2,258 research outputs found
On -functions with bounded spectrum
We consider the class of functions in ,
whose Fourier transform has bounded support. We obtain a description of
continuous maps such that
for every function .
Only injective affine maps have this property
Thermal behaviors of light unflavored tensor mesons in the framework of QCD sum rule
In this study, we investigate the sensitivity of the masses and decay
constants of the light and tensor mesons to the
temperature using QCD sum rule approach. In our calculations, we take into
account the additional operators appearing in operator product expansion at
finite temperature. It is obtained that at deconfinement temperature the decay
constants and masses decrease with amount of and compared to their
vacuum values, respectively. Our results on the masses at zero temperature are
consistent with the vacuum sum rules predictions as well as the experimental
data.Comment: 4 Pages and 1 Table, Prepared for the proceeding of the 4th
International Conference on Hadron Physics (TROIA'14
Thermal QCD Sum Rules Study of Vector Charmonium and Bottomonium States
We calculate the masses and leptonic decay constants of the heavy vector
quarkonia, and mesons at finite temperature. In particular,
considering the thermal spectral density as well as additional operators coming
up at finite temperature, the thermal QCD sum rules are acquired. Our numerical
calculations demonstrate that the masses and decay constants are insensitive to
the variation of temperature up to , however after this point,
they start to fall altering the temperature. At deconfinement temperature, the
decay constants attain roughly to 45% of their vacuum values, while the masses
are diminished about 12%, and 2.5% for and states,
respectively. The obtained results at zero temperature are in good consistency
with the existing experimental data as well as predictions of the other
nonperturbative models. Considerable decreasing in the values of the decay
constants can be considered as a sign of the quark gluon plasma phase
transition.Comment: 14 Pages, 8 Figures and 2 Table
Iranian Dietary Patterns and Risk of Colorectal Cancer
Background: Role of diet on colorectal cancer (CRC) has been considered in terms of single foods and nutrients, but less frequently in terms of dietary patterns in Iran. The objective of this study was to determine the association between Iranian dietary patterns and CRC. Methods: This case-control study was conducted in four hospitals in Tabriz City of Iran including 414 participants aged 35-75 years: 207 cases with CRC confirmed by pathology and colonoscopy findings were selected and 207 controls free of neoplastic conditions and diet-related chronic diseases (from the same hospital at the same period for the cases). Dietary data were assessed using a 123-item semi-quantitative food frequency questionnaire. Two dietary patterns were found by using of Principal Component Analysis (PCA) method;"Healthy pattern" and "Iranian pattern". Multivariate logistic regression analysis was used to estimate adjusted odds ratios (OR) for relationship between dietary patterns and colorectal cancer. Results: After adjusting for confounding factors, the Iranian dietary pattern was significantly associated with an increased odds of colorectal cancer (OR=1.46; 95 Confidenec Interval (CI)=1.05-2.19) while a reduced odds of colorectal cancer was observed with the Healthy dietary pattern (OR=0.18; 95 CI=0.091-0.47). Conclusion: Iranian dietary pattern (IDP) seems to increase the odds of colorectal cancer and protective effect of Healthy dietary pattern
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