While flavor symmetries are useful for studying hadronic B decays, symmetry relations for amplitudes and decay rates are usually violated by first order symmetry breaking corrections. We point out two cases in which first order symmetry breaking is suppressed by a small ratio of amplitudes: (1) An isospin sum rule for four B → Kπ decays, where isospin breaking is shown to be negligible. (2) An ...

A QM/MM method that combines ONIOM quantum chemistry and molecular dynamics is developed and applied to a step in the deamination of cytosine to uracil in yeast cytosine deaminase (yCD). A two-layer ONIOM calculation is used for the reaction complex, with an inner part treated at a high level for the chemical reaction (bond breaking) and a middle part treated at a lower level for relevant prote...

We present a model for string breaking based on the existence of chromoelectric flux tubes. We predict the form of the long-range potential, and obtain an estimate of the string breaking length. A prediction is also obtained for the behaviour with temperature of the string breaking length near the deconfinement phase transition. We plan to use this model as a guide for a program of study of str...

Low-energy QCD in its sector with Nf = 3 flavours of almost massless up and down quarks (mu ≈ md ∼ O(5MeV)) and a slightly heavier strange quark (ms ∼ O(100MeV)) is known to have the following characteristic symmetry breaking pattern: the Goldstone bosons related to spontaneously broken chiral SU(3) × SU(3) symmetry are identified with the pions and kaons. Their masses originate from explicit s...

The role of the off-shell dependence of ρ− ω mixing in the charge symmetry breaking nucleon-nucleon potential is discussed. It is shown that models describing the off-shell dependence of ρ−ω mixing are not sufficient to determine the charge symmetry breaking nucleon-nucleon potential. ∗Permanent address: Department of Physics and Center for Theoretical Physics, University of Maryland, College P...

In this research the sensitivity analysis of the geometric parameters such as: length, thickness and width of a single link flexible manipulator on maximum deflection (MD) of the end effector and vibration energy (VE) of that point are conducted. The equation of motion of the system is developed based on Gibbs-Appel (G-A) formulation. Also for modeling the elastic property of the system the ass...

We consider two SU(3) breaking parameters, R1(mB) and R2(mB), appearing in a relation between B → Kπ and B → ππ amplitudes, which plays an important role in determining the weak phase γ. We identify an isospin-related quantity R2(mD) measured in D decays, exhibiting large SU(3) breaking which is likely due to nonfactorizable effects. With a cautious remark about possible nonfactorizable SU(3) b...

We analyze quark condensates and chiral (scalar) susceptibilities including isospin-breaking effects at finite temperature T. These include mu md contributions as well as electromagnetic (e 0) corrections, both treated in a consistent chiral Lagrangian framework to leading order in SUð2Þ and SUð3Þ chiral perturbation theory, so that our predictions are model-independent. The chiral restoration ...

Abstract Aim To evaluate comparative outcomes of intracorporeal (ICA) and extracorporeal (ECA) anastomosis in laparoscopic right hemicolectomy. Method We conducted a systematic search electronic databases bibliographic reference lists. applied combination free text controlled vocabulary adapted to thesaurus headings, operators limits each the above databases. Overall perioperative morbidity, an...