The Logic of Nature, Complexity and New Physics

The following Sections are included:

• PREFACE

• CONTENTS

In order to understand the parameters of the standard model of electroweak and strong interactions (coupling constants, masses, mixing angles) one needs to embed the standard model into some larger theory that accounts for the observed values. This means some additional sector is needed that fixes and stabilizes the values of the fundamental constants of nature. In these lecture notes we describe in non-technical terms how such a sector can be constructed. Our additional sector is based on rapidly fluctuating scalar fields that, although completely deterministic, evolve in the strongest possible chaotic way and exhibit complex behaviour. These chaotic fields generate potentials for moduli fields, which ultimately fix the fundamental parameters. The chaotic dynamics can be physically interpreted in terms of vacuum fluctuations. These vacuum fluctuations are different from those of QED and QCD but coupled with the same moduli fields as QED and QCD are. The vacuum energy generated by the chaotic fields underlies the currently observed dark energy of the universe. Our theory correctly predicts the numerical values of the electroweak and strong coupling constants using a simple principle, the minimization of vacuum energy. Implementing some additional discrete symmetry assumptions one also obtains predictions for fermion masses, as well as a Higgs mass prediction of 154 GeV.

These lectures provide a short introduction to chiral perturbation theory and to the effective field theory method in general. The focus is mainly on the foundations of the method and only at the end I discuss two recent applications. In a school about complexity, effective field theories provide a nice example of how one can describe complicated nonperturbative phenomena in simple terms.

No received abstract.

We review some recently established connections between the mathematics of black hole entropy in string theory and that of multipartite entanglement in quantum information theory. In the case of N = 2 black holes and the entanglement of three qubits, the quartic [SL(2)]³ invariant, Cayley's hyperdeterminant, provides both the black hole entropy and the measure of tripartite entanglement. In the case of N = 8 black holes and the entanglement of seven qubits, the quartic E₇ invariant of Cartan provides both the black hole entropy and the measure of a particular tripartite entanglement encoded in the Fano plane.

It is now possible to formulate QCD on a space-time lattice with correct chiral and flavour symmetries, and to simulate the dynamical effects of the u, d and s quarks with masses close to their physical values. This short review for non-experts describes the status of the simulation results, and how they are helping us to understand the strong interaction, to test the Standard Model and to search for physics beyond it.

If the observable universe really is a hologram, then of what sort? Is it rich enough to keep track of an eternally inflating multiverse? What physical and mathematical principles underlie it? Is the hologram a lower dimensional quantum field theory, and if so, how many dimensions are explicit, and how many "emerge?" Does the Holographic description provide clues for defining a probability measure on the Landscape?

The purpose of this lecture is first, to briefly review a proposal for a holographic cosmology by Freivogel, Sekino, Susskind, and Yeh (FSSY), and then to develop a physical interpretation in terms of a "Cosmic Census Taker:" an idea introduced in reference [1]. The mathematical structure–a hybrid of the Wheeler DeWitt formalism and holography–is a boundary "Liouville" field theory, whose UV/IR duality is closely related to the time evolution of the Census Taker's observations. That time evolution is represented by the renormalization-group flow of the Liouville theory.

Although quite general, the Census Taker idea was originally introduced in [1], for the purpose of counting bubbles that collide with the Census Taker's bubble. The "Persistence of Memory" phenomenon discovered by Garriga, Guth, and Vilenkin, has a natural RG interpretation, as does slow roll inflation. The RG flow and the related C-theorem are closely connected with generalized entropy bounds.

No abstract received.

This lecture – delivered at the 2006 Erice School – is closely linked to the one delivered in 2004, where the existence of Complexity at the fundamental level has been fully discussed. Here the consequences of Complexity for LHC are treated and the QGCW Project is presented. The references have been updated since the final edition of the lecture has been printed on March 2008. If complexity exists at the fundamental level the expectations must fall outside all possible predictions. The QGCW should be the source for totally unexpected phenomena.

