We discuss production of $W^+ W^-$ pairs and $t \bar t$ quark-antiquark pairs in proton-proton collisions induced by two-photon fusion including transverse momenta of incoming photons. The unintegrated inelastic fluxes (related to proton dissociation) of photons are calculated based on modern parametrizations of deep inelastic structure functions in a broad range of $x$ and $Q^2$. We focus on processes with single and double proton dissociation. Highly excited remnant systems hadronise producing particles that can be vetoed in the calorimeter. We calculate associated gap survival factors. The gap survival factors depend on the process, mass of the remnant system and collision energy. The rapidity gap survival factor due to remnant fragmentation for double dissociative (DD) collisions is smaller than that for single dissociative (SD) process. We observe approximate factorisation: $S_{R,DD} \approx S_{R,SD}^2$ when imposing rapidity veto. For the $W^+W^-$ final state, the remnant fragmentation leads to a taming of the cross section when the rapidity gap requirement is imposed. Also for $t \bar t$ quark-antiquark pairs such a condition reverses the hierarchy observed for the case when such condition is taken into account. Our results imply that for the production of such heavy objects as $t$ quark and $\bar t$ antiquark the virtuality of the photons attached to the dissociative system are very large ($Q^2 <$ 10$^{4}$ GeV$^2$). A similar effect is observed for the $W^+ W^-$ system.
In the paper we discuss contribution of the doubly intrinsic heavy mechanism into the production of $B_c$ meson, the doubly heavy baryons and the all-charm tetraquark at a future fixed-target experiment at the LHC (AFTER@LHC). The production cross sections and the mean values of Feynman-x for the finale states are presented.
We review various production mechanisms of photons and small mass dileptons at large transverse momentum in heavy ion collisions at the LHC. Their relevance as a signal for quark-gluon plasma formation is discussed.
The theoretical analysis of production, lifetime, and decays of doubly heavy baryons is presented. The lifetime of $Ξ_{cc}^{++}$ baryon recently measured by the LHCb Collaboration is used to estimate the lifetimes of other doubly heavy baryons. The production and the possibility of observation of $Ξ_{bc}$ baryon at LHC are discussed.
We calculate the finite part of the heavy quark impact factor at next-to-leading logarithmic accuracy in a form suitable for phenomenological studies such as the calculation of the cross-section for single bottom quark production at the LHC.
We comment on the calculation of the finite part of the heavy quark impact factor at next-to-leading logarithmic (NLx) accuracy. The result is presented in a form suitable for phenomenological studies such as the calculation of the cross-section for single heavy quark production at the LHC within the kT-factorization scheme.
A new version of the $k_T$ factorization approach is formulated for the high energy heavy quark production. The results are in reasonable agreement with the experimental data at LHC energies.
We investigate the production, signatures and backgrounds of new heavy leptons via string inspired $E_{6}$ model at the proposed Linac$\otimes$LHC. Assuming maximal mixing, the production rate is found to be 2000 events per year for masses up to 3 TeV.
The simple method for simulation of ``thermal'' hadron spectra in ultrarelativistic heavy ion collisions including longitudinal, transverse and elliptic flow is developed. The model is realized as fast Monte-Carlo event generator.
Some topics on heavy-ion collisions are reviewed with emphasis on those which are expected to be specially relevant at the Large Hadron Collider programme.
The single diffractive cross section for heavy quarks production is calculated in next-no-leading order (NLO) in nucleus-nucleus collisions. Such processes are expected to occur at the LHC. We start using the hard diffractive factorization formalism, taking into account the recent experimental parameterization for the Pomeron Structure Function (DPDF). Absorptive corrections are accounted by the multiple Pomeron contributions considering a gap survival probability, where its theoretical uncertainty for nuclear collisions is discussed. We estimate the diffractive ratios for single diffraction p…
The phenomenology of gluon saturation at small parton momentum fraction, Bjorken-x, in the proton and in the nucleus is introduced. The experimentally-accessible kinematic domains at the nucleus-nucleus colliders RHIC and LHC are discussed. Finally, the saturation hints emerging from measurements at RHIC and the perspectives for LHC are described.
