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1.
Front Nutr ; 11: 1264658, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38406187

RESUMO

Introduction: Over the years, smallholder farmers have faced more vulnerability to risk and uncertainty in India due to their dependence on cereal crops. One way to reduce this risk is through diversified agriculture, integrating different practices for efficient resource utilization, and adopting a farming systems approach. An integrated farming system (IFS) is one such technique that provides year-round income from different components of enterprises. However, the decision to adopt IFS may be determined by several characteristics of farmers, which needs to be delineated through impact analysis to harness the benefits of a systems approach. Methods: This study analyzes the economic effects of integrated farming systems and assesses their determinants, as well as the dietary diversity patterns of farmers in two states of southern India, i.e., Kerala and Tamil Nadu. A multistage sampling technique was used to obtain cross-sectional data from 367 farmers randomly chosen from one district in Kerala and two districts in Tamil Nadu. The participants have Crop + Horticulture + Animal husbandry (45.45%) as their major system, whereas non-participants have Crop + Animal husbandry (44.35%) as their predominant system. Coarsened exact matching and logit regression methods were used to evaluate the economic impacts of IFS and its influencing factors. Results: The findings of the study indicate that age, education, livestock holding, access to credit, and plantation area have a positive and significant effect on participation by farmers in the program. The matching results show that adoption of IFS resulted in a significant economic impact, generating an additional gross income of Rs. 36,165 ha-1 and a net income of Rs. 35,852 ha-1 and improving the dietary diversity of farm households by 8.6% as compared to non-adopters. Discussion: This study suggests that IFS is a promising approach for improving farmers' livelihoods, economic gains, and nutritional security. Therefore, the integrated farming systems models need to be upscaled through the convergence of government schemes in other regions of India to support smallholder farmers' farming.

2.
Clin Oncol (R Coll Radiol) ; 35(7): 454-462, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37061457

RESUMO

AIMS: This multicentric retrospective study reports long-term clinical outcomes of non-metastatic grade group 5 prostate cancers treated with external beam radiotherapy (EBRT) alone with long-term androgen deprivation therapy (ADT). MATERIALS AND METHODS: Patients treated across 19 institutions were studied. The key endpoints that were evaluated were 5-year biochemical recurrence-free survival (bRFS), metastases-free survival (MFS), overall survival, together with EBRT-related acute and late toxicities. The impact of various prognostic factors on the studied endpoints was analysed using univariate and multivariate analyses. RESULTS: Among the 462 patients, 88% (405) had Gleason 9 disease and 31% (142) had primary Gleason pattern 5. A prostate-specific membrane antigen positron emission tomography-computed tomography scan was used for staging in 33% (153), 80% (371) were staged as T3/T4 and 30% (142) with pelvic nodal disease. The median ADT duration was 24 months; 66% received hypofractionated EBRT and 71.4% (330) received pelvic nodal irradiation. With a median follow-up of 56 months, the 5-year bRFS, MFS and overall survival were 73.1%, 77.4% and 90.5%, respectively. Primary Gleason pattern 5 was associated with worse bRFS, MFS and overall survival with hazard ratios of 0.51 (95% confidence interval 0.35 to 0.73, P < 0.001), 0.64 (95% confidence interval 0.43 to 0.96, P = 0.031) and 0.52 (95% confidence interval 0.28 to 0.97, P = 0.040), respectively, whereas pelvic nodal disease was associated with worse bRFS (hazard ratio 0.67, 95% confidence interval 0.46 to 0.98, P = 0.039) and MFS (hazard ratio 0.56, 95% confidence interval 0.37 to 0.85, P = 0.006). The acute and late radiation-related toxicities were low overall and pelvic nodal irradiation was associated with higher toxicities. CONCLUSION: Contemporary EBRT and long-term ADT led to excellent 5-year clinical outcomes and low rates of toxicity in this cohort of non-metastatic grade group 5 prostate cancers. Primary Gleason pattern 5 and pelvic node disease portends inferior clinical outcomes.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/radioterapia , Antagonistas de Androgênios/uso terapêutico , Androgênios , Próstata/patologia , Estudos Retrospectivos , Biópsia , Antígeno Prostático Específico
3.
Nature ; 611(7935): 265-270, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36261531

