Particle and Astroparticle Physics, Gravitation and Cosmology: Predictions, Observations and New Projects

The following sections are included:

• PREFACE
• ORGANIZING COMMITTEES
• CONTENTS

The 40 years old standard model, the theory of particle physics, seems to describe all experimental data very well. All of its elementary particles were identified and studied apart from the Higgs boson until 2012. After a brief introduction to the basics of the Brout-Englert-Higgs (BEH) mechanism of spontaneous symmetry breaking this lecture overviews the search for the Higgs-boson at LEP and its observation at the Large Hadron Collider.

The most recent results of Standard Model physics studies in proton-proton collisions at 7 TeV and 8 TeV center-of-mass energy based on data recorded by ATLAS and CMS detectors during the LHC Run I are reviewed. This overview includes studies of vector boson production cross section and properties, results on V+jets production with light and heavy flavours, latest VBS and VBF results, measurement of diboson production with an emphasis on ATGC and AQGC searches, as well as results on inclusive jet cross sections with strong coupling constant measurement and PDF constraints. The outlined results are compared to the prediction of the Standard Model.

This paper summarises the latest experimental results on top quark physics by the ATLAS Collaboration using LHC pp collisions data corresponding to an integrated luminosity of 4.7 fb⁻¹ at and 20.3 fb⁻¹ at . Results presented here cover different aspects of the top quark studies including searches for physics beyond the Standard Model.

Questions to discuss:

• Does finding the 125 GeV Higgs boson exclude all other possible mass creation mechanisms?
• Is this the SM Higgs boson? How much space is left for extensions (like the SUSY Higgs sector)?
• How special is the 125 GeV mass in view of the top mass? (What happens to the future of particle physics if the EW vacuum is stable?)
• How does the 125 GeV Higgs boson orient the plans for the next colliders, ILC and/or FCC?
• Is there any role of the Higgs boson in the evolution of the universe?

The accumulation of 20 fb⁻¹ of data at 8 TeV has been a unique window for Supersymmetry searches at the LHC, allowing the CMS collaboration to search for specific supersymmetric particles. This article covers the search for strong and electroweak production of supersymmetric particles in a variety of decay modes as well as channels. It focuses on the search for squarks of 3^rd generation, the lightest scalar top (stop) which might be the only observable in the case where Supersymmetry is realized in nature.

The searches for non-SUSY physics beyond Standard Model are presented, using the 7 TeV and 8 TeV data at LHC. The CMS collaboration has investigated numerous scenarios, including the possibility of new heavy gauge bosons, extra-dimensions, compositeness or dark matter production. The full datasets (5 /fb in 2011 and 20 /fb in 2012) allowed to set lower limits on the mass scale for a large number of models.

These proceedings present a number of searches for supersymmetric particles as well as particles from exotic models. The searches are conducted with the ATLAS experiment at the LHC analysing data taken in 2011 and 2012. Various final states with different numbers of leptons, jets and a varying amount of missing transverse momentum are investigated. Inclusive as well as exclusive searches are performed. Since no new deviations from the Standard Model have been observed, lower limits on the masses of the particles in question are derived. Depending on the particular models, mass limits exist from about 0.1 TeV up to 10 TeV.

Rare decays of beauty and charm hadrons offer a rich playground to make precise tests of the Standard Model and look for New Physics at the level of quantum corrections. A review of recent LHCb results will be presented.

The associated creation of a Higgs and a Z boson in relativistic lepton-antilepton collisions taking place in a strong laser field is studied. The collision energy of the pre-accelerated particles may be vastly increased by their interaction with the intense laser field. The total cross section is calculated and related to field-free collisions of corresponding center-of-mass energy. The required laser parameters and other experimental challenges are specified, as well as possible proof-of-principle experiments.

An overview of beam-related backgrounds at the International Linear Collider and the Compact Linear Collider is presented. Two sources of background are discussed: the beam delivery system and the interaction point. Abundances of background muons, neutrons, beamstrahlung photons and soft e⁺e⁻ pars are quoted for different sub-detectors and both background sources. A difference in the background environment between the two collider options is described. The impact of the background particles on the event reconstruction is sketched. Available tools for rejection of background signals in subdetectors are listed.

