Regular Series


Vol. 42 (2011), No. 11, pp. 2163 – 2515

XXXV International Conference of Theoretical Physics Matter to the Deepest

Ustroń, Poland; September 12–18, 2011

MOND — Particularly as Modified Inertia

abstract

After a succinct review of the MOND paradigm — with its phenomenology, and its various underlying theories — I concentrate on so-called modified inertia (MI) formulations of MOND, which have so far received only little attention. These share with all MOND theories the salient MOND predictions, such as asymptotically flat rotation curves, and the universal mass-asymptotic-speed relation. My emphasis here is, however, on the fact that MI theories can differ substantially from their “modified-gravity” (MG) kin in predicting other phenomena. Because MI theories are nonlocal in time, MOND effects depend on the full trajectory of a system, not only on its instantaneous state, as in MG theories. This may lead to rather different predictions for, e.g., the external-field effect (EFE): A subsystem, such as a globular cluster or a dwarf galaxy, moving in the field of a mother galaxy, or a galaxy in a cluster, may be subject to an EFE that depends on the accelerations all along its orbit, not only on the instantaneous value. And, it is even possible to construct MI theories with practically no EFE. Other predictions that may differ are also discussed. Since we do not yet have a full fledged, modified-inertia formulation, simple, heuristic models have been used to demonstrate these points.


Dark Matter in Dwarf Galaxies of the Local Group

abstract

We review basic properties of the population of dwarf galaxies in the Local Group focusing on dwarf spheroidal galaxies found in the immediate vicinity of the Milky Way. The evidence for Dark Matter in these objects is critically assessed. We describe the methods of dynamical modelling of such objects, using a few examples of the best-studied dwarfs and discuss the sources of uncertainties in mass estimates. We conclude with perspectives for dwarf galaxies as targets for Dark Matter detection experiments.


Neutrinos as Hot or Warm Dark Matter

abstract

Both active and sterile sub-eV neutrinos can serve as hot dark matter (DM). On the other hand, keV sterile neutrinos could be a good candidate for warm DM. The beta-decaying (e.g. ,\(^3{\rm H}\) and \(^{106}{\rm Ru}\)) and EC-decaying (e.g. , \(^{163}{\rm Ho}\)) nuclei are considered as the most promising targets to capture those extremely low energy neutrinos and antineutrinos, respectively. We calculate the capture rates of relic electron neutrinos and antineutrinos against the corresponding beta-decay or EC-decay backgrounds in different flavor mixing schemes. We stress that such direct laboratory measurements of hot or warm DM might not be hopeless in the long term.


Implications of Mirror Dark Matter on Neutron Stars

abstract

We study the implications of asymmetric Dark Matter on neutron stars. We construct a “mixed neutron star” model composed of ordinary baryons and of asymmetric Dark Matter baryons. We derive the general relativistic structure equations for each specie, the equation for the mass within a given radius, and the redshift as function of radius. We present one specific numerical model as an illustrative example. In this example, the mass of the dark neutron equals half that of the ordinary neutron. The main results are: a total mass of \(3.74 M_{\odot }\), a total mass within the neutron-sphere equaling \(1.56 M_{\odot }\), the neutrons mass is \(1.34 M_{\odot }\), the star radius is \(31.9\) km, the neutron-sphere radius is \(11.1\) km, and the redshifts from the neutron-sphere and from the star surface are \(0.72\), \(0.25\), respectively. We comment briefly on possible astrophysical implications.


Symmetry Energy and Neutron Star Equation of State

abstract

Information about many aspects of both nuclear physics and a neutron star structure are encoded in the density dependence of the symmetry energy. Despite the fact that considerable progress has been made in constraining the density dependence of the symmetry energy, it is still the most uncertain part of the asymmetric nuclear matter equation of state (EOS). The analysis of neutron star parameters which are most sensitive to the form of the symmetry energy in the case of nucleon and strangeness-rich matter has been done with the use of the relativistic mean field (RMF) approximation. The mixed vector meson interactions have been introduced to modify the density dependence of the symmetry energy.


Structure of a Warm Hyperon Star

abstract

The analysis based on the relativistic mean field (RMF) theory with the isoscalar–isovector interactions has been performed in order to study properties of a warm, asymmetric nuclear matter in \(\beta \)-equilibrium. The influence of this additional meson interactions on the composition and structure of a neutron star has been studied. The obtained results refer to the case with only nucleon degree of freedom and to a neutron star matter which includes hyperons.