We use a Monte Carlo implementation of recently developped models of double diffractive Higgs production to assess the sensitivity of the LHC experiments.
The ratios of particle densities in lead-lead and proton-lead collisions to particle density in proton-proton collision in the central rapidity region at the LHC energy are predicted on the basis of wounded quark-diquark model.
In this work we estimate the heavy quark production in proton-proton and proton-nucleus collisions at LHC energies using the color dipole formalism and the solution of the running coupling Balitsky-Kovchegov equation. Nuclear effects are considered in the computation of the total cross sections and rapidity distributions for scattering on protons and nuclei.
We investigate the production, signatures and backgrounds of a pair of heavy-exotic charged leptons and a heavy-exotic neutrino together with the exotic charged lepton in the framework of the vector singlet model, vector doublet model, and fermion-mirror-fermion model, at the CERN Large Hadron Collider (LHC). We still show that the cross-sections for the case of the production of a pair of heavy exotic leptons are competitive with the ones for the single production of exotic leptons.
We study the production and signatures of heavy exotic quarks pairs at LHC in the framework of the vector singlet model (VSM), vector doublet model (VDM) and fermion-mirror-fermion (FMF) model. The pair production cross sections for the electroweak and strong sector are computed.
The yield of doubly charmed baryons with excited heavy diquark in $S$ wave and $P$ wave states has been estimated at LHC energies. The observation possibility of such baryons is discussed.
We investigate the importance of unitarity corrections to parton evolution in heavy flavor production at the LHC. The gluon distribution is determined with a fit to HERA data applying a unified BFKL-DGLAP approach, in which the non-linear evolution is described by the Balitsky-Kovchegov equation. First we estimate b anti-b production at CDF and D0. Then, cross sections for heavy quark production at various LHC experiments are estimated, tracing the impact of the unitarity corrections.
The LHC data on the forward heavy flavour hadron production can be a new unique source for estimation of intrinsic charm and bottom contributions to the proton. For example, we analyze the forward heavy baryon production, namely $Λ_b$-baryon, within the soft QCD quark gluon string model and present the predictions for observables which could be measured at the LHC. We also present some predictions for the $D$-meson production in $pp$ collisions made within the perturbative QCD including the intrinsic charm in the proton that can be verified at the LHC.
In this paper we review the hadroproduction mechanisms of double-charm baryons for the different experimental environments and reinterpret the SELEX and LHCb results.
We explore possible signatures for heavy neutrinos and neutral gauge boson, Z', in TeV scale B-L extension of the Standard Model (BLSM) with inverse seesaw mechanisms at the Large Hadron Collider. We show that due to new decay channels of Z' into heavy/inert neutrinos, the LHC stringent bounds imposed on Z' mass can be significantly relaxed. We analyze the pair production of heavy neutrinos decaying to four leptons plus two neutrinos, four jets plus two leptons, or three leptons plus two jets and one neutrino. We show that the 4l + 2 nu is the most promising decay channel for probing both Z' a…
We determine the discovery potential of the Large Hadron Collider (LHC) at 13 TeV center-of-mass energy for a heavy scalar resonance in the dilepton channel. In particular, we consider the singlet-like heavy mass eigenstate of a mixed two Higgs doublet and scalar singlet model in the $U(1)_{B-L}$ extension of the Standard Model. We find that, despite the small coupling of the singlet scalar with the doublets, this heavy scalar can be discovered with 5$σ$ at the LHC with integrated luminosities of $\sim 300$ to $1400$ fb$^{-1}$ in the mass range between 500 GeV and 1 TeV.
The potential of coming experiments on Large Hadron Collider (LHC) to observe the rescattering and energy loss of heavy quarks in the dense matter created in heavy ion collisions is discussed. We analyze the sensitivity of high-mass mu+mu- pairs from BBbar semileptonic decays and secondary J/Psi from single B decays to the medium-induced bottom quark energy loss.
