Production Threshold Research Articles

Exploration of the Soil Cadmium Thresholds for Safe Pepper Production in the High Geochemical Background Area of Shilin County

Exploration of the Soil Cadmium Thresholds for Safe Pepper Production in the High Geochemical Background Area of Shilin County

ASSESSMENT OF SOCIO-ECONOMIC AND INSTITUTIONAL FACTORS INFLUENCING FARMERS’ UTILIZATION OF AGRICULTURAL EXTENSION SERVICE IN KADUNA STATE, NIGERIA

This study assessed the socioeconomic and institutional factors influencing farmers’ utilization of agricultural extension services in Kaduna State, Nigeria. A multi-stage sampling procedure was employed for the study. The first stage involved the purposive selection of two Local Government Areas (LGAs), i.e., Soba and Ikara, based on the threshold of tomato production in the study area. Secondly, a random sampling of four communities from the two LGAs. A total of 214 tomato farmers were used for the study which was calculated using Slovian’s formula. Descriptive statistics and Tobit regression analysis were used for the study. The findings showed that tomato farmers were young with an average of 38 years and relative experience of 15 years in tomato farming and had an average of 9 persons per household. The result of farmers’ utilization of extension service delivery shows that the extension delivery method, farmers’ indigenous knowledge and extension contacts were positive and a significant factor with a coefficient of 0.1346 at 1% probability. Farm size and income were positive and significant factors at 10% level in influencing farmers' utilization of agricultural extension services. The study recommends that structured training should focus on planting techniques, proper fertilizer application, agrochemical usage, mulching, weed control, and efficient harvesting. Therefore, efforts should be made by extension agents to organize field demonstrations and practical workshops that will equip farmers with hands-on skills to optimize yields and improve farm management practices.

Predominantly electric storage ring with nuclear spin control capability

A predominantly electric E&m storage ring, with weak superimposed magnetic bending, is shown to be capable of storing two different particle type bunches, such as helion (h) and deuteron (d), or h and electron (e -), co-traveling with different velocities on the same central orbit. Rear-end collisions occurring periodically in a full acceptance particle detector/polarimeter, allow the (previously inaccessible) direct measurement of the spin dependence of nuclear transmutation for center of mass (CM) kinetic energies (KE) ranging from hundreds of keV up toward pion production thresholds. With the nuclear process occurring in a semi-relativistic moving frame, all initial and final state particles have convenient laboratory frame KEs in the tens to hundreds of MeV. The rear-end collisions occur as faster stored bunches pass through slower bunches. An inexpensive facility capable of meeting these requirements is described, with several nuclear channels as examples. Especially noteworthy are the e+/--induced weak interaction triton (t) β-decay processes, t + e + → h + ν and h + e - → t + ν. Experimental capability of measurement of the spin dependence of the induced triton case is emphasized. For cosmological nuclear physics, the experimental improvement will be produced by the storage ring's capability to investigate the spin dependence of nuclear transmutation processes at reduced kinetic energies compared to what can be obtained with fixed target geometry.

Testing a nutrient composition threshold model to classify brands for marketing restrictions.

Food marketing restrictions often apply nutrient profile models (NPM) to distinguish unhealthy products that should not be advertised, however brand-only marketing remains largely unaddressed. We sought to test a threshold method for classifying packaged food, beverage, or fast-food brands as (non)permitted for marketing, based on the nutrient profile of their product-lines. We retrieved nutrient information from the Nutritrack databases for all products sold by the top 51 packaged food, beverage and fast-food brands in New Zealand, selected by market share. All products under each brand were classified as permitted (or not) to be marketed to children, using the NPM for WHO Western Pacific. The 25%, 50%, 75% and 90% threshold of brands' products permitted to market were compared. The 50% and 75% thresholds were compared to the WHO CLICK method, which is based on assessment of the brand's leading product. The 90% threshold permitted 13% of the brands to be marketed to children. The 25% threshold permitted the marketing of 62% of brands. The 50% and 75% thresholds remained highly sensitive in identifying brands that should not be marketed to children. Comparison to the WHO CLICK method identified that a threshold method is more comprehensive and less arbitrary. A threshold model based on product-line nutrient profiling provides a robust and option for brand classification. The 50% and 75% thresholds may be the most politically preferred options for use in regulation, while remaining highly effective. Brand marketing (e.g. sponsorship) remains largely unaddressed in existing restrictions on unhealthy food and beverage marketing to children.An established Nutrient Profile Model can be applied to a brand's entire product line, allowing calculation of the proportion of products that would not be permitted to be advertised to children.Restricting brand marketing for food and beverage brands with less than 50% or 75% of their products classified as 'permitted to be marketed to children' is a robust and evidence-based method that can be applied in regulation, with potential to mitigate industry challenges.

