I will briefly overview the current status of phenomenological research in exclusive and diffractive photoproduction of excited vector mesons. The talk would cover the formalism and the key results on photo- and electroproduction observables of both heavy quarkonia states and light vector mesons in the color dipole picture. The key challenges in QCD modelling of such reactions including the...
We discuss production of forward charm/anticharm quarks,
$D$ mesons and neutrinos/antineutrinos from their semileptonic decays
in proton-proton collisions at the LHC energies.
The calculation is preformed within $k_t$-factorization
and hybrid model using different unintegrated gluon distribution
functions (UGDFs) from the literature.
We include gluon-gluon fusion, intrinsic charm (IC)...
In this talk I will present analysis of J/ψ yield and polarization in high multiplicity hadron collisions using the CGC+NRQCD framework. Some predictions for pp and pA collisions at LHC energies will be presented.
We investigate improvements on models of dipole cross-section, one of which was originally proposed by Golec-Biernat and W\"usthoff (GBW), and the other is a DGLAP improved model proposed by Bartels, Golec-Biernar and Kowalski (BGK), which has improved small dipole behaviour.
Both models have been very successful in describing saturation phenomenon in small $x$ DIS.
In this study, we...
There has been much recent progress towards extending the BFKL equation to next-to-next-to-leading logarithmic (NNLL) accuracy. One of the remaining ingredients of the BFKL kernel is the one-loop central-emission vertex (CEV) for two gluons which are not strongly ordered in rapidity. In this talk I will discuss our recent extraction of this vertex in N=4 super Yang-Mills (SYM) theory, which is...
Heavy-flavored emissions have been always considered as an excellent channel to test properties of Quantum chromodynamics (QCD) at present and future colliders. Among different regimes, in which heavy-flavor production can be investigated, we focus our attention on the semi-hard one, where $s \gg Q^2 \gg \Lambda_{QCD}$ (s is the squared center-of-mass energy, $\{Q^2\}$ a (set of) hard scale(s)...
We discuss the production mechanism of a new state,
a fully charm tetraquark, discovered two years ago by the LHCb at
M = 6.9 GeV in the $J/\psi J/\psi$ channel.
Both single parton scattering (SPS) and double parton scattering (DPS)
mechanisms are considered. We calculate the distribution in the invariant
mass of the four-quark system $M_{4c}$ for SPS and DPS production of
$c c \bar...
We review our calculations of $\eta_c$(1S,2S) prompt production in proton-proton collisions at $\sqrt{s}= 7\,, 8\,, 13\,{\rm TeV}$, as well as $\chi_{c0}$(1P) and $\chi_{b0}$(1P). The matrix element of the $g^*g^* \to \mathcal{Q}$ is found by taking into account the proper colour factors and coupling constant to quarkonia electromagnetic form factors for $\gamma^*\gamma^*\to \mathcal{Q}$. The...
We review the recent developments of the QCD shockwave approach at Next-to-Leading Order. The general method of this effective action will be sketched, and several examples, in the case of diffractive processes, will be presented.
The cross-sections of diffractive double hadron photo- or electroproduction with large pT, on a nucleon or a nucleus, are calculated to NLO accuracy.
A hybrid formalism mixing collinear factorization and high energy kt factorization, more precisely the shockwave formalism, is used to derive the results.
The cancellation of divergences is explicitly shown, and the finite parts of the NLO...
In this work, we calculate the double-inclusive gluon production within the framework of the dense-dilute Color Glass Condensate (CGC) approach.
As a novelty, we provide the contribution accounting for the quantum correction in which the two gluons come from a single projectile source, thus giving renewed insights about a breaking of the accidental symmetry of the CGC which straightforwardly...
We calculate [1] the contribution from the $q\bar{q}g$ state to the small-$x$ diffractive cross section in deep inelastic scattering in the saturation regime. The obtained cross section is finite by itself and a part of the full next-to-leading order result for the diffractive structure function. We perform the calculation in exact kinematics in the eikonal limit, and show that the previously...
