Building on the achievements of the Large Hadron Collider (LHC) and the projected reach of its high-luminosity upgrade (HL-LHC), the work of the Energy Frontier during the Snowmass 2021 community exercise has focused on building the case for future explorations at and above the TeV scale and has explored possible scenarios beyond the HL-LHC. In this talk I will present highlights of the main...
During the LHC RunII, both ATLAS and CMS experiments collected a large data set. Compared to the LHC RunI results, we have achieved much higher precision on measuring Higgs features like Yukawa couplings and the inclusive cross section. Meanwhile, we gained unprecedented high sensitivity to search for Higgs rare and exotic decays, and also for long-lived particles through Higgs portals. This...
Diffractive phenomena constitute a large fraction of interactions occurring in pp collisions at LHC. Because of their non-perturbative nature, the present understanding is still relatively poor and uncertain. One of the methods to study these processes is forward proton tagging. I will discuss the mechanism of the diffractive processes, recent results, and potential implications. The proton...
I will discuss new developments in the study of physics beyond the Standard Model, including motivations based on the observations of the existence of dark matter and dark sectors, neutrino masses, the baryon asymmetry of the Universe, the flavor structure of the Standard Model fermions, and others. I'll discuss many strategies to resolve the origin of these mysteries, including direct and...
In recent years, increased attention has been devoted to the issue diversity, equity and inclusion (DEI) in societal engagements, in particular in the scientific disciplines. Many institutions have been making efforts—with various degrees of commitment and success—to improve DEI within the context of their institutional activities. During the recent particle physics prioritization exercise,...
Thanks to the high center-of-mass energy of the LHC, millions of top quarks have been produced and recorded, allow us to study the top quark related observables with a high precision. Deviations between theory predictions and experimental measurements in the top quark sector might indicate the first hints for new physics. This presentation focuses on the recent measurements at ATLAS and CMS...
Heavy ion collisions allow access to novel QCD and QED studies in a laboratory setting. Experimental collaborations actively pursue this opportunity at RHIC and the LHC, and this vibrant physics program continues to yield insights into the interactions and properties of excited nuclear matter. Precision measurements of the properties of quark-gluon plasma (QGP) and the strong electromagnetic...
In this talk I review the current state of precision QCD simulations for the LHC and beyond.
Spin is a unique probe to unravel the internal structure and QCD dynamics of nucleons. Exploration of the 3D spin structure of the nucleons is based on the complementarity of lepton scattering processes and purely hadronic probes. Some of the main questions that physicists have been trying to address in spin experiments involving different interactions and probes are: How does the spin of the...
We report the results of a new global QCD analysis including deep-inelastic scattering (DIS) data off $^1$H, $^2$H, $^3$H, and $^3$He targets. Nuclear corrections are treated in terms of a nuclear convolution approach with off-shell bound nucleons. The off-shell corrections responsible for the modification of the structure functions (SFs) of bound nucleons are constrained in a global fit along...
The international ePIC collaboration has formed to design and construct the general purpose detector to be ready at the beginning of operation of the Electron-Ion Collider. ePIC will be located at the IP6 interaction region of the RHIC/EIC accelerator. By measuring inclusive and semi-inclusive DIS (where the target is shattered) and exclusive processes (where the target is left intact) in...
The production of jets and prompt isolated photons at hadron colliders provides stringent tests of perturbative QCD. We present the latest measurements using proton-proton collision data collected by the ATLAS experiment at √s =13 TeV. Prompt inclusive photon production is measured for two distinct photon isolation cones, R=0.2 and 0.4, as well as for their ratio. The measurement is sensitive...
Recently, a novel factorization scheme has been put forward in the context of DIS . This new approach allows to connect the moderate x regime where the partonic picture is manifest to the small x regime best described by strong classical fields. In this work, we explore quantum evolution of the associated 3D gluon distribution that encodes saturation effects. In this framework, we obtain a...
A search for off-shell production of the Higgs boson using 139 fb−1 of 𝑝𝑝 collision data at √𝑠 = 13 TeV collected by the ATLAS detector at the Large Hadron Collider. The observable signature is a pair of on-shell 𝑍 bosons, with contributions both from the virtual Higgs boson and interference with other processes, and the two decay final states, 𝑍 𝑍 → 4ℓ and 𝑍 𝑍 → 2ℓ2𝜈 with ℓ = 𝑒 or 𝜇. The...
We will present results on Spin Density Matrix Elements (SDMEs) measured in hard exclusive muoproduction of $\rho ^0$, $\omega $ and $\phi$ mesons on the proton at COMPASS using 160 GeV/$c$ polarised $\mu ^{+}$ and $\mu^{-}$ beams scattering off a liquid hydrogen target. The measurements cover the range 5 GeV/$c^2$ $< W <$ 17 GeV/$c^2$, 1.0 (GeV/$c$)$^2$ $< Q^2 <$ 10.0 (GeV/$c$)$^2$ and 0.01...
Combining measurements of many production and decay channels of the observed Higgs boson allows for the highest possible measurement precision for the properties of the Higgs boson and its interactions. These combined measurements are interpreted in various ways; specific scenarios of physics beyond the Standard Model are tested, as well as a generic extension in the framework of the Standard...
In relativistic heavy ion collisions, the charged ions produce an intense flux of equivalent photons. Thus, photon-induced processes are the dominant interaction mechanism when the colliding nuclei have a transverse separation larger than the nuclear diameter. In these ultra-peripheral collisions (UPCs), the photon provides a clean, energetic probe of the partonic structure of the nucleus,...
EPIC is a general-purpose detector designed to deliver the full physics program of the Electron-Ion Collider (EIC). Particle identification (PID) at the EIC is an essential asset as well as a challenge: the PID systems have to provide excellent separation of pions, kaons, and protons over a large phase space with significant pion/electron suppression. EPIC addresses the physics requirements by...
We revisit the problem of small Bjorken-$x$ evolution of the gluon and flavor-singlet quark helicity distributions in the shock wave (s-channel) formalism. Earlier works on the subject in the same framework resulted in an evolution equation for the gluon field-strength $F^{12}$ and quark “axial current” $\bar{\psi} \gamma^+ \gamma^5 \psi$ operators in the double-logarithmic approximation...
Excellent particle identification (PID) is one of the key requirements for the central detector of the Electron-Ion collider (EIC). Identification of the hadrons in the final state is important to study how different quark flavors contribute to nucleon properties. A detector with a radial size of only 7-8 cm, which uses the principle of Detection of Internally Reflected Cherenkov light (DIRC),...
The efficiency of non-local subtraction methods such as qT-subtraction or jettiness subtraction is affected by the size of the power corrections below the slicing cutoff used in the calculation. In this talk I will discuss the scaling of the power corrections for different classes of observables, focussing in particular on transverse observables, which do not depend on the rapidity of QCD radiation.
The discovery of the Higgs boson with the mass of 125 GeV confirmed the mass generation mechanism via spontaneous electroweak symmetry breaking and completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many experimental measurements, it is not capable of solely explaining some observations. Many extensions of the Standard...
We present a further step toward a global extraction of gluon generalized parton distributions (GPDs). In our previous work we performed the first global analysis of quark GPDs by including lattice quantum chromodynamics (QCD) calculations, global fitted forward parton distribution functions (PDFs), form factors (FFs), and Deeply Virtual Compton Scattering (DVCS) measurements from JLab and...
The physics program at the High Luminosity LHC (HL-LHC) calls for a precision in the luminosity measurement of 1%. A larger uncertainty would represent the dominant systematic error in several precision measurements, including in the Higgs sector. To fulfil this requirement in an environment characterized by up to 140 simultaneous interactions per bunch crossing (200 in the ultimate scenario),...
The production of W/Z bosons in association with heavy flavor jets or hadrons at the LHC is sensitive to the flavor content of the proton and provides an important test of perturbative QCD. We present the production of Z bosons in association with b-tagged large radius jets. The result highlights issues with modelling of additional hadronic activity and provides distinction between...
The Standard Model predicts several rare Higgs boson decay channels, among which are the decays to a Z boson and a photon, to a low-mass lepton pair and a photon, and to a meson and photon. The observation of some of these decays could open the possibility of studying the CP and coupling properties of the Higgs boson in a complementary way to other analyses. In addition,...
Motivated by the wide range of kinematics covered by current and planned DIS facilities, we revisit the formalism, practical implementation, and numerical impact of target mass corrections (TMCs) for DIS on nuclear targets. These corrections are especially crucial for EIC physics. Within the Operator Product Expansion (OPE) formalism, we extend the analysis from individual nucleon targets...
