56 research outputs found
Study of isolated prompt photon production in -Pb collisions for the ALICE kinematics
Prompt photon production is known as a powerful tool for testing perturbative
QCD predictions and also the validity of parton densities in the nucleon and
nuclei especially of the gluon. In this work, we have performed a detailed
study on this subject focusing on the isolated prompt photon production in -Pb collisions at forward rapidity at the LHC. The impact of input nuclear
modifications obtained from different global analyses by various groups on
several quantities has been investigated to estimate the order of magnitude of
the difference between their predictions. We have also studied in detail the
theoretical uncertainties in the results due to various sources. We found that
there is a remarkable difference between the predictions from the nCTEQ15 and
other groups in all ranges of photon transverse momentum . Their differences become more explicit in the calculation of the nuclear
modification ratio and also the yield asymmetry between the forward and
backward rapidities rather than single differential cross sections. We
emphasize that future measurements with ALICE will be very useful not only for
decreasing the uncertainty of the gluon nuclear modification, but also to
accurately determine its central values, especially in the shadowing region.Comment: 12 pages, 10 figure
Measurement of the Quasi-Two-Body B Decays
We study the contributions of the , and and quasi-two-body decays. There
are no existing previous measurement of the three-body branching fractions for
three final states of the ,
and but several quasi-two-body modes that can decay to this final
state have been seen
Final State Interaction Effect in Pure Annihilation Decay
We analyzed the process of decay in QCD
factorization (QCDF) and final state interaction (FSI) effects. In QCDF for
this decay we have only the annihilation graph and we expected small Branching
ratio. Then we considered FSI effect as a sizable correction where the
intermediate states are , , and
mesons. To consider the amplitudes of these intermediate states, QCDF approach
was used. The experimental branching ratio of is less
than and our result is and from QCDF and FSI, respectively
Predictions for the Isolated Prompt Photon Production at the LHC at s
The prompt photon production in hadronic collisions has a long history of providing information on the substructure of hadrons and testing the perturbative techniques of QCD. Some valuable information about the parton densities in the nucleon and nuclei, especially of the gluon, can also be achieved by analysing the measurements of the prompt photon production cross section whether inclusively or in association with heavy quarks or jets. In this work, we present predictions for the inclusive isolated prompt photon production in pp collisions at center-of-mass energy of 13 TeV using various modern PDF sets. The calculations are presented as a function of both photon transverse energy ETγ and pseudorapidity ηγ for the ATLAS kinematic coverage. We also study in detail the theoretical uncertainty in the cross sections due to the variation of the renormalization, factorization, and fragmentation scales. Moreover, we introduce and calculate the ratios of photon momenta for different rapidity regions and study the impact of various input PDFs on such quantity
Determination of the design parameters for making urban wastewater plants in cold regions of Iran
زمینه و هدف: تعیین مشخصات کمی و کیفی فاضلاب خام ورودی به تصفیه خانه ها یکی از ارکان اصلی طراحی صحیح تصفیه خانه های فاضلاب به حساب می آید. این مطالعه با هدف تعیین پارامترهای طراحی تصفیه خانه های فاضلاب شهری برای مناطق سردسیر کشور انجام شد. روش بررسی: در این مطالعه توصیفی- تحلیلی سه تصفیه خانه فاضلاب شهرکرد، بروجن و فارسان واقع در استان چهارمحال و بختیاری به عنوان پایلوت در منطقه سردسیر انتخاب و مشخصات کمی و کیفی فاضلاب ورودی به آنها در یک دوره یکساله (سال 1386) بررسی گردید. علاوه بر اندازه گیری پیوسته دبی فاضلاب ورودی به تصفیه خانه، دما، pH ورودی، غلظت اکسیژن خواهی شیمیایی (COD)، غلظت اکسیژن خواهی بیوشیمیایی پنج روزه (BOD)، مواد معلق (TSS)، مواد معلق فرار (VSS)، نیتــــروژن کجلدال (TKN)، فسفر فسفاتی، در نمونه های مرکب 24 ساعته متناسب با دبی، اندازه گیری شد.داده ها به کمک آزمون های آماری t و ANOVA تجزیه و تحلیل شدند. یافته ها: میانگین سرانه پارامترهای مورد تحقیق در این مطالعه بر حسب گرم در روز به ازای هر نفر برای BOD5 معادل 41، COD معادل 60، TSS معادل 65، VSS معادل 47، TKN معادل 3/8 و برای فسفات معادل 93/0 و متوسط تولید فاضلاب، 177 لیتر به ازای هر نفر در روز و ضریب حداکثر و حداقل دبی فاضلاب به ترتیب 76/1 و 29/0 بدست آمد. مقایسه نتایج پارامترهای سرانه مورد نظر در سه تصفیه خانه اختلاف معنی داری بین پارامترهای BOD5، COD، نیتروژن کجدال و فسفر وجود نداشت ولی میزان TSS، VSS در تصفیه خانه های مورد مطالعه بیشتر بود (05/0
Berberine as a Natural Modifier of Gut Microbiota to Promote Metabolic Status in Animal Studies and Clinical Trials: A Systematic Review
As a phytochemical, berberine can modulate metabolic parameters via altering gut flora. However, findings are conflicting. In the present systematic review, we aimed to summarize the effects of berberine on gut microbiota in the models of metabolic disorders in both animal studies and clinical trials. Publications in five electronic databases including PubMed, SCOPUS, EMBASE, Web of Science, and Cochrane Library were searched systematically up to 31 May 2021 to find relevant articles with English language. Out of 4102 studies (including 2125 duplicates), 35 studies were included. In animal studies, various effects of berberine on beneficial and harmful microbiota were reported. However, findings also indicated that berberine can decrease the Firmicutes to Bacteroidetes (F/B) ratio. Three out of five studies showed positive effects of berberine on the production of short-chain fatty acids (SCFA), particularly butyrate. In three animal studies, Lipopolysacaride (LPS) concentrations decreased with berberine administration. In clinical trials (n=3) positive effects on microbiota and metabolic status were also reported. However, the quality of clinical trials was mainly low.The present systematic review showed that berberine can modulate key metabolic parameters through improving the balance of intestinal microbiome, decreasing the abundance of harmful microbiota and LPS concentrations, and increasing the production of SCFAs, particularly butyrate in animal models. However, there are limited high-quality evidence regarding the effects of berberine on gut flora in clinical trials. Although berberine can be an effective prebiotic supplement to modulate metabolic parameters, further high-quality clinical trials are needed to confirm this potential
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