Exclusive vector meson production is a powerful process to probe the small Bjorken-$x$ structure of protons and nuclei, as such processes are especially sensitive to gluonic structure and also provide access to the spatial distribution of small-$x$ gluons in nuclei. A powerful theoretical framework to study such high-energy processes is the Color Glass Condensate (CGC) effective field theory....
Using the color dipole picture for DIS, we study the production of a pair of jets initiated by a quark and an antiquark, through coherent diffraction. The transverse momenta of the two jets are taken to be larger than the target saturation momentum. Then the typical final-state configurations are such that the hard dijets are accompanied by a semi-hard gluon jet, with transverse momentum of...
We construct a framework that may be used to compute NLO kT-dependent impact factors from NLO on-shell parton scattering amplitudes. The key point of the method is an extension to the NLO accuracy of the auxillary parton method commonly used in the LO calculations. With the high energy (Regge) factorization at the NLO, the collinear scattering amplitudes are decomposed into the NLO impact...
High energy evolution of scattering amplitudes is governed by the JIMWLK Hamiltonian. At NLO it involves quark contributions. The NLO JIMWLK Hamiltonian with massless quarks has been known for some time.
Yet, the quest for precision requires inclusion of effects due to quark masses. This gap has been filled.
By describing the initial stage of heavy ion collisions in terms of freely-evolving classical fields, we perform a first-principles calculation of the energy density one- and two-point correlation functions at finite proper time. Our approach allows us to systematically resum the contributions of high momentum modes that would make a power series expansion in proper time divergent. In order to...
We study inclusive dijet production in deep inelastic scattering at NLO within the Color Glass Condensate Effective Field Theory. We begin by studying this process in general small-x kinematics where we: (i) show that the differential cross-section is infrared and collinear safe, (ii) demonstrate the factorization of large energy/rapidity logarithms which can then be resummed via JIMWLK...
Using the CGC effective theory together with the hybrid factorisation, we study forward photon+jet production in proton-nucleus collisions beyond leading order. We first compute the "real" next-to-leading order (NLO) corrections, i.e. the radiative corrections associated with a three-parton final state, out of which only two are being measured. Then we move to the "virtual" NLO corrections to...
Probing the structure and dynamics of matter has witnessed a dramatic development overthe last decades with new theoretical advances to probe nucleons and nuclei beyond just a one-dimensional approach through Transverse-Momentum Distribution (TMD) functions. TMDsprovide crucial insight into the confined motion of quarks and gluons with a transverse momen-tumkTinside a nucleon and...
I will talk about phenomenology of Transverse Momentum Dependent distributions and the spin asymmetries observed in a variety of scattering processes.I will argue that those asymmetries have a common origin, namely they arise due to the quantum mechanical interference from multi-parton states of the hadron's wave function. I will explain how the theoretical and phenomenological understanding...
The elastic scattering of protons at 13 TeV is measured in the range of protons transverse momenta allowing the access to the Coulomb-Nuclear-Interference region. The data were collected thanks to dedicated special LHC beta* = 2.5km optics. The total cross section as well as rho-parameter, the ratio of the real to imaginary part of the forward elastic scattering amplitude, are measured and...
We present the preliminary results of unpolarized cross section and transverse single spin asymmetry (TSSA) of $Z^{0}$ measured by the STAR experiment. The cross section results combine 500/510 GeV $p$$+$$p$ data from 2011, 2012, 2013 and 2017, corresponding to a total luminosity of 700 pb$^{-1}$. The differential $Z^{0}$ cross section, measured as a function of the boson's transverse...
The recent PHENIX [1] and STAR [2] data on the nuclear dependence of the transverse single spin asymmetry calls for a careful investigation into potential theoretical mechanisms that would explain this data in a quantitative way. To that end we investigate the transverse single spin asymmetry in forward $p^\uparrow p$ and $p^\uparrow A$ collisions from the odderon mechanism suggested by...
I will present a review of measurements undertaken at various experiments
for determining the Generalized Parton Distributions in the nucleon. Results on Deeply Virtual Compton Scattering with exclusive single-photon
production as well as hard exclusive meson production have been obtained
at HERMES, JLab and COMPASS using electron or muon beams and nucleon
targets in various kinematic...