When parton momentum faction $x$ of hadron becomes small, an enhancement from small-$x$ logarithms shows up, and eventually, we enter into a partonic saturation region. A consistent treatment of the small-$x$ logarithms requires an all-order resummation which can be achieved with the BFKL formalism. However, a boundary to delineate the small-$x$ resummation region from saturation one is...
We consider the extension of the MSHT20 PDFs to an approximate N$^3$LO order. We describe the parameterisation of the missing N$^3$LO contributions and the determination of the theoretical uncertainties and their interpretation. We examine the impact of further data sets and look at the stability of predicted cross sections.
We will present COMPASS measurements of Deeply Virtual Compton Scattering and of exclusive pi0 production on the proton using 160 GeV polarized mu+ and mu- beams at the CERN SPS impinging on a 2.5m long liquid hydrogen target. The target was surrounded by a barrel-shaped time-of-flight system to detect the recoiling target protons. The scattered muons and the produced real photons were...
In this talk, we plan to discuss recent results on third-order (N3LO) perturbative QCD corrections to observables in massive gauge boson production at the LHC. We describe how existing NNLO calculations for vector-boson-plus-jet processes can be utilized to obtain fully differential N3LO predictions for fiducial cross sections in leptonic final states, using the qT subtraction method. The...
A crucial ingredient in all calculations in the Color Glass Condensate framework is the non-perturbative input to the perturbative small-$x$ evolution equation such as the Balitsky-Kovchegov (BK) equation. Due to the non-perturbative nature, it has to be determined from experimental data, most naturally from total DIS cross section measurements.
So far it has not been possible in leading...
The possibility of a joint interaction region and detector which could study ep/eA and pp/pA/AA at the HL-LHC was presented in [1]. Here we show the most recent developments on the design of such novel interaction region where, in ep/eA mode, one hadron or nuclear beam must go through the region unscathed while in hh mode that beam must be focused to collide with the other hadron or nuclear...
The production of single top quarks as well as top-quark pairs in association with electroweak gauge bosons is presented together with the measurement of production asymmetries in ttbar and associated ttbar production. Using the data set collected during run 2 of the LHC (2015-2018, 139/fb of pp collisions at 13 TeV), the ATLAS experiment has observed ttX production, with X=gamma,Z and single...
Measurements of Deep Inelastic Scattering (DIS) provide a powerful tool to probe fundamental structure of protons and other nuclei. The DIS cross sections can be expressed in terms of structure functions which are conventionally constructed via parton distribution functions (PDFs) that obey the DGLAP evolution equations. However, it is also possible to formulate the DGLAP evolution directly in...
Testing the Yukawa couplings of the Higgs boson to quarks and leptons is important to understand the origin of fermion masses. The talk presents several measurements in Higgs boson decays to two bottom quarks or two tau leptons, searches for Higgs boson decays to two charm quarks or two muons, as well as direct constraints of the charm-Yukawa coupling. The production of Higgs bosons in...
We study the single-inclusive particle production from proton-nucleus collisions in the dilute-dense framework of the color glass condensate (CGC) at next-to-leading order (NLO) accuracy. In this regime, the cross section factorizes into hard impact factors and dipole-target scattering amplitude describing the eikonal interaction of the partons in the target color field. We combine, for the...
We calculate the one-loop quark box diagrams relevant to polarized and unpolarized Deep Virtual Compton Scattering by introducing an off-forward momentum $l^\mu$ as an infrared regulator. Such a regularization enables us to unravel the poles $1/l^2$ related to the chiral anomaly in the polarized case and the trace anomaly in the unpolarized case. We interpret our results in terms of the...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton (nucleus) collisions with per nucleon instantaneous luminosities around $10^{34}$ ($10^{33}$) cm$^{-2}$s$^{-1}$. Here we describe the current detector design for such experiments [1,2] and the key developments needed,...
In the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton-proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost...
Parton distribution functions (PDFs) are most commonly determined by parameterizing them at some input scale Q_0 and then evolved to the desired scale Q through the DGLAP evolution equations. Extensions of the DGLAP equations have been proposed to account not only for the splitting of partons but also including non-linear 1/Q^n terms from the recombination of partons which slows down the pace...
With the full Run 2 pp collision dataset collected at 13 TeV, very detailed measurements of Higgs boson properties can be performed using its decays into bosons. This talk presents measurements of Higgs boson properties using decays into bosons, including production mode cross sections and simplified template cross sections, as well as their interpretations.
In the parton branching (PB) approach, Collinear and TMD parton densities have been determined by fits to inclusive deep inelastic scattering (DIS) HERA data. This method allows one to simultaneously take into account soft-gluon emission and the transverse momentum recoils in the parton branchings along the QCD cascade. The latter leads to a natural determination of the TMD PDFs in a proton. A...
We present a lattice QCD determination of the nucleon generalized parton distributions (GPDs) from an analysis of the quasi-GPD matrix element within the leading-twist framework. We preform our study on a Nf=2+1+1 twisted mass fermions ensemble with a clover improvement. The faster and more effective lattice QCD calculations of GPDs using the asymmetric frames was applied so that we can...
ATLAS-ITK Strip Collaboration
(the speaker to be selected by the ITk Speakers Committee after the contribution acceptance)
The inner detector of the present ATLAS experiment has been designed and developed to function in the environment of the present Large Hadron Collider (LHC). At the ATLAS Phase-II Upgrade, the particle densities and radiation levels will exceed current levels by a...
There has been significant discussion in the community regarding a future $\mu^+\mu^-$ collider. While such a facility is still decades away from realization, it is also understood that significant technological development and feasibility demonstrations are necessary at lower beam energies. Here we propose such a possibility coupled with a rich physics program. We propose a future Muon-Ion...
We present theoretical calculations of total cross sections and top-quark transverse-momentum and rapidity distributions in the associated production of a top-antitop pair with a photon ($t{\bar t}\gamma$ production). We include complete QCD and electroweak corrections at NLO as well as soft-gluon corrections at approximate NNLO (aNNLO). The aNNLO corrections are very significant, they...
Both deeply-virtual and photoproduction of mesons offer promising access
to generalized parton distributions and complementary description of different kinematical regions. The higher-order contributions offer stabilizing effect with respect to the dependence on renormalization scales, while higher-twist effects have been identified as especially important in the case of the production of...
Studies of the CP properties of the Higgs boson in various production modes and decay channels are presented. Limits on the mixing of CP-even and CP-odd Higgs states are set by exploiting the properties of diverse final states.
During the last ten years, a key problem in our understanding of particle production at small $x$ has been the fact that single inclusive particle spectra computed at NLO in pA collisions at forward rapidities using the hybrid model become negative at large transverse momenta. Different solutions have been proposed in the literature in the last years, including Sudakov and threshold...
The EIC physics program relies on successful measurements of exclusive final states, which produce charged particles (e.g. protons, pions) at far-forward pseudorapidities. Such particles are within a few millimeters of the outgoing hadron beam. Reconstruction of these particles requires use of silicon detectors placed directly into the accelerator vacuum, in the style of the Roman Pots used ...
Latest results on Z boson measurements are presented using collision data collected by CMS up to now. Differential production cross section measurements on several observables will be discussed.
The so-called Generalized Parton Distribution (GPDs) contain information about the parton's transverse position versus their longitudinal momentum, and can be accessed in hard exclusive reactions (where all products are known). Most of the current models rely on Deeply Virtual Compton Scattering (DVCS) measurements in their parametrization. However, extracting GPDs from other channels will...
The LHCb detector's forward geometry provides unprecedented kinematic
coverage at low Bjorken-x. LHCb's excellent momentum resolution,
vertex reconstruction, and particle identification enable precision
measurements at low transverse momentum and high rapidity in
proton-lead collisions, probing x as small as 10^-6. In this
contribution, we present recent studies of low-x physics using...
We discuss the reconstruction of target jet and the framework of quantifying its internal substructure. Due to momentum and charge conservation, target and current correlation can be exploited which significantly constrains the event-wide particle distributions. We demonstrate this method using Pythia simulations of electron-proton collisions in the context of identifying the flavor of the...
We present recent progress within the NNPDF analysis of parton distribution functions aimed to i) improve the accuracy of the determination by accounting for (approximate) N3LO corrections to the splitting functions and partonic matrix elements, ii) estimate the impact of missing higher order uncertainties within the NNLO global analysis, and iii) account for QED corrections and the impact of...
A new era of hadron collisions will start around 2029 with the High-Luminosity LHC which will allow to collect ten times more data than what has been collected during 10 years of operation at LHC. This will be achieved by higher instantaneous luminosity at the price of higher number of collisions per bunch crossing.