RESUMO

The visible world is founded on the proton, the only composite building block of matter that is stable in nature. Consequently, understanding the formation of matter relies on explaining the dynamics and the properties of the proton's bound state. A fundamental property of the proton involves the response of the system to an external electromagnetic field. It is characterized by the electromagnetic polarizabilities1 that describe how easily the charge and magnetization distributions inside the system are distorted by the electromagnetic field. Moreover, the generalized polarizabilities2 map out the resulting deformation of the densities in a proton subject to an electromagnetic field. They disclose essential information about the underlying system dynamics and provide a key for decoding the proton structure in terms of the theory of the strong interaction that binds its elementary quark and gluon constituents. Of particular interest is a puzzle in the electric generalized polarizability of the proton that remains unresolved for two decades2. Here we report measurements of the proton's electromagnetic generalized polarizabilities at low four-momentum transfer squared. We show evidence of an anomaly to the behaviour of the proton's electric generalized polarizability that contradicts the predictions of nuclear theory and derive its signature in the spatial distribution of the induced polarization in the proton. The reported measurements suggest the presence of a new, not-yet-understood dynamical mechanism in the proton and present notable challenges to the nuclear theory.

4.
Phys Rev Lett ; 129(4): 042501, 2022 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-35939025

RESUMO

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733 fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model) fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

5.
Nature ; 609(7925): 41-45, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36045235

RESUMO

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure1-3, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements3-5. Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction.

6.
J Postgrad Med ; 68(2): 85-92, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35466661

RESUMO

Aims: No Cochrane meta-analysis with grading of evidence is available on use of hydroxychloroquine (HCQ) in type-2 diabetes (T2DM). This meta-analysis evaluated the efficacy and safety of HCQ in T2DM. Methods: Electronic databases were searched using a Boolean search strategy: ((hydroxychloroquine) OR (chloroquine*)) AND ((diabetes) OR ("diabetes mellitus") OR (glycemia) OR (glucose) OR (insulin)) for studies evaluating hydroxychloroquine for glycemic control in T2DM. The primary outcome was a change in glycated haemoglobin (HbA1c). The secondary outcomes were changes in other glycemic/lipid parameters and adverse effects. Results: Data from 11 randomized controlled trials (RCTs) (3 having placebo as controls [passive controls] and 8 having anti-diabetes medications as controls [active controls]) involving 2,723 patients having a median follow-up of 24 weeks were analyzed. About 54.54% of the RCTs were of poor quality as evaluated by the Jadad scale. The performance bias and detection bias were at high risk in 63.64% of the RCTs. The HbA1c reduction with HCQ was marginally better compared to the active (mean differences [MD]-0.17% [95%, CI:-0.30--0.04;P=0.009;I2=89%; very low certainty of evidence, VLCE]), and passive (MD-1.35% [95%CI:-2.10--0.59;P=0.005;I2=74%]) controls. A reduction in fasting glucose (MD-16.63mg/dL[95%, CI: -25.99 - -7.28mg/dL;P<0.001;I2=97%;VLCE]) and post-prandial glucose [MD -8.41mg/dL (95%CI: -14.71 - -2.12mg/dL;P=0.009;I2=87%;VLCE]), appeared better with HCQ compared to active controls. The total adverse events (risk ratio [RR]0.93 [95% CI:0.68-1.28]; P=0.65;I2=66%) were not different with HCQ compared to the controls. Conclusion: The routine use of HCQ in T2DM cannot be recommended based on the current evidence.


Assuntos
Diabetes Mellitus Tipo 2 , Hidroxicloroquina , Glicemia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobinas Glicadas , Humanos , Hidroxicloroquina/efeitos adversos
7.
Phys Rev Lett ; 128(14): 142501, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35476486

RESUMO

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

8.
Phys Rev Lett ; 128(13): 132501, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426696

RESUMO

We report the first measurement of the parity-violating elastic electron scattering asymmetry on ^{27}Al. The ^{27}Al elastic asymmetry is A_{PV}=2.16±0.11(stat)±0.16(syst) ppm, and was measured at ⟨Q^{2}⟩=0.02357±0.00010 GeV^{2}, ⟨θ_{lab}⟩=7.61°±0.02°, and ⟨E_{lab}⟩=1.157 GeV with the Q_{weak} apparatus at Jefferson Lab. Predictions using a simple Born approximation as well as more sophisticated distorted-wave calculations are in good agreement with this result. From this asymmetry the ^{27}Al neutron radius R_{n}=2.89±0.12 fm was determined using a many-models correlation technique. The corresponding neutron skin thickness R_{n}-R_{p}=-0.04±0.12 fm is small, as expected for a light nucleus with a neutron excess of only 1. This result thus serves as a successful benchmark for electroweak determinations of neutron radii on heavier nuclei. A tree-level approach was used to extract the ^{27}Al weak radius R_{w}=3.00±0.15 fm, and the weak skin thickness R_{wk}-R_{ch}=-0.04±0.15 fm. The weak form factor at this Q^{2} is F_{wk}=0.39±0.04.