We study the exclusive photoproduction of a photon-meson pair with a large invariant mass, working at leading twist and leading order in the framework of QCD collinear factorisation. Explicitly,
the produced meson is either a rho meson or a charged pion. This process allows us to extract generalised parton distributions. In particular, unlike in deeply-virtual Compton scattering and...
We present fits to determine parton distribution functions (PDFs) using a diverse set of measurements from the ATLAS experiment at the LHC, including inclusive W and Z boson production, ttbar production, W+jets and Z+jets production, inclusive jet production and direct photon production. These ATLAS measurements are used in combination with deep-inelastic scattering data from HERA. Particular...
I will review recent results on the inclusion of small-x resummation in PDF fits, with emphasis on where we are and where we can/shall go in future, especially in the light of future higher energy colliders and improved theoretical accuracy.
I will present some recent developments in the understanding of
theoretical and experimental uncertainties in PDFs, with special
emphasis on the features of NNPDF 4.0, the regularisation of
experimental covariance matrices and the propagation of matched scale
uncertainties.
Transverse momentum dependent (TMD) parton distributions in a proton
are important in high energy physics from both theoretical and phenomenological
points of view. Using the latest LHC data on the inclusive soft hadron production at small
transverse momenta, we determine the parameters of the initial TMD gluon density,
derived within the soft QCD model at the low scale $\mu_0 \sim 1 -...
Precise theoretical predictions of QCD scattering and radiation
processes are fundamental building blocks for the LHC precision
program. Fixed-order computations must be supplemented by all-order
resummations where logarithmically-enhanced contributions become
large. Among those, small-$x$ logarithms are enhanced when the ratio,
$x=\frac{Q^2}{S}$ between the typical energy scale of a...
The predictions for the atmospheric neutrino flux at high energies strongly depend on the contribution of prompt neutrinos, which are determined by the production of charmed mesons in the atmosphere at extremely high energies and very forward rapidities. Study of charm production in the far-forward directions requires to deal with a very asymmetric kinematics configuration with extremelly...
o calculate the PDFs from first principles in Lattice gauge theories it is convenient to considerthe Ioffe-time distribution defined through gauge-invariant bi-local operators with spacelike separa-tion. Lattice calculations provide values for a limited range of the distance separating the bi-localoperators. In order to perform the Fourier transform and obtain the pseudo- and the quasi-PDFs,it...
In this talk I’ll explain how new physical results in 4D (N=2) supersymmetric matter gauge theories can be found by connecting them to 2D quantum integrable models. In particular, we set up an identification between the basic mathematical and physical objects of the two kind of theories (the Q, Y and T functions of integrability and the periods and masses of the gauge theories) and from this a...
The double differential cross sections of the Drell--Yan lepton pair ($\ell^+\ell^-$, dielectron or dimuon) production, as functions the invariant mass $m_{\ell\ell}$, transverse momentum $p_\mathrm{T}(\ell\ell)$, and
$\varphi^*$, are measured. The $\varphi^*$ observable is highly correlated with
$p_\mathrm{T}(\ell\ell)$ and is used to probe the low-$p_\mathrm{T}(\ell\ell)$
region in a...
On behalf of the ZEUS Collaboration.
Submitted to JHEP.
The exclusive photoproduction reactions gamm p -> J/psi(1S) p and gamma p -> psi(2S) p have been measured at an ep centre-of-mass energy of 318 GeV with the ZEUS detector at HERA using an integrated luminosity of 373 pb-1. The measurement was made in the kinematic range 30 < W < 180 GeV, Q^2 < 1 GeV^2 and |t| < 1 GeV^2, where W is the...
Correlations between charged particles provide important insight about hadronization process. The analysis of the momentum difference between charged hadrons in pp, p-lead, and lead-lead collisions of various energies is performed in order to study the dynamics of hadron formation. The spectra of correlated hadron chains are explored and compared to the predictions based on the quantized...
We present a phenomenological analysis of events with two high transverse momentum jets separated by a large (pseudo-)rapidity interval void of particle activity, also known as jet-gap-jet events. In the limit where the collision energy is much larger than any other momentum scale, the jet-gap-jet process is described in terms of perturbative pomeron exchange between partons within the...
