A novel determination of non-perturbative contributions to Bjorken sum rule

Based on the operator product expansion, the perturbative and nonperturbative contributions to the polarized Bjorken sum rule (BSR) can be separated conveniently, and the nonperturbative one can be fitted via a proper comparison with the experimental data. In the paper, we first give a detailed study on the pQCD corrections to the leading-twist part of BSR. Basing on the accurate pQCD prediction of BSR, we then give a novel fit of the non-perturbative high-twist contributions by comparing with JLab data. Previous pQCD corrections to the leading-twist part derived under conventional scale-setting approach still show strong renormalization scale dependence. The principle of maximum conformality (PMC) provides a systematic and strict way to eliminate conventional renormalization scale-setting ambiguity by determining the accurate $$\alpha _s$$ α s -running behavior of the process with the help of renormalization group equation. Our calculation confirms the PMC prediction satisfies the standard renormalization group invariance, e.g. its fixed-order prediction does scheme-and-scale independent. In low $$Q^2$$ Q 2 -region, the effective momentum of the process is small and in order to derive a reliable prediction, we adopt four low-energy $$\alpha _s$$ α s models to do the analysis, i.e. the model based on the analytic perturbative theory (APT), the Webber model (WEB), the massive pQCD model (MPT) and the model under continuum QCD theory (CON). Our predictions show that even though the high-twist terms are generally power suppressed in high $$Q^2$$ Q 2 -region, they shall have sizable contributions in low and intermediate $$Q^2$$ Q 2 domain. Based on the more accurate scheme-and-scale independent pQCD prediction, our newly fitted results for the high-twist corrections at $$Q^2=1\;\mathrm{GeV}^2$$ Q 2 = 1 GeV 2 are, $$f_2^{p-n}|_{\mathrm{APT}}=-0.120\pm 0.013$$ f 2 p - n | APT = - 0.120 ± 0.013 , $$f_2^{p-n}|_\mathrm{WEB}=-0.081\pm 0.013$$ f 2 p - n | WEB = - 0.081 ± 0.013 , $$f_2^{p-n}|_{\mathrm{MPT}}=-0.128\pm 0.013$$ f 2 p - n | MPT = - 0.128 ± 0.013 and $$f_2^{p-n}|_{\mathrm{CON}}=-0.139\pm 0.013$$ f 2 p - n | CON = - 0.139 ± 0.013 ; $$\mu _6|_\mathrm{APT}=0.003\pm 0.000$$ μ 6 | APT = 0.003 ± 0.000 , $$\mu _6|_{\mathrm{WEB}}=0.001\pm 0.000$$ μ 6 | WEB = 0.001 ± 0.000 , $$\mu _6|_\mathrm{MPT}=0.003\pm 0.000$$ μ 6 | MPT = 0.003 ± 0.000 and $$\mu _6|_{\mathrm{CON}}=0.002\pm 0.000$$ μ 6 | CON = 0.002 ± 0.000 , respectively, where the errors are squared averages of those from the statistical and systematic errors from the measured data.

The P-wave charmonium annihilation into two photons $$\chi _{c0, c2}\rightarrow \gamma \gamma $$ with high-order QCD corrections

In this paper, we present a new analysis on the P-wave charmonium annihilation into two photons up to next-to-next-to-leading order (NNLO) QCD corrections by using the principle of maximum conformality (PMC). The conventional perturbative QCD prediction shows strong scale dependence and deviates largely from the BESIII measurements. After applying the PMC, we obtain a more precise scale-invariant pQCD prediction, which also agrees with the BESIII measurements within errors, i.e. $$R={\Gamma _{\gamma \gamma }(\chi _{c2})} /{\Gamma _{\gamma \gamma }(\chi _{c0})}=0.246\pm 0.013$$ R = Γ γ γ ( χ c 2 ) / Γ γ γ ( χ c 0 ) = 0.246 ± 0.013 , where the error is for $$\Delta \alpha _s(M_\tau )=\pm 0.016$$ Δ α s ( M τ ) = ± 0.016 . By further considering the color-octet contributions, even the central value can be in agreement with the data. This shows the importance of a correct scale-setting approach. We also give a prediction for the ratio involving $$\chi _{b0, b2} \rightarrow \gamma \gamma $$ χ b 0 , b 2 → γ γ , which could be tested in future Belle II experiment.

