Search results for "MBD"
showing 10 items of 646 documents
Hidden-charm pentaquark state inΛb0→J/ψpπ−decay
2016
We study here the ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}p{\ensuremath{\pi}}^{\ensuremath{-}}$ reaction in analogy to the ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}p{K}^{\ensuremath{-}}$ one, and we note that in both decays there is a sharp structure (dip or peak) in the $J/\ensuremath{\psi}p$ mass distribution around 4450 MeV, which is associated in the ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}p{K}^{\ensuremath{-}}$ experiment to an exotic pentaquark baryonic state, although in ${\mathrm{\ensuremath{\Lambda}}}_{b}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}p{\en…
Λb and Λc baryon decays at finite values of heavy quark masses
2000
Semileptonic decays of Lambda_b and Lambda_c baryons are studied within the Relativistic Three-Quark Model using finite heavy quark mass values. Employing the same parameters as have been used previously for the description of exclusive decays of heavy baryons in the heavy quark limit we calculate the six form factors of the process and the corresponding decay rates. Our calculation shows that the ``finite mass'' corrections are important in heavy-to-light transitions and are not negligible in heavy-to-heavy transitions.
Resonances in chiral unitary approaches
2008
The extension of chiral theories to the description of resonances, via the incorporation of unitarity in coupled channels, has provided us with a new theoretical perspective on the nature of some of the observed excited hadrons. In this contribution some of the early achievements in the field of baryonic resonances are reviewed, the recent evidence of the two-pole nature of the Lambda(1405) is discussed and results on charmed baryon resonances are presented.
Cosmic Dark Radiation and Neutrinos
2013
New measurements of the cosmic microwave background (CMB) by the Planck mission have greatly increased our knowledge about the universe. Dark radiation, a weakly interacting component of radiation, is one of the important ingredients in our cosmological model which is testable by Planck and other observational probes. At the moment, the possible existence of dark radiation is an unsolved question. For instance, the discrepancy between the value of the Hubble constant, H-0, inferred from the Planck data and local measurements of H-0 can to some extent be alleviated by enlarging the minimal ACDM model to include additional relativistic degrees of freedom. From a fundamental physics point of v…
Uncertainty on w from large-scale structure
2012
We find that if we live at the center of an inhomogeneity with total density contrast of roughly 0.1, dark energy is not a cosmological constant at 95% confidence level. Observational constraints on the equation of state of dark energy, w, depend strongly on the local matter density around the observer. We model the local inhomogeneity with an exact spherically symmetric solution which features a pressureless matter component and a dark-energy fluid with constant equation of state and negligible sound speed, that reaches a homogeneous solution at finite radius. We fit this model to observations of the local expansion rate, distant supernovae and the cosmic microwave background. We conclude …
POTENTIAL NEW GENETIC AND BIOCHEMICAL MARKERS OF CHRONIC KIDNEY FAILURE
2017
disease (CKD) is an important source of long-term morbidity and mortality. It has been estimated that CKD affects more than 20 million people in the United States. Given that most patients are asymptomatic until the disease has significantly progressed, they remain unaware of the condition. Thus, it is essential to have clinical practice guidelines (BIOMARKERS aimed at early detection, evaluation, diagnosis, and treatment of this condition.
CODEX Weak Lensing Mass Catalogue and implications on the mass-richness relation
2021
The COnstrain Dark Energy with X-ray clusters (CODEX) sample contains the largest flux limited sample of X-ray clusters at $0.35 = \alpha \mu + \beta$, with $\mu = \ln (M_{200c}/M_{\mathrm{piv}})$, and $M_{\mathrm{piv}} = 10^{14.81} M_{\odot}$. We find a slope $\alpha = 0.49^{+0.20}_{-0.15}$, normalization $ \exp(\beta) = 84.0^{+9.2}_{-14.8}$ and $\sigma_{\ln \lambda | \mu} = 0.17^{+0.13}_{-0.09}$ using CFHT richness estimates. In comparison to other weak lensing richness-mass relations, we find the normalization of the richness statistically agreeing with the normalization of other scaling relations from a broad redshift range ($0.0<z<0.65$) and with different cluster selection (X-ray, Sun…
A new assay for O6-alkylguanine-DNA-alkyltransferase to determine DNA repair capacities using lambda-phage DNA as substrate.
1990
One O6-methylguanine (O6-meG) was introduced into each BamHI site of lambda-phage DNA as a substrate for the determination of the DNA repair protein O6-alkylguanine-DNA-alkyltransferase. A new assay using as the detection group 32P-labeled phosphate introduced at the 3' position of the modified nucleoside by incorporation of 32P-labeled TTP in the 3'-neighboring position proved highly sensitive: 10(-16) mol of the DNA lesion was still easily detectable. This DNA, which has greater than 1000 bp represents a good model for cellular DNA and was used as a substrate to measure the individual repair capacities for O6-meG in human lymphocytes of 20 healthy male and female donors. There were great …
Search for the decayB¯0→Λc+p¯pp¯
2014
We report a search for the decay B^0 → Λ^+_cppp. Using a data sample of 471×10^6 BB pairs collected with the BABAR detector at the PEP-II2 storage ring at SLAC, we find no events and set an upper limit on the branching fraction B(B^0 → Λ^+_cppp)×^(B(Λ^+_c→pK^−π^+))_(0.050) <2.8×10^(−6) at 90% C.L., where we have normalized B(Λ^+_c → pK^−π^+) to the world average value.
Analytic first derivatives for a spin-adapted open-shell coupled cluster theory: Evaluation of first-order electrical properties
2014
An analytic scheme is presented for the evaluation of first derivatives of the energy for a unitary group based spin-adapted coupled cluster (CC) theory, namely, the combinatoric open-shell CC (COSCC) approach within the singles and doubles approximation. The widely used Lagrange multiplier approach is employed for the derivation of an analytical expression for the first derivative of the energy, which in combination with the well-established density-matrix formulation, is used for the computation of first-order electrical properties. Derivations of the spin-adapted lambda equations for determining the Lagrange multipliers and the expressions for the spin-free effective density matrices for…