We investigate the sensitivity of the heavy ion mode of the LHC to Higgs boson and Radion production via photon-photon fusion through the analysis of the processes photon to photon photon, photon photon to b anti-b, and photon photon to g g in peripheral heavy ion collisions. We suggest cuts to improve the Higgs and Radion signal over standard model background ratio and determine the capability of LHC to detect these particles production.
One of the major goal of the Large Hadron Collider (LHC) is to probe the electroweak symmetry breaking mechanism and the generation of the masses of the elementary particles. We review the physics of the Higgs sector in the Standard Model. The main production channels of the Higgs production at the LHC are reviewed. The prospects for the discovering the Higgs particles at the LHC and the study of their fundamental properties are summarizes.
We investigate the sensitivity of the heavy ion mode of the LHC to anomalous Higgs boson couplings to photons, H-photon-photon, through the analysis of the processes photon photon to b anti-b and photon photon to photon photon in peripheral heavy ion collisions. We suggest cuts to improve the signal over background ratio and determine the capability of LHC to impose bounds on anomalous couplings by searching for a Higgs boson signal in these modes.
The attenuation of heavy-flavored particles in nucleus-nucleus collisions tests the microscopic dynamics of medium-induced parton energy loss and, in particular, its expected dependence on the identity (color charge and mass) of the parent parton. We discuss the comparison of theoretical calculations with recent single-electron data from RHIC experiments. Then, we present predictions for the heavy-to-light ratios of D and B mesons at LHC energy.
QCD corrections to inclusive Higgs boson production at the LHC are evaluated at next-to-next-to leading order. By performing asymptotic expansion of the cross section near the limit of infinitely heavy top quark we obtained a few first top mass-suppressed terms. The corrections to the hadronic cross sections are found to be small compared to the scale uncertainty, thus justifying the use of heavy top quark approximation in many published results.
In this article we carry out an analysis of LHC potential to search for new dimuon resonance states from extended gauge models and the Randall-Sundrum scenario of TeV-scale gravity.
Heavy charged lepton productions via gluon fusion at the LHC are revisited. Full loop calculations are adopted with an updated parton distribution function and electroweak data. Including contribution from new generation quarks in the loop, pair production of the sequential heavy lepton via gluon fusion at the LHC dominates over that via the Drell-Yan mechanism in some heavy lepton mass range. Exotic lepton single production of vector-like lepton extended models is also calculated. In the later case, the gluon fusion mechanism via the Higgs exchange is emphasized. Our numerical results for bot…
In this talk we present results of our recent calculations of cross sections and distributions for the associate production of top-antitop quark pairs with a heavy boson (Higgs, W, Z) at the LHC, obtained using threshold resummation in direct QCD, i.e. in the Mellin-space approach.
Heavy quarkonium production in the framework of the nonrelativistic quantum chromodynamics and leading order of the parton Reggeization approach at the Tevatron and LHC Colliders is discussed. The new results, which are reviewed in this report, include the comparison with recent data on chi_{c1,c2} production from ATLAS Collaboration and special discussion of heavy quarkonium polarization issues in the considered framework.
We perform a study of the LHC discovery reach on a heavy gluon (G*) and heavy fermions (top and bottom excitations), coming from a new composite sector. We find that heavy fermion resonances have a great impact on the composite gluon phenomenology. If the composite gluon is heavier than composite fermions, as flavor observables seem to suggest, the search in the channel where G* decays into a heavy fermion plus its Standard Model partner is very promising, with the possibility for both the G* and heavy fermions to be discovered at the early stage of the LHC. The channel offers also the possibi…
Transverse momentum imbalance between a jet produced with a hard photon is considered as a signal of medium-induced partonic energy loss in ultrarelativistic heavy ion collisions. We analyze photon-jet correlation in the context of a real experimental situation at the LHC, the problem of neutral pion background being discussed.