As a result of the LHC upgrade after the Long Shutdown 2, the expected luminosity and collision rate during the so called Run 3 will considerably exceed the design parameters for several of the key ALICE detectors systems including the forward trigger detectors. Furthermore, the introduction of a new Muon Forward Tracker significantly reduces the space envelope available for the upgraded Fast Interaction Trigger (FIT) detector on the muon spectrometer side. At the same time, FIT is expected to match and even exceed the functionality and performance currently secured by three ALICE sub-detectors: the time zero detector (T0), the VZERO system, and the Forward Multiplicity Detector (FMD). The harsh conditions of Run 3 would accelerate the ageing and radiation damage (detectable already during Run 1) of the FIT detector if we were to use standard PMTs. The solution came thanks to the latest developments in MCP–PMT technology providing compact photo sensors with excellent characteristics and stability.

TOTEM is an LHC experiment dedicated to forward hadronic physics. In this contribution, an update on two main parts of its physics programme is given: proton-proton elastic scattering and total cross-section.

In this paper we review diffractive physics measurements in LHC Run1 pp collisions performed by the ATLAS experiment. We show the total inelastic proton-proton cross section, the differential cross section as a function of rapidity gaps and finally the dijet production with a veto on additional central jet activity.

The ALICE experiment is equipped with a wide range of detectors providing excellent tracking and particle identification in the central region, as well as forward detectors with extended pseudorapidity coverage, which are well suited for studying diffractive processes. Cross section measurements of single and double diffractive processes performed by ALICE in pp collisions at will be reported. Currently, ALICE is studying double-gap events in pp collisions at , which give an insight into the central diffraction processes: current status and future perspectives will be discussed. The upgrade plans for diffraction studies, further extending the pseudorapidity acceptance of the ALICE setup for the forthcoming Run 2 of the LHC, will be outlined.

High statistics measurements of the diffractive reduced cross section from the H1 collaboration are presented which make use of two different experimental methods to achieve the largest possible coverage of the kinematic phase space at HERA. The diffractive dijet cross sections for photoproduction and deep inelastic scattering were studied with emphasis of studying of factorisation properties of diffractive processes.

By using a Regge-pole model for vector meson production (VMP), that successfully describes the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the Large Hadron Collider (LHC). The role of the low-energy behaviour of VMP cross sections in γp collisions is scrutinized.

Using the unitarity relation in combination with experimental data about the elastic scattering in the diffraction cone, it is shown how the shape and the darkness of the interaction region of colliding protons change with increase of their energies. In particular, the collisions become fully absorptive at small impact parameters at LHC energies that results in some special features of inelastic processes as well. Possible evolution of the shape from the dark core at the LHC to the fully transparent one is discussed that implies the terminology of the black disk would be replaced by the black torus.

Questions to discuss:

• Which problems of principle underlie the diffractive studies?
• What is the Pomeron?
• What is the “true asymptotic regime” (“Asymptopia”), if any?
• How to account for coherent and incoherent states of partons in the proton wavefunctions?
• If QCD has anything concrete to say about diffractive scattering?

The ATLAS and CMS collaborations have performed a wide range of studies of QCD phenomena, from the production of soft particles to hard photons and jets. Differential measurements of inclusive and dijet production by both ATLAS and CMS provide stringent tests of high-order QCD predictions, as well as input for the determination of parton density functions. Measurements of isolated and inclusive photon cross sections for high-p_T photons also test QCD predictions and further constrain PDFs. A survey of these QCD measurements is presented here.

Recent measurements of proton structure, jet production cross sections, the strong coupling constant value, prompt photon production cross sections, charmed hadron production cross sections and the charm and beauty quark mass values, performed by the H1 and ZEUS collaborations at the e^±p collider HERA, are presented.

We discuss characteristic properties of fluctuations of conserved charges expected for the phase boundary in QCD. Probability distribution of the net baryon number and its higher order cumulants are presented for chiral crossover transition in a chiral quark-meson model. Implication for the experimental data on net-proton fluctuation is also discussed.