Analisis Dinamik Model Predator-Prey dengan Efek Pemanenan Pada Populasi Ikan Nike (Awaous Melanocephalus) di Provinsi Gorontalo

Gorontalo Province is one of the areas directly adjacent to Tomini Bay, which is known for its rich natural resources, especially in the fisheries sector such as Nike fish (Awaous melanocephalus). Nike fish is the main food commodity for people in the Gorontalo region. However, intensive fishing activities can pose an extinction threat to this species. This study aims to understand the dynamics of the Nike fish population using a predator-prey model that integrates the effects of harvesting on the prey population. The research process includes formulation of assumptions, model building, model validation, and data analysis through mathematical analysis and numerical simulation. The analysis showed that the model has four equilibrium points, each with different stability conditions. Numerical simulations showed that an increase in harvesting rate and natural mortality of prey, as well as a decrease in birth rate, could threaten the viability of the Nike fish population. Thus, appropriate management efforts are needed to maintain ecosystem balance and the sustainability of the Nike fish population. The calculation results show that the Nike fish production threshold in Gorontalo Province is 8.470.858 kg per year. However, the amount of Nike fish production in Gorontalo Province in 2023 only reached 56,75% of the threshold. This indicates that the production of Nike fish in Gorontalo can still be increased as long as the harvest limit is observed to prevent extinction.

Renormalization of three-body interaction in DDK system

In systems comprising three identical particles, the Efimov effect emerges in the unitary limit. This article, utilizing the method of effective field theory along with the effective range expansion (ERE) and low-momentum expansion, reproduces the Efimov effect beyond unitary limit and identical case and applies to DDK system. It also links the high-energy scale with the ultraviolet cutoff in the three-body system. We discuss a method for obtaining exact solutions for the three-body wave function below the threshold of dimer production, that is D and Ds0⁎(2317). It turns out that introducing this scale is a necessary condition for the emergence of DDK three-body bound state. Since without this scale, the wave function would be solved below threshold with arbitrary binding energy, which violates the conditions of unitarity and energy quantization. The calculation involving this scale results in a discrete spectrum below the threshold and restores unitarity, making the effects induced by this scale significant for the formation of DDK bound state. In order to establish this in a complete formalism, the paper further gives an analytical expression for the three-body coupling constant, and compares it to the numerical calculation in DDK system.

Observation of quantum entanglement with top quarks at the ATLAS detector

Entanglement is a key feature of quantum mechanics1–3, with applications in fields such as metrology, cryptography, quantum information and quantum computation4–8. It has been observed in a wide variety of systems and length scales, ranging from the microscopic9–13 to the macroscopic14–16. However, entanglement remains largely unexplored at the highest accessible energy scales. Here we report the highest-energy observation of entanglement, in top–antitop quark events produced at the Large Hadron Collider, using a proton–proton collision dataset with a centre-of-mass energy of √s = 13 TeV and an integrated luminosity of 140 inverse femtobarns (fb)−1 recorded with the ATLAS experiment. Spin entanglement is detected from the measurement of a single observable D, inferred from the angle between the charged leptons in their parent top- and antitop-quark rest frames. The observable is measured in a narrow interval around the top–antitop quark production threshold, at which the entanglement detection is expected to be significant. It is reported in a fiducial phase space defined with stable particles to minimize the uncertainties that stem from the limitations of the Monte Carlo event generators and the parton shower model in modelling top-quark pair production. The entanglement marker is measured to be D = −0.537 ± 0.002 (stat.) ± 0.019 (syst.) for 340GeV<mtt¯<380GeV\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$340\\,{\\rm{GeV}} < {m}_{t\\bar{t}} < 380\\,{\\rm{GeV}}$$\\end{document}. The observed result is more than five standard deviations from a scenario without entanglement and hence constitutes the first observation of entanglement in a pair of quarks and the highest-energy observation of entanglement so far.

