Multiple parton scatterings in high-energy p+A collisions involve multi-parton correlation inside the projectile and color coherence of multiple jets which will lead to nuclear modification of final hadron spectra relative to that in p+p collisions. Such modification of final hadron spectra in p+A collisions is studied within HIJING 2.1 model which includes initial parton shadowing, transverse momentum broadening, parton flavor and momentum correlation inside the projectile through flavor and momentum conservation and fragmentation of multiple jets. They are shown to modify the partonic flavor content of final jets and momentum spectra of final hadrons in p+A collisions at the Large Hadron Collider.
We demonstrate that rapidity separated di-hadron spectra in high multiplicity proton-proton collisions at the LHC can be quantitatively described by a combination of BFKL and saturation dynamics. Based on these results, we predict the systematics of di-hadron spectra in proton-nucleus collisions at the LHC.
We present a calculation of Pi, D and B mesons production at RHIC and LHC energies based upon the KKT model of gluon saturation. We discuss dependence of the nuclear modification factor on rapidity and transverse momentum.
The centrality dependence of charged-hadron production in relativistic heavy-ion collisions at LHC energies is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources. Theoretical pseudorapidity distributions are compared with preliminary PbPb ALICE data at LHC energy of sqrt(s_NN) = 2.76 TeV for seven centralities, and a previous RDM prediction for this energy is confronted with the data. Refined predictions for 5.52 TeV PbPb based on RDM parameter extrapolations are presented.
We study the medium modification of jets correlated with large transverse momentum photons at the LHC via a transport and perturbative QCD hybrid model which incorporates the contributions from both elastic collisions and radiative energy loss experienced by the parton showers. Calculations are performed for the modification of the photon-tagged jet yield, the photon-jet energy imbalance, and the azimuthal distribution of away-side jets. The modifications of photon-tagged jets with different $x_T = p_{T, J}/p_{T, γ}$ values are studied and they exhibit different centrality and jet cone size de…
In this paper we study the inelastic quarkonium photoproduction in coherent $pp/pPb/PbPb$ interactions. Considering the ultra relativistic hadrons as a source of photons, we estimate the total $ h_1 + h_2 \rightarrow h \otimes V + X$ ($V = J/Ψ$ and $Υ$) cross sections and rapidity distributions at LHC energies. Our results demonstrate that the experimental analysis of this process can be used to understand the underlying mechanism governing heavy quarkonium production.
The vector meson production in coherent hadron-hadron interactions at LHC energies is studied assuming that the color singlet $t$-channel exchange carries large momentum transfer. We consider the non-forward solution of the BFKL equation at high energy and large momentum transfer and estimate the rapidity distribution and total cross section for the process $h_1 h_2 \to h_1 J/ΨX$, where $h_i$ can be a proton or a nucleus. We predict large rates, which implies that the experimental identification can be feasible at the LHC.
We analyze the recent results for suppressed production of charged hadrons for Pb+Pb collisions at the center of mass energy of 2.76 TeV/nucleon-pair. We closely follow the treatment used recently by us where partons lose energy due to radiation of gluons following multiple scatterings while traversing the quark gluon plasma, before fragmenting into hadrons at the center of mass energy of 200 GeV/nucleon-pair. We obtain an empirical value for the momentum transport coefficient $(\widehat{q})$ and provide predictions for azimuthal anisotropy of hadron momenta for non-central collisions.
In this paper we study the $H + γ$ ($H = J/Ψ$ and $Υ$) production in coherent hadron - hadron interactions at LHC energies. Considering the ultrarelativistic protons as a source of photons, we estimate the $γ+ p \rightarrow H + γ+ X$ cross section using the non-relativistic QCD (NRQCD) factorization formalism and considering different sets of values for the matrix elements. Our results for the total $ p + p \rightarrow p + H + γ+ X$ cross sections and rapidity distributions at $\sqrt{s} = 7$ and 14 TeV demonstrate that the experimental analysis of the $J/Ψ+ γ$ production at LHC is feasible.
