248 results on '"Kotikov, A. V."'
Search Results
2. Fractional Analytic QCD beyond Leading Order in timelike region
- Author
-
Kotikov, A. V., Zemlyakov, I. A., Kotikov, A. V., and Zemlyakov, I. A.
- Abstract
In this paper we show that, as in the spacelike case, the inverse logarithmic expansion is applicable for all values of the argument of the analytic coupling constant. We present two different approaches, one of which is based primarily on trigonometric functions, and the latter is based on dispersion integrals. The results obtained up to the 5th order of perturbation theory, have a compact form and their acquiring is much easier than the methods that have been used before. As an example, we apply our results to study the Higgs boson decay into a bb pair., Comment: 30 pages, 9 figures. arXiv admin note: substantial text overlap with arXiv:2203.09307
- Published
- 2023
- Full Text
- View/download PDF
3. Bjorken sum rule with analytic coupling at low Q2 values
- Author
-
Gabdrakhmanov, I. R., Gramotkov, N. A, Kotikov, A. V., Volkova, D. A., Zemlyakov, I. A., Gabdrakhmanov, I. R., Gramotkov, N. A, Kotikov, A. V., Volkova, D. A., and Zemlyakov, I. A.
- Abstract
The experimental data obtained for the polarized Bjorken sum rule \Gamma^{(p-n)}_1(Q^2) for small values of Q2 are approximated by the predictions obtained in the framework of analytic QCD up to the 5th order perturbation theory, whose coupling constant does not contain the Landau pole. We found an excellent agreement between the experimental data and the predictions of analytic QCD, as well as a strong difference between these data and the results obtained in the framework of standard QCD., Comment: 9 pages, 1 figure
- Published
- 2023
4. On ultrahigh-energy neutrino-nucleon deep-inelastic scattering and the Froissart bound
- Author
-
Kotikov, A. V., Kotikov, I. A., Kotikov, A. V., and Kotikov, I. A.
- Abstract
A brief review of the results for the total cross section \sigma^{\nu N} of ultrahigh-energy neutrino deep inelastic scattering on isoscalar nuclear targets is presented. These results are based on simple approximations for \sigma^{\nu N} and are compared with the experimental data of the IceCube Collaboration. The total cross section \sigma^{\nu N} is proportional to the structure function F_2^{\nu N}(M_V^2/s,M_V^2), where M_V is the intermediate boson mass and s is square of the energy of the center of mass. The coefficient in the front of F_2^{\nu N}(M_V^2/s,M_V^2) depends on the asymptotic behavior of F_2^{\nu N} at low values of x. It contains an additional term \sim \ln{s} if F_2^{\nu N} is scaled by the power \ln(1/x). Therefore, the asymptotic behavior of F_2^{\nu N}\propto\ln^2(1/x) for small x often assumed in the literature already leads to violation of the Froissart bound for \sigma^{\nu N}., Comment: 10 pages, 1 figure, contribution to the proceedings of the 4th International Symposium on Cosmic Rays and Astrophysics (June 27-29, Moscow, Russia)
- Published
- 2023
5. On x-independence of RQ = FLQ/F2Q ratio at low x
- Author
-
Abdulov, N. A., Kotikov, A. V., Lipatov, A. V., Abdulov, N. A., Kotikov, A. V., and Lipatov, A. V.
- Abstract
We give predictions for the ratio RQ(x,Q2)=FLQ(x,Q2)/F2Q(x,Q2) at small values of Bjorken variable x in the first three orders of perturbation theory. We show an approximate x-independence of RQ(x,Q2) at low x and non-large Q2 values (Q2 < 8--10 m2Q), irrespectively on the gluon density in a proton used in the calculations. This observation could be useful in subsequent phenomenological studies of the heavy flavor production at future lepton-hadron and hadron-hadron colliders., Comment: 10 pages, 3 figures
- Published
- 2023
- Full Text
- View/download PDF
6. The strong coupling constant: State of the art and the decade ahead
- Author
-
d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., Xie, K., d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., and Xie, K.
- Abstract
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\alpha_s(m^2_Z)$. Each of the extraction methods proposed provides a "wish list" of experimental and theoretical developments required in order to achieve an ideal permille precision on $\alpha_s(m^2_Z)$ within the next 10 years., Comment: 130 pages, 82 figures. White paper submitted to the Energy Frontier "Proceedings of the US Community Study on the Future of Particle Physics" (Snowmass 2021)
- Published
- 2022
7. About Fractional Analytic QCD beyond Leading Order
- Author
-
Kotikov, A. V., Zemlyakov, I. A., Kotikov, A. V., and Zemlyakov, I. A.
- Abstract
We present an overview of fractional analytic QCD beyond leading order, following the results recently obtained in Ref. [1]. We demonstrate four different representations, the details of their derivation, and show the applicability of analytic QCD to the analysis of the Bjorken sum rule., Comment: 25 pages, 14 figures, contribution to the proceedings of the International Workshop on Elementary Particles and Nuclear Physics (April 24-30, Almaty, Kazakhstan)
- Published
- 2022
8. On series and integral representations of some NRQCD master integrals
- Author
-
Bezuglov, M. A., Kotikov, A. V., Onishchenko, A. I., Bezuglov, M. A., Kotikov, A. V., and Onishchenko, A. I.