Many charmonium-like and bottomonium-like XYZ resonances have been observed by the Belle, Babar, CLEO and BESIII collaborations in the past decade. They are difficult to fit in the conventional quark model and thus are considered as candidates of exotic hadrons, such as multi-quark states, meson molecules, and hybrids. In this talk, we first briefly introduce the method of QCD sum rules and then provide a short review of the mass spectra of the quarkonium-like tetraquark states and the heavy quarkonium hybrids in the QCD sum rules approach. Possible interpretations of the XYZ resonances are briefly discussed.

The BES-III experiment in Beijing takes data in tau-charm domain since 2009. For the moment the world largest samples of J/ψ, ψ(3686), ψ(3770), ψ(4040) and Y (4260) data have been collected. The current status of the BES-III experiment is presented. The overview of recent observation of charmonium-like states is given.

The number of the baryon states observed in the analysis of the πN elastic data is significantly smaller than that predicted by all existing models of strong interactions at low energies. In the present paper we report the result of the analysis of the meson photoproduction data taken recently in a number of experimental facilities over the world. The combined analysis of the new data and the data on pion induced reactions reveals a set of new baryon states which escaped the identification in previous analyses of the elastic data. The performed analysis also allows us to determine a number of new properties of the known baryons with a good precision.

Questions to discuss:

• Is heavy quark flavor physics really needed in the LHC era? If LHC discovers new physics, how will flavor physics help to interpret it? What if LHC finds nothing new?
• There is a flow of experimental results on XYZ states and their interpretations. Is there a convergence or a consensus on any of these?
• Most of experiments deal with s-channel formation of baryons. Are other mechanisms like t-channel useful as a complementary source?
• Is there a feasible unification of data presentation from various experiments for mesons similar to what is done for baryon spectroscopy?
• Where are glueballs?

To date, quantum mechanics has proven to be our most successful theoretical model. However, it is still surrounded by a “mysterious halo”, which can be summarized in a simple but challenging question: Why quantum phenomena are not understood under the same logic as classical ones? Although this is an open question (probably without an answer), from a pragmatist's point of view there is still room enough to further explore the quantum world, marveling ourselves with new physical insights. We just need to look back in the historical evolution of the quantum theory and thoroughly reconsider three key issues: (1) how this theory has developed since its early stages at a conceptual level, (2) what kind of experiments can be performed at present in a laboratory, and (3) what nonstandard conceptual models are available to extract some extra information. This contribution is aimed at providing some answers (and, perhaps, also raising some issues) to these questions through one of such models, namely Bohmian mechanics, a hydrodynamic formulation of the quantum theory, which is currently trying to open new pathways of understanding. Specifically, the Chapter constitutes a brief and personal overview on the historic and contextual evolution of this quantum formulation, its physical meaning and interest (leaving aside metaphysical issues), and how it may help to overcome some preconceived paradoxical aspects of the quantum theory.

A brief account of interesting moments in the genesis of the quark paradigm is presented.

Measurements of direct photon and neutral pion production in heavy-ion collisions provide a comprehensive set of observables characterizing properties of the hot QCD medium. Direct photons provide means to test the initial stage of an AA collision and carry information about the temperature and space-time evolution of the hot medium. Neutral pion suppression probes the parton energy loss in the hot medium. Measurements of neutral meson spectra in pp collisions at LHC energies serve as a reference for heavy-ion collisions and also provide valuable input data for parameterization of the QCD parton Fragmentation Functions. In this talk, results from the ALICE experiment on direct photon and neutral pion production in pp and Pb–Pb collisions are summarized.

Recent experimental results obtained at the Relativistic Heavy-Ion Collider (RHIC) will be discussed. Investigations of different nucleus-nucleus collisions in recent years focus on two main tasks, namely, the detailed study of sQGP properties and the exploration of the QCD phase diagram. Results at top RHIC energy provide important information about event shapes as well as transport and thermodynamic properties of the hot medium for various flavors. Heavy-ion collisions are a unique tool for the study of topological properties of theory. Experimental results obtained for discrete QCD symmetries at finite temperatures are discussed. These results confirm indirectly the topologically non-trivial structure of the QCD vacuum. Most results obtained during phase-I of the RHIC beam energy scan (BES) program show smooth behavior vs initial energy. However, certain results suggest the transition in the domain of dominance of hadronic degrees of freedom at center-of-mass energies between 10-20 GeV. Future developments and more precise studies of features of the QCD phase diagram in the framework of phase-II of RHIC BES will be briefly discussed.