In order to withstand the high expected radiation doses and the harsher...
The elastic scattering of protons at 13 TeV is measured in the range of the 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...
Generalized Parton Distributions (GPDs) have been one of the most important tools to access the nucleon 3D structure including its mass, angular momentum and mechanical properties. However, the extraction of GPDs has been challenging due to its high-dimension nature. Recent progress in lattice QCD have brought in many insights into the studies of GPDs. In this talk I will introduce the GPDs...
We provide a summary of recent developments on the MSHT parton distribution functions. This includes the addition of a variety of new data sets into the fit, and the potential impact of EIC data. The primary impact is seen on the details of the high-$x$ PDFs. We also consider the impact of procedural choices, and the effect of changes of PDFs on predicted cross sections.
The substructure of QCD jets has been the subject of intense investigation following the development of infrared and collinear safe clustering algorithms and observables. A particularly illuminating observable to study the radiation patterns of light and heavy partons is the Lund jet plane (LJP), where various types of emissions such as soft-collinear, hard-collinear, and non-perturbative...
Recent results on the EW sector from the CMS Collaboration will be presented.
We discuss recent developments in the global QCD analysis of parton distribution functions by CTEQ-TEA collaboration.
This talk presents ATLAS recent measurements of distributions sensitive to Underlying event, the hadronic activity observed in relationship with the hard scattering in the event using the full ATLAS dataset at center-of-mass energy of 13 TeV. Measurement of charged-particle distributions as a function of Upsilon momentum and different Upsilon states will be discussed. The measurement benefits...
The ATLAS Muon Spectrometer is designed to provide Muon triggering, identification and momentum measurement. It consists of resistive plat chambers (RPCs) and thin gap chambers (TGCs) that are used as primary trigger detectors, while monitored drift tubes (MDTs) and cathode strip chambers (CSCs) are utilized for precision trackering. To improve the Muon transverse momentum (pT) resolution at...
Various measurements related to the study of hadronic jets substructure in proton collisions at 13 TeV with the CMS experiment are presented. The differential jet production cross section as a function of the jet mass and transverse momentum is shown in events with a Z boson plus jet topology, with and without the soft radiation within a jet removed by a jet grooming algorithm. Measurement of...
The Large Hadron Collider (LHC) at CERN is the largest and most powerful particle collider today. The Phase-II Upgrade of the LHC will increase the instantaneous luminosity by a factor of 7 leading to the High Luminosity LHC (HL-LHC). At the HL-LHC, the number of proton-proton collisions in one bunch crossing (called pileup) increases significantly, putting more stringent requirements on the...
Gluons are found to become increasingly dominant constituents of nuclear matter when being probed at higher energies or smaller Bjorken-$x$ values. This has led to the question of the ultimate fate of nuclear gluonic structure and its interaction with external probes at extreme density regimes when approaching the limit allowed by unitarity. In ultraperipheral collisions (UPCs) of relativistic...
The weak mixing angle is a probe of the vector-axial coupling structure of electroweak interactions. It has been measured precisely at the $Z$-pole by experiments at the LEP and SLD colliders, but its energy dependence above $𝑚_Z$ remains unconstrained.
In this contribution we propose to exploit measurements of Neutral-Current Drell-Yan at large invariant dilepton masses at the Large...
The question of the existence and possible magnitude of nonperturbative (often called "intrinsic") charm in the proton has long confounded attempts to cleanly isolate such a contribution in global analyses of high-energy experiments. In this talk, we show that the available (non)perturbative QCD theory and hadronic data have still not developed to a sufficient level to clearly resolve this...
SND@LHC is a compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in a hitherto unexplored pseudo-rapidity region of 7.2 < 𝜂 < 8.6, complementary to all the other experiments at the LHC. The experiment is located 480 m downstream of IP1 in the unused TI18 tunnel. The detector is composed of a hybrid system based on an 800 kg target mass of tungsten...
We report about the impact of novel high-precision top-quark pair production 13 TeV measurements and other HF data from ATLAS and CMS on the CT18 global analysis of PDFs. We discuss features of a new top-quark data combination which complements the CT18 baseline. We discuss the impact on the gluon PDF and the extraction of the mass of the top quark in the pole mass approximation.
This...
Precision theory predictions are crucial for interpreting LHC data. In
this talk, we present our public code and predictions for Drell-Yan
production up to the order N3LO, including transverse momentum
resummation up to N4LLp. We discuss the impact of these higher-order
corrections and compare them with experimental data. Furthermore, we
investigate the influence of N3LO parton...
Since 2011 a wide variety of measurements suggest the existence of strong collectivity in collisions of small systems such as proton-proton (pp) and proton-nucleus (pPb) with hydrodynamic models and gluon saturation in the initial state as two theory alternatives showing consistency with the observations. These results raise the question as to whether such phenomena may be present in even...
The production mechanism of quarkonia in $p$+$p$ collisions involves both the perturbative and non-perturbative QCD processes and is a topic of active investigation. Quarkonium production from Color Singlet Model and Color Octet Mechanism is expected to result in different jet activities, i.e., the number of jets associated with quarkonium creation, due to different numbers of emitted hard...
We present a phenomenological analysis of events with two high transverse momentum jets separated by a large 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...
In the Standard Model, the ground state of the Higgs field is not found at zero but instead corresponds to one of the degenerate solutions minimising the Higgs potential. In turn, this spontaneous electroweak symmetry breaking provides a mechanism for the mass generation of nearly all fundamental particles. The Standard Model makes a definite prediction for the Higgs boson self-coupling and...
We present the xFitter project which provides an open-source software framework for the determination of the proton's parton distribution functions and for the interpretation of the physics analyses in the context of Quantum Chromodynamics. The project has been used for a number of analyses performed by the LHC collaborations and theory community, which are summarised briefly. The xFitter...
In order to solve the proton spin problem, the small-$x$ asymptotics of the helicity parton distribution functions (hPDFs) need to be understood. New theory has been developed for the small-$x$ evolution of these hPDFs, able to extrapolate the small-$x$ behaviour of the quark and gluon hPDFs. At large $N_c \& N_f$, these evolution equations close and are amenable to numerical computation. In...
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 HERA 2 at a center of mass energy of 318 GeV and correspond to an integrated luminosity of 347 pb−1. Massless jets, reconstructed using the kT-algorithm in the Breit reference frame, are measured as a function of the...
Transverse Single Spin Asymmetries (TSSAs) in transversely polarized proton-proton collisions ($p^{\uparrow}+p$) have been a fruitful source for studying the spin structure of the proton. In the 2015 RHIC data taking periods, collisions of polarized protons with nuclei ($p^{\uparrow}+A$) were studied for the first time. The measurements of TSSAs in $p^{\uparrow}+p$ and $p^{\uparrow}+A$...
Recent measurements of jet cross sections in proton-proton collisions with the CMS experiment are presented. The measured jet cross sections are corrected for detector effects and compared with the predictions from perturbative QCD, and exploited to derive constraints on parton distribution functions and to mesure alpha_S.
The LHC produces a vast sample of top quark pairs and single top quarks. Measurements of the inclusive top quark production rates at the LHC have reached a precision of several percent and test advanced Next-to-Next-to-Leading Order predictions in QCD. Differential measurements in several observables are important to test SM predictions and improve Monte Carlo generator predictions. In this...
The large integrated luminosity collected by the ATLAS detector at the highest proton-proton collision energy provided by LHC allows to probe the presence of new physics that could enhance the rate of very rare processes in the SM. The LHC can therefore gain considerable sensitivity for Flavour Changing Neutral Current (FCNC) interactions of the top quark. In the SM, FCNC involving the...
The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus on a narrower range of masses: the natural scenario where dark matter originates from thermal contact with familiar matter in the early Universe requires the DM mass to lie within about an MeV to 100 TeV. Considerable...
There have been numerous attempts in the last couple of decades to understand the origin of the unexpectedly large transverse single spin asymmetry ($A_{N}$) of inclusive hadron production at forward rapidities observed in $p^{\uparrow}$+$p$ collisions at different center-of-mass energies ($\sqrt{s}$). The current theoretical framework to explain such a puzzle includes the twist-3...
SeaQuest has measured dimuon events from the interaction of 120 GeV proton beam on liquid hydrogen and deuterium targets with dimuon mass between 2 and 8 GeV. These dimuon events contain both the Drell-Yan process and the charmonium ($J/\psi$ and $\psi^\prime$) production. The first result of the Drell-Yan $(p+d)/2(p+p)$ cross section ratio, based on the analysis of a fraction of the collected...
