SCIENCE BRINGS NATIONS TOGETHER Helmholtz International School "Modern Colliders - Theory and Experiment 2018" and Workshop "Calculations for Modern and Future Colliders (CALC2018)"

22 Jul 2018, 08:00 → 1 Aug 2018, 18:00 Europe/Moscow

International Conference Hall, JINR

The Helmholtz International Summer School "Modern Colliders - Theory and Experiment 2018" will be held in the International Conference Hall of JINR (JINR, Dubna). The main topics to be covered by the lectures are:

• Introduction to hadron collider physics
• Higgs physics
• QCD for colliders
• Top-quark physics
• Beyond the Standard Model
• Computational techniques for the LHC
• Modern computational methods for scattering amplitudes
• Flavor physics
• Future colliders

During the School, the Workshop "Calculations for Modern and Future Colliders" (CALC2018) will be held in parallel. The participants are invited to give presentations on the following topics:

• Precision theoretical calculations for collider experiments
• Techniques of multiloop calculations and ressumation
• Computer codes for calculations in HEP
• Theoretical predictions beyond the Standard Model
• Modern computational methods for scattering amplitudes

 The Workshop is dedicated to the memory of Dmitry Yu. Bardin (1945-2017).

For registration for both school and workshop please fill in the on-line registration form accessible by the menu on the left. The deadline for workshop application and abstract submission is 7 June 2018 extended until 21 June 2018.

The list of accepted school participants will be announced on 14 June 2018.

The recommended arrival day is 22 July 2018. The recommended departure day is 1 August 2018.

The School and Workshop are organized in cooperation by the Joint Institute for Nuclear Research and Helmholtz Association.

Poster The School-Workshop poster

Sunday 22 July

08:00 → 18:00 Arrival

Monday 23 July

08:00 → 08:20 Registration

08:20 → 08:30 Opening

Slides CALC2018_Intro.pdf

08:30 → 11:10 Bardin's day

08:30 D.Yu. Bardin, Scientific Biography

Speakers: Dr Andrey Sapronov (JINR), Prof. Lidia Kalinovskaya (JINR)

Slides CALC_DB.pdf

08:50 A legacy of Dima Bardin: ZFITTER and the future

Speaker: Dr Tord Riemann (DESY)

Slides riemanntord-calc2018-slides.pdf

09:50 Coffee break

10:10 Radiative Corrections to DIS at CERN and DESY

Speaker: Prof. Arif Akhundov (Valencia)

Slides CALC-2018.pdf

11:10 → 12:30 Lunch

12:30 → 17:00 Bardin's day

12:30 Project SANC and applications to ATLAS

Speaker: Dr Andrej Arbuzov (BLTP JINR)

Slides arbuzov_CALC_2018.pdf

13:30 Genuine weak corrections and factorizations: from LEP to LHC with Dizet library of Dima Bardin

Speaker: Prof. Zbigniew Was (ifj pan)

Slides Dima.pdf

14:10 Bardin-Shumeyko's method and its development

Speaker: Dr Vladimir Zykunov (Leading Researcher of Laboratory of High Energy Physics of Joint Institute for Nuclear Research, Dubna, Russia)

Slides bsm-calc2018.pdf

14:40 Coffee break

15:00 Precision measurements with polarized beams

Speaker: Dr Sabine Riemann (DESY)

Slides SRiemann_pol_BardinsDay.pdf SRiemann_pol_BardinsDay.pptx

15:20 ARIeL - new project for FCCee

Speaker: Dr Renat Sadykov (JINR)

Slides sadykov.pdf

15:40 Bremsstrahlung helicity amplitudes with massive fermions

Speaker: Mr Yahor Dydyshka (JINR)

Slides Dydyshka_CALC_2018.pdf

16:00 In the pursuit of precision. Homage to Dima Bardin.

