The modelling of Minimum Bias (MB) is a crucial ingredient to learn about the description of soft QCD processes and to simulate the environment at the LHC with many concurrent pp interactions (pile-up).
We summarise the ATLAS minimum bias measurements with proton-proton collision at 13 TeV center-of-mass-energy at the Large Hadron Collider.
Exclusive diffraction results from CMS
The LHC-forward (LHCf) experiment, situated at the LHC accelerator, has measured neutral particles production in a very forward region (pseudo-rapidity $\eta > 8.4$, including zero degree) in proton-proton and proton-lead collisions.
The main purpose of the LHCf experiment is to test the hadronic interaction models used in ground based cosmic rays experiments to simulate cosmic rays induced...
Collider experiment is an efficient way to verify and improve the hadronic interaction models. Abundant of energy flow in the forward region of the collisions are believed to have large influence to the development of air-shower. LHCf is the experiment dedicate to verify the hadronic interaction models by measuring the forward neutral particle production at the LHC. According to the LHCf...
An extensive programme of diffractive studies was carried out by the H1 and ZEUS collaborations using data from the full 15 year lifetime of the HERA electron-proton collider. This talk will review the results from that programme, particularly where they relate to studies at the LHC. The main topics will be quasi-elastic vector meson photoproduction and electroproduction and soft and hard...
Using a phenomenological approach, I investigate the importance
of higher twist corrections to parton processes in high energy
proton-proton scattering.
Coulomb-Nuclear Interference (CNI) mechanism of single-spin asymmetry in small-angle elastic scattering of polarized protons offers a unique way to measure the spin-flip part of the Pomeron. We analyze recent data from RHIC on single-spin asymmetry in pp and pA elastic scattering in the CNI region, aiming at determination of $r_5$, the fractional spin-flip component of the hadronic elastic...
The color dipole approach enables us to evaluate the diffractive particle production observables beyond the concept of diffractive factorisation. In this talk, I will overview the current status of research in this direction and present preliminary results on single-diffractive non-Abelian Bremsstrahlung processes with di-jets and quarkonia final states.
At the LHC, collision final states have been studied principally in the central kinematic region, where, generally, perturbative QCD can be used. However, there is rich soil for measurements in the forward direction, which probe the nucleon structure at small Bjorken-x values where saturation effects are expected.
A full set of saturation probes in the forward rapidity region of ALICE will be...
Nuclear emulsion is high sensitive photographic film used for detection of three-dimensional trajectory of charged particles. These trajectories are recorded as tracks consist of chain of silver particles. The size of silver particles is less than 1 micrometer, so that nuclear emulsion has sub-micron three-dimensional spatial resolution, which gives us an angular resolution of a few mrad in...
Nuclear emulsion records all trajectories of charged particles with sub-micron spatial resolution and specializes in detailed measurements of topologies of various particle interactions. Remarkable increase in the readout speed of the emulsion scanning system has realized data acquisition from the full volume of emulsion chambers and the minimum-biased analysis. In this talk, we report the...
The hadronic interaction model at 1--10 GeV for the calculation of atmospheric neutrino is studied with the atmospheric muon data in 1 GeV -- 1 TeV for vertical directions and in 100 GeV -- 10 TeV for horizontal directions. Some preliminary result on the calculation of atmospheric neutrino flux are also shown.
RHICf is an experiment to measure neutral particles emitted around the zero degree in the 510GeV proton-proton collisions at RHIC. The detector was installed in the interaction point of STAR and physics operation was carried out from 25 to 27 June, 2017. Introduction to the experiment and the first results are presented in the workshop. Forward particle cross sections are useful to...
Since single spin asymmetry(AN) was measured, AN has been useful physical observable value in searching intrinsic structure of nucleon and interactions among nucleons. In case of forward region, One Pion Exchange model and Reggeon exchange model have shown good consensus with AN from inclusive neutron measurement via PHENIX Zero Degree Calorimetry(ZDC) at RHIC. One of goals in RHICf experiment...
Evidence for GeV Cosmic Rays from White Dwarfs in the Local Cosmic Ray Spectra and in the Gamma-ray Emissivity of the Inner Galaxy
We propose to constrain the gluon Wigner distribution in the nucleon by studying the exclusive diffractive dijet production process in ultraperipheral proton-nucleus collisions (UPCs) at RHIC and the LHC. Compared to the previous proposal to study the same observable in lepton-nucleon scattering, the use of UPCs has a few advantages: not only the cross section is larger, but also the...
We review and update our current understanding of quarkonium and heavy-meson production at forward rapidities in the CGC framework.
I am going to report on study the production of forward di-jets in proton-lead and proton-proton collisions at the Large Hadron Collider. Such configurations, with both jets produced in the forward direction, impose a dilute-dense asymmetry which allows to probe the gluon density of the lead or proton target at small longitudinal momentum fractions. Even though the jet momenta are always much...
We report a current status of a new Monte-Carlo event generator for high energy
nuclear collisions based on the Pythia8 event generator:nPythia.
Nuclear collisions are modeled by the successive nucleon-nucleon
(NN) collisions based on the Glauber type model.
For each NN collision, we use Pythia8, but taking account
of conservation laws for a whole system.
It is found that incoherent sum of NN...
$\ $In high-energy heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and at the Large Hadron Collider (LHC) strongly interacting matter is produced in which quarks and gluons are deconfined. The ALICE experiment studies the properties of this so-called Quark-Gluon Plasma at the LHC. However, there are still many unanswered questions with regards to the initial state of these...
GenEx - a new Monte Carlo tool for exclusive light meson production
will be presented. This tool is being developed by our group and is
complementary to the existing MC generators. The generator is
self-adapting to the provided matrix element and acceptance cuts. The
modular structure of the code, designed for easy process
implementation, will be shown. As an example, the exclusive...
Forward Physics with tagged protons at the LHC: from the Pomeron structure to the search for quartic anomalous couplings
The CMS-TOTEM Precision Proton Spectrometer allows the extension of the LHC physics program by detecting scattered protons in the very forward region of CMS. The detector includes tracking and timing stations installed along the beam pipe at $\sim 210$ m from the CMS interaction point on both sides. The tracking detector is presently constituted by one silicon strip and one silicon 3D pixel...
The installation of the second arm of the Atlas Forward Proton (AFP) detector system has been completed in time for the 2017 running of LHC, opening the road for measurements of processes with two forward protons. This talk will describe the status of the project, its rich physics programme, as well as first perfomance and measurements with beams. Further ATLAS results with just one or without...
We present the calculation of the impact factor for the γ(∗)→qq¯¯γ(∗)→qq¯ transition with one loop accuracy in arbitrary kinematics. The calculation was done within Balitsky’s high energy operator expansion. Together with our previous result for the γ(∗)→qq¯¯gγ(∗)→qq¯g Born impact factor it allows one to derive cross sections for 2- (one loop) and 3-jet (Born) difractive electroproduction. We...