PENGARUH DUKUNGAN SOSIAL TEMAN SEBAYA TERHADAP PERENCANAAN KARIER SISWA

This research is motivated by the finding of students who are still confused in choosing a major to enter higher education. The purpose of this study was to describe the effect of peer social support on student career planning. This type of research is a qualitative descriptive study, using a natural setting approach, which places more emphasis on what the informants experience naturally. Determination of informants in this study using purposive sampling method. Collecting data using observation, interview, documentation, and tri-accounting techniques. Data analysis uses the Miles Hurberman method, in which Miles Huberman divides 3 stages in data analysis, namely data reduction, display data, and conclusion drawing / verification. The results showed that there was an effect of peer social support on student career planning, it was shown from emotional support, support, appreciation, information support.

Outdoor Recreation: Perencanaan Dan Pemberdayaan Masyarakat Dalam Pengembangan Wisata Pendidikan Ciungwanara

Peran serta masyarakat sebagai penggerak roda dan pendukung terciptanya Ciungwanara sebagai salah satu lokasi pendidikan berbasis alam dan budaya masih kurang sehingga perlu adanya inovasi untuk meningkatkan keberlangsungan objek wisata tersebut. Penelitian ini bertema pengembangan objek wisata Ciungwanara Karangkamulyan Kabupaten Ciamis dengan spesifikasi penelitian berfokus pada pengembangan wisata pendidikan rekreasi. Metode penelitian yang digunakan yaitu penelitian kualitatif dengan pendekatan natural setting dan community approach. Parameter yang digunakan pada penelitian ini yaitu tipologi bangunan rekreasi. Observasi awal pada penelitian ini yaitu masih kurangnya pengembangan objek wisata rekreasi berbasis pendidikan di Ciungwanara mengenai tata kelola dan pengembangannya sehingga tindakan yang dilakukan oleh peneliti mengenai kekurangan tersebut yaitu memasukan beberapa indikator mengenai tipologi bangunan wisata rekreasi berbasis pendidikan dihubungankan dengan hasil temuan dilapangan. Hasil kajian yang diperoleh yaitu dari segi perencanaan bahwa perlu menciptakan perencanaan partisipatif antara pemangku kebijakan dengan beberapa tim ahli pendidikan dan pakar budaya mengenai penerapan objek wisata Ciungwanara sebagai objek wisata rekreasi berbasis pendidikan alam dan budaya. Pemberdayaan masyarakat harus memiliki peran aktif dalam pengembangan potensi alam Ciungwanara sebagai wahana pendidikan berbasis alam terbuka (outdoor recreation).Community participation as a driving force and support for the creation of Ciungwanara as one of the locations for education based on nature and culture is still lacking, so there is a need for innovation to improve the sustainability of these tourist objects. This research has the theme of developing a tourist attraction in Ciungwanara Karangkamulyan, Ciamis Regency. The research specification focuses on the development of recreational educational tourism. The research method used is qualitative research with a natural setting approach and a community approach. The parameters used in this study are the typology of recreational buildings. Initial observations in this study are that there is still a lack of development of educational-based recreational tourism objects in Ciungwanara regarding its management and development so that the actions taken by researchers regarding these deficiencies are including several indicators regarding the typology of educational-based recreational tourism buildings related to the findings in the field. The results of the study obtained are in terms of planning that it is necessary to create participatory planning between policy makers and several teams of education experts and cultural experts regarding the application of Ciungwanara tourism object as a recreation tourism object based on natural and cultural education. Community empowerment must have an active role in developing Ciungwanara's natural potential as a vehicle for outdoor based education (outdoor recreation).