Speaker: Dr Alexander Kuzemsky (BLTP JINR)

Slides BardinDY18.pdf

16:20 Memories of friends

Speaker: Dr Wladimir von Schlippe (Queen Mary)

17:00 → 18:30 Welcome party

Tuesday 24 July

08:30 → 11:50 Morning session

08:30 Top-quark physics (Part 1)

Speaker: Lev Dudko (SINP MSU)

Slides TopQuark_lekcii_Dubna_1.pdf

09:30 Coffee break

09:50 Top-quark physics (Part 2)

Speaker: Lev Dudko (SINP MSU)

10:50 Linear e+e- colliders

Speaker: Dr Frank Zimmermann (CERN)

Slides frankz

11:50 → 13:30 Lunch

13:30 → 14:30 Afternoon session

13:30 A geometrical approach to the evaluation of Feynman diagrams (Part 1)

Speaker: Andrei Davydychev (Moscow State University)

Slides Lectures 1-3

14:30 → 14:50 Coffee break

14:50 → 17:20 CALC2018 Workshop

14:50 Evaluating `elliptic' master integrals at special kinematic values: using differential equations and their solutions via expansions near singular points

An algorithm to find a solution of differential equations for master integrals in the form of an $\epsilon$-expansion series with numerical coefficients is presented. The algorithm is based on using generalized power series expansions near singular points of the differential system, solving difference equations for the corresponding coefficients in these expansions and using matching to connect series expansions at two neighboring points. Four-loop generalized sunset diagrams with three massive and two massless propagators are considered as an example. Analytical results for the three master integrals at threshold, $p^2=9 m^2$, in an expansion in $\ep$ up to $\ep^1$ are obtained. This is done with the help of the presented algorithm which us used to obtain high precision values, with the accuracy of 20000 digits. Then the PSLQ algorithm is applied to obtain results in an analytical form. They are expressed in terms of multiple polylogarithm values at sixth roots of unity.

Speaker: Vladimir Smirnov (Skobeltsyn Institute of Nuclear Physics of Moscow State University)

Slides vsmirnov.pdf

15:20 Functional reduction of Feynman integrals

An algorithm for finding functional equations allowing to essentially simplify evaluation of Feynman integrals is proposed. With the help of such functional equations new compact analytic results for the one loop 3-, 4- and 5- point functions with massless propagators are derived. The obtained results are valid for arbitrary space-time dimension and arbitrary values of kinematical variables.

Speaker: Dr Oleg Tarasov (JINR Dubna, Moscow Region, Russia)

Slides Tarasov_func_red.pdf

15:50 Constraints on epsilon-expansion of "elliptic" integrals.

Speaker: Dr Roman Lee (Budker Institute of Nuclear Physics)

Slides ACinES1.pdf

16:20 Feynman Integral evaluation and reduction at supercomputers

During the last years the CPU speed is not growing much, and parallization with the use of shared memory is widely used but also has it limits. Still there are new reduction and evaluation tasks and new approaches are needed. So how can the supercomputers be used in order to help researcher with these tasks? In this talk we are going to disscuss an already existing modification of FIESTA that makes it possible to apply it at supercomputers, as well as an approach that leads to the possiblity to perform Feynman integral reduction with the use of supercomputers.

Speaker: Alexander Smirnov (MSU RCC)

Slides Feynman-SC.pdf

Wednesday 25 July

08:30 → 11:50 Morning session

08:30 Circular e+e- colliders

Speaker: Dr Frank Zimmermann (CERN)

Slides frankz

09:30 Coffee break

09:50 Future hadron colliders and beyond

Speaker: Dr Frank Zimmermann (CERN)

Slides frankz frankz

10:50 Top-quark physics (Part 3)

Speaker: Lev Dudko (SINP MSU)

Slides TopQuark_lekcii_Dubna_2.pdf

11:50 → 13:30 Lunch

13:30 → 15:15 Afternoon session

13:30 A geometrical approach to the evaluation of Feynman diagrams (Part 2)

Speaker: Andrei Davydychev (Moscow State University)

Slides CALC2018_LECTURES_ad_v3.PDF

14:30 High energy photon collider

Speaker: Prof. Ilya Ginzburg (Sobolev Inst. of Mathematics SB RAS)

Slides PLCHEtransplect.pdf

15:15 → 15:35 Coffee break

15:35 → 17:05 CALC2018 Workshop

15:35 The generalized Crewther relation in QCD : is it valid in the prposed recently C-scheme?