Today the future of underground science appears challenging and rich. This is true in particular for the INFN Gran Sasso Laboratory whose main characteristics, present scientific activity and future perspectives I present here.

The B Factories PEP-II and KEKB operating since 1999 have produced a rich harvest of beautiful and somehow intriguing experimental results in the flavor sector. After the discovery of the indirect (2001). and the direct (2004) CP violation [1-4] in the B sector, the present experimental situation is in a phase of precision measurements of sides and angles of the Unitarity Triangle, potentially able to produce more precise tests of CKM model. As well known, the CP violation accounted by CKM in the standard model fails in the explanation of amount of deficit of antimatter with respect to the matter in the universe. If we still assume CP as the origin of such a deficit, one should expect contribution coming from phases related to New Physics. Lepton Flavor Violation (LFV) in τ decay and in general rare τ and B decays would allow some evidence of New Physics. The status of B Factories measurements is reported here, together with ideas of a future facility operating at a luminosity ≥ 10³⁶cm²s^-1, much higher than the present B, Factories PEP-II and KEKB.

Collisions of heavy ions at the Relativistic Heavy Ion Collider (RHIC) form a hot system at energy densities greater than 5 GeV/fm³, where normal hadrons cannot exist and a quark-gluon plasma is expected to be formed. The system cools rapidly to a temperature T ~ 175 MeV at the quark-hadron phase boundary predicted by lattice QCD where hadrons coalesce from quarks. A large amount of collective flow at the quark level provides evidence for strong pressure gradients in the initial partonic stage of the collision when the system is dense and highly interacting prior to coalescence into hadrons. This flow and the subsequent distributions of hadrons are described by ideal hydrodynamics with zero viscosity, suggesting a nearly perfect fluid is formed. Such low viscosities approach a universal lower bound postulated from string theory. The suppression of both light (u, d, s) and heavy (c, b) hadrons at large transverse momenta and the quenching of di-jets provide evidence for extremely large energy loss of partons as they propagate through a dense, strongly-coupled medium.

The International Linear Collider (ILC) is a proposed electron-positron collider that will explore the Terascale. The ILC can be characterized as a precision machine that will study the discoveries made at the Large Hadron Collider (LHC), at CERN. These two giant machines are highly complementary. The concept of Electro-weak symmetry breaking and the Higgs Boson are the Holy Grail of particle physics. It is expected that the Higgs Boson will be discovered at the LHC. The ILC will be a superb instrument to measure precisely the properties of the Higgs Boson and thus provide a discovery window into the physics beyond the Standard Model. Even greater discoveries are anticipated at the LHC, such as Super-symmetry and evidence for extra dimensions of space. The basic configuration of the accelerator is presented. The ILC accelerator R&D program developing around the world is discussed.

The following sections are included:

• Kinematics of Deep Inelastic Scattering and Diffractive Scattering

• Regge Phenomenology versus Perturbative QCD

• Exclusive Vector-Meson Production
  • Can the Vector-Meson Mass be a Hard Scale?
  • Can Q² provide a Hard Scale?
  • Can |t| provide a Hard Scale?
  • The Pomeron Trajectory

• Deeply-Virtual Compton Scattering

• Inclusive Diffraction
  • Comparison of the Methods to select Diffractive Events
  • Diffractive Cross-Section and Diffractive Structure-Functions
  • Results on Inclusive Diffraction
    • Result from the proton-detection method
    • Result from the large rapidity-gap method (LRG)
    • H1 fits of the diffractive structure-functions
    • Results from the ZEUS M_X-method
    • Ratio of diffractive DIS to the total DIS cross-section
    • Are diffractive parton-distributions (dpdf) universal?
    • HERA dpdfs and prediction for data from the Tevatron

• Summary

• References

No abstract received.

