS figure

Coherence function control of Quantum Dot Superluminescent Light Emitting Diodes by frequency selective optical feedback.

Low coherent light interferometry requires broad bandwidth light sources to achieve high axial resolution. Here, Superluminescent Light Emitting Diodes (SLDs) utilizing Quantum Dot (QD) gain materials are promising devices as they unify large spectral bandwidths with sufficient power at desired emission wavelengths. However, frequently a dip occurs in the optical spectrum that translates into high side lobes in the coherence function thereby reducing axial resolution and image quality. We apply the experimental technique of frequency selective feedback to shape the optical spectrum of the QD-SLD, hence optimizing the coherence properties. For well-selected feedback parameters, a strong reduction of the parasitic side lobes by a factor of 3.5 was achieved accompanied by a power increase of 40% and an improvement of 10% in the coherence length. The experimental results are in excellent agreement with simulations that even indicate potential for further optimizations

Viability of MSSM scenarios at very large tan(beta)

We investigate the MSSM with very large tan(beta) > 50, where the fermion masses are strongly affected by loop-induced couplings to the "wrong" Higgs, imposing perturbative Yukawa couplings and constraints from flavour physics. Performing a low-energy scan of the MSSM with flavour-blind soft terms, we find that the branching ratio of B->tau nu and the anomalous magnetic moment of the muon are the strongest constraints at very large tan(beta) and identify the viable regions in parameter space. Furthermore we determine the scale at which the perturbativity of the Yukawa sector breaks down, depending on the low-energy MSSM parameters. Next, we analyse the very large tan(beta) regime of General Gauge Mediation (GGM) with a low mediation scale. We investigate the requirements on the parameter space and discuss the implied flavour phenomenology. We point out that the possibility of a vanishing Bmu term at a mediation scale M = 100 TeV is challenged by the experimental data on B->tau nu and the anomalous magnetic moment of the muon.Comment: 29 pages, 7 figures. v2: discussion in sections 1 and 4 expanded, conclusions unchanged. Matches version published in JHE

An Alternative Yukawa Unified SUSY Scenario

Supersymmetric SO(10) Grand Unified Theories with Yukawa unification represent an appealing possibility for physics beyond the Standard Model. However Yukawa unification is made difficult by large threshold corrections to the bottom mass. Generally one is led to consider models where the sfermion masses are large in order to suppress these corrections. Here we present another possibility, in which the top and bottom GUT scale Yukawa couplings are equal to a component of the charged lepton Yukawa matrix at the GUT scale in a basis where this matrix is not diagonal. Physically, this weak eigenstate Yukawa unification scenario corresponds to the case where the charged leptons that are in the 16 of SO(10) containing the top and bottom quarks mix with their counterparts in another SO(10) multiplet. Diagonalizing the resulting Yukawa matrix introduces mixings in the neutrino sector. Specifically we find that for a large region of parameter space with relatively light sparticles, and which has not been ruled out by current LHC or other data, the mixing induced in the neutrino sector is such that $sin^2 2\Theta_{23} \approx 1$, in agreement with data. The phenomenological implications are analyzed in some detail.Comment: 32 pages, 22 Figure

No-Scale Scenarios in the Light of New Measurement of Muon Anomalous Magnetic Moment

Supersymmetric contribution to the muon anomalous magnetic moment a_\mu is discussed in the no-scale-type supersymmetry breaking scenarios. Taking the correlation between the supersymmetric contributions to a_\mu and Br(b\to s\gamma), it is shown that the precise measurements of these quantities serve an important constraint on the relative sign of the gaugino masses; combining the 2.6-\sigma deviation in a_\mu from the standard-model prediction measured by the E821 experiment and Br(b\to s\gamma) measured by CLEO, the sign of the product M_2M_3 is strongly preferred to be positive, where M_2 and M_3 are SU(2)_L and SU(3)_C gaugino mass parameters, respectively. In particular, no-scale-type models with universal gaugino masses are in accord with the two constraints and also with the Higgs mass bound. In addition, it is also shown that future improvements in the measurements of a_\mu and Br(b\to s\gamma) may provide serious test of the cases with M_2M_3<0.Comment: 10 pages, 4 figures, published versio