We study effects of the hadronic rescattering on final observables especially for multi-strange hadrons such as $ϕ$, $Ξ$ and $Ω$ in high-energy heavy-ion collisions within an integrated dynamical approach. In this approach, (3+1)-dimensional ideal hydrodynamics is combined with a microscopic transport model, JAM. We simulate the collisions with or without hadronic rescatterings and compare observables between these two options so that we quantify the effects of the hadronic rescattering. We find that the mean transverse momentum and the elliptic flow parameter of multi-strange hadrons are less…
The upcoming p+Pb run at the LHC will probe the nuclear gluon distribution at very small Bjorken x (from $x \sim 10^{-4}$ at mid-rapidity down to $x \sim 10^{-6}$ in the proton fragmentation region) and will allow to test approaches based on parton saturation. Here, we present the predictions of the KLN model for hadron multiplicities and multiplicity distributions in p+Pb collisions at a center-of-mass energy of 4.4 TeV. We also compare the model to the existing pp, dA and AA data from RHIC and LHC.
We have studied the probability of two succinct particle production mechanisms, likely to occur in the transition from the deconfined medium produced in RHIC and LHC heavy ion collisions back to the hadron gas, which is abundant at lower temperatures. Evidence has been found for in-medium fragmentation of non-equilibrated partons in the deconfined medium as well as bound state formation in the quark-gluon phase itself, as described by lattice QCD . Through the comparison to PNJL model calculations we attempt to quantify an extended phase of mixed degrees of freedom in a temperature range just …
We use an event-by-event hydrodynamical description of the heavy-ion collision process with Glauber initial conditions to calculate the thermal emission of photons. The photon rates in the hadronic phase follow from a spectral function approach and a density expansion, while in the partonic phase they follow from the AMY perturbative rates. The calculated photon elliptic flows are lower than those reported recently by both the ALICE and PHENIX collaborations.
The generic features of parton energy loss effects on the quenching of single hadron spectra in heavy-ion collisions are discussed, paying attention to the expected differences from RHIC to LHC. The need for precise baseline measurements in p-Pb collisions at the LHC is also emphasized. Finally I briefly mention the production of prompt photons in heavy-ion collisions as well as some open questions.
Predictions are presented within the framework of the statistical hadronization model for integrated yields of bottomonia in Pb-Pb collisions at the LHC. We investigate the centrality dependence of $Υ$ production and provide predictions for a large set of still-unmeasured open-beauty hadrons.
One of the open questions of the strong interaction theory is the existence of the Odderon, which is an unambiguous prediction of Quantum Chromodynamics, but still not confirmed in the experiment. In this paper we propose the study of the diffractive $η_c$ photoproduction in coherent interactions as a new alternative to probe the Odderon in $pp$ and $PbPb$ collisions at CERN - LHC. As the Pomeron exchange cannot contribute to this process, its observation would indicate the existence of the Odderon. We predict total cross sections of order of $pb \, (μb)$ for $pp \, (PbPb)$ collisions and larg…
The properties of strange pseudoscalar and vectors mesons as well as strange baryon resonances in dense matter are reviewed. Some open questions on the properties of strange hadrons in medium are addressed, such as the experimental signatures of in-medium effects coming from the hadronic phase on the final observables in heavy-ion collisions for the experimental conditions at SIS, RHIC and LHC energies.
The energy dependence of charged-hadron production in proton-proton collisions at RHIC and LHC energies is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources for particle production. Calculated charged-hadron pseudorapidity distributions for pp at RHIC energies of sqrt(s) = 0.2 and 0.41 TeV, and at LHC energies of 0.9, 2.36 and 7 TeV are optimized with respect to the available data. Predictions for 14 TeV are made. The central source arising from gluon-gluon collisions becomes the major origin of particle production at LHC energies. The midrapidi…
The recent LHC data have once more brought the issue of the formation of thermalized state of matter in hadron-hadron collisions into the forefront. In this letter, we have shown that the scaling of the information entropy of the chaotically produced particles is valid up to recently available data from p+p collisions at $\sqrt{s}$ = 2.36 TeV obtained by ALICE experiment. We predict that at the highest energies projected for LHC, almost all the particles will be produced chaotically, indicating that a collective behavior should be observed in hadronic collisions, as indicated by one of present…
An addendum to our previous papers in Phys. Lett. B539 (2002) 46 and Phys. Lett. B502 (2001) 51, contributed to the CERN meeting "First data from the LHC heavy ion run", March 4, 2011
The exclusive $Υ$ photoproduction in proton-proton and proton - nucleus collisions at LHC energies is investigated using the color dipole formalism and considering different models for the $Υ$ wave function and forward dipole - target scattering amplitude. Our goal is to update the color dipole predictions and estimate the theoretical uncertainty present in these predictions. We present predictions for the kinematical ranges probed by the ALICE, CMS and LHCb Collaborations.