9.
Phys Rev Lett ; 128(13): 132003, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35426713

RESUMO

The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19

11.
J Chem Phys ; 155(7): 074701, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34418937

RESUMO

We studied the dissociation of water (H2O*, with * denoting adspecies) on atomic oxygen (O*)-covered Rh nanoclusters (RhO* ) supported on a graphene film grown on a Ru(0001) surface [G/Ru(0001)] under ultrahigh-vacuum conditions and with varied surface-probe techniques and calculations based on density-functional theory. The graphene had a single rotational domain; its lattice expanded by about 5.7% to match the Ru substrate structurally better. The Rh clusters were grown by depositing Rh vapors onto G/Ru(0001); they had an fcc phase and grew in (111) orientation. Water adsorbed on the Rh clusters was dissociated exclusively in the presence of O*, like that on a Rh(111) single-crystal surface. Contrary to the case on Rh(111)O* , excess O* (even at a saturation level) on small RhO* clusters (diameter of 30-34 Å) continued to promote, instead of inhibiting, the dissociation of water; the produced hydroxyl (OH*) increased generally with the concentration of O* on the clusters. The difference results from more reactive O* on the RhO* clusters. O* on RhO* clusters activated the dissociation via both the formation of hydrogen bonds with H2O* and abstraction of H directly from H2O*, whereas O* on Rh(111)O* assisted the dissociation largely via the formation of hydrogen bonds, which was readily obstructed with an increased O* coverage. As the disproportionation (2 OH* → H2O* + O*) is endothermic on the RhO* clusters but exothermic on Rh(111)O* , OH* produced on RhO* clusters showed a thermal stability superior to that on the Rh(111)O* surface-thermally stable up to 400 K.

12.
Mymensingh Med J ; 30(3): 860-862, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34226481

RESUMO

Dermoid cysts (DC) are benign cutaneous developmental anomalies comprising of hair follicles, sweat glands and sebaceous glands, and lined by stratified squamous epithelium. They are most commonly found on the face, lower back, and ovaries. We present a case of DC with intracranial extension in a 9 year old boy who presented with headache and a fluctuant scalp swelling. Magnetic resonance imaging revealed a midline scalp mass with intracranial extension. The lesion was excised with superior sagittal sinus preservation; and confirmed as DC by histopathological examination. The boy made good recovery.


Assuntos
Cisto Dermoide , Criança , Cisto Dermoide/complicações , Cisto Dermoide/diagnóstico , Cisto Dermoide/cirurgia , Face , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino
13.
Phys Rev Lett ; 126(17): 172502, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988387

RESUMO

We report a precision measurement of the parity-violating asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A_{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(Q^{2}=0.00616 GeV^{2})=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R_{n}-R_{p}=0.283±0.071 fm. The result also yields the first significant direct measurement of the interior weak density of ^{208}Pb: ρ_{W}^{0}=-0.0796±0.0036(exp)±0.0013(theo) fm^{-3} leading to the interior baryon density ρ_{b}^{0}=0.1480±0.0036(exp)±0.0013(theo) fm^{-3}. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

14.
Phys Rev Lett ; 126(8): 082301, 2021 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-33709760

RESUMO

Quasielastic ^{12}C(e,e^{'}p) scattering was measured at spacelike 4-momentum transfer squared Q^{2}=8, 9.4, 11.4, and 14.2 (GeV/c)^{2}, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q^{2} dependence, up to proton momenta of 8.5 GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q^{2} scales in exclusive (e,e^{'}p) reactions. These results impose strict constraints on models of color transparency for protons.

15.
Curr Med Res Opin ; 37(3): 403-409, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33319626

RESUMO

Type 2 diabetes mellitus (T2DM) is a global epidemic. According to international guidelines, the management protocol of T2DM includes lowering of blood glucose, along with preventing disease-related complications and maintaining optimal quality of life. Further, the guidelines recommend the use of a patient-centric approaches for the management of T2DM; however, Asian population is underrepresented in landmark cardiovascular outcome trials (CVOTs). There are several guidelines available today for the diagnosis and management of T2DM, and hence there is much confusion among practitioners about which guidelines to follow. A group of thirty international clinical experts comprising of endocrinologists, diabetologists and cardiologist from South Asia, Middle East and Africa met at New Delhi, India on February 8 and 9, 2020 and developed an international expert opinion statements via a structured modified Delphi method on the glucodynamic properties of OADs and the glucocratic treatment approach for the management of T2DM. In this modified Delphi consensus report, we document the glucodynamic properties of Modern SUs in terms of glucoconfidence, glucosafety, and gluconomics. According to glucodynamics theory, an ideal antidiabetic drug should be efficacious, safe, and affordable. Modern SUs as a class of OADs that have demonstrated optimal glucodynamics in terms of glucoconfidence, glucosafety, and gluconomics. Hence, modern SUs are most suitable second line drug after metformin for developing countries. Based on the current evidence, we recommend a glucocratic approach for the treatment of T2DM, where an individualized treatment plan with phenotype, lifestyle, environmental, social, and cultural factors should be considered for persons with T2DM in the South Asian, Middle Eastern and African regions.