- Abstract
We consider new ways of obtaining series and integral representations for master integrals arising in the process of matching of QCD to NRQCD. The latter results are exact in space-time dimension $d$. In addition, we discuss series expansion of the obtained results at fixed values of $d$., Comment: 15 pages, 1 figure
- Published
- 2022
- Full Text
- View/download PDF
9. The strong coupling constant: State of the art and the decade ahead
- Author
-
d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., Xie, K., d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., and Xie, K.
- Abstract
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\alpha_s(m^2_Z)$. Each of the extraction methods proposed provides a "wish list" of experimental and theoretical developments required in order to achieve an ideal permille precision on $\alpha_s(m^2_Z)$ within the next 10 years., Comment: 130 pages, 82 figures. White paper submitted to the Energy Frontier "Proceedings of the US Community Study on the Future of Particle Physics" (Snowmass 2021)
- Published
- 2022
10. alpha_s in DIS scheme
- Author
-
Kotikov, A. V., Krivokhizhin, V. G., Shaikhatdenov, B. G., Kotikov, A. V., Krivokhizhin, V. G., and Shaikhatdenov, B. G.
- Abstract
Deep inelastic scattering data on $F_2$ structure function from various fixed-target experiments were analyzed in a nonsinglet approximation in the MSbar and DIS scheme. The study of high statistics deep inelastic scattering data provided by BCDMS, SLAC and NMC collaborations, was carried out using a combined analysis. The application of the DIS scheme leads to the resummation of contributions that are important for large x values. It is found that using the DIS scheme does not significantly change the strong coupling constant itself but does strongly change the values of the twist-four corrections., Comment: 7 pages
- Published
- 2022
- Full Text
- View/download PDF
11. Fractional Analytic QCD beyond Leading Order
- Author
-
Kotikov, A. V., Zemlyakov, I. A., Kotikov, A. V., and Zemlyakov, I. A.
- Abstract
Fractional analytic QCD is constructed beyond leading order. We present four different views, details of their production, and show their applicability., Comment: 34 pages, 16 figures
- Published
- 2022
12. The strong coupling constant: State of the art and the decade ahead
- Author
-
d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., Xie, K., d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., and Xie, K.
- Abstract
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\alpha_s(m^2_Z)$. Each of the extraction methods proposed provides a "wish list" of experimental and theoretical developments required in order to achieve an ideal permille precision on $\alpha_s(m^2_Z)$ within the next 10 years., Comment: 130 pages, 82 figures. White paper submitted to the Energy Frontier "Proceedings of the US Community Study on the Future of Particle Physics" (Snowmass 2021)
- Published
- 2022
13. Parametrizations of collinear and k_T-dependent parton densities in a proton
- Author
-
Abdulov, N. A., Kotikov, A. V., Lipatov, A. V., Abdulov, N. A., Kotikov, A. V., and Lipatov, A. V.
- Abstract
A new type of parametrization for parton distribution functions in a proton, based on their $Q^2$-evolution at large and small $x$ values, is constructed. In our analysis, the valence and nonsinglet parts obey the Gross-Llewellyn-Smith and Gottfried sum rules, respectively. For the singlet quark and gluon densities momentum conservation is taken into account. Then, using the Kimber-Martin-Ryskin prescription, we extend the consideration to Transverse Momentum Dependent (TMD, or unintegrated) gluon and quark distributions in a proton, which currently plays an important role in a number of phenomenological applications. The analytical expressions for the latter, valid for both low and large $x$, are derived for the first time., Comment: 28 pages, 8 figures
- Published
- 2022
14. Sunrise integral in non-relativistic QCD with elliptics
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
The main steps of the process of obtaining the result [1] in terms of elliptic polylogarithms for a two-loop sunrise integral with two different internal masses with pseudothreshold kinematics for all orders of the dimensional regulator are shown., Comment: 7 pages, contribution to the proceedings of the International Conference on Quantum Field Theory, High-Energy Physics, and Cosmology (July 18 - 21, 2022; Dubna, Russia)
- Published
- 2022
- Full Text
- View/download PDF
15. Gluon density in the rescaling model
- Author
-
Abdulov, N. A., Kotikov, A. V., Lipatov, A. V., Abdulov, N. A., Kotikov, A. V., and Lipatov, A. V.
- Abstract
The behavior of the gluon density in nuclei is investigated in the framework of the rescaling model., Comment: 6 pages, 1 figure
- Published
- 2022
16. The strong coupling constant: State of the art and the decade ahead
- Author
-
d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., Xie, K., d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., and Xie, K.
