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Victor T. Kim

Publications and source records attributed to Victor T. Kim.

At least 19 recordsLinked to original sources
arXiv2026

Dijets with a large rapidity separation in the next-to-leading order BFKL formalism for searches of large extra dimensions at colliders

Search for the gravity with large extra dimensions at collider energies is considered in the trans-Planckian eikonal regime, i.e., when $\sqrt{\hat{s}} \gg M_D \gg \sqrt{-\hat{t}}$. Here $\hat{s}$ and $\hat{t}$ are the Mandelstam variables of colliding parton-parton system and $M_D$ is the Planck mass scale in the space-time with compactified $n_D$ extra dimensions. A relevant observable for this regime may be the cross section of high-mass ($M_{jj}\sim\sqrt{\hat{s}} \gg M_D$) dijet production with a large rapidity separation. Then the standard model background should be calculated within the next-to-leading logarithmic (NLL) approximation of Lipatov-Fadin-Kuraev-Balitsky (BFKL) formalism of quantum chromodynamics (QCD) suitable for $\sqrt{\hat{s}}\gg\sqrt{-\hat{t}}\ggΛ_\mathrm{QCD}$. In this work the signal of the large extra dimension gravity as well as the NLL BFKL QCD background are estimated for the high-luminosity Large Hadron Collider (HL-LHC) and future colliders such as FCCpp and CEPC-SppC.

hep-ph↗
arXiv2023

Next-to-leading BFKL evolution for dijets with large rapidity separation at different LHC energies

The calculations based on the next-to-leading logarithm (NLL) approximation for the Balitsky-Fadin-Kuraev-Lipatov (BKFL) evolution are presented for the Mueller-Navelet (MN) dijet production cross section, as well as for their ratios at different collision energies. The MN dijet denotes the jet pair consists of jets, which were selected with $p_{\perp} > p_{\perp\min}$ and with maximal rapidity separation in the event. The NLL BFKL predictions for the MN cross sections are given for the $pp$ collisions at $\sqrt{s}=2.76$, $8$, and $13$ TeV, for $p_{\perp\min} = 20$ and $35$ GeV. The results are in agreement with the measurement by the CMS experiment in $pp$ collisions at $\sqrt{s}=2.76$ TeV and $p_{\perp\min} = 35$ GeV within the theoretical and experimental uncertainties. The predictions of the NLL BFKL calculation of ratios of the MN cross sections at different collision energies and $p_{\perp\min}$ are also presented.

hep-ph↗
arXiv2018

Skewed Sudakov Regime, Harmonic Numbers, and Multiple Polylogarithms

On the example of massless QED we study an asymptotic of the vertex when only one of the two virtualities of the external fermions is sent to zero. We call this regime the skewed Sudakov regime. First, we show that the asymptotic is described with a single form factor, for which we derive a linear evolution equation. The linear operator involved in this equation has a discrete spectrum. Its eigenfunctions and eigenvalues are found. The spectrum is a shifted sequence of harmonic numbers. With the spectrum found, we represent the expansion of the asymptotic in the fine structure constant in terms of multiple polylogarithms. Using this representation, the exponentiation of the doubly logarithmic corrections of the Sudakov form factor is recovered. It is pointed out that the form factor of the skewed Sudakov regime is growing with the virtuality of a fermion decreasing at a fixed virtuality of another fermion.

hep-th↗
arXiv2010

Towards a common origin of the elliptic flow, ridge and alignment

It is claimed that elliptic flow, ridge and alignment are effects of azimuthal asymmetry, which have a common origin evolving with primary energy and stemming from the general structure of field-theoretical matrix elements. It interrelates a new ridge-phenomenon, recently found at the LHC and RHIC, with known coplanarity feature observed in collider jet physics as well as in cosmic ray studies.

hep-ph↗
arXiv2009

Higgs boson decay into heavy quarks and heavy leptons: higher order corrections

Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_H< 2M_W, are briefly reviewed. The effects of higher order perturbative QCD (up to alpha_s^4-level) and QED corrections are considered. The uncertainties of the decay width of Higgs boson into bb and tau+tau- are discussed.

hep-ph↗
arXiv2007

On Naturalness of Scalar Fields and Standard Model

We discuss how naturalness predicts the scale of new physics. Two conditions on the scale are considered. The first is the more conservative condition due to Veltman (Acta Phys. Polon. B 12, 437 (1981)). It requires that radiative corrections to the electroweak mass scale would be reasonably small. The second is the condition due to Barbieri and Giudice (Nucl. Phys. B 306, 63 (1988)), which is more popular lately. It requires that physical mass scale would not be oversensitive to the values of the input parameters. We show here that the above two conditions behave differently if higher order corrections are taken into account. Veltman's condition is robust (insensitive to higher order corrections), while Barbieri-Giudice condition changes qualitatively. We conclude that higher order perturbative corrections take care of the fine tuning problem, and, in this respect, scalar field is a natural system. We apply the Barbieri-Giudice condition with higher order corrections taken into account to the Standard Model, and obtain new restrictions on the Higgs boson mass.

