Sequential Flavour Symmetry Breaking

The gauge sector of the Standard Model (SM) exhibits a flavour symmetry which allows for independent unitary transformations of the fermion multiplets. In the SM the flavour symmetry is broken by the Yukawa couplings to the Higgs boson, and the resulting fermion masses and mixing angles show a pronounced hierarchy. In this work we connect the observed hierarchy to a sequence of intermediate effective theories, where the flavour symmetries are broken in a step-wise fashion by vacuum expectation values of suitably constructed spurion fields. We identify the possible scenarios in the quark sector and discuss some implications of this approach.Comment: 22 pages latex, no figure

Extracting V_{ub} Without Recourse to Structure Functions

We present a closed form expression for |V_{ub}|^2/ |V_{tb} V_{ts}^*|^2 in terms of the endpoint photon and lepton spectra from the inclusive decays B -> X_s\gamma and B -> X_u\ell\nu, respectively, which includes the resummation of the endpoint logs at next to leading order and is completely independent of the B meson structure function. The use of this expression for extracting V_{ub} would eliminate the large systematic errors usually incurred due to the modeling of the heavy quarks' Fermi motion.Comment: 20 pages, no figures, minor typos correcte

b→sγb \to s \gamma decays in the Left-Right Symmetric Model

We consider $b \to s \gamma$ decays in the Left-Right Symmetric Model. Values of observables sensitive to chiral structure such as the $\Lambda$ polarization in the $\Lambda_b \to \Lambda \gamma$ decays and the mixing-induced CP asymmetries in the $B_{d,s} \to M^0 \gamma$ decays can deviate in the LRSM significantly from the SM values. The combined analysis of $P_\Lambda$ and $A_{CP}$ as well as ${\cal BR}(b \to s \gamma)$ can be used to determine the model parameters.Comment: 16 pages with 7 figures, Version to be published in PR

Cometary dust collected by MIDAS on board Rosetta II. Particle shape descriptors and pristineness evaluation

The MIDAS (Micro-Imaging Dust Analysis System) atomic force microscope on board the Rosetta comet orbiter investigated and measured the 3D topography of a few hundred nm to tens of $\mu$m sized dust particles of 67P/Churyumov-Gerasimenko with resolutions down to a few nanometers, giving insights into the physical processes of our early Solar System. We analyze the shapes of the cometary dust particles collected by MIDAS on the basis of a recently updated particle catalog with the aim to determine which structural properties remained pristine. We develop a set of shape descriptors and metrics such as aspect ratio, elongation, circularity, convexity, and particle surface/volume distribution, which can be used to describe the distribution of particle shapes. Furthermore, we compare the structure of the MIDAS dust particles and the clusters in which the particles were deposited to those found in previous laboratory experiments and by Rosetta/COSIMA. Finally, we combine our findings to calculate a pristineness score for MIDAS particles and determine the most pristine particles and their properties. We find that the morphological properties of all cometary dust particles at the micrometer scale are surprisingly homogeneous despite originating from diverse cometary environments (e.g., different collection targets that are associated with cometary activities/source regions and collection velocities/periods). We next find that the types of clusters found by MIDAS show good agreement with those defined by previous laboratory experiments, however, there are some differences to those found by Rosetta/COSIMA. Based on our result, we rate 19 out of 1082 MIDAS particles at least moderately pristine, i.e., they are not substantially flattened by impact, not fragmented, and/or not part of a fragmentation cluster.Comment: 40 pages, 31 figures, 1 online tabl

NRG Oncology/RTOG 0921: A phase 2 study of postoperative intensity-modulated radiotherapy with concurrent cisplatin and bevacizumab followed by carboplatin and paclitaxel for patients with endometrial cancer.

