Recent results from the H1 and ZEUS collaborations will be presented. Topics will include cross sections for prompt photon production, J/psi and psi' production and rho and rho' production, a study of collective effects, and a fit to diffractive DIS data.
Inclusive single diffractive dissociation (pp->pX) is studied using data collected by the ATLAS experiment at the LHC. The intact proton is reconstructed and measured in the ALFA forward spectrometer, while charged particles from the dissociative system (X) are reconstructed and measured using the ATLAS inner tracking detector and calorimeters. Differential cross sections are presented as a...
Here we present overview of the results on diffractive and exclusive measurements with CMS only and CMS-TOTEM data.
Photon-induced processes in proton-proton interactions have become
recently very topical. The large energy at the LHC, when combined with
relatively large luminosity at run II, allows starting the exploration of such processes.
We discuss the production of $W^+ W^-$ pairs and $t \bar t$ quark-antiquark pairs in proton-proton collisions induced by two-photon fusion including, for
a first...
We present a partonic picture for diffractive onium - nucleus scattering from which the distribution of rapidity gap in a certain kinematic region can be deduced. This picture allows us to draw a parallel between diffractive dissociation and the genealogy of partonic evolution, the latter being essentially similar to a branching - diffusion process. In particular, we show that the rapidity ...
We outline a novel search strategy for scalar leptons and dark matter targeting a key area of phase space favoured by cosmological observations and muon g-2 anomalies. This region is experimentally challenging and currently inaccessible at the LHC. By using the LHC protons to source photon-photon interactions and detecting the intact protons with forward detectors, recently installed by the...
We analyze in detail the LHC prospects at the center-of-mass enery of 14 TeV for charged electroweakino searches, decaying to leptons, in compressed supersymmetry scenarios, via exclusive photon-initiated pair production. This provides a potentially increased sensitivity in comparison to inclusive channels, where the background is often overwhelming. We pay particular attention to the...
P. Lebiedowicz, O. Nachtmann and A. Szczurek
Last year results of the TOTEM collaboration suggest
that the odderon exchange can be responsible for a disagreement
of theoretical calculations and the TOTEM data (recent Nicolescu papers)
for elastic proton-proton scattering. Similar conclusion can be drawn when
comparing recent $p p$ result for $\sqrt{s}$ = 2.74 TeV with the Tevatron...
We will present new results for the Pomeron and Odderon Slope, Intercept and Wave functions using Infra-red regulator, in particular the Wilsonian ERG ideas.
We will present the first results and the physics prospects from the CMS Precision Proton Spectrometers namely the observation of exclusive dileptons at high mass, and the search for quartic anomalous couplings and axion like particles at high masses at the LHC in the CMS collaboration.
The existence of a deconfined state of matter (quark-gluon plasma, QGP)
in heavy-ion collisions have been shown in large experiments in the past
decades. However, it was the CERN LHC Run-2 data taking period that
really allowed for precision measurements aimed at the understanding of
its properties in detail. The excellent particle identification
capabilities of the ALICE experiment...
his talk covers the results on photoproduction in pPb and PbPb collision with CMS experiment
Predictions have been compiled for the $p+$Pb LHC runs, focusing on production of hard probes in cold nuclear matter [1-3]. These predictions were first made for the $\sqrt{s_{_{NN}}} = 5.02$ TeV $p+$Pb run [1] and were later compared to the available data in Ref.~[2]. A similar set of predictions were published for the 8.16~TeV $p+$Pb run in Ref.~[3].
In this talk, we review a selection...
Using previously described functional techniques for some non–perturbative, gauge invariant, renormalized QCD processes, a simplified version of the amplitudes — in which forms akin to Pomerons naturally appear — provides fits to ISR and LHC–TOTEM pp elastic scattering data. Those amplitudes rely on a specific function φ(b) which describes the fluctuations of the transverse position of quarks...
Bogdan Pawlik for the STAR Collaboration
We report the first results on differential, total and elastic cross sections in proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) at $\sqrt{s}=200$ GeV. The data were obtained with the Roman Pot Detector subsystem of the STAR experiment. The data used for this analysis cover the four-momentum transfer squared ($t$) range $ 0.045...