On behalf of the H1 and ZEUS Collaborations.
Eur. Phys. J. C82 (2022) 243
The HERAPDF2.0 ensemble of parton distribution functions (PDFs) was introduced in2015. The final stage is presented, a next-to-next-to-leading-order (NNLO) analysis of theHERA data on inclusive deep inelasticepscattering together with jet data as published bythe H1 and ZEUS collaborations. A perturbative QCD fit,...
The LHCb detector is able to probe kinematic coverage at low Bjorken-x down to 1e-5 or lower due to its forward rapidity coverage. In this talk, studies of vector boson and hadron production in proton-proton and proton-lead collisions are presented. The Z boson events are used to probe the proton structure while a relatively unknown low-x region is studied with charged and neutral hadron...
On behalf of the ZEUS Collaboration.
A new measurement of inclusive jet cross sections in neutral current deep inelastic scattering using the ZEUS detector at the HERA collider is obtained. The data were taken at HERA2 at a center of mass energy of 318 GeV and correspond to an integrated luminosity of 347 pb-1. Massless jets, reconstructed using the k_T-algorithm in the Breit reference...
Single, double and central diffractive dissociation of protons is studied at high energies in a Regge-pole model. The main premises are: 1) Regge factorization, 2) inelastic vertices identified with DIS SFs, 3) Duality relation between high- and low missing masses, 4) Non-linear, complex Regge trajectories, updated.
The new results concern: 1) the dip-bump structure in the differential...
We review the computation of anomalous dimensions in planar N=4 super Yang-Mills theory from an integrable system, i.e. AdS_5/CFT_4 ''integrability''. We then introduce the hexagon operator originally designed by Basso, Komatsu, and Vieira for three-point functions. It is argued that four- and higher-point functions can be studied using hexagon tessellations. A ''gluing prescription'' for the...
Recent CMS results from gamma-gamma and gamma-p interactions in UPC
will be reviewed.
Relativistic heavy-ion beams at the LHC are accompanied by a large flux of equivalent photons,
leading to multiple photon-induced processes. This talk presents a series of measurements of such
processes performed by the ATLAS Collaboration. New measurements of exclusive dilepton production
(electron, muon, and tau pairs) are discussed. Furthermore, the tau-pair production measurements
can...
The Precision Proton Spectrometer (PPS) is a new subdetector of CMS introduced for the LHC Run 2. The talk will present the recent results on photon-induced processes explored with PPS, illustrating the unique sensitivity which can be achieved using proton tagging.
We describe the gain on sensitivities to quartic 𝛾𝛾𝛾𝛾, 𝛾𝛾𝑊𝑊 and 𝛾𝛾𝛾𝑍 anomalous couplings and to the search for Axion-Like Particles by two or three orders of magnitude with respect to standard methods at the LHC by tagging intact protons in the final state, and matching the information from the intact protons and the 𝑊𝑊, 𝑍𝑍, 𝛾𝑍, 𝛾𝛾 in the main CMS and ATLAS detectors. We will also describe the...
Till recently, light-by-light scattering ($\gamma \gamma \to \gamma \gamma$) was not accessible for experiments because the corresponding cross section is relatively low. Measurements of diphotons in ultra-peripheral collisions (UPCs) of lead-lead nuclei have been reported recently by the ATLAS and CMS Collaborations. Our theoretical results [1] based on the equivalent photon approximation in...
Studies of vector meson exclusive production in pp collisions will be discussed. At the LHC energy, measurements of diffractive events probe interesting QCD phenomenology, including the nature of pomerons, low-x gluon distributions and saturation effects.
Photon-photon and photonuclear reactions are induced by the strong electromagnetic fields generated by ultrarelativistic heavy-ion collisions. These processes have been extensively studied in ultra-peripheral collisions with impact parameters larger than twice the nuclear radii. Photoproduced quarkonia can probe the nuclear gluon distributions at low Bjorken-x. The continuum dilepton...