Speaker: Dr Andrei Kataev (Institute for Nuclear Research of RAS)

Slides KataevCalc-2018.pdf

16:05 QCD description with a lattice-motivated coupling

A QCD coupling is constructed which at low momenta qualitatively agrees with the lattice coupling in the MiniMOM scheme. The latter coupling is the product of the gluon dressing function and the square of the ghost dressing function, evaluated in large volume lattice calculations in the Landau gauge. These lattice calculations show that such a coupling $A_{latt.}(Q^2)$ behaves as $\sim Q^2$ when $Q^2 \to 0$, and has for positive $Q^2$ the local maximum at $Q^2 \approx 0.135 GeV^2$ (in the usual ${\overline \Lambda}$ scaling). Our constructed QCD coupling fulfills these (low-momenta) conditions; in addition, at intermediate momenta it reproduces the well-established value of the semihadronic $\tau$ lepton decay ratio, and at high momenta it becomes practically equal to the perturbative coupling (in the MiniMOM scheme). The coupling thus reproduces the known QCD phenomenology at high and intermediate momenta, and at low momenta it fulfills lattice-motivated conditions. As a test, the coupling is then applied with success in evaluation of various QCD quantities.

Speaker: Gorazd Cvetic (Univ. Tecnica Federico Santa Maria)

Slides Dubna2018GCvetic.pdf

16:35 Scalar one-loop Feynman integrals in arbitrary space-time dimension

Speaker: Dr Tord Riemann (DESY)

Slides riemann-calc2018-oneloop.pdf

Thursday 26 July

08:00 → 14:00 Free time, Picnic, Boat trip

Friday 27 July

08:30 → 11:50 Morning session

08:30 Symbolic Programming in HEP (Part 1)

Speaker: Dr Ben Ruijl (ETH Zurich)

Slides lecture1.pdf

09:30 Coffee break

09:50 Modern computational methods for scattering amplitudes (Part 1)

Speaker: Prof. Johannes Henn (Mainz University)

Slides 2018_07_27_dubna_jmh_1.pdf

10:50 Effective theories in heavy quark physics (Part 1)

Speaker: Dr Andrey Grozin (Budker Institute of Nuclear Physics)

Slides 3._eft.pdf

11:50 → 13:30 Lunch

13:30 → 14:30 Afternoon session

13:30 A geometrical approach to the evaluation of Feynman diagrams (Part 3)

Speaker: Andrei Davydychev (Moscow State University)

Slides CALC2018_LECTURES_ad_v3.PDF

14:30 → 14:50 Coffee break

14:50 → 17:00 CALC2018 Workshop

14:50 The all-loop conjecture for integrands of reggeon amplitudes in N=4 SYM

Speaker: Dr Leonid Bork (ITEP, CFAR VNIIA)

Slides Presentation_AllLoopBCFW_Reggeons_BORK_2018_CALC.pdf

15:20 Multiloop Baxter equations and Quantum Spectral Curve

In this talk we discuss solutions of multiloop Baxter equations arising in quantum spectral curve description of various supersymmetric quantum field theories. We are interested in perturbative solution for anomalous dimensions of operators in sl(2) sector at arbitrary spin values. For these types of problems we propose a new method for the solution of mentioned nonhomogeneous second order difference equations directly in spectral parameter u-space for in principle arbitrary loop order. As an example we consider ABJM model and anomalous dimensions of twist 1 operators up to six loop order. The solution involves new highly nontrivial identities between hypergeometric functions, which may have various other applications. We expect this method to be generalizable to operators of other twists as well as to other theories, such as N=4 SYM.