- Abstract
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\alpha_s(m^2_Z)$. Each of the extraction methods proposed provides a "wish list" of experimental and theoretical developments required in order to achieve an ideal permille precision on $\alpha_s(m^2_Z)$ within the next 10 years., Comment: 130 pages, 82 figures. White paper submitted to the Energy Frontier "Proceedings of the US Community Study on the Future of Particle Physics" (Snowmass 2021)
- Published
- 2022
17. The strong coupling constant: State of the art and the decade ahead
- Author
-
d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., Xie, K., d'Enterria, D., Kluth, S., Zanderighi, G., Ayala, C., Benitez-Rathgeb, M. A., Bluemlein, J., Boito, D., Brambilla, N., Britzger, D., Camarda, S., Cooper-Sarkar, A. M., Cridge, T., Cvetic, G., Brida, M. Dalla, Deur, A., Giuli, F., Golterman, M., Hoang, A. H., Huston, J., Jamin, M., Kotikov, A. V., Krivokhizhin, V. G., Kronfeld, A. S., Leino, V., Lipka, K., Makela, T., Malaescu, B., Maltman, K., Marzani, S., Mateu, V., Moch, S., Monni, P. F., Nadolsky, P., Nason, P., Nesterenko, A. V., Perez-Ramos, R., Peris, S., Petreczky, P., Pich, A., Rabbertz, K., Ramos, A., Reichelt, D., Rodriguez-Sanchez, A., Rojo, J., Saragnese, M., Sawyer, L., Schott, M., Schumann, S., Shaikhatdenov, B. G., Sint, S., Soyez, G., Teca, D., Vairo, A., Vos, M., Waits, C., Weber, J. H., Wobisch, M., and Xie, K.
- Abstract
This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\alpha_s(m^2_Z)$. Each of the extraction methods proposed provides a "wish list" of experimental and theoretical developments required in order to achieve an ideal permille precision on $\alpha_s(m^2_Z)$ within the next 10 years., Comment: 130 pages, 82 figures. White paper submitted to the Energy Frontier "Proceedings of the US Community Study on the Future of Particle Physics" (Snowmass 2021)
- Published
- 2022
18. Some examples of calculation of massless and massive Feynman integrals
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
We show some examples of calculations of massless and massive Feynman integrals., Comment: 22 pages. arXiv admin note: text overlap with arXiv:2004.06625
- Published
- 2021
19. Transverse momentum dependent parton densities in processes with heavy quark generations
- Author
-
Kotikov, A. V., Lipatov, A. V., Zhang, P., Kotikov, A. V., Lipatov, A. V., and Zhang, P.
- Abstract
To study the heavy quark production processes, we use the transverse momentum dependent (TMD, or unintegrated) gluon distribution function in a proton obtained recently using the Kimber-Martin-Ryskin prescription from the Bessel-inspired behavior of parton densities at small Bjorken $x$ values. We obtained a good agreement of our results with the latest HERA experimental data for reduced cross sections $\sigma^{c\overline{c}}_{\rm red}(x,Q^2)$ and $\sigma^{b\overline{b}}_{\rm red}(x,Q^2)$, and also for deep inelastic structure functions $F_2^c(x,Q^2)$ and $F_2^b(x,Q^2)$ in a wide range of $x$ and $Q^2$ values. Comparisons with the predictions based on the Ciafaloni-Catani-Fiorani-Marchesini evolution equation and with the results of conventional pQCD calculations performed at first three orders of perturbative expansion are presented., Comment: 28 pages, 5 figures
- Published
- 2021
- Full Text
- View/download PDF
20. Differential equations and Feynman integrals
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
The role of differential equations in the process of calculating Feynman integrals is reviewed. An example of a diagram is given for which the method of differential equations was introduced, the properties of the inverse-mass-expansion coefficients are shown, and modern methods based on differential equations are considered., Comment: 22 pages; contribution to the proceedings of the International Conference "Antidifferentiation and the Calculation of Feynman Amplitudes" (4-9 October 2020, Zeuthen, Germany). arXiv admin note: text overlap with arXiv:2004.06625
- Published
- 2021
21. About calculation of massless and massive Feynman integrals
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
We report some results of calculations of massless and massive Feynman integrals particularly focusing on difference equations for coefficients of for their series expansions, Comment: 51 pages; contribution to the proceedings of Helmholtz International Summer School "Quantum Field Theory at the Limits: from Strong Fields to Heavy Quarks" (July 22 - August 2, 2019; Dubna, Russia)
- Published
- 2020
22. About calculation of massless and massive Feynman integrals
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
We report some results of calculations of massless and massive Feynman integrals particularly focusing on difference equations for coefficients of for their series expansions, Comment: 51 pages; contribution to the proceedings of Helmholtz International Summer School "Quantum Field Theory at the Limits: from Strong Fields to Heavy Quarks" (July 22 - August 2, 2019; Dubna, Russia)
- Published
- 2020
23. SUSY, Casimir scaling and probabilistic properties of gluon and quark jets evolution
- Author
-
Kotikov, Anatoly V., Teryaev, Oleg V., Kotikov, Anatoly V., and Teryaev, Oleg V.
- Abstract
We study the new relation [1] between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations for the first Mellin moments D_{q,g}(\mu^2) of the fragmentation functions, which correspond to the average multiplicities of hadrons in jets initiated by quarks and gluons, respectively. This relation is shown to lead to probabilistic properties of the properly rescaled parton jet multiplicities obtained from standard ones by extracting the quark and gluon "color charges" C_F and C_A, respectively., Comment: 17 pages
- Published
- 2020
- Full Text
- View/download PDF
24. Four-loop singularities of the massless fermion propagator in quenched three-dimensional QED
- Author
-
Pikelner, A. F., Gusynin, V. P., Kotikov, A. V., Teber, S., Pikelner, A. F., Gusynin, V. P., Kotikov, A. V., and Teber, S.