Measurements of quarkonia production in peripheral and ultra-peripheral heavy-ion collisions are sensitive to photon-photon and photon-nucleus interactions, the partonic structure of nuclei, and the mechanisms of vector-meson production. LHCb has studied both coherent and incoherent production of 𝐽/𝜓 mesons in peripheral and ultra-peripheral collisions using PbPb data at forward rapidity with...
We present a detailed study of transition form factors for axial-vector meson production via the two-photon fusion process $\gamma^* \gamma^* \to 1^{++}$, with space-like virtual photons in the initial state and a $P$-wave axial-vector quarkonium in the final state. In this analysis, we employ the formalism of light-front quarkonium wave functions obtained from a solution of the Schr\"odinger...
The Forward Physics Facility (FPF) is a proposal to enlarge an existing cavern in the far-forward region of ATLAS to house a suite of experiments with groundbreaking new capabilities for many Standard Model studies and new physics searches. Although existing LHC detectors have great coverage of the central region, the production of particles in the far-forward direction is poorly constrained....
Two far-forward experiments are currently taking data during Run 3 at the Large Hadron Collider (LHC): FASERnu [1] and SND@LHC [2]. They are sensitive to some classes of BSM particles, muons and neutrinos produced in the ATLAS interaction point (IP) and propagating for several hundred meters along the tangent to the accelerator beamline, up to two caverns located in opposite directions with...
We calculate the Next-to-Leading Order (NLO) virtual correction to the Higgs-induced DIS in the infinite top mass limit. Since we want to use this result in the framework of $k_t$-factorization to resum small-x logarithms up to Next-to-Leading-Logarithm (NLL), we work in light-cone gauge and we keep the incoming gluon off-shell. This choice raises many challenging points like the presence of...
We address the issue of negative total cross sections for inclusive hadroproduction of pseudoscalar quarkonia ($\eta_Q$) and photoproduction of vector quarkonia ($\psi$, $\Upsilon$) at increasing energies in NLO collinear-factorisation computations in the $\overline{MS}$ scheme. We discuss two solutions:
- fixing the factorisation scale to avoid an over-subtraction of the collinear...
It is widely recognized that high-energy calculations performed via the NLL BFKL resummation of energy logarithms suffer from strong instabilities that become manifest when renormalization and factorization scales are varied from their natural values, namely the ones dictated by kinematics. In the case of observables featuring light-particle emissions, such as Muller--Navelet and...
We present high-accuracy QCD predictions for the transverse-momentum (qT) distribution and fiducial cross sections of Drell-Yan lepton pairs produced in hadronic collisions. At small values of qT we resum to all perturbative orders the logarithmically enhanced contributions up to next-to-next-to-next-to-leading logarithmic (N3LL) accuracy, including all the next-to-next-to-next-to-leading...
I describe resummation of colour-singlet transverse momentum and related observables in momentum space, as well as ensuing recent fiducial predictions in Drell Yan at third order in perturbation theory.
In this talk, I will disucss a framework to resum soft and next-to-soft enhanced logarithms to all orders in perturbative QCD. These large logarithms are comprises of distributions log^i (1−z)/(1−z) resulting from soft plus virtual (SV) and logarithms of the kind log^i(1−z) from next to SV (NSV) contributions. We use collinear factorisation and renormalisation group invariance as the...
Parton branching methods underlie the Monte Carlo (MC) generators, being therefore of key importance for obtaining high energy physics predictions.
We construct a new parton branching algorithm which for the first time incorporates the off-shell, transverse-momentum dependent (TMD) splitting functions, defined from the high-energy limit of partonic decay amplitudes.
Based on these TMD...
We present a full NLO result for the forward Higgs boson impact factor, obtained in the infinite top-mass limit. We discuss problems associated with a high-energy computation in the presence of the Higgs-gluons effective vertex.
This impact factor is a key ingredient to describe the inclusive hadroproduction of a forward Higgs in the limit of small Bjorken x, as well to study inclusive...