An ecological framework to index crop yields using productivity and Ecosystem Fit: A case study from India

On the global scale, agricultural crop yields have decreased or plateaued over the last several decades. This suggests that the current focus on selecting crop varieties based on a plant’s light-use efficiency (photosynthetic and nitrogen-use-efficiency metrics) may not be sensitive to the site’s edaphic parameters, which limit growth. This study introduces a new framework to determine if crops can achieve higher yield potentials by assessing how plants adapt to the edaphic properties that impact growth, especially when contending with climate change. The new approach calculates an Ecosystem Fit index using a ratio of remotely sensed (or observed) total net primary productivity to the theoretical maximum productivity of the site. Then, it uses that index as a benchmark to judge quantitatively whether any new crop species or variety is improving potential biomass or economic yields at that specific site. It can also determine the best soil types for those crop varieties and monitor their potential adaptability relative to climate change over time. This study used a database of 356 spatially independent reference sites to develop this framework using a landcover classification of crops across 21 ecoregions and five biomes in India. It includes total net primary productivity data, theoretical maximum productivity potential, and soil and climatic data. This comparison showed that the light-use efficiency model, as intended, was not sensitive to variations in soil characteristics, temperature, or precipitation. Our framework showed significant differences in growth by soil type and precipitation and three significant productivity thresholds by soil type. The results of this study demonstrate that total crop productivity and Ecosystem Fit create a useful index for local land managers to assess growth and yield potentials across diverse edaphic landscapes and for decision-making with changing climates.

Missing-Mass Measurement of the 12C(K-, K+) Reaction at 1.8 GeV/c with the Superconducting Kaon Spectrometer

Abstract We performed a measurement of the inclusive missing-mass spectrum of the $^{12}$C$(K^-, K^+)$ reaction at an incident beam momentum of 1.8 GeV/c. This measurement was carried out by using the Superconducting Kaon Spectrometer (SKS) and the K1.8 beamline spectrometer at the Hadron Experimental Facility in J-PARC. From the missing-mass of the $^{12}$C$(K^-, K^+)$ reaction, the binding energy of a $\Xi ^-$ hyperon in a core $^{11}$B nucleus, $B_{\Xi ^-}$, can be calculated. Our experimental setup yielded a good energy resolution of 8.2 MeV (full width at half maximum), which allowed us to observe significant enhancements in the proximity of the $^{12}_{\Xi }$Be production threshold region. In order to extract information from the missing-mass spectrum, we employed several fitting parameters assumptions. A good agreement with the spectrum shape was obtained by adding two Gaussian functions, with the constant experimental resolution for the $\Xi$-hypernuclear states, to the background distribution. The peak positions were obtained to be $B_{\Xi ^-} = 8.9 \pm 1.4$ (stat.) $^{+3.8}_{-3.1}$ (syst.) MeV and $B_{\Xi ^-} = -2.4 \pm 1.3$ (stat.) $^{+2.8}_{-1.2}$ (syst.) MeV. Another model assumption, one Breit–Wigner function with $B_{\Xi ^-} = -2.7 \pm 2.2$ (stat.) $^{+0.5}_{-0.7}$ (syst.) MeV and $\Gamma = 4.1 \pm 2.1$ (stat.) $^{+1.2}_{-0.7}$ (syst.) MeV, also yielded a similar $\chi ^2$ value.

Study of the decays χcJ→ΛΛ¯ϕ

Based on (2712.4±14.3)×106 e+e−→ψ(3686) events collected with the BESIII detector operating at the BEPCII Collider, we report the first evidence of χc0→ΛΛ¯ϕ decays and the first observation of χc1,2→ΛΛ¯ϕ decays, with significances of 4.1σ, 11.3σ and 13.0σ, respectively. The decay branching fractions of χc0,1,2→ΛΛ¯ϕ are measured to be (2.99±1.24±0.19)×10−5, (6.01±0.90±0.40)×10−5, and (7.13±0.81±0.36)×10−5, where the first uncertainties are statistical and the second systematic. No obvious enhancement near the ΛΛ¯ production threshold or excited Λ state is found in the Λϕ (or Λ¯ϕ) system. Published by the American Physical Society 2024

Long-range near-side correlation in e+e− collisions at 183-209 GeV with ALEPH archived data

The first measurement of two-particle angular correlations for charged particles with LEP-II data is presented. The study is performed using archived hadronic e+e− data collected by ALEPH at center-of-mass energies up to 209 GeV, above the W+W− production threshold, which provide access to unprecedented charged-particle multiplicities and more complex color-string configurations if compared to previous measurements at LEP-I energies. An intriguing long-range near-side excess is observed in the correlation function measured with respect to the thrust axis in the highest multiplicity interval (Ntrk≥50). Such a structure is not predicted by the Monte-Carlo simulation. The harmonic anisotropy coefficients vn, which result from the Fourier expansion of the two-particle correlation functions, were also measured for the first time in e+e− data, and compared to pythia 6 predictions and to the results obtained in proton-proton collisions. The results presented in the Letter provide novel experimental constraints on the formation of collective phenomena in point-like e+e− collisions.