The associated production of direct photons and heavy quarks at the LHC is presented. Predictions for the nuclear modification factor to the cross-section at ALICE are shown. It is demonstrated that this process is a great probe of the gluon and heavy quark nuclear PDFs, as over 80 % of its nPDF dependence at NLO comes from those nPDFs. Therefore measurements of this process will provide an excellent constraint on the gluon nPDF, and will distinguish between different nPDF sets currently out on the market.
In this talk I discuss the status and future prospects of testing the Higgs self-couplings at the High Luminosity LHC (HL-LHC) as well as several Beyond Standard Model (BSM) scenarios that could be probed via Higgs pair production in the coming years.
Due to coherence, there are strong electromagnetic fields of short duration in very peripheral heavy ion collisions. They give rise to photon-photon and photon-nucleus collisions with high flux. Photon-photon and photon-hadron physics at various invariant mass scales are discussed.
We investigate the anomalous interactions of heavy up-type quark t' in a $γγ$ collision at the LHC. We have obtained 95% confidence level(CL)limit of $t'q γ$ anomalous coupling by taking into account three forward detector acceptances: $0.0015<ξ<0.15$,$0.0015<ξ<0.5$, and $0.1<ξ<0.5$.
Recent theoretical progress in the evaluation of Higgs boson production at the LHC within the Standard Model and its minimal supersymmetric extension is reviewed. In particular the two-loop QCD corrections to the squark loop contributions to scalar Higgs production in the MSSM and soft gluon resummation effects in Standard and SUSY Higgs production via the gluon fusion mechanism are discussed.
This is a continuation of recent studies of $Υ(nS)$ production at the LHC in p-p collisions. Our previous studies were for 2.76 TeV, while the present predictions are for 7.0 TeV collisions.
Exclusive photoproduction of heavy quarkonia at HERA is analyzed in the framework of the Regge-eikonal approach together with the nonrelativistic bound state formalism. Total and differential cross-sections for the process $γ+p\to (Q\bar{Q})_{1S}+p$ are calculated. The model predicts cross-sections of Exclusive Double Diffractive Events (EDDE) at TeVatron and LHC.
We discuss various aspects of the multiparticle production processes at the LHC energy range with emphasis on the collective effects associated with appearance of the new scattering mode, which corresponds to the reflective scattering and its impact on multiparticle production processes.
We present the general introduction to the Parton Reggeization Approach and discuss some new results on large-p_T production for heavy quarks at the LHC. We concentrate here on study of different correlation spectra for b\barb-jet pairs, D\barD-meson pairs and DD-meson pairs.
We calculate the leading order cross section for the associated production of Z and J/ψ. Processes that include associated production of electroweak bosons and heavy quarlonium can give valuable insight to the production mechanism of quarkonia. We conclude that this process is accessible by the LHC statistics.
We use the POMWIG Monte Carlo generator to predict the cross-sections for double diffractive higgs and di-photon production at the Tevatron and LHC. We find that the higgs production cross-section is too small to be observable at Tevatron energies, and even at the LHC observation would be difficult. Double diffractive di-photon production, however, should be observable within one year of Tevatron Run II.
This is a review of the physics prospects for relativistic heavy ion collisions in the CERN Large Hadron Collider. The motivation for the study of superdense matter created in relativistic heavy ion collision is the prospect of observing a novel state of strongly interacting matter, the quark-gluon plasma. Experiments at the CERN Super Proton Synchrotron (SPS) and the Relativistic Heavy Ion Collider (RHIC) at Brookhaven have yielded important clues of the characteristic signatures of this new state. The LHC will extend the range of energy densities that can be explored and facilitate the obser…
We study the production of the heavy W' and Z' bosons in the three site higgsless model at the LHC. We focus on the s-channel production mode to estimate the prospects for measuring their suppressed couplings to standard model fermions.