I present prediction for cross section of Mueller-Tang jets (jet-gap-jet) processes at LHC, obtained by using the BFKL approach, where both impact factors and gluon Green functions are calculated in the next-to-leading logarithmic approximation (NLLA). I discuss also the issue of the validity of the standard BFKL factorization for such processes, and show that the actual violation is small,...
The high-energy limit of 2 $\to$ 2 QCD scattering amplitudes has a rich history and recently there has been much renewed interest in the perturbative regime. In this talk, I review the salient features of this limit and present an overview of recent results. At Leading Logarithmic (LL) accuracy the partonic amplitude is governed by Regge poles in the complex angular momentum plane. Beyond LL,...
The Polarized Atomic Hydrogen Gas Jet Target polarimeter (HJET) is used to precisely, $\sigma_P^{\rm syst}/P\sim0.5\%$, measure the absolute (vertical) polarization of the proton beams at the Relativistic Heavy Ion Collider (RHIC). At HJET, the recoil protons from the beam Coulomb-nuclear interference scattering ($0.0013<-t<0.018\,\rm{GeV}^2$) off the jet target are detected in the vertically...
The anomalous excess of small-kT photons radiated along with multi-hadron production, is challenging the physics community over four decades, but no solution has been proposed so far. We argue that the problem is rooted in the comparison with an incorrect model, usually called “bremsstrahlung model”.
The Low theorem, proven only for diffractive photon radiation, relates it to the elastic...
Soft hadronic collisions with multiple production of (anti)quarks accompanied with soft photon radiation are described in terms of higher Fock states of the colliding hadrons, which contain a photon component as well. The Fock state distribution functions are shaped with the Quark-Gluon String Model. Photon radiation by quarks is described within the color-dipole phenomenology. The results of...
The production of jets at hadron provides stringent tests of perturbative QCD. We present the latest measurements using proton-proton collision data collected by the ATLAS experiment at $\sqrt{s}=13$ TeV. We will discuss the measurement of new event-shape jet observables defined in terms of reference geometries with cylindrical and circular symmetries using the energy movers distance. The...
Central diffractive event topologies at the LHC energies can be identified by two different approaches. First, the forward scattered protons can be measured in Roman pots. Second, a veto on hadronic activity away from midrapidity can be imposed to define a double gap topology. Such a double gap trigger has been implemented by the ALICE collaboration in Run 1 and Run 2 of the LHC. The analysis...
I will introduce the physics scope and state-of-the-art technology of GRANIITTI [[github.com/mieskolainen/graniitti][1]], a fully multithreaded C++17 language-driven Monte Carlo event generator designed especially for the central exclusive glueball searches and studies at the LHC and beyond. The extendable set of processes span currently from $\gamma\gamma$-EW and Durham QCD to...
Coherent photoproduction of heavy quarkonia on nuclear targets is studied within the QCD color dipole formalism including several main phenomena:
-i) The higher-twist nuclear shadowing related to the $Q\bar Q$ Fock state of the photon;
-ii) The correlation between impact parameter of a collision $\vec b$ and dipole orientation $\vec r$;
-iii) The leading-twist gluon shadowing corresponding...
We discuss the current status of the ongoing project on
searches for the QCD instantons at hadron colliders
in events with large rapidity gaps. These gaps in rapidity
are formed by either Pomeron or photon exchanges or a combination
of the two. We computed for the first time the relevant
differential cross-sections for a complete set of instanton production
in single diffraction and...
We turn high energy elastic scattering of hadrons into an initial value problem using an evolution equation based on the Regge Field Theory, which has a form of the complex nonlinear reaction-diffusion equation, with time being played by the logarithm of energy. The initial conditions are provided by the data-driven models for the real and imaginary parts of the amplitude. Numerical...
We study the rapidity dependence of the central exclusive production cross sections of C-even mesons in pA and AA collisions, where A is a heavy ion. We observe qualitatively different behaviour of the contributions arising from photon-Odderon and Pomeron–Pomeron fusion mechanisms. This can be used to extract the Odderon signal from C-even mesons exclusively produced in the forward region....