Lowering the string scale in the TeV region provides a theoretical framework for solving the mass hierarchy problem and unifying all interactions. The apparent weakness of gravity can then be accounted by the existence of large internal dimensions, in the submillimeter region, and transverse to a braneworld where we must be confined. I review the main properties of this scenario and its implications for observations at both particle colliders, and in non-accelerator gravity experiments.

Current status of general purpose and custom supercomputers for basic science is discussed with a couple of examples of recent applications.

The following sections are included:

• Acknowledgment

• References

We construct functions and tensors on noncommutative spacetime by systematically twisting the corresponding commutative structures. The study of the deformed diffeomorphisms (and Poincaré) Lie algebra allows to construct a noncomutative theory of gravity.

The analysis of events with isolated leptons and missing transverse momentum in the H1 experiment is discussed for the electron, muon and tau channels. In the Standard Model (SM) framework, production of real W-bosons gives rise to such topologies. Contributions to the background are dominated by QCD processes. An excess of observed signal over background presents a chance of the discovery of new physics. The results using the HERA 1994-2006 data set corresponding to 341 pb^-1 are presented While the e^-p sample shows good agreement between data and SM expectation, in e⁺p collisions an excess over the SM expectation with 3.4σ significance is observed at high hadronic transverse momentum.

With high energy heavy ion collisions one tries to create a new forms of matter that is similar to the one present at the birth of our Universe. Recent development on flow pattern, initial energy-density and freeze-out temperature shows that most likely this new form of matter is in a deconfined state, has colored degrees of freedom and is more fluid-like than gas-like. In present paper we calculate estimations on the physical properties of this new-old matter.

In this paper I discuss the extension of the analogy between gravitation and some systems of condensed matter physics from kinematics to dynamics. I will focus my attention on two applications of the analogy to the dynamics of fluids that have been recently proposed: the study of backreaction effects and the calculation of the depletion in Bose-Einstein condensates, showing how this extension is possible and stressing the main differences with respect to the gravitational context. I will conclude with some remarks about the actual reliability of the proposed scheme, pointing out the basis issues that have still to be addressed.

Although dark matter is supposed to provide with more than 0.9 of the total fraction of the mass-energy in universe, its amount and properties can only be defined a posteriori. In this context, a crucial point concerns the identification of a possible clear feature of dark matter fields which is not arbitrary, i.e. a property which has to be satisfied by dark matter fluctuations under some very general theoretical conditions. We discuss the fact that this property, in standard cosmological models, is represented by super-homogeneity, i.e. a very fine tuned balance between negative and positive correlations of density fluctuations, which must be imprinted both in the anisotropies of the CMBR and in the large scale distribution of galaxies. We review the main aspects of this property, considering examples of super-homogeneous systems well-studied in statistical physics, and discuss its possible observational evidences.

Supersymmetry (SUSY) is a baryon-fermion symmetry postulated to be underlying the symmetries of the Standard Model of Particle Physics (SM). This symmetry was first proposed in the context of String Theory in 1971[1], and soon after the first SUSY theories in 3+1 dimensions were built by Wess and Zumino[2] and others. Ever since, SUSY searches have been part of the Physics program of every major collider experiment. Theoretically, SUSY is a very attractive idea, since it was proved in [3] to be the only space-time extension to the Poincaré algebra and it is required to exist at some energy scale by String Theories. In addition, SUSY at the TeV scale is especially attractive because it solves the Hierarchy Problem, protects the Higgs mass against radiative corrections and easily provides a candidate for Dark Matter. However, so far, no experiment has been able to discover TeV-scale SUSY. Nevertheless, with the advent of the LHC, a discovery machine designed precisely to scan an energy scale of up to a few TeV, the prospects of either discovering or ruling out TeV SUSY have become very plausible in the vast majority of the existing models.

In this context, it has become compulsory for the LHC experiments to be ready to make the measurements that will lead to the discovery or non-discovery of SUSY. In the following sections we summarize the experimental approach under preparation by the ATLAS collaboration in order to perform the so-called inclusive measurements, which will soon after the LHC startup shed light into the questions of the existence and nature of Supersymmetry.