Cost-Effectiveness of Low-Dose Computed Tomography Screenings for Lung Cancer in High-Risk Populations: A Markov Model.

Domestic and foreign studies on lung cancer have been oriented to the medical efficacy of low-dose computed tomography (LDCT), but there is a lack of studies on the costs, value and cost-effectiveness of the treatment. There is a scarcity of conclusive evidence regarding the cost-effectiveness of LDCT within the specific context of Taiwan. This study is designed to address this gap by conducting a comprehensive analysis of the cost-effectiveness of LDCT and chest X-ray (CXR) as screening methods for lung cancer. Markov decision model simulation was used to estimate the cost-effectiveness of biennial screening with LDCT and CXR based on a health provider perspective. Inputs are based on probabilities, health status utility (quality-adjusted life years (QALYs)), costs of lung cancer screening, diagnosis, and treatment from the literatures, and expert opinion. A total of 1,000 simulations and five cycles of Markov bootstrapping simulations were performed to compare the incremental cost-utility ratio (ICUR) of these two screening strategies. Probability and one-way sensitivity analyses were also performed. The ICUR of early lung cancer screening compared LDCT to CXR is $-24,757.65/QALYs, and 100% of the probability agree to adopt it under a willingness-to-pay (WTP) threshold of the Taiwan gross domestic product (GDP) per capita ($35,513). The one-way sensitivity analysis also showed that ICUR depends heavily on recall rate. Based on the prevalence rate of 39.7 lung cancer cases per 100,000 people in 2020, it could be estimated that LDCT screening for high-risk populations could save $17,154,115. LDCT can detect more early lung cancers, reduce mortality and is cost-saving than CXR in a long-term simulation of Taiwan's healthcare system. This study provides valuable insights for healthcare decision-makers and suggests analyzing cost-effectiveness for additional variables in future research.

Study of the Financial Feasibility of a Dairy Farming Business after the FMD Outbreak in Kampung Susu Lawu, Plaosan District, Magetan Regency

&lt;p&gt;&lt;strong&gt;Objective:&lt;/strong&gt; An outbreak of Foot-and-Mouth Disease (FMD) in Indonesia targeted ruminants, notably impacting dairy cows and precipitating a significant downturn in milk production during the year 2022. This research aimed to determine the financial feasibility and break-even point of post-FMD dairy farming within the Kampung Susu Lawu livestock group in Plaosan District, Magetan Regency.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods:&lt;/strong&gt; Employing a quantitative descriptive method, this study utilized survey techniques involving 50 dairy farmers affiliated with the Livestock Group of Kampung Susu Lawu. The data analysis encompassed investment analysis, including the Benefit Cost Ratio (BCR), Net Present Value (NPV), Internal Rate of Return (IRR), Pay Back Period of Credit (PPC), and Break-Even Point (BEP).&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; The findings revealed a BCR value of 1.49, NPV amounting to IDR 38,888,178.00, IRR at 26.36%, PPC of 3.46 years, BEP pegged at IDR 33,043,062.00/year, and BEP based on the unit set at 7,396 liters of milk/year. Financial analysis indicated a positive NPV, a BCR exceeding 1, an IRR surpassing prevailing bank interest rates, and a PPC duration of 3.46 years, collectively affirming the financial feasibility of the dairy farming business.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; This investigation shows that the post-FMD smallholder dairy business is economically feasible. Farmers stand to accrue benefits by surpassing the production threshold of 7,396 liters of milk/year or by maintaining a herd of productive dairy cows numbering more than three.&lt;/p&gt;

Financing and cost-effectiveness of emergency medical services in low- and middle-income countries