The Drell-Yan lepton pair productions have been measured to an unprecedented precision level at the LHC. In companion, the theoretical calculations should reach the same level. However, a visible discrepancy among different next-to-next-to-leading order (NNLO) calculations has been discovered by both the CTEQ-TEA group and also by S. Alekhin~\emph{et al.} In this study, we carefully examine...
The LUXE experiment (Laser Und XFEL Experiment) is an experiment in planning at DESY Hamburg using the electron beam of the European XFEL. LUXE is intended to study collisions between a high-intensity optical laser pulse and 16.5 GeV electrons from the XFEL electron beam, as well as collisions between the laser pulse and high-energy secondary photons. This will elucidate quantum...
The remarkably large dataset collected with the ATLAS detector at the highest proton-proton collision energy provided by LHC allows to use the large sample of top quark events to test theoretical predictions with unprecedented precision. Recent highlights are the new measurement of W-boson polarisation in ttbar events single-top quark polarisation, new top-quark mass measurements as well as...
Using the light-front wave functions (LFWFs) overlap representation, we built a theoretical model for the pion state, that parametrizes different pion parton distribution functions. The model is constructed with two sets of parameters, that can be fitted separately by performing two independent fits: one for the collinear, and one for the transverse direction.
At present, we have been able to...
We present the first measurement of two-particle angular correlations of charged particles emitted in high energy $e^+e^-$ annihilation up to $\sqrt{s}=$209~GeV and anti-kT jet energy spectrum and substructure measurements using the archived ALEPH $e^+e^-$ data taken between 1992 and 2000.
The correlation functions are measured as a function of charged particle multiplicity for the first...
For the CTEQ-TEA Collaboration
We present predictions of the cross section of high-energy neutrino-nucleon scattering.
The calculations are based on CT18NNLO parton distribution functions, and their uncertainties. For the highest energies, we extrapolate the PDFs to small x according to several assumptions, which affect the uncertainties at such high energies.
The results can be applied...
While the unpolarized valence quark ($d$ and $u$) distributions are well determined from DIS and $pp/p\bar{p}$ experiments, their sea quark counterparts, $\bar{d}$ and $\bar{u}$, are much less constrained, in particular, near the valence region.
Measurements of $W^+/W^-$ production ratio in $pp$ collider experiments, such as the STAR experiment at RHIC, are sensitive to the $\bar{d}/\bar{u}$...
We study the small-$x$ asymptotics of the flavor non-singlet T-odd leading-twist quark transverse momentum dependent parton distributions (TMDs). While the leading eikonal small-$x$ asymptotics of the quark Sivers function is given by the spin-dependent odderon, we are interested in revisiting the sub-eikonal correction considered by us earlier. We first simplify the expression for the TMD at...
Missing abstract
Presented are the latest updates of the measurement of the azimuthal decorrelation angle and the transverse momentum imbalance between the leading jet and the scattered lepton in deep inelastic scattering with the ZEUS detector at HERA. During the HERA II data-taking period, electrons and positrons collided with protons with a center of mass energy of 318 GeV. The total integrated luminosity...
Accurate theory calculations for neutrino-nucleus scattering rates are essential in the interpretation of neutrino experiments, from oscillation measurements to astroparticle physics at neutrino telescopes. In the deep-inelastic (DIS) regime, neutrino structure functions can be reliably evaluated in the framework of perturbative QCD (pQCD). However, large uncertainties affect these structure...
It is known that the trace anomaly in the QCD energy-momentum tensor $T^{\mu \nu}$ can be attributed to the anomalies for each of the gauge-invariant quark part and gluon part of $T^{\mu \nu}$, and their explicit three-loop formulas have been derived in the $\overline{\rm MS}$ scheme in the dimensional regularization. The matrix elements of this quark/gluon decomposition of the QCD trace...
Correlations between charged particles provide important insight about the 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...
As one of the essential building blocks of ordinary matter, understanding the proton and the strong force that binds its constituents are of crucial importance. At low $Q^2$, the perturbative description of QCD fails, and it is necessary to employ effective theories such as Chiral Perturbation Theory. One way of directly testing these effective theories is the measurement of polarizabilities,...
Recasting phenomenological Lagrangians in terms of SM effective field theory (SMEFT) provides a valuable means of connecting potential BSM physics at momenta well above the electroweak scale to experimental signatures at lower energies. We jointly fit the Wilson coefficients of SMEFT operators as well as the PDFs in an extension of the CT18 global analysis framework, obtaining self-consistent...
A fixed target experiment, HERCULES, similar to HERMES but with 500 times higher electron-nucleon luminosity, at EIC will allow a big advance in hadron physics. The internal target with the polarized hadron beam also has an important physics program. The high intensity photon beam will allow to study photo-production of the $c\bar c$ excited states and recently discovered XYZ states. We will...
Measurements of multiboson production at the LHC probe the electroweak gauge structure of the Standard Model for contributions for anomalous gauge couplings. Processes involving quartic gauge couplings have become experimentally accessible at the LHC. We present recent ATLAS results of vector-boson scattering in the Zgamma channel, where the Z boson decays to neutrinos producing missing...
We review various methods used to estimate uncertainties in quantum correlation functions, such as parton distribution functions (PDFs). Using a toy model of a PDF, we compare the uncertainty estimates yielded by the traditional Hessian and data resampling methods, as well as from explicitly Bayesian analyses using nested sampling or hybrid Markov chain Monte Carlo techniques. We investigate...
Measurements of the longitudinal double-spin asymmetry, $A_{LL}$, by the STAR experiment have contributed significantly to our understanding of the gluon helicity distribution, $\Delta g(x)$, inside the proton. Results from the 2009 inclusive jet measurement, when included into global analyses, indicated substantial positive polarization for gluons with partonic momentum fraction $x$ greater...
It is well known that the small x calculations for the variety of observables are characterized by large corrections at the next-to-leading order (NLO). Resummation procedure for the gluon Green's function was constructed some time ago, which takes into account correct collinear limits, through appropriate subtractions of higher order poles and shifts of the leading poles. In the present work...
Precise and accurate parton distributions are necessary to reach the physics goals of future colliders, from search for new physics to claims on non-perturbative QCD. In the last years, the CT group has expanded the concept of uncertainties in PDF analyses, in particular by including the concept of “sampling accuracy” in contrast to “fitting accuracy.” The exploration of the sampling accuracy...
Coherent electro-production of $J/\psi$ on $^4$He offers a unique opportunity to explore the gluonic component of its matter distribution directly. The gluonic matter form factor of $^4$He can be experimentally accessed by performing a measurement of the reaction $^4 He(e, e' ^4He)J/\psi$ where the $J/\psi$ is reconstructed via missing mass. Such measurement requires the coincidence detection...
The potential discovery of gluon saturation is one of the chief goals of the future Electron-Ion Collider (EIC) program. The Color Glass Condensate (CGC) is an effective field theory (EFT) to characterize this novel regime of nuclear matter. In recent years, tremendous efforts have been carried out to promote the theory and phenomenology of the CGC EFT to higher precision.
We contribute to...
The spin physics program at the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) remains an essential tool in illuminating the internal spin structure of the proton. One major emphasis of the program is the measurement of longitudinal double spin asymmetries $(A_{LL})$ in a number of different final states from collisions of longitudinally polarized protons $(\vec{p} +...
Vector boson scattering is a key production process to probe the electroweak symmetry breaking of the standard model, since it involves both self-couplings of vector bosons and coupling with the Higgs boson. If the Higgs mechanism is not the sole source of electroweak symmetry breaking, the scattering amplitude deviates from the standard model prediction at high scattering energy. Moreover,...
We present a methodology to improve the determination of PDF parametrization, the Fantômas4QCD package. It is achieved through Bézier curve fitting. Thanks to the implementation of our technique in the xFitter package, we have performed a global analysis of the pion PDF — the first analysis to account for the role of the functional form in its uncertainty.
easurements of multiboson production at the LHC are important probes of the electroweak gauge structure of the Standard Model and give constraints on anomalous gauge boson couplings. In this talk we present recent ATLAS measurement of double-polarization in WZ events and highlight the first observation of simultaneous pair-production of longitudinally polarized vector bosons. We also show...
One of the primary goals of the RHIC spin program is to determine the polarized gluon distribution
function, $\Delta g$, within the proton. At the leading order, proton-proton collisions involve a mixture of
quark-quark, quark-gluon, and gluon-gluon scatterings. At RHIC kinematics, the quark-gluon
and gluon-gluon contributions dominate, which makes RHIC an ideal tool to study $\Delta g$....
