12,480 research outputs found
Precision radiative corrections to the Dalitz plot of baryon semileptonic decays including the spin-momentum correlation of the decaying baryon and the emitted charged lepton
We calculate the radiative corrections to the angular correlation between the
polarization of the decaying baryon and the direction of the emitted charged
lepton in the semileptonic decays of spin one-half baryons to order
(\alpha/\pi)(q/M_1). The final results are presented, first, with the triple
integration of the bremsstrahlung photon ready to be performed numerically and,
second, in an analytical form. A third presentation of our results in the form
of numerical arrays of coefficients to be multiplied on the quadratic products
of form factors is discussed. This latter may be the most practical one to use
in Monte Carlo simulations. A series of crosschecks is performed. The results
are useful in the analysis of the Dalitz plot of precision experiments
involving light and heavy quarks and is not compromised to fixing the form
factors at predetermined values. It is assumed that the real photons are
kinematically discriminated. Otherwise, our results have a general
model-independent applicability.Comment: 8 pages, RevTex4, 5 tables, no figures. Shortened version; results
and conclusions remain unchange
Precision radiative corrections to the semileptonic Dalitz plot with angular correlation between polarized decaying and emitted baryons: Effects of the four-body region
Analytical radiative corrections of order (\alpha/\pi)(q/M_1) are calculated
for the four-body region of the Dalitz plot of baryon semileptonic decays when
the s_1 \cdot p_2 correlation is present. Once the final result is available,
it is possible to exhibit it in terms of the corresponding final result of the
three-body region following a set of simple changes in the latter. We cover two
cases, a charged and a neutral polarized decaying baryon.Comment: Revtex4, 7 pages, no figure
A Machine Learning-Based Approach for Audio Signals Classification using Chebychev Moments and Mel-Coefficients
This paper proposes a machine learning-based architecture for audio signals classification based on a joint exploitation of the Chebychev moments and the Mel-Frequency Cepstrum Coefficients. The procedure starts with the computation of the Mel-spectrogram of the recorded audio signals; then, Chebychev moments are obtained projecting the Cadence Frequency Diagram derived from the Mel-spectrogram into the base of Chebychev moments. These moments are then concatenated with the Mel-Frequency Cepstrum Coefficients to form the final feature vector. By doing so, the architecture exploits the peculiarities of the discrete Chebychev moments such as their symmetry characteristics. The effectiveness of the procedure is assessed on two challenging datasets, UrbanSound8K and ESC-50
Radiative corrections to the three-body region of the Dalitz plot of baryon semileptonic decays with angular correlation between polarized emitted baryons and charged leptons: The initial-baryon rest frame case
We complement the results for the radiative corrections to the s2.l angular
correlation of baryon semileptonic decays of Ref. [1] with the final results in
the rest frame of the decaying baryon.Comment: 7 pages, Revtex4, no figure
Discovery of Water Vapor in the High-redshift Quasar APM 08279+5255 at z = 3.91
We report a detection of the excited 2_(20)-2_(11) rotational transition of para-H_2O in APM 08279+5255 using the IRAM Plateau de Bure Interferometer. At z = 3.91, this is the highest-redshift detection of interstellar water to date. From large velocity gradient modeling, we conclude that this transition is predominantly radiatively pumped and on its own does not provide a good estimate of the water abundance. However, additional water transitions are predicted to be detectable in this source, which would lead to an improved excitation model. We also present a sensitive upper limit for the hydrogen fluoride (HF) J = 1-0 absorption toward APM 08279+5255. While the face-on geometry of this source is not favorable for absorption studies, the lack of HF absorption is still puzzling and may be indicative of a lower fluorine abundance at z = 3.91 compared with the Galactic interstellar medium
Targeting the phosphatidylinositol 3-kinase/Akt/mechanistic target of rapamycin signaling pathway in B-lineage acute lymphoblastic leukemia: An update
Despite considerable progress in treatment protocols, B-lineage acute lymphoblastic leukemia (B-ALL) displays a poor prognosis in about 15–20% of pediatric cases and about 60% of adult patients. In addition, life-long irreversible late effects from chemo- and radiation therapy, including secondary malignancies, are a growing problem for leukemia survivors. Targeted therapy holds promising perspectives for cancer treatment as it may be more effective and have fewer side effects than conventional therapies. The phosphatidylinositol 3-phosphate kinase (PI3K)/Akt/mechanistic target of rapamycin (mTOR) signaling pathway is a key regulatory cascade which controls proliferation, survival and drug-resistance of cancer cells, and it is frequently upregulated in the different subtypes of B-ALL, where it plays important roles in the pathophysiology, maintenance and progression of the disease. Moreover, activation of this signaling cascade portends a poorer prognosis in both pediatric and adult B-ALL patients. Promising preclinical data on PI3K/Akt/mTOR inhibitors have documented their anticancer activity in B-ALL and some of these novel drugs have entered clinical trials as they could lead to a longer event-free survival and reduce therapy-associated toxicity for patients with B-ALL. This review highlights the current status of PI3K/Akt/mTOR inhibitors in B-ALL, with an emphasis on emerging evidence of the superior efficacy of synergistic combinations involving the use of traditional chemotherapeutics or other novel, targeted agents
Numerical precision radiative corrections to the Dalitz plot of baryon semileptonic decays including the spin-momentum correlation of the decaying and emitted baryons
We calculate the radiative corrections to the angular correlation between the
polarization of the decaying and the direction of the emitted spin one-half
baryons in the semileptonic decay mode. The final results are presented, first,
with the triple integration of the bremsstrahlung photon ready to be performed
numerically and, second, in an analytical form. A third presentation of our
results in the form of numerical arrays of coefficients to be multiplied by the
quadratic products of form factors is discussed. This latter may be the most
practical one to use in Monte Carlo simulations. A series of crosschecks is
performed. Previous results to order (alpha/pi)(q/M_1) for the decays of
unpolarized baryons are reviewed, too, where q is the momentum transfer and M_1
is the mass of the decaying baryon. This paper is self-contained and organized
to make it accessible and reliable in the analysis of the Dalitz plot of
precision experiments involving heavy quarks and is not compromised to fixing
the form factors at predetermined values. It is assumed that the real photons
are kinematically discriminated. Otherwise, our results have a general
model-independent applicability.Comment: 34 pages, 4 tables, no figures. Some sections have been shortened.
Conclusions remain unchange
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