arXiv subjects

R. A. Ryutin

Publications and source records attributed to R. A. Ryutin.

At least 19 recordsLinked to original sources

arXiv2023

Central exclusive diffractive $p$ $\bar{p}$ production in the Regge-eikonal model in the "scalar'' proton approximation

Central exclusive diffractive production (CEDP) of proton anti-proton pairs was calculated in the Regge-eikonal approach taking into account continuum and possible $f_0(2100)$ resonance. We use the simple model with the ``scalar'' proton. Data from ISR and STAR were analysed and compared with theoretical description. Some predictions for the LHC at 13~TeV are also presented. We discuss shortly possible nuances, problems and prospects of investigations of this process at present and future hadron colliders.

hep-ph↗

arXiv2022

Central exclusive diffractive production of two-pions from continuum and decays of resonances in the Regge-eikonal model

Calculations of central exclusive diffractive production (CEDP) of two pions via continuum and resonance mechanism are presented in the Regge-eikonal approach. Data from STAR, ISR, CDF and CMS were analysed and compared with theoretical description. Preliminary extraction of $f_0(500)$, $f_0(980)$ and $f_2(1270)$ couplings to Pomeron, and also $ρ$ meson contribution from photoproduction mechanism to the CEDP cross-section are considered. We show possible nuances and problems of calculations and prospects of investigations at present and future hadron colliders.

hep-ph↗

arXiv2020

Central exclusive diffractive production of two-pion continuum at hadron colliders

Calculations of central exclusive diffractive di-pion continuum production are presented in the Regge-eikonal approach. Data from ISR, STAR, CDF and CMS were analyzed and compared with theoretical description. We also consider theoretical predictions for LHC, possible nuances and problems of calculations and prospects of investigations at present and future hadron colliders.

hep-ph↗

arXiv2018

ExDiff Monte Carlo generator for Exclusive Diffraction. Version 1.0. Physics and manual

ExDiff is a Monte Carlo event generator for simulation of Exclusive Diffractive processes in proton-proton collisions. The present version includes reactions: elastic scattering $pp\to pp$ at 7, 8, 13, 14~TeV; $pp\to p+R+p$, $R = f_0(1710),\, f_2(1950)$ at 13~TeV. In the future versions many processes of Central Exclusive Diffractive Production will be added.

hep-ph↗

arXiv2018

ExDiff Monte Carlo generator for Exclusive Diffraction. Version 2.0. Physics and manual

ExDiff2.0 is a Monte Carlo event generator for simulation of Exclusive Diffractive processes in proton-proton collisions. The present version includes reactions: elastic scattering $pp\to pp$ at 7, 8, 13, 14~TeV; $pp\to p+R+p$, $R = f_0(1500)$, $f_0(1710)$, $f_2(1950)$ at 8 and 13~TeV, $f_2(1270)$ at 8~TeV, $f_2(2220)$ at 13~TeV. In the future versions many processes of Central Exclusive Diffractive Production will be added. This version is linked to PYTHIA 8 (to make resonance decays and hadronization) and also to ROOT and HEPMC output via PYTHIA 8 interface. Also some test files of Born distributions for CEDP of two pions are added.

hep-ph↗

arXiv2017

Total pion-proton cross-section from the new LHCf data on leading neutrons spectra

In the light of the latest data by LHCf collaboration of the LHC on leading neutrons spectra it is possible to obtain total pion-proton cross-sections in the TeV energy region. In this work the exact extraction procedure is shown. Final numbers for the pion-proton cross-section are collected at several different values of the colliding energy and compared with some popular theoretical predictions. Errors of results are estimated.

hep-ph↗

arXiv2015

Single and double diffractive dissociation and the problem of extraction of the proton-Pomeron cross-section

Diffractive dissociation processes are analysed in the framework of covariant reggeization. We have considered the general form of hadronic tensor and its asymptotic behaviour for $t\rightarrow 0$ in the case of conserved tensor currents before reggeization. Resulting expressions for differential cross-section of single dissociation (SD) process ($pp \rightarrow p M$), double dissociation (DD) ($pp\rightarrow M_1 M_2$) and for the proton-Pomeron cross-section are given in detail, and corresponding problems of the approach are discussed.

hep-ph↗

arXiv2014

High-Energy Scattering vs Static QCD Strings

We discuss the shape of the interaction region of the elastically scattered protons stipulated by the high-energy Pomeron exchange which turns out to be very similar with the shape of the static string representing the confining QCD flux tube. This similarity disappears when we enter the LHC energy region, which corresponds to many-Pomeron exchanges. Reversing the argument we conjecture a modified relationship between the width and the length of the confining string at very large lengths.