In 2023, the 76th World Health Assembly declared coordinated emergency, critical, and operative care services fundamental for comprehensive universal health coverage in low- and middle-income countries. With increasing mortality from noncommunicable diseases, an organized emergency care system has the capacity to treat a variety of conditions with a common set of resources, optimizing per-unit cost efficiency by applying economies of scope and increasing cost-effectiveness. However, the financing and cost-effectiveness of emergency medical services remain poorly understood despite affordability and financial barriers comprising some of the most significant obstacles to development. Cost-effectiveness analyses generate incremental cost-effectiveness ratios for comparison against per-capita gross domestic product thresholds to determine cost-effectiveness, promoted by the World Health Organization’s Choosing Interventions that are Cost-Effective program. Incremental cost-effectiveness ratios may be used as context-specific indicators of value alongside budget impact and feasibility considerations. Currently, there are few high-quality cost-effectiveness studies of emergency care in low- and middle-income countries, demonstrating significant methodologic heterogeneity, little geographic diversity, neglecting descriptions of assumptions used in cost-effectiveness calculations and comparators used, and lacking incremental cost-effectiveness ratios for comparison. The assessment of emergency care cost-effectiveness is challenging, given the significant breadth of conditions encountered and difficulty in projecting subsequent impact. Without improved epidemiologic surveillance and data-collection infrastructure, data inputs for cost-effectiveness calculations will remain limited. Future efforts should practice standard cost-effectiveness methodologies to permit comparison of incremental cost-effectiveness ratios across interventions and settings while incorporating trauma registry data to longitudinally track patient outcomes over sufficient time horizons to determine impact. New indices that expand the scope of analysis to capture broader secondary impacts of emergency care for future cost-effectiveness studies are needed. In this article, we summarize the key steps for economic evaluations for prehospital care systems and recommend considerations for future prehospital emergency care cost-effectiveness analyses, determining the optimal structure for financing mechanisms well-suited to resource-limited settings are critical for future investigation.

Cost-Utility Analysis of TNF-α Inhibitors, B Cell Inhibitors, and JAK Inhibitors Versus csDMARDs for Rheumatoid Arthritis Treatment.

Rheumatoid arthritis (RA) is a progressive and debilitating disease, causing persistent joint pain that limits daily activities requiring long-term treatment. Newer targeted therapies expand RA treatment options, but their high cost necessitates a focus on cost effectiveness. To address this, we aim to conduct a cost-utility analysis of these newer RA pharmacotherapies to support evidence-based policy decision-making. We analyzed the cost-utility of sequential treatment with TNF-α, B cell and JAK-inhibitors compared with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) for RA treatment in methotrexate (MTX) nonresponders. We used a Markov model with lifetime horizon and 6-month cycles from an Indian health system perspective. Costs (INR 2022) and quality-adjusted life years (QALYs) were used to determine the incremental cost-effectiveness ratios (ICERs) at a cost-effectiveness threshold of India's gross domestic product (GDP) per capita (2022). We assessed uncertainty using univariate, probabilistic sensitivity, and scenario analyses. Despite additional QALYs, TNF-α, B cell, and JAK inhibitors were not cost-effective for treating moderate-to-severe patients with RA unresponsive to csDMARDs (including MTX) in India, as increased costs outweighed their clinical benefits. ICERs ranged from 10,46,206 to 31,09,207Indian Rupees in the base case analysis, exceeding three times India's GDP per-capita [approximately USD $13,287 to $39,487 and GBP £10,776 to £32,025]. Sensitivity analyses confirmed the results' robustness. Scenario analysis suggested that a cost reduction of over 75% in drug prices could make most of the interventions cost effective compared with csDMARDs. TNF-α, B cell, and JAK-inhibitors are not cost-effective compared with csDMARDs for patients with RA who have not responded to MTX in India at the current prices. Cost-effectiveness estimates were highly influenced by drug pricing variations. Therefore, reducing the prices of these interventions could enhance affordability, potentially leading to their inclusion in publicly funded health programs.

Electroweak Corrections to Double Higgs Production at the LHC.

We present the results for the complete next-to-leading order electroweak corrections to pp→HH at the Large Hadron Collider, focusing on the dominant gluon-gluon fusion process. While the corrections at the total cross-section level are approximately -4%, those near the energy of HH production threshold exceed +15%, and corrections at the high-energy region are around -10%, leading to a shape distortion for the differential distributions. Our findings substantially diminish the theoretical uncertainties associated with this pivotal process, providing valuable input for understanding the shape of the Higgs boson potential upon comparison with experimental measurements.