Hard scattered partons lose a significant fraction of their energy traversing the medium created in high energy collisions of heavy nuclei, resulting in yields suppression of final state high p_T hadrons. Results from the PHENIX experiment at RHIC on the suppression of high p_T hadrons at midrapidity in central Au+Au and Cu+Cu collisions at are presented. In addition, results on direct photon yields, which don't suffer energy loss due to the strong nuclear force, and suppression of the high p_T electrons and positrons from the decays of hadrons containing open heavy quarks are presented for Au+Au and d+Au collisions too.

Initially produced quark-gluon matter at RHIC and LHC does not have a temperature. A quark-gluon plasma has a high temperature. From this quark-gluon matter to the quark-gluon plasma is the early thermalization or the rapid creation of temperature. Elastic three-parton scattering plays a key role in the process. The temperature originates from the two-parton scattering, the three-parton scattering, the four-parton scattering and so forth in quark-gluon matter.

Questions to discuss:

• Which experimental data (dis)prove deconfinement of the QCD matter created in heavy ion collisions?
• Which grounds are there for thermodynamics application to describe the QCD matter produced at RHIC and LHC energies?
• Which experimental data confirm existence or absence of phase transition in heavy ion collisions?
• Which new properties of quark-gluon matter are observed at LHC compared with those at RHIC and which are plans for the future?
• Is there any evolution in our understanding of the QCD matter from RHIC to LHC energies?

Decays of b-hadrons are the ideal place to perform measurements of CP violation. Many decay channels allow to over-constrain the unitarity triangles of the CKM matrix and test the SM hypothesis that a single phase is the origin of all CP violation. Charm decays also allow for tests of the SM. Recent results from LHCb are reviewed.

This article reports about recent results obtained by Belle Collaboration: first observation of the charm mixing in D → Kπ, evidence of mixing and search of CP violation in D → K_sπ⁺π⁻, precise measurement of the lifetime of τ-lepton, observation of the neutral exotic state in the transition Υ(10860) → Υ(nS)π⁰π⁰, observation of the reaction e⁺e⁻ → π⁺π⁻π⁰χ_bJ and search for the exotic state X_b in the transition X_b → ωΥ(1S).

Nonzero of mixing angle θ₁₃ has some phenomenological consequences on neutrino physics beyond the standard model. If the mixing angle θ₁₃ ≠ 0, then there is the possibility of the CP violation existence on the neutrino sector. To obtain a nonzero of mixing angle θ₁₃ from neutrino mass matrix obey μ – τ, we break it by introducing one small parameter x into neutrino mass matrix and then calculated the Jarlskog invariant as a measure of CP violation existence using the reported experimental data as input and put m₁ = 0 for neutrino mass in normal hierarchy and Dirac phase δ as function of parameter x.

The Hyper-Kamiokande is a next generation large water Cherenkov detector proposed to be built in Kamioka, Japan. It aims at precision studies of neutrino oscillation parameters, including the CP violation phase δ_CP , using neutrinos from the J-PARC accelerator as well as atmospheric neutrinos. The detector also serves as a general purpose observatory, expanding the existing sensitivities by an order of magnitude in the searches for nucleon decays, solar and galactic WIMPs, and supernova neutrinos.

Super-Kamiokande (Super-K) is the world largest water cherenkov detector built in the Kamioka mine, Japan. One of the most important subjects of Super-K is to detect supernova neutrinos. In case of a supernova which happens near the center of our galaxy, several thousand neutrino events will be detected by Super-K, and the direction of the supernova can be obtained with an uncertainty of few degree. In this presentation, an introduction to our online supernova monitoring system is given, and future plans related to the supernova neutrino detection are discussed.

The OPERA experiment aims at providing a direct proof of the ν_μ → ν_τ oscillations by observing ν_τ CC interactions in an high purity ν_μ accelerator beam, the CNGS (CERN Neutrinos to Gran Sasso). The beam exposure started in 2008 and ended in 2012. Events recorded in the Emulsion Cloud Chamber detectors, made of lead plates and nuclear emulsions, are being analysed since 2008. In the last period, a large amount of data has been extracted additionally, leading to the validation of the 4th ν_τ candidate event. This new result brings the observation of the oscillation with a significance exceeding 4 sigma.