hep-ph↗

arXiv2014

Visualizations of the Exclusive Central Diffraction

The case of the low invariant mass exclusive central diffractive production is considered in the general theoretical framework. It is shown that diffractive patterns (differential cross-sections on variables like transfer momenta squared, the azimuthal angle between final hadrons and their combinations) can serve as a unique tool to explore the picture of the $pp$ interaction and falsify theoretical models. Basic kinematical and dynamical properties of the process are considered in detail. As an example, visualizations of diffractive patterns in the model with three pomerons for processes $p+p\to p+R+p$ and $p+p\to p+π^{+}π^{-}+p$ are presented.

hep-ph↗

arXiv2013

Exclusive Double Diffractive Events: general framework and prospects

We consider the general theoretical framework to study exclusive double diffractive events (EDDE). It is a powerful tool to study the picture of the $pp$ interaction. Basic kinematical and dynamical properties of the process, and also normalization of parameters via standard processes like the exclusive vector meson production (EVMP), are considered in detail. As an example, calculations of the cross-sections in the model with three pomerons for the process $p+p\to p+M+p$ are presented for Tevatron and LHC energies.

hep-ph↗

arXiv2012

Hadron multiplicity induced by top quark decays at the LHC

The average charged hadron multiplicities induced by top quark decays are calculated in pQCD at LHC energies. Different modes of top production are considered. Proposed measurements can be used as an additional test of pQCD calculations independent on a fragmentation model.

hep-ph↗

arXiv2011

Can We Get Deeper Inside the Pion at the LHC?

We propose a measurement of leading neutrons spectra at LHC in order to extract inclusive $π^+ p$ and $π^+π^+$ cross-sections with high $p_T$ jets production. The cross-sections for these processes are simulated with the use of parton distributions in hadrons. In this work we estimate the possibility to extract parton distributions in the pion from the data on these cross-sections and also search for signatures of fundamental differences in the pion and proton structure.

hep-ph↗

arXiv2011

MonChER: Monte-Carlo generator for CHarge Exchange Reactions. Version 1.1. Physics and Manual

MonChER is a Monte Carlo event generator for simulation of single and double charge exchange reactions in proton-proton collisions at energies from 0.9 to 14 TeV. Such reactions, $pp\to n+X$ and $pp\to n+X+n$, are characterized by leading neutron production. They are dominated by $π^+$ exchange and could provide us with more information about total and elastic $π^+ p$ and $π^+π^+$ cross sections and parton distributions in pions in the still unexplored kinematical region.

hep-ph↗

arXiv2010

Towards Extraction of $π^+ p$ and $π^+π^+$ cross-sections from Charge Exchange Processes at the LHC

We study the possibilities to analyse the data on leading neutrons production at first LHC runs. These data could be used to extract from it $π^+ p$ and $π^+π^+$ cross-sections. In this note we estimate relative contributions of $π$, $ρ$ and $a_2$ reggeons to charge exchanges and discuss related problems of measurements.

hep-ph↗

arXiv2010

Elastic $π^{+}p$ and $π^{+}π^{+}$ scattering at LHC

We discuss the possibility of measuring leading neutron production at the LHC. These data could be used to extract from it $π^+ p$ and $π^+π^+$ cross-sections. In this note we give some estimates for the case of elastic cross-sections and discuss related problems and prospects.

hep-ph↗

arXiv2009

LHC as $πp$ and $ππ$ Collider

We propose an experiment at the LHC with leading neutron production.The latter can be used to extract from it the total $π^+ p$ cross-sections. With two leading neutrons we can get access to the total $π^+π^+$ cross-sections. In this note we give some estimates and discuss related problems and prospects.

hep-ph↗

arXiv2007

EDDE Monte Carlo event generator.Version 2.1

EDDE is a Monte Carlo event generator for different Exclusive and Semi-Inclusive Double Diffractive processes. The program is based on the extended Regge-eikonal approach for "soft" processes. Standard Model and its extensions are used for "hard" fusion processes.

hep-ph↗

arXiv2007

Patterns of the Exclusive Double Diffraction

We consider Exclusive Double Diffractive Events (EDDE) as a powerfull tool to study the picture of the $pp$ interaction. Calculations of the cross-sections for the process $p+p\to p+M+p$ are presented in the convenient form for further experimental applications. We propose measurements of t-distributions in the joint CMS-TOTEM experiment. It is shown that important information on the interaction region could be extracted from the diffractive pattern.

hep-ph↗