hep-ph↗
arXiv2003

Central Higgs Production at LHC from Single-Pomeron-Exchange

Contrary to common perceptions about systems produced in Single-Pomeron-Exchange (SPE) pp interactions, the hard diffractive process discovered at the CERN SPS-Collider leads to dominant central production of Higgs bosons at the LHC. The rate for SPE production of Higgs bosons is calculated to be 7-9 % of the total inclusive Higgs rate. In addition, an SPE measurement program of dijet events is outlined for the early days of LHC running which should answer many fundamental questions about the Pomeron structure and its effective flux factor in the proton.

hep-ph↗
arXiv2001

High-Energy Asymptotics of Photon--Photon Collisions in QCD

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is presented. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in excellent agreement with recent OPAL and L3 data at CERN LEP2.

hep-ph↗
arXiv2001

The Challenge of Light-Front Quantisation: Recent Results

We explain what is the challenge of light-front quantisation, and how we can now answer it because of recent progress in solving the problem of zero modes in the case of non-Abelian gauge theories. We also give a description of the light-front Hamiltonian for SU(2) finite volume gluodynamics resulting from this recent solution to the problem of light-front zero modes.

hep-th↗
arXiv2000

Canonical Formulation of the Light-Front Gluodynamics and Quantization of the Non-Abelian Plane Waves

Without a gauge fixing, canonical variables for the light-front SU(2) gluodynamics are determined. The Gauss law is written in terms of the canonical variables. The system is qualified as a generalized dynamical system with first class constraints. Abeliazation is a specific feature of the formulation (most of the canonical variables transform nontrivially only under the action of an Abelian subgroup of the gauge transformations). At finite volume, a discrete spectrum of the light-front Hamiltonian $P_+$ is obtained in the sector of vanishing $P_-$. We obtain, therefore, a quantized form of the classical solutions previously known as non-Abelian plane waves. Then, considering the infinite volume limit, we find that the presence of the mass gap depends on the way the infinite volume limit is taken, which may suggest the presence of different ``phases'' of the infinite volume theory. We also check that the formulation obtained is in accord with the standard perturbation theory if the latter is taken in the covariant gauges.

hep-th↗
arXiv2000

Parton Scattering at Small-x and Scaling Violation

Scaling violation of inclusive jet production at small-$x$ in hadron scattering with increasing total collision energy is discussed. Perturbative QCD based on the factorisation theorem for hard processes and GLAPD evolution equations predicts a minimum for scaled cross-section ratio that depends on jet rapidity. Studies of such a scaling violation can reveal a vivid indication of new dynamical effects in the high-energy limit of QCD. The BFKL effects, which seem to be seen in recent L3 data at CERN LEP2, should give different results from GLAPD predictions.

hep-ph↗
arXiv1999

The Next-to-Leading Dynamics of the BFKL Pomeron

The next-to-leading order (NLO) corrections to the BFKL equation in the BLM optimal scale setting are briefly discussed. A striking feature of the BLM approach is rather weak Q^2-dependence of the Pomeron intercept, which might indicate an approximate conformal symmetry of the equation. An application of the NLO BFKL resummation for the virtual gamma-gamma total cross section shows a good agreement with recent L3 data at CERN LEP2 energies.

hep-ph↗
arXiv1999

The Next-to-Leading BFKL Pomeron with Optimal Renormalization

The next-to-leading order (NLO) corrections to the BFKL equation in the BLM optimal scale setting are briefly discussed. A striking feature of the BLM approach is rather weak Q^2-dependence of the Pomeron intercept, which might indicate an approximate conformal symmetry of the equation. An application of the NLO BFKL resummation for the virtual gamma-gamma total cross section shows a good agreement with recent L3 data at the CERN LEP2.

hep-ph↗
arXiv1999

A New Qualitative Prediction of the Parton Model for High Energy Hadron Collisions

Inclusive single jet production in hadron collisions is considered. It is shown that the QCD parton model predicts a nonmonotonic dependence of the inclusive cross section on the fraction of the energy deposited in the jet registered, if it is normalized on the same cross section measured at another collision energy. Specifically, if the cross section is normalized by the one measured at a higher collision energy, it possesses a minimum which depends on jet rapidity. This prediction can be tested at the Fermilab Tevatron, at the CERN LHC, and at the Very Large Hadron Collider under discussion.

hep-ph↗
arXiv1999

The QCD Pomeron with Optimal Renormalization

It is shown that the next-to-leading order (NLO) corrections to the QCD Pomeron intercept obtained from the BFKL equation, when evaluated in non-Abelian physical renormalization schemes with BLM optimal scale setting do not exhibit the serious problems encountered in the $\overline{\mbox{MS}}$-scheme. A striking feature of the NLO BFKL Pomeron intercept in the BLM approach is its rather weak dependence on the virtuality of the reggeized gluon. This remarkable property yields an important approximate conformal invariance. The results obtained provide an opportunity for applications of NLO BFKL resummation to high-energy phenomenology.

hep-ph↗
arXiv1997

New Effective Feynman-like Rules for the Multi-Regge QCD Asymptotics of Inclusive Multijet Production

New effective Feynman-like rules are defined for inclusive multijet cross sections in the multi-Regge regime. The solution of the BFKL equation is used as a starting point. The resulting rules involve conformal weight and rapidity as a momentum and a coordinate respectively and are translation invariant in the coordinates. We use the effective rules to calculate ultra high energy asymptotics of inclusive multijet production. The dependence on the parton densities occurs only in the overall normalization of the asymptotic cross sections.

hep-ph↗