Theoretical understanding of the observed jet quenching measurements at RHIC and LHC is challenging in QCD because it requires understanding of parton to hadron fragmentation function in non-equilibrium QCD. In this paper, by using closed-time path integral formalism, we derive the gauge invariant definition of the gluon to hadron fragmentation function in non-equilibrium QCD which is consistent with factorization theorem in non-equilibrium QCD from first principles.
We study the production of charmonia and charmed hadrons in nucleus-nucleus collisions at SPS, RHIC, and LHC energies within the framework of the statistical hadronization model. Results from this model are compared to the measured yields and centrality dependence of J/psi production at SPS and RHIC energies. We explore and contrast the centrality dependence of the production of mesons with open and hidden charm at SPS, RHIC, and LHC. The sensitivity of the results to various input parameters is analyzed in detail for RHIC energy.
We discuss the possibility to observe hadron modification in hot matter via the correlation of identical particles. We find that the hadron modification causes a new type of correlation, back-to-back correlation.
Ratio of the yield of strange hadrons to pions is considered as an important observable in studying the properties of the system produced in relativistic heavy ion collisions. Production of strange hadrons $K, \bar{K}, Λ, Σ, Ξ$ and $Ω$ have been evaluated microscopically using rate equations by considering their hadronic interaction cross sections in an expanding medium. The yields obtained from rate equations are normalized with thermal pions and compared with the measurements from Pb-Pb collisions at various multiplicities at LHC energy. The calculation has been done for various initial and …
We extend the SHM analysis of hadron production results showing here consistency with the increased experimental data set, stability of the fit with regard to inclusion of finite resonance widths and 2-star hyperon resonances. We present new results on strangeness yield as a function of centrality and present their interpretation in terms of QGP inspired model of strangeness abundance in the hadronizing fireball.
We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider (LHC) at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.
The energy dependence of charged-hadron production in relativistic heavy-ion collisions is investigated in a nonequilibrium-statistical relativistic diffusion model (RDM) with three sources. Theoretical pseudorapidity distributions are compared with Au + Au data at RHIC energies of sqrt(s_NN) = 0.13 and 0.2 TeV, and computed for Pb + Pb central collisions at LHC energies of 2.76 and 5.52 TeV. The central, nearly equilibrated source arising from gluon-gluon collisions becomes the major origin of particle production at LHC energies. The midrapidity dip is determined by the interplay of the three…
We confront the hypothesis of chemical freeze-out in ultra-relativistic heavy-ion collisions with the hypothesis of large modifications of hadron masses in nuclear medium. We find that the thermal-model predictions for the ratios of particle multiplicities are sensitive to the values of in-medium hadronic masses. In particular, the $π^+/p$ ratio decreases by 35% when the masses of all hadrons (except for pseudo-Goldstone bosons) are scaled down by 30%.
High precision soft hadron abundance data produced in relativistic nuclear collisions at LHC at $\sqrt{s_{\rm NN}}\le 5500$ GeV will become available beginning in 2007/8. We explore, within the statistical hadronization model, how these results can help us understand the properties of the deconfined quark--gluon phase at its breakup. We make assumptions about the physical properties of the fireball and obtain particle production predictions. Then, we develop a strategy to measure parameters of interest, such as strangeness occupancy $γ_s$, chemical potentials $μ_{\rm B}$ and $μ_{\rm S}$.
We present a detailed phenomenological analysis of single-inclusive hadron production at the CERN-LHC in both proton-proton and proton-lead collisions. First data from the LHC experiments on charged hadron spectra are compared to next-to-leading order QCD expectations, and predictions are made for identified pion, kaon, and proton distributions differential in transverse momentum and rapidity for LHC energies from 900 GeV to 14 TeV. The results are obtained with the latest sets of vacuum fragmentation functions based on global QCD analyses, and recently proposed medium modified fragmentation f…
The diffractive vector meson photoproduction with hadron dissociation in coherent hadron-hadron interactions at LHC energies is studied assuming that the color singlet $t$-channel exchange carries large momentum transfer. We estimate the rapidity distribution and total cross section for the processes $pp \rightarrow p V X$ and $PbPb \rightarrow Pb V X$ ($V = ρ$ or $Υ$) considering the non-forward solution of the BFKL equation at high energy and large momentum transfer. Our results indicate that the experimental identification of these processes can be feasible at the LHC.