- Abstract
We calculate the three- and four-loop corrections to the massless fermion propagator in three-dimensional quenched Quantum Electrodynamics with four-component fermions. The three-loop correction is finite and gauge invariant but the four-loop one has singularities except in the Feynman gauge where it is also finite. Our results explicitly show that, up to four loops, gauge-dependent terms are completely determined by lower order ones in agreement with the Landau-Khalatnikov-Fradkin transformation., Comment: 11+4 pages
- Published
- 2020
- Full Text
- View/download PDF
25. Landau-Khalatnikov-Fradkin transformation and hatted zeta-values
- Author
-
Kotikov, A. V., Teber, S., Kotikov, A. V., and Teber, S.
- Abstract
We show an exact formula obtained in [1], which relates hatted and standard zeta-values to all orders of perturbation theory. The formula is based on the Landau-Khalatnikov-Fradkin (LKF) transformation between the massless propagators of charged particles interacting with gauge fields, in two different gauges., Comment: 8 pages; contribution to the proceedings of International Bogolyubov Conference "Problems of Theoretical and Mathematical Physics" (September 9 - 13, 2019; Dubna, Russia); based on arXiv:1906.10930
- Published
- 2019
- Full Text
- View/download PDF
26. Landau-Khalatnikov-Fradkin transformation of the fermion propagator in massless reduced QED
- Author
-
James, A., Kotikov, A. V., Teber, S., James, A., Kotikov, A. V., and Teber, S.
- Abstract
We study the gauge-covariance of the massless fermion propagator in reduced Quantum Electrodynamics (QED). Starting from its value in some gauge, we evaluate an all order expression for it in another gauge by means of the Landau-Khalatnikov-Fradkin transformation. We find that the weak coupling expansions thus derived are in perfect agreement with the exact calculations. We also prove that the fermion anomalous dimension of reduced QED is gauge invariant to all orders of perturbation theory except for the first one., Comment: (v2) 11 pages, two-column format, no figure, published in Phys. Rev. D, edits in text (some per referee's comments) and references added, no change in results. (v1) 23 pages, no figure
- Published
- 2019
- Full Text
- View/download PDF
27. Two-loop diagrams in non-relativistic QCD with elliptics
- Author
-
Kniehl, B. A., Kotikov, A. V., Onishchenko, A. I, Veretin, O. L., Kniehl, B. A., Kotikov, A. V., Onishchenko, A. I, and Veretin, O. L.
- Abstract
In this paper we consider two-loop two-, three- and four-point diagrams with elliptic structure in the case of two different masses $m$ and $M$. The latter diagrams generally arise within NRQCD matching procedures and are relevant for parapositronium decay and top pair production at threshold. We present the obtained results in several different representations: series solution with binomial coefficients, integral representation and representation in terms of generalized hypergeometric functions. The results are valid up to $\mathcal{O}(\varepsilon)$ terms in $d=4-2\varepsilon$ space-time dimensions. In the limit of equal masses $m=M$ the obtained results are written in terms of elliptic constants with explicit series representation., Comment: 31 pages, 2 figures, matches journal version
- Published
- 2019
- Full Text
- View/download PDF
28. Addendum to 'Critical behaviour of ($2+1$)-dimensional QED: $1/N_f$-corrections in an arbitrary non-local gauge'
- Author
-
Kotikov, A. V., Teber, S., Kotikov, A. V., and Teber, S.
- Abstract
Dynamical chiral symmetry breaking (D$\chi$SB) is studied within ($2+1$)-dimensional QED with $N$ four-component fermions. The leading and next-to-leading orders of the $N$ expansion were computed exactly in Refs.~[\onlinecite{Gusynin:2016som,Kotikov:2016prf}] in an arbitrary non-local gauge. In this addendum to [\onlinecite{Kotikov:2016prf}], we show that the resummation of the wave-function renormalization constant at the level of the gap equation yields a {\it complete} cancellation of the gauge dependence of the critical fermion flavour number resulting in: $N_c= 2.8469$, which is such that D$\chi$SB takes place for $N
- Published
- 2019
- Full Text
- View/download PDF
29. Landau-Khalatnikov-Fradkin transformation of the fermion propagator in massless reduced QED
- Author
-
James, A., Kotikov, A. V., Teber, S., James, A., Kotikov, A. V., and Teber, S.