Heavy quarkonium production of high transverse momentum ($p_T$) in hadronic collisions can be studied in the QCD factorization formalism in both leading and the first subleading power in $1/p_T$ expansion with heavy quarkonium fragmentation functions (FFs) [1]. The scale evolution of quarkonium FFs enables us to resum logarithmically enhanced corrections $\alpha_s\ln(p_T^2/m^2)$ with heavy...
The Liquid Argon Calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic and forward calorimetry in the region from |η| = 1.5 to |η| = 4.9. They also provide inputs to the first level of the ATLAS trigger. After successful period of data taking during the LHC Run-2 between 2015 and 2018 the ATLAS detector entered into the...
Using the spectral representation of the quark propagator we study the Dirac decomposition of the gauge invariant quark propagator, whose imaginary part describes the hadronization of a quark as this interacts with the vacuum.
In light-like axial gauge, we obtain a new sum rule for the spectral function associated to the gauge fixing vector. We then demonstrate the formal gauge invariance...
An overview of the latest NA62 results and the future prospect of the experiment are presented. The NA62 experiment at CERN collected the world’s largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio of the ultra-rare $K^+ \rightarrow \pi^+ \bar\nu \nu$ decay, based on 20 candidates.
The radiative kaon decay $K^+ \rightarrow \pi^0 e^+ \nu...
The lepton-jet momentum imbalance in deep inelastic scattering events offers a useful set of observables for unifying collinear and transverse-momentum-dependent frameworks for describing high energy Quantum Chromodynamics (QCD) interactions. The imbalance in the laboratory frame was measured recently [1] using positron-proton collisions from HERA Run II. With a new machine learning method,...
In the 1970's, Fermilab discovered that $\Lambda$ hyperons are polarized in collisions of unpolarized protons on beryllium. This discovery initiated a 50 year long series of measurements which aimed at solving this $\Lambda$ hyperon polarization puzzle. Although this puzzle remains to be an open question, the self-polarizing feature of $\Lambda$ hyperon has been providing an important...
Experimental uncertainties related to hadronic object reconstruction can limit the precision of physics analyses at the LHC, and so improvements in performance have the potential to broadly increase the impact of results. Recent refinements to reconstruction and calibration procedures for ATLAS jets and MET result in reduced uncertainties, improved pileup stability and other performance gains....
We propose semi-inclusive diffractive deep inelastic scattering (SIDDIS) to investigate the gluon tomography in the nucleon and nuclei at small-x. The relevant diffractive quark and gluon parton distribution functions (DPDF) can be computed in terms of the color dipole S-matrices in the fundamental and adjoint representations, respectively.
The mechanism of the nuclear modifications of parton densities at $x > 0.3$ (EMC effect) observed in DIS experiments remains a major open question in QCD. In inclusive nuclear DIS, $e + A \rightarrow e’ + X$, one observes only the average effect but cannot learn anything about the underlying nuclear interactions. In DIS on the deuteron with spectator nucleon tagging, $e + D \rightarrow e’ + X...
The electron-ion collider (EIC) will be the first collider capable of simultaneously polarizing the spin of both the leptons and hadrons involved. This opens the possibility for measurements of the nucleon spin structure and Parity-Violating (PV) asymmetry in Deep Inelastic Scattering (DIS), for the first time, at a collider setting. At the meantime, it also calls for a complete derivation of...
We calculate [1] the contribution from the $q \bar q g$ state production to the diffractive cross sections in deep inelastic scattering [2,3] at high energy. The obtained cross section is finite by itself and a part of the full next-to-leading order result for the diffractive structure functions. We perform the calculation in exact kinematics in the eikonal limit, and show that the previously...
Hadronic object reconstruction is one of the most promising settings for cutting-edge machine learning and artificial intelligence algorithms at the LHC. In this contribution, selected highlights of ML/AI applications by ATLAS to particle and boosted-object identification, MET reconstruction and other tasks will be presented.
At leading order in positron-proton collisions, a lepton scatters off a quark through virtual photon exchange, producing a quark jet and scattered lepton in the final state. The total transverse momentum of the system is typically small, however deviations from zero can be attributed to perturbative initial and final state radiations in the form of soft gluon radiation when the transverse...
Transverse Λ (uds) polarization observed over four decades ago contradicted expectations from early leading-order perturbative QCD calculations. Recent studies have linked the polarization to the process of hadronization, where hyperon polarization from unpolarized proton-proton and proton-nucleus collisions comes from either including higher-order twist-3 collinear multi-parton correlation...
The gluon density has been observed to increase rapidly with energy, which would eventually violate unitarity. At high energies, however, nonlinear effects start to become important, slowing down the evolution of the gluon density and hence giving rise to gluon saturation. To study this saturation region of QCD one possibility is to look at diffractive processes, as being approximately...
Prospects for inclusive physics studies at the Electron-Ion Collider (EIC) using the EPIC detector are explored. EPIC is currently under rapid development and is expected to be operational from the first day of data taking. Simulations are used to determine the detector acceptance and resolutions, and to estimate some significant sources of systematic uncertainty such as backgrounds and...
The radiation pattern within high energy quark and gluon jets (jet substructure) is used extensively as a precision probe of the strong force as well as an environment for optimizing event generators for nearly all tasks in high energy particle and nuclear physics. While there has been major advances in studying jet substructure at hadron colliders, the precision achievable by collisions...
Muon reconstruction performance plays a crucial role in the precision and sensitivity of the Large Hadron Collider (LHC) data analysis of the ATLAS experiment. Using di-muon Resonances we are able to calibrate to per-mil accuracy the detector response for muons. Innovative techniques developed throughout the Run-2 period and during the collider's shut-down significantly improve the measurement...
We perform a renormalization group (RG) analysis of cold nuclear matter effect on hadron production in semi-inclusive DIS. We focus on the asymptotic limit where the ratio $t = E/(\mu_D^2 L)\rightarrow \infty$, with $E$, $L$, $\mu_D$ being the energy of the jet, the nuclear size, and the inverse interaction range in cold nuclear matter, while the opacity of the medium remains at order unity....
Presentation of the performance of the trigger system of the CMS experiment in Run 2 and the first year of Run 3 of the LHC.
In the high energy heavy ion collisions the ions can act as intense sources of electromagnetic radiation, or in the language of particle physics, photon-photon collisions. This is in particular the case for so--called ultraperipheral collisions (UPCs), where the impact parameter separation of the ions is significantly larger than the range of QCD, with the ions remaining intact after the...
A precise reconstruction of the kinematic variables $x$, $y$ and $Q^2$ is essential for the physics program at the future EIC. Conventional reconstruction methods usually rely on two of the four measured quantities (energy and angle of the scattered electron and hadronic final state) with the resolution of each method depending on the kinematic regime under study, detector performance, and...
In this talk, we present numerical results on diffractive dissociation of virtual photon in the scattering off hadron. The calculation employs the dipole picture of diffractive deep inelastic scattering and solutions to nonlinear Kovchegov-Levin equation, taking into account the running coupling correction and a simple treatment of impact parameter dependence. The (generalized)...
The axial-vector form factors of the light, singly and doubly charmed baryons are investigated in the framework of $SU(4)$ chiral constituent quark model. The axial-vector form factors having physical significance correspond to the generators of the $SU(4)$ group with flavor singlet $\lambda^0$, flavor isovector $\lambda^3$, flavor hypercharge $\lambda^8$ and flavor charmed $\lambda^{15}$...
The CMS experiment at CERN underwent several detector upgrades before the Large Hadron Collider (LHC) Run 3 started in 2022, delivering integrated proton collision luminosity of 38 fb-1 to CMS. LHC will continue with the planned proton-proton and lead ion collision programmes until the Run-3 concludes in 2025.
During High Luminosity operations (2029-2038), LHC is expected to deliver 3000 fb-1...
In this talk, we explore machine learning-based jet and event identification at the future Electron-Ion Collider (EIC). We study the effectiveness of machine learning-based classifiers at relatively low EIC energies, focusing on (i) identifying the flavor of the jet and (ii) identifying the underlying hard process of the event. We propose applications of our machine learning-based jet...
Understanding the detailed structure of energy flow within jets, a field known as jet substructure, plays a central role in searches for new physics, and precision studies of QCD. Many applications of jet substructure require an understanding of jets initiated by heavy quarks, whose description has lagged behind remarkable recent progress for massless jets.
In this work we initiate a study of...