The main goal of the OPERA experiment is the direct observation of ν_μ → ν_τ oscillations in appearance mode in the quasi pure ν_μ CNGS beam. Profiting of the tracking capabilities of the OPERA active target it is possible to detect and reconstruct ν_e interactions and therefore to study the subdominant ν_μ → ν_e oscillation channel. Current results on this channel in the three-flavour mixing model are presented. The same data allow to constrain the non-standard oscillation parameters indicated by the LSND and MiniBooNE experiments.

The existence of a heavy neutrino, ν_H, in the K⁺ → μ⁺ν_H decays was tested using the E949 experimental data with an exposure of 1.70 × 10¹² stopped kaons. The allowed heavy neutrino mass region for the analysis is from 175 MeV/c² to 300 MeV/c². With major background from the radiative K⁺ → μ⁺ν_μγ decay understood and suppressed, the preliminary new upper limits (90% C.L.) on the neutrino mixing matrix element between muon and heavy neutrino, |U_μH|², were set at the level of 10⁻⁸ to 10⁻⁹.

The NOνA experiment is a long-baseline accelerator-based neutrino oscillation experiment. It uses the upgraded NuMI beam from Fermilab and measures electron-neutrino appearance and muon-neutrino disappearance at its far detector in Ash River, Minnesota. Goals of the experiment include measurements of θ₁₃, mass hierarchy and the CP violating phase. NOνA has begun to take neutrino data and first neutrino candidates are observed in its detectors. This document provides an overview of the scientific reach of the experiment, the status of detector operation and physics analysis, as well as the first data.

The IceCube experiment has recently released 3 years of data of the first ever detected high-energy (≳ 30 TeV) neutrinos, which are consistent with an extraterrestrial origin. In this talk, we compute the compatibility of the observed track-to-shower ratio with possible combinations of neutrino flavors with relative proportion (α_e : α_μ : α_τ)_⊕. We obtain the best-fit for (1 : 0 : 0)_⊕ at Earth, which cannot be achieved from any flavor ratio at sources with averaged oscillations during propagation. Although it is not statistically significant at present, if confirmed, this result would suggest either a misunderstanding of the expected background events, or a misidentification of tracks as showers, or the presence of some exotic physics which deviates from the standard scenario.

Questions to discuss:

• Can sidereal time analysis of the long time neutrino observations give information about the galaxy distribution in the Local Universe?
• How well do we need to know the PMNS matrix elements?
• Is the existence of MSW effect proved experimentally?
• Are there new species of neutrino (e.g. the sterile one)?
• What are other most important problems in neutrino physics (CP-violation)?
• Can sidereal time analysis of the long time neutrino observations give information about the galaxy distribution in the Local Universe?
• Perspectives of existing and future neutrino experiments (LNBF, LAGUNA, ICARUS, SHIP …)

The Pierre Auger Observatory is collecting data of ultra-high energy cosmic rays with unprecedented statistics and quality. The latest results on the energy spectrum, mass composition and anisotropy searches are summarized. These results rise new questions and open challenges that call for an upgrade of the Observatory.

Several methods developed within the Pierre Auger Collaboration for the estimation of the muonic component of the Extensive Air Showers observed in the surface Cherenkov detectors are described. The results derived from the data show a deficit of muons predicted by the current hadronic interactions models at ultra-high energies.

I provide references to the latest AMS publications on cosmic-ray electron and positron fluxes.

Questions to discuss:

• What is the origin of the GZK-like suppression of the cosmic ray (CR) flux? Is it due to energy loss during propagation or due to reaching maximum energy achievable in a source?
• Are the data on mass composition of ultra-high energy CRs consistent with a hypothesis that primary particles are 100% proton? Or an admixture of heavy nuclei is also allowed?
• Does the deficit of muons in LHC-tuned MC simulations mean that current hadronic interaction models must be seriously corrected?
• Does the anomalous positron fraction (PF) approach a stable asymptotic value or a sharp cutoff at higher energies is possible?
• Do we observe annihilation of a dark matter or nearby pulsar contribution? Will anisotropy in an arrival direction of CR leptons rule out a dark matter interpretation of PF?
• Is low-mass WIMP region completely excluded by the data?