- Abstract
We study the gauge-covariance of the massless fermion propagator in reduced Quantum Electrodynamics (QED). Starting from its value in some gauge, we evaluate an all order expression for it in another gauge by means of the Landau-Khalatnikov-Fradkin transformation. We find that the weak coupling expansions thus derived are in perfect agreement with the exact calculations. We also prove that the fermion anomalous dimension of reduced QED is gauge invariant to all orders of perturbation theory except for the first one., Comment: (v2) 11 pages, two-column format, no figure, published in Phys. Rev. D, edits in text (some per referee's comments) and references added, no change in results. (v1) 23 pages, no figure
- Published
- 2019
- Full Text
- View/download PDF
30. Gluon evolution for the Berger-Block-Tan form of the structure function F2
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
We present a nonlinear modification of the evolution of the gluon density, obtained at small x from the Berger-Block-Tan form of the deep inelastic structure function F2 in the leading order of perturbation theory., Comment: 7 pages
- Published
- 2019
- Full Text
- View/download PDF
31. Transverse momentum dependent parton densities in a proton from the generalized DAS approach
- Author
-
Kotikov, A. V., Lipatov, A. V., Shaikhatdenov, B. G., Zhang, P., Kotikov, A. V., Lipatov, A. V., Shaikhatdenov, B. G., and Zhang, P.
- Abstract
We use the Bessel-inspired behavior of parton densities at small Bjorken $x$ values, obtained in the case of the flat initial conditions for DGLAP evolution equations in the double scaling QCD approximation (DAS), to evaluate the transverse momentum dependent (TMD, or unintegrated) quark and gluon distribution functions in a proton. The calculations are performed analytically using the Kimber-Martin-Ryskin (KMR) prescription with different implementation of kinematical constraint, reflecting the angular and strong ordering conditions. The relations between the differential and integral formulation of the KMR approach is discussed. Several phenomenological applications of the proposed TMD parton densities to the LHC processes are given., Comment: 24 pages, 9 figures
- Published
- 2019
- Full Text
- View/download PDF
32. DGLAP and BFKL equations in $\mathcal{N}=4$ SYM: from weak to strong coupling
- Author
-
Kotikov, A. V., Onishchenko, A. I., Kotikov, A. V., and Onishchenko, A. I.
- Abstract
DGLAP and BFKL equations are among the cornestones of the contemporary QCD. Moreover, they also played an important role in the recent studies of integrability structure of $\mathcal{N}=4$ SYM. Here, we review the results obtained along this way together with a brief account of approaches and methods used., Comment: 35 pages, will be published in a book dedicated to the memory of Lev Lipatov
- Published
- 2019
33. Landau-Khalatnikov-Fradkin transformation and the mystery of even $\zeta$-values in Euclidean massless correlators
- Author
-
Kotikov, A. V., Teber, S., Kotikov, A. V., and Teber, S.
- Abstract
The Landau-Khalatnikov-Fradkin (LKF) transformation is a powerful and elegant transformation allowing to study the gauge dependence of the propagator of charged particles interacting with gauge fields. With the help of this transformation, we derive a non-perturbative identity between massless propagators in two different gauges. From this identity, we find that the corresponding perturbative series can be exactly expressed in terms of a hatted transcendental basis that eliminates all even Euler $\zeta$-functions. This explains the mystery of even $\zeta$-values observed in multi-loop calculations of Euclidean massless correlators for almost three decades now. Our construction further allows us to derive an exact formula relating hatted and standard $\zeta$-functions to all orders of perturbation theory., Comment: (v2) 9 pages, no figure, published in PRD, few edits in text (some per referee's comments) and references added, no change in results. (v1) 9 pages, no figure
- Published
- 2019
- Full Text
- View/download PDF
34. Two-loop diagrams in non-relativistic QCD with elliptics
- Author
-
Kniehl, B. A., Kotikov, A. V., Onishchenko, A. I, Veretin, O. L., Kniehl, B. A., Kotikov, A. V., Onishchenko, A. I, and Veretin, O. L.
- Abstract
In this paper we consider two-loop two-, three- and four-point diagrams with elliptic structure in the case of two different masses $m$ and $M$. The latter diagrams generally arise within NRQCD matching procedures and are relevant for parapositronium decay and top pair production at threshold. We present the obtained results in several different representations: series solution with binomial coefficients, integral representation and representation in terms of generalized hypergeometric functions. The results are valid up to $\mathcal{O}(\varepsilon)$ terms in $d=4-2\varepsilon$ space-time dimensions. In the limit of equal masses $m=M$ the obtained results are written in terms of elliptic constants with explicit series representation., Comment: 31 pages, 2 figures, matches journal version
- Published
- 2019
- Full Text
- View/download PDF
35. Extracting the longitudinal structure function FL(x,Q2) at small x from a Froissart-bounded parametrization of F2(x,Q2)
- Author
-
Kaptari, L. P., Kotikov, A. V., Chernikova, N. Yu., Zhang, Pengming, Kaptari, L. P., Kotikov, A. V., Chernikova, N. Yu., and Zhang, Pengming
- Abstract
We present a method to extract, in the leading and next-to-leading order approximations, the longitudinal deep-inelastic scattering structure function FL(x,Q2) from the experimental data by relying on a Froissart-bounded parametrization of the transversal structure function F2(x,Q2) and, partially, on the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi equations. Particular attention is paid on kinematics of low and ultra low values of the Bjorken variable x. Analytical expressions for FL(x,Q2) in terms of the effective parameters of the parametrization of F2(x,Q2) are presented explicitly. We argue that the obtained structure functions FL(x,Q2) within both, the leading and next-to-leading order approximations, manifestly obey the Froissart boundary conditions. Numerical calculations and comparison with available data from ZEUS and H1-Collaborations at HERA demonstrate that the suggested method provides reliable structure functions FL(x,Q2) at low x in a wide range of the momentum transfer (1 GeV2 < Q2 < 3000 GeV2) and can be applied as well in analyses of ultra-high energy processes with cosmic neutrinos., Comment: 30 pages, 4 figures
- Published
- 2019
- Full Text
- View/download PDF
36. Multi-loop techniques for massless Feynman diagram calculations
- Author
-
Kotikov, A. V., Teber, S., Kotikov, A. V., and Teber, S.