We present here the most recent $BABAR$ results on searches for new particles with masses below the electroweak scale predicted by many extensions of the Standard Model (SM). The results are based on the full data set of about 470 $\text{fb}^{-1}$ collected at the $\Upsilon(4S)$ resonance at the PEP-II collider, including a search for an Axion-Like Particle, $a$, produced in the...
The proposed Electron-Ion Collider (EIC) will utilize high-luminosity high-energy electron+proton ($e+p$) and electron+nucleus ($e+A$) collisions to solve several fundamental questions including searching for gluon saturation and studying the proton/nuclear structure. Due to their high masses ($M_{c,b} > \Lambda_{QCD}$), heavy quarks do not transfer into other quarks or gluons once they are...
New light resonances are a generic signature of models of new phenomena beyond the Standard Model. The diphoton final states provides a clean final state and provides sensitivity to a wide class of such signals, in particular axion-like particles (ALPs). Several results of several such searches, both inclusive and in association with other particles, will be presented.
In operation since 2002, COMPASS is a fixed-target experiment located along the M2 beamline of the CERN SPS. One of the key measurements of its broad physics programme is the investigation of the transverse-momentum and transverse-spin structure of the nucleon, which has been pursued e.g. via measurements of Semi-Inclusive Deep Inelastic Scattering using a 160 GeV/$c$ muon beam and...
We present theoretical results for the associated production of a single top quark and a $Z$ boson ($tqZ$ production) at LHC energies. We calculate higher-order corrections from soft-gluon emission for this process. We compute the approximate NNLO (aNNLO) cross section at LHC energies, including uncertainties from scale dependence and from parton distributions. We also calculate the top-quark...
Solenoidal Large Intensity Detector (SoLID) is a large acceptance, high luminosity device proposed for exploiting the full potential of the Jefferson Lab 12 GeV energy upgrade. The scientific program of SoLID includes three semi-inclusive deep inelastic scattering (SIDIS) experiments with multiple run-group experiments. One of the major tasks of SoLID is to deepen our knowledge of the nucleon...
Lorentz and CPT symmetry in the quark sector of the Standard Model are studied in the context of an effective field theory using ZEUS ep data. Symmetry-violating effects can lead to time-dependent oscillations of otherwise time-independent observables, including scattering cross sections. An analysis using five years of inclusive neutral-current deep inelastic scattering events corresponding...
I will summarize recent progress in a reformulation of TMD factorization that guarantees a parsonic structure description of the small transverse momentum region while matching to standard fixed order collinear factorization at large transverse momentum. The focus will be on applications to semi-inclusive DIS.
Many new physics models predict the existence of resonances decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for Vy, VV, and VH resonances have been performed in various final states. In some of these searches, jet substructure techniques are used to disentangle the hadronic decay products in highly boosted...
In this talk, we will provide an overview of future parity violation deep inelastic scattering (PVDIS) experiments by using the Solenoidal Large Intensity Device (SoLID) at Jefferson Lab (JLab) Hall A. We will obtain data with high statistic and large kinematic coverage for Bjorken $0.25
In this talk, I will present NNLO QCD predictions for several differential distributions of B-hadrons in top-pair events at the LHC. In an extension of previous work, the decay of the produced B-hadron to a muon or a J/ψ meson has been incorporated, allowing us to make predictions for distributions involving those decay products as well. Additionally, a new set of B-hadron fragmentation...
A precision measurement of inclusive neutron spin structure function $g_{2} (x,Q^{2})$, will be run in parallel with SIDIS experiments E12-010-006 (transversely polarized $^{3}$He target) and E12-11-007 (longitudinally polarized $^{3}$He target) by using a Solenoidal Large Intensity Device (SoLID) at Jefferson Lab (JLab) Hall A, as has been approved by JLab PAC48 in 2020. In the proposed...
The identification of jets containing b-hadrons is key to many physics analyses at the LHC, including measurements involving Higgs bosons or top quarks, and searches for physics beyond the Standard Model. In this contribution, the most recent enhancements in the capability of ATLAS to separate b-jets from jets stemming from lighter quarks will be presented. The improved performance originates...
The high-x data from the ZEUS Collaboration are used to extract parton density distributions of the proton deep in the perturbative regime of QCD. The data primarily constrain the up-quark valence distribution and new results are presented on its x-dependence as well as on the momentum carried by the up-quark. The results were obtained using Bayesian analysis methods which can serve as a...
Measurement of near threshold quarkonia photoproduction cross section provides a unique tool to probe gluonic structure inside the nucleon, hence allowing extraction of gluonic form factors and mass radii. $J/\Psi$-007 experiment (E12-16-007) was conducted at Hall-C of the Thomas Jefferson National Accelerator Facility to measure near threshold 2-D differential $J/\Psi$ photoproduction cross...
Various theories beyond the Standard Model predict new, long-lived particles with unique signatures which are difficult to reconstruct and for which estimating the background rates is also a challenge. Signatures from displaced and/or delayed decays anywhere from the inner detector to the muon spectrometer, as well as those of new particles with fractional or multiple values of the charge of...
An intuitive definition of the partonic flavor of a jet in quantum chromodynamics is often only well-defined in the deep ultraviolet, where the strong force becomes a free theory and a jet consists of a single parton. However, measurements are performed in the infrared, where a jet consists of numerous particles and requires an algorithmic procedure
to define their phase space boundaries. In...
Exclusive charmonium photoproduction near threshold opens the door for studying the gluonic properties of the proton: gluonic GPDs, anomalous contribution to the mass of the proton, gravitational form factors, the mass radius of the proton. However, such an ambitious program requires precise measurements to validate the theoretical assumptions that relate the experimental results to the above...
The investigation of the hadrons spin-(in)dependent structure is one of the main goals of the COMPASS experiment at the M2 beamline of the CERN SPS. In particular, azimuthal transverse spin asymmetries provide a clean access to the transverse momentum dependent parton distribution functions (TMD PDFs) of the nucleon, still poorly known. In 2015 and 2018 COMPASS performed measurements of the...
Leptoquarks are predicted by many new physics theories to describe the similarities between the lepton and quark sectors of the Standard Model and offer an attractive potential explanation for the B-physics anomalies observed at LHCb and flavour factories. The ATLAS experiment has a broad program of direct searches for leptoquarks, coupling to the first-, second- or third-generation particles....
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton collisions with per nucleon instantaneous luminosities around $10^{34}$ cm$^{-2}$s$^{-1}$. In this talk we will review the opportunities for measuring standard and anomalous top couplings, both to lighter quarks and to...
The structure of the proton has been studied by measuring the parton distribution function, which is the parton density distribution as a function of the longitudinal momentum of the parton, for long time. In the last few decades, the three-dimensional imaging of nucleon, such as the transverse momentum dependent parton distribution functions (TMDs), has received attention to better understand...
The dependence of the top-quark mass measurement in top-quark production on the parton distribution functions (PDF) is explored through differential mass distributions in $t\bar{t}$ and $t\bar{t}j$ production at the LHC and a future 100 TeV proton-proton collider. The top-quark mass uncertainty is obtained from chi-squared fits to invariant mass distributions from simulations assuming...
We present the new CJ22 global QCD analysis of unpolarized parton distributions The work focuses on the light antiquark sea to incorporate constraints from recent SeaQuest and STAR electroweak boson production data. We make use of a more flexible antiquark imbalance parametrization than in the CJ15 analysis, that in turn is sensitive to mid-rapidity correlations between the $\bar d / \bar u$...
Investigating particle production in various collision systems has become in-
strumental in probing non-perturbative contributions to hadron structure and
hadronization. The LHCb spectrometer’s unique geometry among the LHC de-
tectors along with its particle identification and tracking capabilities allow for
new studies in hadron production to identify how said contributions manifest...
Extractions of the structure functions from inclusive h(e,e′) and d(e, e′) reactions are important for the study of nucleon structure. Such extractions help with constraining the PDF (specially at large Bjorken X), facilitate the studies of Quark Hadron Duality and are important for non-singlet moments calculation as a test of LQCD and many more. Experiment E12-10-002 ran in Hall C at JLab in...
One of the most important unresolved puzzles of the proton is the “proton spin puzzle”. Originally, the proton spin was assumed to be produced only by the valence quark spins, with no contribution from sea quarks or from gluons, and no contribution from orbital angular momentum. However, the contribution of the spins of both quarks and antiquarks to the proton spin have been measured over the...
In recent years, discrepancies from standard-model predictions, which suggest violation of lepton-flavor universality, have emerged in multiple measurements of B meson decays. This talk reports on related, recent Belle II results on lepton-flavour universality and long-lived particles.