Speaker: Dr Andrei Onishchenko (JINR)

Slides BaxterQSC-CALC2018.pdf

15:50 Helicity amplitudes for QCD with massive quarks

The novel massive spinor-helicity formalism of Arkani-Hamed, Huang and Huang provides an elegant way to calculate scattering amplitudes in quantum chromodynamics for arbitrary quark spin projections. In this talk I discuss the computation of two all-multiplicity families of tree-level QCD amplitudes with one massive quark pair and n-2 gluons. In these formulae the spin quantization axes can be tuned at will, which includes the case of the definite-helicity quark states.

Speaker: Dr Alexander Ochirov (ETH Zurich)

Slides Calc2018.pdf

16:20 On the Renormalization in Maximally Supersymmetric Gauge Theories

The purpose of this work is to consider leading and subleading UV divergencies for the four-point on-shell scattering amplitudes in D=6 (8,10) supersymmetric Yang-Mills theories in the planar limit. It will be showed how the divergencies appear and how to evaluate them in all orders of the perturbation theory with the help of generalized RG equations. The subtraction scheme dependence of these results also will be noted in the sense that in full analogy with renormalizable theories the scheme dependence can be absorbed into the redefinition of the couplings. At the end the renewed view on the renormalization procedure in MSYM theories will be presented.

Speaker: Mr Arthur Borlakov (JINR)

Slides Helmholtz.pdf

16:40 Finite-temperature effective potentials in models with extended Higgs sector and critical temperatures

In this report authors discuss features of some topological methods for baryogenesis and phase transition analysis, including models with an extended scalar sectors at finite temperatures. The first and second differential forms are implemented for the effective potential. The classic picture of baryogenesis in grand unification theories has changed significantly with the standard model development and the phase diagram of electroweak interactions specification with experimental data on Higgs boson physics. Currently the minimal extension of the scalar sector has a less likely to be realized, therefore, an important role is played by researching of the non-minimal extensions. In previous papers authors considered a general scalar Higgs sector, including the violation of CP-invariance and temperature corrections for control parameters, conditions for the effective potential that lead to the phase transition of the strong first order required for the generation of the observed baryon asymmetry. Additional chiral field plays here the role of the phase transition stabilizing foam. The feature of the upcoming research is that the violations of symmetries and temperature contributions of the self-potential affect the dark sector is supersymmetric models, which could have consequences for cosmology. That is possibility to significantly change the mass of the cold dark matter particles and intensity of their interaction with other particles and the ability to participate in electroweak decays, including the decay of Higgs bosons. Results for Higgs fields in the case of CP-violating and temperature corrections are used for dark sector physical parameters calculations. Also, the annihilation of neutralinos in the framework of quantum field theory in conjunction with Feynman diagram approach was taking into account with one-loop corrections. Temperature one-loop effective potential for NMSSM is reconstructed. Physical masses conditions is determined and the one-loop corrections to the dimensionless parameters of the effective potential are evaluated in the framework of NMSSM. The general case is investigated for calculations of one-loop diagrams with different masses in finite temperature field theory, some representations of infinite series and generalized function of Hurwitz are proposed. Surfaces of the stationary points in space background fields and matrix stability are reconstructed, including difference from SM physical basis in the alignment limit. Scenarios of stationary points and critical temperatures were determined, extreme curves and surfaces based on the definition of Grobner bases are also considered.