BACKGROUND: The current study was conducted to assess acute and late adverse events (AEs), overall survival (OS), pelvic failure, regional failure, distant failure, and disease-free survival in a prospective phase 2 clinical trial of bevacizumab and pelvic intensity-modulated radiotherapy (IMRT) with chemotherapy in patients with high-risk endometrial cancer. METHODS: Patients underwent a hysterectomy and lymph node removal, and had ≥1 of the following high-risk factors: grade 3 carcinoma with \u3e50% myometrial invasion, grade 2 or 3 disease with any cervical stromal invasion, or known extrauterine extension confined to the pelvis. Treatment included pelvic IMRT and concurrent cisplatin on days 1 and 29 of radiation and bevacizumab (at a dose of 5 mg/kg on days 1, 15, and 29 of radiation) followed by adjuvant carboplatin and paclitaxel for 4 cycles. The primary endpoint was grade ≥3 AEs occurring within the first 90 days (toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events [version 4.0]). RESULTS: A total of 34 patients were accrued from November 2009 through December 2011, 30 of whom were eligible and received study treatment. Seven of 30 patients (23.3%; 1-sided 95% confidence interval, 10.6%-36.0%) developed grade ≥3 treatment-related nonhematologic toxicities within 90 days; an additional 6 patients experienced grade ≥3 toxicities between 90 and 365 days after treatment. The 2-year OS rate was 96.7% and the disease-free survival rate was 79.1%. No patient developed a within-field pelvic failure and no patients with International Federation of Gynecology and Obstetrics stage I to IIIA disease developed disease recurrence after a median follow-up of 26 months. CONCLUSIONS: Postoperative bevacizumab added to chemotherapy and pelvic IMRT appears to be well tolerated and results in high OS rates at 2 years for patients with high-risk endometrial carcinoma

Brief review on semileptonic B decays

We concisely review semileptonic B decays, focussing on recent progress on both theoretical and experimental sides.Comment: 18 pages, 2 figures; version to be published in Mod. Phys. Lett.

Heavy Quarkonium Effective Theory

We formulate a QCD-based effective theory approach to heavy quarkonia-like systems as $\bar{c} c$ and $\bar{b} b$ resonances and $B_c$ states. We apply the method to inclusive decays, working out a few examples in detail.Comment: 52 pages, LaTeX, 3 uuencoded and compressed figures, uses epsf.sty, CERN-TH.7468/9

Enhancements in Mass Transfer for Carbon Capture Solvents Part I: Homogeneous Catalyst

The novel small molecule carbonic anhydrase (CA) mimic [CoIII(Salphen-COO−)Cl]HNEt3 (1), was synthesized as an additive for increasing CO2 absorption rates in amine-based post-combustion carbon capture processes (CCS), and its efficacy was verified. 1 was designed for use in a kinetically slow but thermally stable blended solvent, containing the primary amines 1-amino-2-propanol (A2P) and 2-amino-2-methyl-1-propanol (AMP). Together, the A2P/AMP solvent and 1 reduce the overall energy penalty associated with CO2 capture from coal-derived flue gas, relative to the baseline solvent MEA. 1 is also effective at increasing absorption kinetics of kinetically fast solvents, such as MEA, which can reduce capital costs by requiring a smaller absorber tower. The transition from catalyst testing under idealized laboratory conditions, to process relevant lab- and bench-scale testing adds many additional variables that are not well understood and rarely discussed. The stepwise testing of both 1 and the novel A2P/AMP solvent blend is described through a transition process that identifies many of these process and evaluation challenges not often addressed when designing a chemical or catalytic additive for industrial CCS systems, where consideration of solvent chemistry is typically the primary goal

Status and overview of development of the Silicon Pixel Detector for the PHENIX experiment at the BNL RHIC

We have developed a silicon pixel detector to enhance the physics capabilities of the PHENIX experiment. This detector, consisting of two layers of sensors, will be installed around the beam pipe at the collision point and covers a pseudo-rapidity of | \eta | < 1.2 and an azimuth angle of | \phi | ~ 2{\pi}. The detector uses 200 um thick silicon sensors and readout chips developed for the ALICE experiment. In order to meet the PHENIX DAQ readout requirements, it is necessary to read out 4 readout chips in parallel. The physics goals of PHENIX require that radiation thickness of the detector be minimized. To meet these criteria, the detector has been designed and developed. In this paper, we report the current status of the development, especially the development of the low-mass readout bus and the front-end readout electronics.Comment: 9 pages, 8 figures and 1 table in DOCX (Word 2007); PIXEL 2008 workshop proceedings, will be published in the Proceedings Section of JINST(Journal of Instrumentation

Application of heavy-quark effective theory to lattice QCD: I. Power Corrections

Heavy-quark effective theory (HQET) is applied to lattice QCD with Wilson fermions at fixed lattice spacing a. This description is possible because heavy-quark symmetries are respected. It is desirable because the ultraviolet cutoff $1/a$ in current numerical work and the heavy-quark mass $m_Q$ are comparable. Effects of both short distances, a and $1/m_Q$, are captured fully into coefficient functions, which multiply the operators of the usual HQET. Standard tools of HQET are used to develop heavy-quark expansions of lattice observables and, thus, to propagate heavy-quark discretization errors. Three explicit examples are given: namely, the mass, decay constant, and semileptonic form factors of heavy-light mesons.Comment: 41 pp., no figs; Phys Rev D version, improving argument that an HQET holds for all m_Q