{Observables involving heavy quarks can be computed in perturbative QCD in two different approximation schemes: either the quark mass dependence is fully retained, or it is retained only where needed to regulate the collinear singularity. The two schemes have different advantages and drawbacks. In particular, it is known that the structure of large logarithms arising from soft emissions is...
for SoLID Collaboration
The proposed Solenoidal Large Intensity Device (SoLID) in Hall A at Jefferson Lab, will fully utilize the great physics potential of the 12-GeV energy upgrade by combining high luminosities and large acceptance to explore physics needs large statistics. We plan a common
setup to measure JPsi production near threshold, timeline compton scattering and double deeply...
We review the status of the Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode after the publication of the update of the 2012 Conceptual Design Report in [1] and the studies on a joint $eh-hh$ interaction region and experiment in [2]. We also comment on the main technical challenges of these proposals and describe further steps of work towards the Update...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton collisions with per nucleon instantaneous luminosities around $10^{34}$ cm$^{-2}$s$^{-1}$. We review the possibilities for detection of physics beyond the SM in these machines, focusing on feebly interacting particles...
In this talk I will present a recent idea for which one could use the deadcone, a region suppressed by QCD in vacuum to massive kinematic effects, to measure properties of the Quark-Gluon-Plasma, due to in-medium enhancements for massive emitters.
The precision-level reached at collider experiments offer us the unique opportunity to probe the inner structure of the protons and heavy nuclei, described in the language of parton density functions (PDFs), at an unprecedented accuracy. Despite that current determination of the proton PDFs account for nuclear effects and reciprocally the determination of the nuclear PDFs (nPDFs) depend on the...
With the pp collision dataset collected at 13 TeV, detailed measurements of Higgs boson properties can be performed. The Higgs kinematic properties can be measured with increasing granularity, and interpreted to constrain beyond-the-Standard-Model phenomena. This talk presents the measurements of Higgs boson differential and fiducial cross sections with various decay modes, as well as their...
Understanding the spin structure of the proton is of large interest to the nuclear physics community and it is one of the main goals of the spin physics program at the Relativistic Heavy Ion Collider (RHIC). Measurements from data taken by the PHENIX detector with transverse (p$^{\uparrow}$ + p, p$^{\uparrow}$ + Al, p$^{\uparrow}$ + Au) proton polarization play an important role in this, in...
The future electron-ion collider (EIC) will provide the first electron-nucleus collisions for a variety of nuclei species with high luminosity, wide kinematic coverage, and excellent detector resolution, providing new insights into cold nuclear matter effects and transport phenomena. As jets are an accurate proxy of the struck quark that traverses the nucleus, the signature of the nuclear...
Charmonium is one of the most prominent probes used to investigate and quantify the properties of the quark-gluon plasma (QGP) created in ultra-relativistic heavy-ion collisions. Thanks to its larger size and weaker binding energy, the excited $\psi$(2S) state is expected to be affected differently by the nuclear medium with respect to the J/$\psi$ state, therefore the effects of nuclear...
The presence of a non-baryonic Dark Matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If Dark Matter interacts weakly with the Standard Model (SM) it could be produced at the LHC. The ATLAS Collaboration has developed a broad search program for DM candidates in final states with large missing transverse momentum produced in association...
The structure of hadrons relevant for deep-inelastic scattering are completely characterised by the Compton amplitude. A direct calculation of the Compton amplitude provides a complementary way to accessing the structure functions, circumventing the operator mixing and renormalisation issues of the standard operator product expansion approach.
In this talk, we focus on the QCDSF/UKQCD...
The Good-Walker paradigm is widely used for studying ultra-peripheral collisions (UPCs) and underlies much of the exclusive photoproduction/electroproduction program at the future electron-ion collider (EIC). It relates the cross-section for coherent photoproduction, $d\sigma/dt$ to the transverse distribution of scattering centers in a target, and ties the incoherent cross-section to...
The production of quarkonium, a bound state of a heavy quark (charm or bottom) and its corresponding antiquark, can be decomposed in a hard-scale perturbative production of the quark-antiquark pair, and its subsequent hadronization into the bound state which can only be described by non-perturbative models, such as NRQCD. In hadronic collisions, the underlying event activity, usually...
Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. This talk will present the latest results from SUSY searches conducted by the ATLAS experiment. The searches target multiple final states and different assumptions about the decay mode of the produced SUSY particles,...
We perform the first simultaneous extraction of di-hadron fragmentation functions (DiFFs) and transversity PDFs using data from single-inclusive annihilation (SIA) in electron-positron collisions, semi-inclusive DIS, and proton-proton collisions. In particular, we include new SIA data from Belle that provides, for the first time, experimental constraints on the unpolarized DiFFs, as well as...
Photon-induced reactions in ultra-peripheral collisions (UPCs) of heavy nuclei at the LHC have been studied using the ALICE detector for several years. The ALICE detector can measure the photoproduction cross section for vector mesons at various rapidities, centre-of-mass energies and
collision systems. Beyond the recent ALICE studies of the rapidity and momentum transfer dependence of...
Inclusive Diffractive Deep Inelastic Scattering ($ep \rightarrow eXp$) is mediated by the $t$-channel exchange of net-colourless strongly interacting objects related to mesons and to the pomeron. The high performance beam-line proton spectrometers and central detector components that are included in detector designs for the future Electron Ion Collider will lead to measurements of this process...
We present the first physical-continuum limit $x$-dependent nucleon gluon distribution from lattice QCD using the pseudo-PDF approach, on lattice ensembles with $2+1+1$ flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration. We use clover fermions for the valence action on three lattice spacings $a \approx 0.9$, 0.12 and 0.15~fm and three pion masses $M_\pi \approx...
The transversity distribution function, $h_1^{q}(x)$, where $x$ is the longitudinal momentum fraction of the proton carried by quark $q$, encodes the proton's transverse spin structure at the leading twist. Extraction of $h_1^{q}(x)$ is difficult because of its chiral-odd nature. However, it can be coupled with a spin-dependent interference fragmentation function (FF), $H_1^{\sphericalangle,...
Belle II offers unique possibilities for discovering and interpreting exotic multiquark bound states to probe the fundamentals of QCD. This talk presents recent results on a unique data set collected at energies above the $\Upsilon$(4S), including searches for the hidden bottom transition between Y(10750) and $\chi_{bJ}$.
High energy photons originating from the electromagnetic field of ultrarelativistic lead nuclei can interact with the other lead beam. These reactions are studied in the ultra-peripheral heavy ion collisions to probe the physics of strong interactions. The analysis of dipion and dikaon photoproduction was carried out using the ALICE 2015 Pb-Pb data at center-of-mass energy $\sqrt{s_{NN}}=5.02$...
This talk presents recent results about heavy flavor spectroscopy and exotic hadrons at CMS.
Parton distribution functions (PDFs) are defined from matrix elements of operators separated along the light cone, which cannot be determined directly from calculations performed in Euclidean space. Despite this, various approaches for extracting information on PDFs from lattice QCD have been developed, all of which involve a factorization of the lattice QCD computed matrix element with...
The Precision Proton Spectrometer (PPS) is a new subdetector of CMS introduced for the LHC Run 2 and will continue to operate during LHC Run 3. PPS provides a powerful tool for the advancement of BSM searches. The talk will present recent results obtained with the PPS subdetector illustrating the unique sensitivity achieved using proton tagging.
The Belle experiment at the asymmetric e+e- collider KEKB provides a large data set not only for the exploration of flavor physics but also for precision QCD studies. The clean initial state is particularly well suited to investigate the process of high-energetic partons fragmenting into final state hadrons. This talk will report the results of recent measurements sensitive to fragmentation...
Multi-jet rates at hadron colliders provide a unique possibility for probing Quantum Chromodynamics (QCD), the theory of strong interactions. By comparing theory predictions with collider data, one can directly test perturbative QCD, extract fundamental parameters like the strong coupling and search for physics beyond the Standard Model. Recent developments enabled lifting three-jet...
Baryon number is a strictly conserved quantity in QCD. Conventionally it is assumed to be split between the three valence quarks, but the baryon junction has also been proposed as a way of constructing a gauge-invariant baryon wave function. The baryon junction is a nonperturbative Y-shaped configuration of gluons that is connected to all three valence quarks and carries the baryon number. ...
We present a lattice QCD calculation of the unpolarized isovector quark parton distribution function (PDF) of the proton utilizing a perturbative matching at next-to-next-leading-order (NNLO). The calculations are carried out using a single ensemble of gauge configurations generated with $N_f$ = 2+1 highly improved staggered quarks with physical masses and a lattice spacing of a =0.076 fm. We...