In this letter we update our predictions for exclusive $J/Ψ$ and $Υ$ photoproduction in proton-proton and nucleus - nucleus collisions at the Run 2 LHC energies obtained with the color dipole formalism and considering the impact parameter Color Glass Condensate model (bCGC) for the forward dipole - target scattering amplitude. A comparison with the LHCb data on rapidity distributions and photon - hadron cross sections is presented. Our results demonstrate that the current data can be quite well described by the bCGC model, which takes into account nonlinear effects in the QCD dynamics and repr…
We provide quantitative predictions for the rapidity, centrality and energy dependencies of inclusive charged-hadron productions for the forthcoming LHC measurements in nucleus-nucleus collisions based on the idea of gluon saturation in the color-glass condensate framework. Our formulation gives very good descriptions of the first data from the LHC for the inclusive charged-hadron production in proton-proton collisions, the deep inelastic scattering at HERA at small Bjorken-x, and the hadron multiplicities in nucleus-nucleus collisions at RHIC.
In anticipating the upcoming proton-lead run at the LHC in the near future, we present predictions for the nuclear modification factor of transverse momentum spectrum of $Z^0$ production and transverse momentum broadening of vector boson ($J/ψ$, $Υ$, $W/Z^0$) production in proton-lead collisions at $\sqrt{s}=5$ TeV, respectively. We find that the measurement of nuclear modification factor of $Z^0$ production provides a clean and unambiguous test of the nuclear anti-shadowing proposed in the recent EPS09. In addition, the dramatic difference in transverse momentum broadening between the heavy q…
It has been observed that the yields of strange and multi-strange hadrons relative to pion increase significantly with the event charged-particle multiplicity. We notice from experimental data that yield ratios between non-strange hadrons, like p/$π$ or hadrons of same strange content, like $Λ$/K$_s^0$, show similar enhancement. We have studied this behavior within the ambit of a parton model (EPOS3) and A Multi-Phase Transport (AMPT) model in pp and p-Pb collisions at LHC energies. We investigate model predictions of yields and yield ratios of different identified hadron productions as a func…
The recent results in \sqrt{s}=2.76 TeV Pb+Pb collisions at the Large Hadron Collider (LHC) reported by the ALICE collaboration shows that the power-law energy-dependence of charged hadron multiplicity in Pb+Pb collisions is significantly different from p+p collisions. We show that this different energy-dependence can be explained by inclusion of a strong angular-ordering in the gluon-decay cascade within the Color-Glass-Condensate (or gluon saturation) approach. This effect is more important in nucleus-nucleus collisions where the saturation scale is larger than 1 GeV. Our prescription gives …
We examine whether it is possible to simultaneously describe the experimental data from RHIC and LHC on nuclear suppression of light hadrons and non-photonic single electrons in the pQCD picture of parton energy loss. We perform calculations accounting for both radiative and collisional energy loss. We show that once the coupling constant is fixed from comparison with data on the nuclear modification factor for light hadrons it gives a satisfactory agreement with data on the electron R_{AA} and azimuthal anisotropy v_2. Our results show that the collisional mechanism is only of marginal signif…
We present results on rapidity and transverse momentum distributions of inclusive charm quark production in hadronic and heavy-ion collisions at RHIC and LHC energies, including the next-to-leading order, $O(α_s^3)$, radiative corrections and the nuclear shadowing effect. We determine the hadronic and the {\it effective} (in-medium) K-factor for the differential and total inclusive charm cross sections. We find the fraction of central and inelastic events that contain at least one charm quark pair at LHC energies and obtain the effective $A$-dependence of the inclusive charm production in prot…
We compare the jet-path length and beam-energy dependence of the pion nuclear modification factor and a parton-jet nuclear modification factor at RHIC and LHC. We contrast predictions based on a linear pQCD and a highly non-linear hybrid-AdS holographic model of jet-energy loss. We find that both models require a reduction of the jet-medium coupling from RHIC to LHC to account for the measured pion nuclear modification factor. In case of the parton-jet nuclear modification factor, however, which serves as a lower bound for the LO jet nuclear modification factor of reconstructed jets, the extra…
We discuss the inclusive high-pT charged-particle production in proton-proton collisions at the LHC. The experimental data are compared to the NLO perturbative QCD calculations employing various sets of parton-to-hadron fragmentation functions. Most of the theoretical predictions are found to disastrously overpredict the measured cross sections, even if the scale variations and PDF errors are accounted for. The problem appears to arise from the presently too hard gluon-to-hadron fragmentation functions.