Assuntos
Diabetes Mellitus Tipo 2 , Ásia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hipoglicemiantes , Qualidade de Vida , Compostos de Sulfonilureia
16.
J Intern Med ; 289(3): 293-308, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32910532

RESUMO

Clostridioides (Clostridium) difficile (C. difficile) infection is one of the most common causes of increased morbidity and mortality. Approximately 500 000 C. difficile infections (CDIs) occur each year in the United States, and they result in more than 29 000 deaths. Patients with haematologic diseases are at a higher risk for this infection due to frequent hospitalization and exposure to treatment-associated risk factors. Whilst several currently available antimicrobial agents offer resolution, recurrence of infection remains a major concern. Recent advancement in deciphering C. difficile virulence mechanisms and identification of its allies in contributing to the infection has led to the development of alternative treatment strategies. Here, we will provide a contemporary discussion of how major risk factors in haematologic diseases, such as immunosuppression, chemoradiation, use of antibiotic, proton pump inhibitor and opioid, and deficiency in butyrate and antimicrobial peptides contribute to C. difficile infection. Next, we will highlight different approaches to control and mitigate this infection such as antibiotic stewardship and faecal microbiota transplantation. Finally, we will explore several emerging treatments such as use of pre- and probiotics, immunotherapy and microbiome-sparing agents.


Assuntos
Infecções por Clostridium/tratamento farmacológico , Infecções por Clostridium/etiologia , Doenças Hematológicas/complicações , Clostridioides difficile/patogenicidade , Microbioma Gastrointestinal , Hospitalização , Humanos , Fatores de Risco , Virulência
17.
J Intern Med ; 290(1): 40-56, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33372309

RESUMO

Cancer treatment options have evolved to include immunotherapy and targeted therapy, in addition to traditional chemoradiation. Chemoradiation places the patient at a higher risk of infection through a myelosuppressive effect. High clinical suspicion and early use of antimicrobials play a major role in decreasing any associated morbidity and mortality. This has led to a widespread use of antimicrobials in cancer patients. Antimicrobial use, however, does not come without its perils. Dysbiosis caused by antimicrobial use affects responses to chemotherapeutic agents and is prognostic in the development and severity of certain cancer treatment-related complications such as graft-versus-host disease and Clostridioides difficile infections. Studies have also demonstrated that an intact gut microbiota is essential in the anticancer immune response. Antimicrobial use can therefore modulate responses and outcomes with immunotherapy targeting immune checkpoints. In this review, we highlight the perils associated with antimicrobial use during cancer therapy and the importance of a more judicious approach. We discuss the nature of the pathologic changes in the gut microbiota resulting from antimicrobial use. We explore the effect these changes have on responses and outcomes to different cancer treatment modalities including chemotherapy and immunotherapy, as well as potential adverse clinical consequences in the setting of stem cell transplant.


Assuntos
Antibacterianos/efeitos adversos , Antineoplásicos/uso terapêutico , Disbiose/induzido quimicamente , Microbioma Gastrointestinal/efeitos dos fármacos , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunoterapia , Inflamação/fisiopatologia , Neoplasias/fisiopatologia
18.
Phys Rev Lett ; 125(11): 112502, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32976004

RESUMO

A beam-normal single-spin asymmetry generated in the scattering of transversely polarized electrons from unpolarized nucleons is an observable related to the imaginary part of the two-photon exchange process. We report a 2% precision measurement of the beam-normal single-spin asymmetry in elastic electron-proton scattering with a mean scattering angle of θ_{lab}=7.9° and a mean energy of 1.149 GeV. The asymmetry result is B_{n}=-5.194±0.067(stat)±0.082 (syst) ppm. This is the most precise measurement of this quantity available to date and therefore provides a stringent test of two-photon exchange models at far-forward scattering angles (θ_{lab}→0) where they should be most reliable.

19.
Phys Rev Lett ; 124(21): 212501, 2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32530643

RESUMO

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9 (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500 MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350 MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250 MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500 MeV/c.

20.
Science ; 368(6490): 506-509, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32355026

RESUMO

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π0 into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π0 photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

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