- Abstract
We review several multi-loop techniques for analytical massless Feynman diagram calculations in relativistic quantum field theories: integration by parts, the method of uniqueness, functional equations and the Gegenbauer polynomial technique. A brief, historically oriented, overview of some of the results obtained over the decades for the massless 2-loop propagator-type diagram is given. Concrete examples of up to $5$-loop diagram calculations are also provided., Comment: Review article. LaTeX file with feynMF package. (v2) references added and minor typos corrected. 65 pages, 8 figures. (v1) 64 pages, 8 figures
- Published
- 2018
- Full Text
- View/download PDF
37. Field theoretic renormalization study of reduced quantum electrodynamics and applications to the ultra-relativistic limit of Dirac liquids
- Author
-
Teber, S., Kotikov, A. V., Teber, S., and Kotikov, A. V.
- Abstract
The field theoretic renormalization study of reduced quantum electrodynamics (QED) is performed up to two loops. In the condensed matter context, reduced QED constitutes a very natural effective relativistic field theory describing (planar) Dirac liquids, e.g., graphene and graphene-like materials, the surface states of some topological insulators and possibly half-filled fractional quantum Hall systems. From the field theory point of view, the model involves an effective (reduced) gauge field propagating with a fractional power of the d'Alembertian in marked contrast with usual QEDs. The use of the BPHZ prescription allows for a simple and clear understanding of the structure of the model. In particular, in relation with the ultra-relativistic limit of graphene, we straightforwardly recover the results for both the interaction correction to the optical conductivity: $\mathcal{C}^*=(92-9\pi^2)/(18\pi)$ and the anomalous dimension of the fermion field: $\gamma_{\psi}(\bar{\alpha},\xi) = 2 \bar{\alpha}\,(1-3\xi)/3 -16\,\left( \zeta_2 N_F + 4/27 \right)\, \bar{\alpha}^2 + O(\bar{\alpha}^3)$, where $\bar{\alpha} = e^2/(4\pi)^2$ and $\xi$ is the gauge-fixing parameter., Comment: (v2) Published in PRD. Some references added. No change in results. (v1) LaTeX file with feynMF package. 15 pages, 4 figures
- Published
- 2018
- Full Text
- View/download PDF
38. Multi-loop techniques for massless Feynman diagram calculations
- Author
-
Kotikov, A. V., Teber, S., Kotikov, A. V., and Teber, S.
- Abstract
We review several multi-loop techniques for analytical massless Feynman diagram calculations in relativistic quantum field theories: integration by parts, the method of uniqueness, functional equations and the Gegenbauer polynomial technique. A brief, historically oriented, overview of some of the results obtained over the decades for the massless 2-loop propagator-type diagram is given. Concrete examples of up to $5$-loop diagram calculations are also provided., Comment: Review article. LaTeX file with feynMF package. (v2) references added and minor typos corrected. 65 pages, 8 figures. (v1) 64 pages, 8 figures
- Published
- 2018
- Full Text
- View/download PDF
39. Field theoretic renormalization study of interaction corrections to the universal ac conductivity of graphene
- Author
-
Teber, S., Kotikov, A. V., Teber, S., and Kotikov, A. V.
- Abstract
The two-loop interaction correction coefficient to the universal ac conductivity of disorder-free intrinsic graphene is computed with the help of a field theoretic renormalization study using the BPHZ prescription. Non-standard Ward identities imply that divergent subgraphs (related to Fermi velocity renormalization) contribute to the renormalized optical conductivity. Proceeding either via density-density or via current-current correlation functions, a single well-defined value is obtained: $\mathcal{C}= (19-6\pi)/12) = 0.01$ in agreement with the result first obtained by Mishchenko and which is compatible with experimental uncertainties., Comment: LaTeX file with feynMF package. (v2) Footnotes and references added to answer referee's questions and comments. No change in results. 23 pages (JHEP format), 4 figures (v1) 12 pages, 4 figures
- Published
- 2018
- Full Text
- View/download PDF
40. Antishadowing in the rescaling model at x ~ 0.1
- Author
-
Kotikov, A. V., Shaikhatdenov, B. G., Zhang, Pengming, Kotikov, A. V., Shaikhatdenov, B. G., and Zhang, Pengming
- Abstract
The antishadowing behavior of the sea and valence quark densities in nuclei is investigated in the framework of the rescaling model at the values x ~ 0.1 of the Bjorken variable x., Comment: 5 pages, 1 figure
- Published
- 2018
- Full Text
- View/download PDF
41. Bjorken polarized sum rule and infrared-safe QCD couplings
- Author
-
Ayala, Cesar, Cvetic, Gorazd, Kotikov, Anatoly V., Shaikhatdenov, Binur G., Ayala, Cesar, Cvetic, Gorazd, Kotikov, Anatoly V., and Shaikhatdenov, Binur G.