Recent LHC data on Pb+Pb reactions at sqrt(s_{NN})=2.7 TeV suggests that the p/pi is incompatible with thermal models. We explore several hadron ratios (K/pi, p/pi, Lambda/pi, Xi/pi) within a hydrodynamic model with hadronic after burner, namely UrQMD 3.3, and show that the deviations can be understood as a final state effect. We propose the p/pi as an observable sensitive on whether final state interactions take place or not. The measured values of the hadron ratios do then allow to gauge the transition energy density from hydrodynamics to the Boltzmann description. We find that the data can …
In high density QCD the hadron production stems from decay of mini-jets that have the transverse momenta of the order of the saturation scale. It is shown in this paper that this idea is able to describe in a unique fashion both the inclusive hadron production for \sqrt{s} \geq 546 GeV including the first data from LHC and the deep inelastic scattering at HERA. Recently reported data from ALICE, CMS and ATLAS including inclusive charged-hadron transverse-momentum and multiplicity distribution in pp collisions are well described in our approach. We provide predictions for the upcoming LHC measu…
The parton and hadron cascade model PACIAE based on PYTHIA was utilized to systematically investigate the strange particle production in pp collisions at the RHIC and LHC energies. Taking the mechanism of reduction of the strange quark suppression into account the STAR and ALICE data of strange particle production in pp collisions are well reproduced. It turned out that the K/π ratio as a function of reaction energy in pp collisions shows slightly increasing from sqrt(s)=0.2 to 0.9 TeV and then turning to saturation.
Using the EPOS3 model with UrQMD to describe the hadronic phase, we study the production of short-lived hadronic resonances and the modification of their yields and $p_{T}$ spectra in p-Pb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. High-multiplicity p-Pb collisions exhibit similar behavior to mid-peripheral Pb-Pb collisions at LHC energies, and we find indications of a short-lived hadronic phase in p-Pb collisions that can modify resonance yields and $p_{T}$ spectra through scattering processes. The evolution of resonance production is investigated as a function of the system size, which is rel…
Hadron production in leading order pQCD is reviewed. The shape of the single inclusive particle spectra is well described for $p_T \geq 2-3$ GeV at center of mass energies from 20 GeV to 2 TeV. The phenomenological K-factor is found to decrease systematically with $\sqrt{s}$. For ultra-relativistic heavy ion reactions the calculation is augmented with the effects of initial multiple parton scattering and final state radiative energy loss. Baseline CERN-LHC predictions for hadron production in $p+p$ and suppression in central $Pb+Pb$ reactions at $\sqrt{s} = 5.5$ TeV are given in comparison to …
We re-evaluate the nuclear suppression of forward $J/ψ$ production at high energy in the Color Glass Condensate framework. We use the collinear approximation for the projectile proton probed at large $x$ and an up to date dipole cross section fitted to HERA data to describe the target in proton-proton collisions. We show that using the Glauber approach to generalize the proton dipole cross section to the case of a nucleus target leads to a nuclear modification factor much closer to LHC data than previous estimates using the same framework.