Speaker: Mr Mikhail Dolgopolov (Samara University)

Slides untitled_(16).pdf

Saturday 28 July

08:30 → 12:50 Morning session

08:30 Symbolic Programming in HEP (Part 2)

Speaker: Dr Ben Ruijl (ETH Zurich)

Slides lecture2.pdf

09:30 Coffee break

09:50 Modern computational methods for scattering amplitudes (Part 2)

Speaker: Prof. Johannes Henn (Mainz University)

10:50 Effective theories in heavy quark physics (Part 2)

Speaker: Dr Andrey Grozin (Budker Institute of Nuclear Physics)

Slides All 3 lectures

11:50 Symbolic Programming in HEP (Part 3)

Speaker: Thomas Hahn (MPI f. Physik)

examples hahn-calc18.tar.gz

Slides hahn-calc18.pdf

12:50 → 19:00 Free Time / City Day of Dubna

Sunday 29 July

08:30 → 11:50 Morning session

08:30 Symbolic Programming in HEP (Part 4)

Speaker: Thomas Hahn (MPI f. Physik)

09:30 Coffee break

09:50 Modern computational methods for scattering amplitudes (Part 3)

Speaker: Prof. Johannes Henn (Mainz University)

10:50 Effective theories in heavy quark physics (Part 3)

Speaker: Dr Andrey Grozin (Budker Institute of Nuclear Physics)

Slides All 3 lectures

11:50 → 13:30 Lunch

13:30 → 14:30 CALC2018 Workshop

13:30 Hypergeometric approach in Feynman Integral calculation

Speaker: Mr Vladimir Bytev (JINR)

Slides doklad.pdf

14:00 Rings: a library for asymptotically fast commutative algebra

Computer algebra and in particular computational commutative algebra (along with algebraic number theory and algebraic geometry) is a quite important ingredient of practical computations in high energy physics. Importance of fast algebraic methods is especially manifested when e.g. considering physical processes at modern colliders within (N*)NLO accuracy: methods such as rational function arithmetic, solving (non-)linear systems of equations, Groebner bases etc. are essential parts of many computational pipelines often become a "bottle-neck" when doing practical calculations. The talk is devoted to the `Rings` library, which implements the most part of basic asymptotically fast algorithms in the fields of commutative algebra, number theory and algebraic geometry. Specific attention will be paid to the implementational aspects, benchmarks and applications of the library in typical computations in HEP.

Speaker: Dr Stanislav Poslavsky (Institute for High Energy Physics NRC Kurchatov Institute)

Slides main_short.pdf

14:30 → 14:50 Coffee break

14:50 → 17:00 CALC2018 Workshop

14:50 SUSY-like relation in evolution of gluon and quark jet multiplicities

We show the new relationship 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 of the quark and gluon fragmentation functions, which correspond to the average hadron multiplicities in jets initiated by quarks and gluons, respectively. This relationship 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.

Speaker: Anatoly Kotikov (JINR)

Slides RSC17.pdf

15:20 Calculation of the QED contributions to the electron anomalous magnetic moment on graphics processors

High-precision calculation of the electron anomalous magnetic moment requires evaluation of QED Feynman diagrams with 4 independent loops and even more. To make this calculation practically feasible it is necessary to remove all infrared and ultraviolet divergences before an integration. A procedure of removing both infrared and ultraviolet divergences in each individual Feynman diagram will be presented. This procedure leads immediately to finite Feynman-parametric integrals. A method of Monte Carlo integration of these Feynman-parametric integrands will be presented. The method is based on importance sampling. The probability density function is constructed for each Feynman diagram individually by using the information about ultraviolet degrees of divergence in this diagram. The results of the computations on NVidia GPU rent from Google Cloud Platform will be presented: 1) contributions of all QED Feynman diagrams without lepton cycles up to 4 loops; 2) contributions of some individual Feynman diagrams up to 6 loops.

Speaker: Mr Sergey Volkov (SINP MSU; DLNP JINR)

Slides volkov_29_07_2018.pdf

15:50 Relation between pole and running heavy quark masses in QCD : $\mathcal{O}(\alpha_s^4)$ level and beyond

The PT higher order corrections and their flavor dependence for the QCD relation between pole and running masses of heavy quarks are estimated by means of the effective charges motivated methods, defined in the Euclidean and Minkowskian regions, and the renormalon-based approach, predicting the asymptotic behavior of the corresponding PT series. These methods unambiguously forecast a decrease of the five and six-loop contributions to the pole mass of top-quark, expressing through its running analogs in the $\rm{\overline{MS}}$-scheme. Thus we conclude about the legitimacy of using the concept of pole mass of $t$-quark up to six-loop level.