The TOTEM experiment at the interaction point 5 of the LHC has measured the total, elastic and inelastic proton-proton cross sections in a centre-of-mass energy range from 2.76 to 13 TeV, mostly in dedicated fills with special beam optics.
Most recently, TOTEM has performed a series of detailed measurements at $\sqrt{s}$ = 13 TeV. The total, elastic and inelastic proton-proton cross-sections...
I will discuss exclusive J/psi and eta_c production in electron-proton collisions, mediated in the lowest order QCD by 2- and 3-gluon exchanges. In the recently developed model, we relate the amplitudes for those processes to the correlators of the quark current in the light-cone wave function of the proton. We obtain new estimates of eta_c cross-section at the energy W~10 GeV.
Proton-proton differential and total cross sections provide information on the energy dependence of proton shape and size. This will be discussed both from a phenomenological and theoretical perspectives. This will include the role of pion cloud, (e.g., Jenkowsky, Szanyi and Tan, hep-ph:1710.10594), new phenomenology based on AdS/CFT, (e.g., Watanabe, et al., hep-ph:1901.09564), and the...
Theoretical calculations for jet substructure observables with accuracy beyond leading-logarithm have recently become available. Such observables are significant not only for probing a new regime of QCD at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many searches for physics beyond the Standard Model. In this talk, we present...
Precision measurements of the production cross sections of W and Z bosons in proton-proton collisions provide stringent tests of perturbative QCD and yield important information about the parton distribution functions (PDFs) for quarks within the proton. We report measurements of fiducial integrated and differential cross sections for inclusive W+, W- and Z boson production, analysed in the...
The lepton angular distributions of the Drell-Yan process in fixed-target experiments and the Z-boson production at colliders are investigated by an intuitive geometric approach together with perturbative QCD calculations. We show that the main features of the kinematic dependencies of the lepton angular distributions can be well understood in the geometrical approach. Implications of this...
The IceCube Neutrino Observatory, located at the South Pole, is a
Cherenkov detector that continuously monitors a cubic kilometer of instrumented glacial ice for neutrino interactions in the sub-TeV to EeV energy range. Its
primary design goal is the study of powerful astrophysical objects
that could act as natural particle accelerators and thus as sources of
(ultra) high energy cosmic...
Nucleon structure has been a major subject of study in the recent decades. Its composition in terms of quarks and gluons and how it depends on the momentum, position and spin has been one of the main fields of research of the COMPASS Collaboration. The COMPASS experiment is in operation at CERN since 2002 and presently approved to continue at least till 2021. During these years several...
The Relativistic Heavy Ion Collide (RHIC) is the only polarized (both longitudinal and transverse) proton collider in the world, capable of reaching center of mass energies of √s = 200 GeV and 510 GeV. At these energies, the dominating processes are quark-gluon and gluon-gluon scattering, allowing the major RHIC experiments probe partons inside the nucleus. The RHIC spin program has...
The 2015 U.S. Nuclear Physics Long-Range Plan recommended the realization of an electron-ion collider (EIC) as the next large construction project in the United States. A U.S.-based EIC has also recently been endorsed by the U.S. National Academy of Sciences. In their report released in July 2018 they find the scientific case “compelling, unique, and timely”. With its high luminosity, wide...
Jets produced in the pseudo-rapidity range, $-1.0 < \eta < 1.0$, from $pp$ collisions at RHIC kinematics are dominated by quark-gluon and gluon-gluon scattering processes. Therefore the longitudinal double-spin asymmetry $A_{LL}$ for jets is an effective channel to explore the longitudinal gluon polarization in the proton. At STAR, jets are reconstructed in full azimuth, from the...
An ongoing program of evaluating transverse momentum-dependent (TMD)
observables in hadrons within Lattice QCD is reviewed, summarizing
recent progress with respect to several challenges faced by such
calculations. These lattice calculations are based on a definition of
TMDs through hadronic matrix elements of quark bilocal operators,
including an appropriate gauge connection between the...