- Abstract
Experimental data obtained for the polarized Bjorken sum rule (BSR) $\Gamma_1^{p-n}(Q^2)$ are fitted by using predictions derived within a truncated operator product expansion (OPE) approach to QCD. Four QCD versions are considered: perturbative QCD (pQCD) in the MSbar scheme, Analytic Perturbation Theory (APT), and 2$\delta$ and 3$\delta$ analytic QCD versions. In contrast to pQCD, these QCD variants do not have Landau singularities at low positive $Q^2$, which facilitates the fitting procedure significantly. The fitting procedure is applied first to the experimental data of the inelastic part of BSR, and the known elastic contributions are added after the fitting. In general, when 2$\delta$ and 3$\delta$ QCD coupling is used the fitted curves give the best results, within the $Q^2$-range of the fit as well as in extended $Q^2$-intervals. When the fitting procedure is applied to the total BSR, i.e., to the sum of the experimental data and the elastic contribution, the quality of the results deteriorates significantly., Comment: 29 pages, 8 figures; to appear in EPJ C
- Published
- 2018
- Full Text
- View/download PDF
42. Longitudinal structure function FL at small x extracted from the Berger-Block-Tan parametrization of F2
- Author
-
Kaptari, L. P., Kotikov, A. V., Chernikova, N. Yu., Zhang, Pengming, Kaptari, L. P., Kotikov, A. V., Chernikova, N. Yu., and Zhang, Pengming
- Abstract
The longitudinal structure function FL(x,Q2) is extracted at low values of the Bjorken variable x from the Berger-Block-Tan parametrization of F2(x,Q2). The obtained FL(x,Q2) does not violate the high-energy asymptotic Froissart boundary and is in a reasonable good agreement with the available experimental data., Comment: 6 pages, 1 figure
- Published
- 2018
- Full Text
- View/download PDF
43. Field theoretic renormalization study of interaction corrections to the universal ac conductivity of graphene
- Author
-
Teber, S., Kotikov, A. V., Teber, S., and Kotikov, A. V.
- Abstract
The two-loop interaction correction coefficient to the universal ac conductivity of disorder-free intrinsic graphene is computed with the help of a field theoretic renormalization study using the BPHZ prescription. Non-standard Ward identities imply that divergent subgraphs (related to Fermi velocity renormalization) contribute to the renormalized optical conductivity. Proceeding either via density-density or via current-current correlation functions, a single well-defined value is obtained: $\mathcal{C}= (19-6\pi)/12) = 0.01$ in agreement with the result first obtained by Mishchenko and which is compatible with experimental uncertainties., Comment: LaTeX file with feynMF package. (v2) Footnotes and references added to answer referee's questions and comments. No change in results. 23 pages (JHEP format), 4 figures (v1) 12 pages, 4 figures
- Published
- 2018
- Full Text
- View/download PDF
44. $\alpha_s$ from hadron multiplicities via SUSY-like relation between anomalous dimensions
- Author
-
Kniehl, Bernd A., Kotikov, Anatoly V., Kniehl, Bernd A., and Kotikov, Anatoly V.
- Abstract
We recover in QCD an amazingly simple relationship between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations for the first Mellin moments $D_{q,g}(\mu^2)$ of the quark and gluon fragmentation functions, which correspond to the average hadron multiplicities in jets initiated by quarks and gluons, respectively. This relationship, which is independent of the number of quark flavors, dramatically improves previous treatments by allowing for an exact solution of the evolution equations. So far, such relationships have only been known from supersymmetric QCD, where $C_F/C_A=1$. This also allows us to extend our knowledge of the ratio $D_g^-(\mu^2)/D_q^-(\mu^2)$ of the minus components by one order in $\sqrt{\alpha_s}$. Exploiting available next-to-next-to-next-to-leading-order information on the ratio $D_g^+(\mu^2)/D_q^+(\mu^2)$ of the dominant plus components, we fit the world data of $D_{q,g}(\mu^2)$ for charged hadrons measured in $e^+e^-$ annihilation to obtain $\alpha_s^{(5)}(M_Z)=0.1205\genfrac{}{}{0pt}{}{+0.016}{-0.0020}$., Comment: 8 pages, 2 figures
- Published
- 2017
45. Bjorken sum rule in QCD with analytic coupling
- Author
-
Ayala, C., Cvetic, G., Kotikov, A. V., Shaikhatdenov, B. G., Ayala, C., Cvetic, G., Kotikov, A. V., and Shaikhatdenov, B. G.