Scale-fixed predictions for γ + ηc production in electron-positron collisions at NNLO in perturbative QCD

In the paper, we present QCD predictions for γ + ηc production at an electron-positron collider up to next-to-next-to-leading order (NNLO) accuracy without renormalization scale ambiguities. The NNLO total cross-section for e+ + e− → γ + ηc using the conventional scale-setting approach has large renormalization scale ambiguities, usually estimated by choosing the renormalization scale to be the e+e− center-of-mass collision energy $$ \sqrt{s} $$ s . The Principle of Maximum Conformality (PMC) provides a systematic way to eliminate such renormalization scale ambiguities by summing the nonconformal β contributions into the QCD coupling αs(Q2). The renormalization group equation then sets the value of αs for the process. The PMC renormalization scale reflects the virtuality of the underlying process, and the resulting predictions satisfy all of the requirements of renormalization group invariance, including renormalization scheme invariance. After applying the PMC, we obtain a renormalization scale-and-scheme independent prediction, σ|NNLO,PMC ≃ 41.18 fb for $$ \sqrt{s} $$ s =10.6 GeV. The resulting pQCD series matches the series for conformal theory and thus has no divergent renormalon contributions. The large K factor which contributes to this process reinforces the importance of uncalculated NNNLO and higher-order terms. Using the PMC scale-and-scheme independent conformal series and the Padé approximation approach, we predict σ|NNNLO,PMC+Pade ≃ 18.99 fb, which is consistent with the recent BELLE measurement $$ {\sigma}^{\mathrm{obs}}={16.58}_{-9.93}^{+10.51} $$ σ obs = 16.58 − 9.93 + 10.51 fb at $$ \sqrt{s} $$ s ≃ 10.6 GeV. This procedure also provides a first estimate of the NNNLO contribution.

Condition Setting in Sport: A Case Study Approach to Explore Program Planning by Canadian University Coaches

Based on a condition-setting approach derived from organizational psychology, the authors investigated the conditions that university sport coaches considered and implemented prior to a competitive season. Using a collective case study approach, semistructured interviews were conducted at two time points, with five head coaches across different sports. Student-athletes from each team (n = 5) and the high performance director from the institution were also interviewed. The data were analyzed thematically to highlight the relevant conditions for coaches and their individual athletes and were then generalized across teams within the institution. The authors’ results support the utility of the condition-setting approach outlined by Hackman for sport. Specifically, coaches emphasized the need to (a) create a team vision with clear objectives, (b) opt for athletes of best fit, (c) assign team roles and expectations, (d) confirm and allocate necessary resources, and (e) have competent and prepared team coaching. Despite the generalizability of these themes, the authors’ results highlight the need to consider the context, as both the university environment generally and each specific program were bound by unique constraints (e.g., funding). Herein, the authors discuss their findings in relation to the broader literature, propose future directions, and provide practical implications for sport coaches and institutions.

On a new robust workflow for the statistical and spatial analysis of fracture data collected with scanlines (or the importance of stationarity)

We present an innovative workflow for the statistical analysis of fracture data collected along scanlines, composed of two major stages, each one with alternative options. A prerequisite in our analysis is the assessment of stationarity of the dataset, which is motivated by statistical and geological considerations. Calculating statistics on non-stationary data can be statistically meaningless, and moreover the normalization and/or sub-setting approach that we discuss here can greatly improve our understanding of geological deformation processes. Our methodology is based on performing non-parametric statistical tests, which allow detecting important features of the spatial distribution of fractures, and on the analysis of the cumulative spacing function (CSF) and cumulative spacing derivative (CSD), which allows defining the boundaries of stationary domains in an objective way. Once stationarity has been analysed, other statistical methods already known in the literature can be applied. Here we discuss in detail methods aimed at understanding the degree of saturation of fracture systems based on the type of spacing distribution, and we evidence their limits in cases in which they are not supported by a proper spatial statistical analysis.

The Spirit of ‘WE’ in the Learning Environment: ‘WE LEaRN’—A Space for Students and Teachers to Become

This chapter advances the idea that in order to improve twenty-first-century learning environments for students and particularly for teachers, it is necessary to enhance the spirit of collective culture, called ‘WE’, versus the spirit of individualism, called ‘I’, and provides an example of how this is reflected in the design of learning spaces. Both of these cohorts use learning, working and doing processes, and face major changes from educational mandates. A ‘WE’ cultural environment will be discussed in order to support multiple aspects of collaboration and creativity, where hub-specific solutions empower the two groups as collectives, supporting a ‘WE LEaRN HUB’ setting. Connecting practice to research, a process of change in school design related to the ‘WE’ culture is presented through an academic park built in Israel. This academic park uses an introductory design of the hub’s setting approach, supporting the ‘WE’ of both communities and reflecting new approaches in learning processes.