The transverse momentum spectra of seven identified hadrons produced in Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ and 5.02 TeV at the CERN Large Hadron Collider (LHC) have been investigated in the framework of the recombination model (RM). Soft, semihard and hard partons all play important roles in our model and are uniformly treated for all hadrons produced.The investigation has been extended to non-central collisions and the parameters controlling the momentum degradation of semihard partons have been tuned. Our study shows good agreement between theoretical results and experimental data. To …
In this article, we will present a systematic analysis of transverse momentum spectra of the strange hadron in different multiplicity events produced in pp collision at $\sqrt{s}$ = 7 TeV, pPb collision at $\sqrt{s_{NN}}$ = 5.02 TeV and PbPb collision at $\sqrt{s_{NN}}$ = 2.76 TeV. The differential freeze out scenario of strange hadron $K^{0}_{s}$ assumed while analyzing the data using a Tsallis distribution which is modified to include transverse flow. The $p_{T}$ distributions of strange hadron in different systems are characterized in terms of the parameters namely, Tsallis temperature ($T$…
The latest, high-accuracy identified hadron spectra measurements in high-energy nuclear collisions led us to the investigation of the strongly interacting particles and collective effects in small systems. Since microscopical processes result in a statistical Tsallis-Pareto distribution, the fit parameters $q$ and $T$ are well suited for identifying system size scalings and initial conditions. Moreover, parameter values provide information on the deviation from the extensive, Boltzmann-Gibbs statistics in finite-volumes. We apply here the fit procedure developed in our earlier study for proton…
We provide predictions for the nuclear modification factor R_{pA} for pions and direct photon production in p+A collisions at LHC energy at midrapidity within different saturation models fitted to HERA data. In our approach we have no free parameters to adjust and all model parameters are fitted to other reactions. Our approach gives a rather good description of PHENIX data for R_{pA} for pions. We show that, in various saturation models, the pion Cronin enhancement is replaced by a moderate suppression at LHC energy at midrapidity due to gluon shadowing effects. However, Cronin enhancement of…
We confront soft Pomeron and gluon saturation models with the first LHC data on inclusive hadron production. We claim that while the first type of models are not able to describe some part of the LHC data, the Colour-Glass-Condensate (gluon saturation) approach gives an adequate description of the data. Here, we compare our published predictions with the recently available 7 TeV data. We firmly believe that if further experimental measurements confirm that the gluon saturation works, it will be a major discovery.
The relativistic hydrodynamics together with the single-freeze-out statistical hadronization model is used to describe the midrapidity hadron production in ultra-relativistic heavy-ion collisions at RHIC and LHC. At the highest RHIC energy our approach gives a quite satisfactory global description of soft hadronic observables including the HBT radii. With the increased initial energy, from RHIC to LHC, we expect the saturation of the pion elliptic flow and the moderate increase of the correlation radii.
This proceeding briefly summarizes our recent VISHNU hybrid model investigations on the chemical and thermal freeze-out of various hadrons species in 2.76 A TeV Pb+Pb collisions. Detailed analysis on the evolution of particle yields and the last elastic collisions distributions during the hadronic evolution reveals that the two multi-strange hadrons, $Ξ$ and $Ω$, experience early chemical and thermal freeze-out when compared with other hadron species.
In this article, we investigate the potential of low-mass lepton pair production in proton-ion collisions at the LHC to constrain nuclear modifications of parton densities. Similarly to prompt photon production, the transverse momentum spectrum is shown to be dominated by the QCD Compton process, but has virtually no fragmentation or isolation uncertainties. Depending on the orientation of the proton and ion beams and on the use of central or forward detector components, all interesting regions of nuclear effects (shadowing, antishadowing, isospin and EMC effects) can be probed. Ratios of cros…
We consider pp, dAu and AuAu production of photons at RHIC energies, and PbPb collisions at LHC energy. We show that the inclusive spectrum of photons in the transverse momentum range of 1 GeV < pT <= 4 GeV satisfies geometric scaling. Geometric scaling is a property of hadronic interactions predicted by theories of gluon saturation, and expresses rates in terms of dimensionless ratios of the transverse momentum to saturation momentum. We show excellent agreement with geometric scaling with the only input being the previously measured dependence of the saturation momentum upon Bjorken x and ce…
We investigate semi-inclusive photon-hadron production in the color glass condensate (CGC) framework at RHIC and the LHC energies in proton-proton (pp) and proton-nucleus (pA) collisions. We calculate the coincidence probability for azimuthal correlation of pairs of photon-hadron and show that the away-side correlations have a double-peak or a single-peak structure depending on trigger particle selection and kinematics. This novel feature is unique for semi-inclusive photon-hadron production compared to a similar measurement for double inclusive dihadron production in pA collisions. We obtain …
Meson production cross sections in ultra-peripheral relativistic heavy ion collisions at LHC are revisited. The relevance of meson models and of exotic QCD states is discussed. This study includes states that have not been considered before in the literature.
The medium modification of vector meson properties and its effects on thermal photon and dilepton emission rates from hot/dense hadronic matter are discussed. The role of spectral changes of hadrons in explaining the WA98 photon data and the CERES/NA45 dilepton data with similar initial conditions is demonstrated.