- Abstract
We present details of study of the Bjorken polarized sum rule carried out recently in [1] within the range of energies where the data were collected by JLAB collaboration, 0.05 GeV2 < Q2 < 3 GeV2. Three approaches to QCD with analytic (holomorphic) coupling are considered: Analytic Perturbation Theory (APT), Two-delta analytic QCD, and Three-delta lattice-motivated analytic QCD in the three-loop and four-loop MiniMOM schemes. The new frameworks with respective couplings give results which agree well with the experimental data for 0.5 GeV2 < Q2 < 3GeV2 already when only one higher-twist term is taken into account., Comment: 6 pages, 2 figures, talk given at the XVIIth International Workshop on High Energy Spin Physics (DSPIN-17), September 11 - 15, 2017
- Published
- 2017
- Full Text
- View/download PDF
46. SUSY-like relation in evolution of gluon and quark jet multiplicities
- Author
-
Kniehl, Bernd A., Kotikov, Anatoly V., Kniehl, Bernd A., and Kotikov, Anatoly V.
- Abstract
We show the new relationship [1] between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations for the first Mellin moments D{q,g}(\mu2) of the quark and gluon fragmentation functions, which correspond to the average hadron multiplicities in jets initiated by quarks and gluons, respectively. This relationship, which is independent of the number of quark flavors, strongly improves previous treatments by allowing for an exact solution of the evolution equations. So far, such relationships have only been known from supersymmetric QCD., Comment: 4 pages, talk given at the International Workshop "Supersymmetries and Quantum Symmetries" (SQS'2017), July 31 - August 5, 2017 and the IVth Russian-Spanish Congress "Particle, Nuclear, Astroparticle Physics and Cosmology", September 4 - 8, 2017
- Published
- 2017
- Full Text
- View/download PDF
47. Bjorken sum rule in QCD frameworks with analytic (holomorphic) coupling
- Author
-
Ayala, Cesar, Cvetic, Gorazd, Kotikov, Anatoly V., Shaikhatdenov, Binur G., Ayala, Cesar, Cvetic, Gorazd, Kotikov, Anatoly V., and Shaikhatdenov, Binur G.
- Abstract
We investigate the Bjorken polarized sum rule (BSR) in three approaches to QCD with analytic (holomorphic) coupling: Analytic Perturbation Theory (APT), Two-delta analytic QCD (2$\delta$anQCD), and Three-delta lattice-motivated analytic QCD in the three-loop and four-loop MOM scheme (3l3$\delta$anQCD, 4l3$\delta$anQCD). These couplings do not have unphysical (Landau) singularities, and have finite values when the transferred momentum goes to zero, which allows us to explore the infrared regime. With the exception of APT, these theories at high momenta practically coincide with the underlying perturbative QCD (pQCD) in the same scheme. We apply them in order to verify the Bjorken sum rule within the range of energies available in the data collected by the experimental JLAB collaboration, i.e., $0.05 GeV^2
- Published
- 2017
- Full Text
- View/download PDF
48. Application of the rescaling model at small Bjorken $x$ values
- Author
-
Kotikov, A. V., Shaikhatdenov, B. G., Zhang, Pengming, Kotikov, A. V., Shaikhatdenov, B. G., and Zhang, Pengming
- Abstract
The Bessel-inspired behavior of parton densities at small Bjorken $x$ values, obtained in the case of the flat initial conditions for DGLAP evolution equations, is used along with "frozen" and analytic modifications of the strong coupling constant to study the so-called EMC effect. Among other results, this approach allowed predicting small $x$ behavior of the gluon density in nuclei., Comment: 13 pp, 4 figs
- Published
- 2017
- Full Text
- View/download PDF
49. $\alpha_s$ from hadron multiplicities via SUSY-like relation between anomalous dimensions
- Author
-
Kniehl, Bernd A., Kotikov, Anatoly V., Kniehl, Bernd A., and Kotikov, Anatoly V.
- Abstract
We recover in QCD an amazingly simple relationship between the anomalous dimensions, resummed through next-to-next-to-leading-logarithmic order, in the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations for the first Mellin moments $D_{q,g}(\mu^2)$ of the quark and gluon fragmentation functions, which correspond to the average hadron multiplicities in jets initiated by quarks and gluons, respectively. This relationship, which is independent of the number of quark flavors, dramatically improves previous treatments by allowing for an exact solution of the evolution equations. So far, such relationships have only been known from supersymmetric QCD, where $C_F/C_A=1$. This also allows us to extend our knowledge of the ratio $D_g^-(\mu^2)/D_q^-(\mu^2)$ of the minus components by one order in $\sqrt{\alpha_s}$. Exploiting available next-to-next-to-next-to-leading-order information on the ratio $D_g^+(\mu^2)/D_q^+(\mu^2)$ of the dominant plus components, we fit the world data of $D_{q,g}(\mu^2)$ for charged hadrons measured in $e^+e^-$ annihilation to obtain $\alpha_s^{(5)}(M_Z)=0.1205\genfrac{}{}{0pt}{}{+0.016}{-0.0020}$., Comment: 8 pages, 2 figures
- Published
- 2017
50. The property of maximal transcendentality: calculation of Feynman integrals
- Author
-
Kotikov, A. V. and Kotikov, A. V.
- Abstract
We review some results of calculations, having the property of maximal transcendentality., Comment: 15 pages, 3 figures, talk given at the V International Conference "Models in Quantum Field Theory" (MQFT-2015), September 21-25, 2015, V.A. Fock Physical Research Institute, Petergof, Russia. arXiv admin note: substantial text overlap with arXiv:1212.3732
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.