It is well known that the DIS and Drell-Yan processes are two key experimental approaches to reveal the partonic structure of nucleons via either the space-like or time-like virtual photons. Conventionally the nucleon GPDs are explored by DVCS and DVMP processes using lepton beam. In this talk I will introduce a complementary measurement of nucleon GPDs by the exclusive pion-induced Drell-Yan...
We present the new CTEQ-TEA global analysis of Quantum Chromodynamics (QCD). In this analysis, parton distribution functions (PDFs) of the nucleon are determined within the Hessian method at the next-to-next-to-leading order (NNLO) in perturbative QCD, based on the most recent measurements from the Large Hadron Collider (LHC) and a variety of world experimental collider data. Next-to-leading...
We present fits to determine parton distribution functions (PDFs) using top-antitop, inclusive W/Z-boson, as well as W+ and W- boson production measurements in association with jets from ATLAS, in combination with deep-inelastic scattering data from HERA. The ATLAS W and Z boson data exhibit sensitivity to the valence quark distributions and the light quark sea composition, whereas the...
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 recently for a number of analyses performed by the LHC collaborations and theory community, which are summarized briefly. The...
Here we present overview of the recent results on the Soft QCD and Double Parton Scattering
Measurements of multiple parton scattering in proton-proton collisions provide insight into the structure and long-range low-momentum scale interactions of the proton. In this talk we present two recent measurements using proton-proton collision data collected by the ATLAS experiment. The first measurement determines the double-parton scattering contribution to four-lepton events at √s=8 TeV....
We discuss $\gamma^* \gamma^* \to \eta_c(1S)\, , \,\eta_c(2S)$ transition form factor
for both virtual photons. The general formula is given.
We use different models for the $c \bar c$ wave function
obtained from the solution of the Schr\"odinger equation for
different $c \bar c$ potentials: harmonic oscillator, Cornell,
logarithmic, power-law, Coulomb and Buchm\"uller-Tye.
We compare our...
Quantifying the differences between nuclear and hadronic collisions, phenomenological known as medium modification due to multiple scatterings between the hard probe and medium, can provide a solid baseline for unambiguous identification of the fundamental medium property. In this talk, we consider parton propagation in cold nuclear matter within the framework of high twist expansion, which...
Parton distribution functions (PDFs) are mandatory inputs in high energy scattering and also play an important role in searching for new physics at high energy. The recently proposed large momentum effective theory allows one to access the PDFs from first principle Lattice QCD. In this talk, I will discuss the recent progresses on quasi-PDFs, in particular on the gluon quasi-PDFs.
to be provided by Richard Brower.
Sign problem is an obstacle in lattice studies of supersymmetric gauge theories including a numerical verification of AdS/CFT. Tensor network is an attractive approach to overcome this problem. We present a numerical result of the tensor network approach in two-dimensional complex phi^4 theory with finite chemical potential.
Abstract:
For long time, gravity is used for learning dynamical aspects of QCD, because holography connects gravity and QFT. In this talk, I will review the opposite direction: learning about gravity from QFT. In particular, I will focus on the quantum nature of black hole. Techniques developed among QCD-practitioners turned out to be useful for quantum gravity. At the same time, quantum...
The production of prompt isolated photons at hadron colliders provides stringent tests of perturbative QCD and can be used to evaluate probability density functions of partons in the proton. In this talk, we present the measurements of the isolated-photon plus two jets and the inclusive isolated-photons cross sections, both measured using proton-proton collision data collected by the ATLAS...
Measurements of weak boson production in association with jets are presented. First, differential cross sections for Z-boson and W-boson production in association with jets are presented, with the measurements performed using proton-proton collisions at √s = 8 TeV. The data are compared to next-to-leading order QCD calculations and predictions from a variety of different parton distribution...
A measurement of the ratio of the real to imaginary elastic scattering amplitude at zero momentum transfer (the rho parameter), and the total proton-proton scattering cross section are presented at √s=8 TeV. The measurement is made using the differential elastic cross section as a function of the Mandelstam momentum transfer variable, which is reconstructed using the ALFA forward spectrometer...