In the history of cosmology physical paradoxes played important role for development of contemporary world models. Within the modern standard cosmological model there are both observational and conceptual cosmological paradoxes which stimulate to search their solution. Confrontation of theoretical predictions of the standard cosmological model with the latest astrophysical observational data is considered. A review of conceptual problems of the Friedmann space expending models, which are in the bases of modern cosmological model, is discussed. The main paradoxes, which are discussed in modern literature, are the Newtonian character of the exact Friedmann equation, the violation of the energy conservation within any comoving local volume, violation of the limiting recession velocity of galaxies for the observed high redshift objects. Possible observational tests of the nature of the cosmological redshift are discussed.

The evolution of the main components of the ΛCDM universe is studied in perfect fluid approximation. We assume dark matter to consist of neutralinos and dark energy due to fluctuations of the metric. The effect of particle annihilations and decouplings on the thermal history is considered. The sterile neutrino density is found in agreement with expectations, when at the end of inflation their evolution starts in temperature equilibrium with the other components.

Leptogenesis is an attractive scenario in which neutrino masses and baryon asymmetry of the Universe are explained together under a minimal set of assumptions.

After formulating the problem of initial conditions and introducing the strong thermal leptogenesis conditions as solution, we show that, within the framework provided by the SO(10)-inspired model of leptogenesis, the latter lead to a set of testable predictions on the same neutrino parameters currently under experimental investigations.

The emerging scenario selects the normal ordering of the neutrino mass pattern, a large value for the reactor mixing angle, 2° ≲ θ₁₃ ≲ 20°, as well as a non maximal atmospheric mixing angle, 16° ≲ θ₂₃ ≲ 41°, and favours negative values for the Dirac phase δ. The signature of the proposed strong thermal SO(10)-inspired solutions is in the relation obtained between the effective Majorana mass and the lightest neutrino mass: m_ee ≈ 0.8 m₁ ≈ 15 meV.

There are two new observational facts: the mass spectrum of neutron stars and black hole candidates (or collapsars) shows an evident absence of compact objects with masses within the interval from 2 M⊙ (with a peak for neutron stars about 1.4 M⊙) to about 6 M⊙, and in close binary stellar systems with a low-massive (about 0.6 M⊙) optical companion the most probable mass value (the peak in the masses distribution of black hole candidates) is close to 7 M⊙. The problem of the compact objects discrete mass spectra demands some solution both in the context of the supernovae and gamma-ray bursts relation, and in connection with the core-collapse supernovae explosion mechanism itself. In the totally non-metric scalar-tensor model of gravitational interaction (in a modified or extended Feynman field approach to gravitation) the total mass of a compact relativistic object with extremely strong gravitational field (an analog of black holes in General Relativity) is approximately equal to 6.7 M⊙ with radius of a region filled with a matter (quark-gluon plasma) ≈ 10 km. Polarized emission of long gamma-ray bursts, a black-body component in their spectrum and other observed properties could be explained by the direct manifestation of a surface of these collapsars.

It is pointed out that according to RTG based on the Minkowski space the presence of the quintessence is necessary to explain the Universe accelerated expansion. RTG based on the deSitter background space predicts acceleration without any quintessence.

Generation of the B-mode of CMB polarization by background of relic gravitational wave is discussed in connection with the BICEP2 measurements. Description of the polarization maps in terms of the eigenvectors of the polarization matrix is considered. is emphasized.

Questions to discuss:

• Is there a conflict of BICEP2 data with the PLANCK measurements on the relic gravitational waves generated during the Universe inflation?
• Do sterile neutrinos with the mass about 0.5 eV really relax PLANCK constraints on both the amplitude of tensor modes of inhomogeneity and Hubble rate?
• Why the dark matter particles are still not detected in conflict with direct expectations of cosmological models?
• The baryogenesis is dead, the leptogenesis is prospective, isn't it?
• Are there crucial astrophysical observational tests which can distinct between alternative cosmological models?
• Is it possible that observations of the large scale spatial galaxy distribution will change the SCM paradigm?
• How does Feynman's field gravity approach change predictions for observational effects in relativistic astrophysics?

The following sections are included:

• Program of the XXX-th International Workshop on High Energy Physics
  • The Time Schedule
  • Registration
  • List of Participants