Optimal rainfall threshold for monsoon rice production in India varies across space and time

Climate change affects Indian agriculture, which depends heavily on the spatiotemporal distribution of monsoon rainfall. Despite the nonlinear relationship between crop yield and rainfall, little is known about the optimal rainfall threshold, particularly for monsoon rice. Here, we investigate the responses of rice yield to monsoon rainfall in India by analyzing historical rice production statistics and climate data from 1990 to 2017. Results show that excessive and deficit rainfall reduces rice yield by 33.7% and 19%, respectively. The overall optimal rainfall threshold nationwide is 1621 ± 34 mm beyond which rice yield declines by 6.4 kg per hectare per 100 mm of rainfall, while the identifiable thresholds vary spatially across 14 states. The temporal variations in rice yield are influenced by rainfall anomalies featured by El Niño-Southern Oscillation events.

Economic evaluation of trastuzumab in HER2-positive early breast cancer in Indonesia: A cost-effectiveness analysis.

Trastuzumab has significantly enhanced the survival and prognosis of individuals diagnosed with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. Considering its relatively high costs, we aimed to examine the cost-effectiveness of trastuzumab plus chemotherapy compared with chemotherapy alone in HER2-positive early breast cancer from an Indonesian healthcare payer's perspective. A Markov model was developed to project the lifetime health benefits and costs associated with trastuzumab treatment for a cohort of women with HER2-positive early breast cancer. Efficacy data and baseline characteristics in the base-case analysis were primarily derived from the 11-year results of the HERA trial. Costs were based on verified reimbursement data from Indonesia's Health and Social Security Agency (BPJS Kesehatan) of the year 2020. A scenario analysis was conducted with efficacy data based on the joint analysis from the NSABP B-31 and NCCTG N9831 trials, allowing for subgroup analysis by age at diagnosis. Univariate and probabilistic sensitivity analyses were conducted to assess the influence of parameter uncertainty. In the base-case analysis, the results indicated that the lifetime costs for trastuzumab plus chemotherapy and chemotherapy alone were US$33,744 and US$22,720, respectively, resulting in substantial incremental savings of US$11,024 per patient for the former. Trastuzumab plus chemotherapy also led to higher total quality-adjusted life years (QALYs) and life years gained (LYG), resulting in incremental cost-effectiveness ratios (ICERs) of US$6,842 per QALY and US$5,510 per LYG. In scenario analysis, the subgroup with an age at diagnosis <40 years old reflected the most cost-effective subgroup. Both the base-case and scenario analyses demonstrated cost-effectiveness with a willingness-to-pay threshold of three-times Gross Domestic Product (GDP). Sensitivity analyses confirmed the robustness of the findings and conclusions. In Indonesia, trastuzumab plus chemotherapy can be considered cost-effective compared to chemotherapy alone at a willingness-to-pay threshold of three times GDP, and it is likely most cost-effective in women <40 years of age.

Semi-inclusive single-jet production in DIS at next-to-leading order in the Color Glass Condensate

Within the Color Glass Condensate (CGC) effective field theory, we derive the next-to-leading order (NLO) cross-section for the single-jet semi-inclusive cross-section in deep inelastic scattering (DIS) at small x, for both longitudinally and transversely polarized virtual photons. We provide analytic expressions, valid at finite Nc and suitable for numerical evaluation, for both the cross-section differential in rapidity and transverse momentum and the cross-section differential in rapidity only. Our NLO formulae demonstrate that the very forward rapidity regime is plagued by large double logarithmic corrections coming from phase space constraints on soft gluons close to the kinematic threshold for jet production. A joint resummation of small-x and threshold logarithms at single logarithmic accuracy is proposed to remedy the instability of the cross-section in this regime. By integrating over the single-jet phase space, we recover known results for the NLO DIS structure functions at small x, previously obtained using the optical theorem.

Relativistic corrections to prompt double charmonium hadroproduction near threshold

We calculate the relativistic corrections to prompt J/ψ pair and J/ψ+ψ(2S) hadroproduction through the color singlet channel within the framework of nonrelativistic-QCD (NRQCD) factorization. The short-distance coefficients are obtained by matching full-QCD and NRQCD calculations at the partonic level, in which both squared amplitude and phase space are expanded in v2. We find that such an expansion of the phase space spoils the convergence of NRQCD factorization near the production threshold. To fix this problem, we propose to modify the matching between full QCD and NRQCD by adopting the physical phase space. In this modified approach, the theoretical uncertainties due to the choice of charm quark mass mc are largely reduced and the overall agreement of our predictions with LHC data is significantly improved, both for total and differential cross sections. Published by the American Physical Society 2024