We define a general procedure, based on analyticity and dispersion relations, to estimate low energy amplitudes for processes like: ϕ → e⁺e^-M and ϕ → γM, starting from cross section data on e⁺e^- → ϕM, where M is a generic light scalar or pseudoscalar meson. In particular this procedure is constructed to obtain predictions on the radiative decay rate which are crucially linked on the assumed quark structure for the meson M under consideration.

Three cases are analyzed: M = η, and . While in the η case the estimate of the branching fraction for the radiative decay ϕ → ηγ is in agreement with the data, in the case of f₀, such agreement is obtained only under the hypothesis of a tetraquark scalar meson.

The following sections are included:

• Introduction

• Vacuum Stability and Dielectric Screening

• Nuclear Matter and String Models

• String Entropy

• String Fragmentation

• Conclusions

• Acknowledgements

• References

We discuss how the exclusive production of ρ⁰ in deep inelastic ep scattering at HERA can be used to map the transverse distribution of gluons in the proton. We then present the experimental challenge in a precise determination of the slope of the four-momentum transfer squared distribution, which can be directly linked to the size of the proton.

This talk is based on the paper hep-th/0607177 where we demonstrate how one can construct renormalizable perturbative expansion in formally nonrenormalizable higher dimensional scalar theories. It is based on 1/N-expansion and results in a logarithmically divergent perturbation theory in arbitrary high odd space-time dimension. The resulting effective coupling is dimensionless and is running in accordance with the usual RG equations. The corresponding beta function is calculated in the leading order and is nonpolynomial in effective coupling. It exhibits either UV asymptotically free or IR free behaviour depending on the dimension of space-time. In this talk we mainly discussed the problems concerning the Renormalization Group.

We show that quantum mechanics and general relativity imply the existence of a minimal length. To be more precise, we show that no operational device subject to quantum mechanics, general relativity and causality could exclude the discreteness of spacetime on lengths shorter than the Planck length. We then consider the fundamental limit coming from quantum mechanics, general relativity and causality on the precision of length measurement.

I introduce the upcoming MEG experiment, which will search for the rare decay μ → eγ down to the branching ratio of 10^-13. In order to suppress the background and achieve this unprecedented sensitivity, a great deal of thought went into designing this experiment. Here, I describe the essential components of this experiment, the beam line, the positron spectrometer, and the liquid xenon γ-ray detector.

It is shown that classical actions for some "physically interesting" quantum field theories can be obtained as effective actions from the single "fundamental" theory of the Chern–Simons form. The physical degrees of freedom are encoded in the space of cohomologies of a certain differential operator. This observation suggests a different perspective on some of the supersymmetric properties of these effective theories. Namely, it is possibie to construct a superfield formalism which allows to find off-shell SUSY actions for the on-shell supersymmetric theories, where conventional superfield formalism does not work. This formalism contains even auxiliary variables λ^α in addition to conventional odd variables θ^α. This idea is similar to the Pure Spinor construction. This paper is a short review of papers [11, 12]. Original results discussed below were obtained in collaboration with V. Alexandrov, A. Gorodentsev, A. Losev and V. Lysov.

We report on the measurement of the CKM angle γ in B^± → DK^± decays with the BABAR detector. A general overview of different methods of analysis and a critical discussion of the most sensitive methods are presented here.

The aim of this work is to extend to LHC the results observed for two-particle correlations at RHIC, especially in terms of jet quenching effects. In this study a parton quenching model developed in the BDMPS-Z-SW framework is considered and implemented as an afterburner for PYTHIA and HIJING. A simplified parametrization of the quenching mechanism at the parton level is included in one of the most popular Monte Carlo event generators for AA collisions, HIJING. The simulation method, tuned on the RHIC data, is then used to make predictions for the LHC energy regime in order to probe the scenario we will study in the ALICE experiment.

The following Sections are included:

• DIPLOMAS

• AWARDS

• PARTICIPANTS