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 searches for physics beyond the standard model enabled by photon-photon processes in both di-tau and di-photon final states. The tau-pair production measurements can constrain the tau lepton's anomalous magnetic dipole moment (g-2), and...
Exclusive coherent and incoherent \jpsi photoproduction in Au$+$Au ultra-peripheral collisions (UPC) are measured at
$\sqrt{s_{_\mathrm{NN}}}=200$ GeV using the STAR detector.
Measurements of the differential cross sections as functions of rapidity $y$ and \ptSquare $\approx -t$ of the $J/\psi$ are reported.
Results for different combinations of neutron emission, detected in zero degree...
The fact that lattice QCD is defined in a finite-Euclidean spacetime, prohibits direct access of inclusive scattering observables from lattice QCD. In principle, one can envision determining such quantities from real-time computations, such as those that may be eventually performed using quantum computers. Looking forward into the future, in this talk I outline a possible pathway towards...
The Large Hadron Collider beauty (LHCb) experiment provides an opportu-
nity to study hadronization processes, how particular hadrons are formed from scattered quarks and gluons (partons), in the forward region, 2 < η < 5. Going beyond traditional collinear non-perturbative fragmentation functions (FFs), transverse-momentum-dependent (TMD) FFs provide multidimensional information on the...
I shall discuss complete calculation of one-loop triple-collinear splitting operators in QCD for all five channels. The results are accurate to second order in dimensional-regularization parameter. This accuracy is sufficient for use in subtraction schemes at next-to-next-to-next-to leading order.
In this talk, we will discuss the physics prospects of photon-induced measurements using the high granularity FoCal detector to be installed at the ALICE experiment, covering the pseudorapidity interval $3.4 \leq \eta \leq 5.8$. This new detector, scheduled to be in operation from Run 4, will explore the small Bjorken-$x$ physics region in an unprecedented way. In this region the gluon...
The High-Luminosity Large Hadron Collider (HL-LHC) is expected to deliver an integrated luminosity of up to 3000 fb-1. The very high instantaneous luminosity will lead to about 200 proton-proton collisions per bunch crossing (“pileup”) superimposed to each event of interest, therefore providing extremely challenging experimental conditions. Prospects for SM measurements and searches for beyond...
This talk presents recent results about heavy flavor production at CMS.
Factorization theorems have long been a successful and elegant tool to describe and interpret hadronic structure. The early parton model picture, first developed by Feynman, has now been generalized past the leading power description of inclusive processes like deep inelastic scattering (DIS) to semi-inclusive ones like SIDIS and much more. However, a consistent description of both collinear...
We present the latest results of the MAP collaboration about the extraction of Transverse-Momentum-Dependent (TMD) distributions at the N$^3$LL logarithmic accuracy in the resummation of q$_T$-logarithms. Firstly, we present the most recent extraction of unpolarized quark TMD parton distribution functions (TMD PDFs) in the proton and fragmentation functions (TMD FFs) from a global fit of...
Artificial Neural Networks (ANNs) are quickly becoming an invaluable tool for information extraction and modeling. An unbiased ANN model can be built to make predictions of the Transverse Momentum-dependent Distributions (TMDs) based on global fit to Semi Inclusive Deep Inelastic Scattering (SIDIS) and Drell-Yan (DY) data. A preliminary analysis will be presented on the extraction of the...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton collisions with per nucleon instantaneous luminosities around $10^{34}$ cm$^{-2}$s$^{-1}$. In this talk we review the opportunities that these proposals offer for the determination of the structure of the proton. The...
The splitting functions determine the scaling violations of deep-inelastic scattering structure functions and govern the evolution of Parton densities. A determination of N3LO Parton densities requires the knowledge of 4-loop splitting functions. It is important to find efficient methods to compute 4-loop splitting functions. The method of computing the off-shell matrix elements with a...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton (nucleus) collisions with per nucleon instantaneous luminosities around $10^{34}$ ($10^{33}$) cm$^{-2}$s$^{-1}$. In this talk we will review how the study of diffraction, both inclusive and exclusive, will provide...
Photonuclear interactions are studied in ultra-peripheral p-Pb collisions with the ALICE experiment, where the photon radiated by a Pb nucleus probes the gluon density of the proton at low Bjorken-x. The exclusive J/𝜓 photoproduction cross section 𝜎(𝛾+𝑝→𝐽/𝜓+𝑝) is expected to follow a power law trend as x decreases, but it should deviate from this trend at low x due to gluon saturation. In...
In this talk we discuss on recent result on massless and massive Wilson
coefficients in the polarized and unpolarized case up to 3-loop order.
This includes the gluonic massive operator matrix element $A_{gg}$
which enters the definition of the Variable-Falvor-Number-Scheme, and the
calculation of the unpolarized and polarized massless Wilson coefficients.
While the calculation of the...
We have calculated the $n_f^2$ and $n_f^3$ contributions to the flavour non-singlet structure functions $F_2$ and $F_L$ in inclusive deep-inelastic scattering at the fourth order in the strong coupling $\alpha_s$. The coefficient functions have been obtained by computing a very large number of Mellin-N moments using the method of differential equations, and then determining the analytic forms...
The Large Hadron-electron Collider and the Future Circular Collider in electron-hadron mode [1] will make possible the study of DIS in the TeV regime providing electron-proton (nucleus) collisions with per nucleon instantaneous luminosities around $10^{34}$ ($10^{33}$) cm$^{-2}$s$^{-1}$. In this talk we review the opportunities for the determination of the nuclear parton structure at small $x$...
We describe the status of the ATLAS Forward Proton Detectors (AFP) in Run 2 and the outlook for Run 3 analyses.
The performance as well as Run 3 improvements of detector subsystems are discussed in detail. This includes the Tracking and Time-of-Flight Detectors, the electronics, the trigger, the readout, detector control and data quality monitoring.
Additionally, key physics results from the...
In the light-front quark-diquark model (LFQDM), the higher twist generalized transverse momentum dependent distribution (GTMD) $F_{31}(x, {\bf p_\perp^2},{\bf \Delta_\perp^2})$ for the proton has been analyzed. We have derived the GTMD overlap equation by the analysis of GTMD correlator, employing the light-front wave functions in both the scalar and vector diquark situations. With the...
The factorization theorem plays an important role in the analysis of high energy quantum chromodynamic (QCD) processes, separating the nonperturbative hadronic interaction into the universal parton distribution functions (PDFs) and fragmentation functions (FFs) and the process-dependent interactions into short distance perturbative calculations, with any interference power suppressed. With a...
The purpose of the ALFA detector is to measure protons scattered at very small angles. ALFA aims to study elastic and diffractive events, exclusive production and photon-induced interactions. In LHC Run 2, ALFA participated in the ATLAS high-luminosity data taking, as well as, special runs with reduced luminosity and dedicated optics.
This report presents the status of the ALFA detector...
The large dataset of about 3 ab-1 that will be collected at the High Luminosity LHC (HL-LHC) will be used to measure Higgs boson processes in detail. Studies based on current analyses have been carried out to understand the expected precision and limitations of these measurements. The large dataset will also allow for better sensitivity to di-Higgs processes and the Higgs boson self coupling....
Experimental and theoretical aspects of current W boson mass, status and future prospects for theory calculations and measurements.
One of the main tasks for modern QCD theory for colliders is to provide computations of the short-distance factors (typically, partonic cross sections) at high orders of perturbation theory. The past two decades have seen tremendous progress on the development of the theoretical framework needed to match the accuracy reached by the experiments. In this talk I will review the status and latest...
The hotspot model has proven to be an efficient tool to study coherent and incoherent diffraction HERA data by modeling the initial state fluctuations of the gluon density of the proton. The hotspot model in its original form is a non-perturbative model applicable for low momentum transfer and underestimates the incoherent cross section in orders of magnitude when extended for large momentum...
With the recent computation of cross-section calculations up to the third order in perturbative QCD, and the appearance of the first PDF fits at N3LO (albeit only approximately), it becomes interesting to study if the improved precision is accompanied by an analogue improvement in accuracy in describing experimental data.
To this aim, we calculated the theoretical total cross-sections for...
The first measurement of two-particle angular correlations of charged particles emitted in high energy $e^+e^-$ annihilation up to $\sqrt{s} = 209$~GeV is presented, using data collected with the ALEPH detector at LEP between 1992 and 2000. The correlation functions are measured over a broad range of pseudorapidity and full azimuth as a function of charged particle multiplicity for the first...