The Real Extended Bialas-Bzdak (ReBB) model is shown here to describe, in the $0.37 \le -t \le 1.2$ GeV$^2$ region, the proton-proton elastic differential cross section data published by the TOTEM Collaboration at LHC at $\sqrt{s} = 8 $ TeV center of mass energy. In this kinematic range, corresponding to the diffractive minimum-maximum region, a model-dependent Odderon signal higher than 18...
We analyze, model-independently, the scaling properties of the differential cross-section of elastic proton-proton cross-sections, including new TOTEM data published in 2022 at sqrt(s) = 8 TeV. We show that outside the signal region for Odderon exchange, the scaling function of elastic proton-proton data at 8, 7, 2.76 TeV and that of elastic proton-antiproton scattering data at 1.96 TeV are...
he differential cross section of proton-proton elastic scattering 𝑑𝜎/𝑑𝑡, as a function of the magnitude of the four-momentum transfer squared |𝑡|, evolves in a consistent way with 𝑠√ at LHC energies, all the curves being translated in the (|𝑡|, 𝑑𝜎/𝑑𝑡) plane for different center-of-mass energies. This means that the cross sections vary according to a scaling law in center-of-mass energy 𝑠√ and...
The pp elastic cross section at 1.96 TeV, obtained from a data-driven extrapolation of the cross sections measured by TOTEM at 2.76, 7, 8, and 13 TeV, have been compared with the D0 ppbar elastic cross section at 1.96 TeV in the region of the diffractive minimum and the second maximum of the pp cross section [1]. The two 1.96 TeV data sets have been found disagree at the 3.4σ level and thus...
On behalf of the ZEUS Collaboration.
JHEP 12 (2021) 102
Collective behaviour of final-state hadrons, and multiparton interactions are studied in high-multiplicity ep scattering at a centre-of-mass energy sqrt(s) = 318GeV with the ZEUS detector at HERA. Two- and four-particle azimuthal correlations, as well as multiplicity, transverse momentum, and pseudorapidity distributions for...
The goal of LHCspin is to develop, in the next few years, innovative solutions and cutting-edge technologies to access spin physics in high-energy polarized fixed-target collisions, by exploring a unique kinematic regime given by the LHC beam and by exploiting new probes.
This ambitious task poses its basis on the recent installation of SMOG2, the unpolarized gas target in front of the LHCb...
The LHeC and the FCC-eh will open a new realm in our understanding of nuclear structure and the dynamics in processes involving nuclei, in an unexplored kinematic domain. In this talk we will review the most recent studies as shown in the update of the 2012 CDR [1]. We will discuss the determination of nuclear parton densities in the framework of global fits and for a single nucleus. Then we...
The Electron-ion Collider to be constructed at Brookhaven National Lab is considered to be the next generation "dream machine" in future nuclear physics research. Extending the acceptance of the detector to the far forward region ($\eta > 4$) is extremely important for a wide range of measurements to be performed at EIC. The designs of the far-forward detectors (B0-spectrometer and...
Firstly, we will discuss the multipherical structure of BFKL final states.
Secondly,the conformal spin dependence of the perturbative QCD vacuum singularity will be shown in detail.
I present prediction for cross section of Mueller-Tang jets (jet-gap-jet) processes at LHC, obtained by using the BFKL approach, where both impact factors and gluon Green functions are calculated in the next-to-leading logarithmic approximation (NLLA). I discuss also the issue of the validity of the standard BFKL factorization for such processes, and show that the actual violation is small,...
Many standard model processes in proton-proton collisions at the LHC are produced through diffractive interactions where one or both protons may survive the collisions. The dominant production of diffractive interactions is where only one proton emerges intact (hard single diffraction). We propose using the LHC data to study the diffractive production of EW boson and heavy flavor quarks as a...
New constraints on PDFs using recent CMS data will be shown in this talk
The latest developments from MSHT including N3LO predictions, which have strong impact at low-x, will be reviewed.
I summarize recent studies of various types of uncertainties in the global analysis of parton distribution functions (PDFs) by the CTEQ-TEA group. Sampling of the multivariate PDF parameter space introduces an important source of uncertainty that has implications for critical collider applications such as W boson mass measurement and Higgs physics. Parametrization and sampling uncertainties...