Charm production in pp collisions is considered in the framework of perturbative QCD. The values of two parameters, the charm quark mass $m_c$ and the QCD scale mu^2, are determined from the comparison of the theoretical calculations with experimental data. The RHIC data on charm and beauty production are compared with the k_T-factorization approach predictions and with standard NLO QCD. The calculated results underestimate the STAR Collaboration data. The role of possible nuclear effects is discussed. The predictions for LHC energies are also given.
I review the color dipole formulation of heavy quark production in the light of recent RHIC data. Since charm and bottom production directly probe the gluon density, these processes allow one to study shadowing and parton saturation at RHIC and LHC. The dipole approach provides a convenient framework to calculate these nuclear effects. I present numerical results for open charm and bottom production in proton-proton and proton-nucleus collisions and discuss transverse momentum broadening of heavy quarkonia.
We discuss the different models of central diffractive production of the Higgs boson at the Tevatron and the LHC. We also describe how the models can be tested using diffractive production data being taken at the Tevatron. We finally discuss the advantages of using diffractive events to reconstruct the mass of the Higgs boson especially at the LHC.
We discuss charm production at LHC. The production of single $c \bar c$ pairs is calculated in the $k_t$-factorization approach. We use several unintegrated gluon distributions from the literature. Differential distributions for several charmed mesons are presented and compared to recent results of the ALICE and LHCb collaborations. Some missing strength can be observed. Furthermore we discuss production of two $c \bar c$ pairs within a simple formalism of double-parton scattering (DPS). Surprisingly large cross sections, comparable to single-parton scattering (SPS) contribution to $c \bar c$ …
This is a continuation of recent studies of $Υ(nS)$ production at the LHC in pp collisions. Our previous studies were for rapidity y=-1 to 1 for the CMS detector, while the present study is for y=2.5 to 4.0 at the LHC.
In most extensions of the Standard Model, heavy charged Higgs bosons at the LHC are dominantly produced in association with heavy quarks. An up-to-date determination of the next-to-leading order total cross section in a type-II two-Higgs-doublet model is presented, including a thorough estimate of the theoretical uncertainties due to missing higher-order corrections, parton distribution functions and physical input parameters. Predictions in the four- and five-flavour schemes are compared and reconciled through a recently proposed scale-setting prescription. A four- and five-flavour scheme mat…
We present predictions for heavy-quark production for proton-lead collisions at LHC energy 5.5 TeV from Glauber-Gribov theory of nuclear shadowing. We have also made predictions for baseline cold-matter (in other words inital-state) nuclear effects in lead-lead collisions at the same energy that has to be taken into account to understand properly final-state effects.
Associated production of different flavor heavy quarks can provide a probe for $W'$ bosons at the LHC. We study $pp\to t'\bar{b'}X$ process with the subsequent decays $t'\to W^+b$ and $\bar{b'}\to W^-W^+\bar b$, and compare the results with the $t\bar{b}$ final state. The effects of the $W'$ boson to the different flavor pair production cross section are shown to be important in some parameter region for the heavy quark masses of 600 and 700 GeV. We present accessible mass limits for the $W'$ boson at the LHC with $\sqrt s$=14 TeV.
We examine the flavor dependence of the nuclear modification factor $R_{AA}$ in the pQCD calculations at LHC energies. The computations are performed accounting for radiative and collisional parton energy loss with running coupling constant. Our results show that the recent LHC data on the $R_{AA}$ for charged hadrons, D-mesons and non-photonic electrons agree reasonably with the pQCD picture of the parton energy loss with the dominating contribution from the radiative mechanism.
One of the versions of the SU(3)$_L\otimesU(1)_N$ electroweak model predicts charged heavy-leptons which do not belong to any class of heavy-leptons proposed up to now. We investigate the production and signatures of pairs of these heavy-leptons {\it via} the Drell-Yan process and the gluon-gluon fusion at the CERN Large Hadron Collider (LHC). As an example we study the decay of the exotic leptons into another ones. We see that the lifetime of the exotic leptons can be short.