Speaker: Mr Victor Molokoedov (MIPT, INR RAS, Landau Inst.)

Slides CALC-18-Molokoedov.pdf

16:10 LPPG — Monte-Carlo event generator for experiments at colliders.

Recent results on the development of generator LPPG with wise phase space parameterization and multi-channel optimization approach are presented. LPPG suited for description of different processes at hadron and lepton colliders at the one-loop precision level. Matching with shower is performed using Powheg-like method.

Speaker: Mr Vitaly Yermolchyk (INP BSU)

Slides yermolchyk.pdf

16:30 Supersymmetric Dynamics, Statistical Sums and Zeta-Functions

Boson, fermion, and super oscillators and (statistical) mechanism of osmological constant; finite approximation of the zeta-function and fermion factorization of the bosonic statistical sum considered.

Speaker: Dr Nugzar Makhaldiani (JINR)

Slides Makhaldiani_CALC_2018_talk.pdf

Monday 30 July

08:30 → 11:50 Morning session

08:30 Beyond the Standard Model (Part 1)

Speaker: Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))

Slides Grojean_BSM_Dubna_2018_1.pdf

09:30 Coffee break

09:50 Beyond the Standard Model (Part 2)

Speaker: Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))

Slides Grojean_BSM_Dubna_2018_2.pdf

10:50 Higgs Physics (Part 1)

Speaker: Sven Heinemeyer (IFT/IFCA (CSIC, Madrid/Santander))

Slides sven1.pdf

11:50 → 13:30 Lunch

13:30 → 14:30 CALC2018 Workshop

13:30 NLO and FSR NNLO radiative corrections for Drell-Yan processes at LHC

The NLO electroweak and QCD radiative corrections to Drell-Yan process at extra large invariant dilepton mass (M) in fully differential form have been studied. The results are the compact expressions, they expand via Sudakov and collinear logarithms. The new G/N-method of taking into account of radiative events without any approximations is demonstrated. At the parton/hadron level FORTRAN code READY gives fast convergence and a good coincidence for cross section and forward-backward asymmetry with other groups at M>0.5 TeV. We have also first result on "soft" FSR NNLO radiative corrections to Drell-Yan process.

Speaker: Dr Vladimir Zykunov (Leading Researcher of Laboratory of High Energy Physics of Joint Institute for Nuclear Research, Dubna, Russia)

Slides calc18-zykunov.pdf

14:00 Hard photons in proton-antiproton annihilation to a lepton pair for PANDA experiment

The hard photons effect in the annihilation of proton and antiproton to electron-positron pair is investigated.

Speaker: Dr Yury Bystritskiy (JINR)

Slides Bystritskiy.pdf

14:30 → 14:50 Coffee break

14:50 → 17:15 CALC2018 Workshop

14:50 Search for light dark matter at accelerators

We review current and future experimental efforts on search for light dark matter at accelerators including NA64 experiment at CERN

Speaker: Prof. Nikolay Krasnikov (INR RAS)

Slides Krasnikov.Dubna2018.pdf

15:35 Decoding the Nature of Dark Matter in collider and non-collider searches

Determination of the nature of Dark Matter (DM) is one of the most fundamental problems of particle physics and cosmology. If DM is light enough and interacts with Standard Model particles directly or via some mediators with a strength beyond the gravitational one, it can be directly produced at the Large Hadron Collider or future particle accelerators. The typical signature from DM produced in particles collisions is missing transverse energy, MET, due to the fact that they escape undetected from the experimental apparatus. We have found that different energy dependence of the cross-sections is connected to a different distributions of the invariant mass of the DM pair, and consequently to different MET distributions such that certain DM operators can be distinguished from each other and, through this, it is possible to characterise the spin of DM in some cases. On the other hand DM searches in non-collider experiments -- DM direct and indirect detection ones provide independent complimentary potential to probe the nature of DM and DM theory space.

Speaker: Prof. Alexander Belyaev (University of Southampton)

Slides Belyaev-CALC-2018.pdf

16:15 Difficulties of N-body cosmological simulations and the physics of dark matter

Speaker: Prof. Anton Baushev (Joint Institute for Nuclear Research, Dubna, Russia)

Slides Calc2018.pdf

16:45 GW170817: Multi-frequency Observations and Modeling

Speaker: Dr Maxim Barkov (Purdue University)

Slides GWNS_Dubna_2018.pdf

Tuesday 31 July

08:30 → 11:50 Morning session

08:30 Beyond the Standard Model (Part 3)

Speaker: Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))

Slides Grojean_BSM_Dubna_2018_3.pdf

09:30 Coffee break

09:50 ​Higgs Physics (Part 2)

Speaker: Sven Heinemeyer (IFT/IFCA (CSIC, Madrid/Santander))

Slides sven2.pdf sven3.pdf

10:50 Higgs Physics (Part 3)

Speaker: Sven Heinemeyer (IFT/IFCA (CSIC, Madrid/Santander))

Slides sven4.pdf

11:50 → 13:30 Lunch

13:30 → 14:30 Afternoon session

13:30 Physics at NICA

Speaker: Dr Oleg Rogachevskiy (JINR)

14:30 → 14:50 Coffee break

14:50 → 16:20 CALC2018 Workshop

14:50 Dispersive approach to QCD and its applications

The dispersive approach to QCD, which extends the applicability range of perturbation theory towards the infrared domain, is applied to the study of hadronic vacuum polarization function and related quantities. This approach merges, in a self-consistent way, the intrinsically nonperturbative constraints, which originate in the kinematic restrictions on the relevant physical processes, with corresponding perturbative input. The obtained hadronic vacuum polarization function agrees with pertinent lattice simulation data. The evaluated hadronic contributions to the muon anomalous magnetic moment and to the shift of the electromagnetic fine structure constant conform with recent estimations of these quantities. The effects due to continuation of the spacelike perturbative results into the timelike domain are elucidated. [1] A.V.Nesterenko, "Strong interactions in spacelike and timelike domains: Dispersive approach". Elsevier, Amsterdam, 222p., 2016 [2] A.V.Nesterenko, Eur. Phys. J. C 77, 844 (2017) [3] A.V.Nesterenko, J. Phys. G 42, 085004 (2015)

Speaker: Dr Alexander Nesterenko (BLTPh JINR)

15:20 On the one-loop calculations in Lipatov's EFT

The structure of one-loop calculations in Lipatov's Gauge-invariant EFT for Multi-Regge processes in QCD will be reviewed. I will focus on rapidity divergences, their relation with Reggeization of t-channel particles, consistent regularization and techniques to compute one-loop integrals with several scales. Preliminary results of this work have been published in [1]. The new results include computation of three-point integrals with two scales and one or two light-cone propagators. The results can be applied to the computation of NLO corrections to BFKL equation with Reggeized gluons/quarks/scalars in t-channel, computation of NLO corrections to the tranzition kernels with several Reggeons, which appear in High-Energy QCD, and to the computation of NLO corrections in Parton Reggeization Approach. References: [1] M. Nefedov and V. Saleev, ``On the one-loop calculations with Reggeized quarks,'' Mod. Phys. Lett. A 32, no. 40, 1750207 (2017) [arXiv:1709.06246 [hep-th]].

Speaker: Mr Maxim Nefedov (Samara National Research University; II Institute for Theoretical Physics, Hamburg University)

Slides Nefedov_loop-HEEFT-CALC18.pdf

15:50 Computing Nuclear Parton Distributions

Speaker: Sergey Kulagin (INR, Moscow)

Slides kulagin-calc2018.pdf

16:20 → 16:30 Closing

Wednesday 1 August

07:00 → 17:00 Departure