New Results for the Inert Doublet Model

abstract

New results for the Inert Doublet Model (IDM) are discussed. It is very special among the \(D\)-symmetric 2HDMs, offering a good DM candidate. New stringent unitarity constraints were derived for the IDM and SM-like light Higgs boson scenario in the Mixed Model.

See Erratum Acta Phys. Pol. B 43, 481 (2012)


Dark Matter Data and Quartic Self-couplings in Inert Doublet Model

abstract

We analyse the thermal evolution of the Universe in the Inert Doublet Model for three viable regions of Dark Matter mass: low, medium and high DM mass. Those three regions exhibit different behaviour in the possible types of evolution. We argue that the quartic self-couplings in IDM are significant parameters for the astrophysical analysis.


Pragmatic Extensions of the Standard Model

abstract

We discuss models that allow to ameliorate the Standard Model little hierarchy problem by adding extra scalar degrees of freedom. We argue that extra gauge-singlet real scalars can both soften the little hierarchy problem and provide a realistic source of Dark Matter. For that, a setup consistent with the present LHC bounds for the Higgs-boson mass is provided e.g. by \(N = 6\) scalars with masses \(m \sim 1.5\)–\(3\) TeV and the UV cutoff \({\mit \Lambda } \sim 4.5\)–\(10\) TeV. We explore the possibility that a second Higgs-boson doublet is added do the Standard Model in such a way that quadratic divergences in corrections to the scalar two-point Green functions are canceled. Although the cancellation allows for substantial amount of CP violation in the scalar potential, it is not consistent with Dark Matter being a component of one of the two Higgs doublets. Therefore, either a third (inert) doublet or a singlet must be added.


Cosmology of Multi-singlet-scalar Extensions of the Standard Model

abstract

An extension of the Standard Model by extra scalar singlets was considered. Theoretical (unitarity, vacuum stability, triviality) and cosmological (dark matter relic abundance, direct detection experiments, constraints on dark matter self-interaction) constraints were discussed.


Cosmological Models and Misunderstandings about Them

abstract

Advantages of inhomogeneous cosmological models that are exact solutions of Einstein’s equations over linearised perturbations of homogeneous models are presented. Examples of effects that can be described in the inhomogeneous ones are given: the non-repeatable light paths, the observed anisotropies in the cosmic microwave background, the redshift drift and the maximum diameter distance. Criticisms of inhomogeneous models that are based on misunderstandings or fallacious reasonings are pointed out and corrected; these include the “weak singularity”, the positivity of deceleration “theorem”, the “pathology” of redshift behaviour at the “critical point” and the alleged necessity of the bang time to be constant.


Cosmic Topology Affects Dynamics

abstract

The role of global topology in the dynamics of the Universe is poorly understood. Along with observational programmes for determining the topology of the Universe, some small theoretical steps have recently been made. Heuristic Newtonian-like arguments suggest a topological acceleration effect that differs for differing spatial sections. A relativistic space-time solution shows that the effect is not just a Newtonian artefact.


Fluctuations of Cosmic Parameters Due to Inhomogeneities

abstract

We present the fluctuations of the cosmic parameters on different scales. For large scales we use standard perturbation theory, for small scales the relativistic Zel’dovich approximation. We find that \(1\%\) curvature fluctuations reach out to scales of \(600\,{\rm h}^{-1}\) Mpc and that backreaction contributes up to \(15\%\) to the cosmic energy budget on scales of \(50\) Mpc.


Gravitational Lenses as Standard Rulers in Cosmology

abstract

The accelerating expansion of the Universe is a great challenge for both physics and cosmology. From the observational point of view, it is crucial to have various methods to assess cosmic expansion history, which can be alternative to standard candles (SNIa in cosmological context). Strongly gravitationally lensed systems create such a new opportunity by combining stellar kinematics with lensing geometry. Using strong gravitational lenses as probes of cosmic expansion is becoming attractive in light of ongoing surveys like SLACS based on different protocols than older searches focused on potential sources. In this approach, pursued recently by the authors, strongly lensed systems with known central velocity dispersions act as “standard rulers” — Einstein radius being standardized by stellar kinematics.


Distance Duality in Different Cosmological Models

abstract

At cosmological scales, one can actually measure two types of distances: luminosity distance \(d_{\rm L}\) and angular diameter distance \(d_{\rm A}\). Within General Relativity, providing there are no processes eliminating photons from the beam, these two distances are related by the so-called distance duality relation. In this paper we used the measurements of the angular diameter distance of 38 cluster of galaxies by Bonamente et al. together with our own fits on the latest Union2 compilation of supernovae to test the distance duality relation in different cosmological models invoked to explain accelerating expansion of the Universe. Our results demonstrate that distance duality violation parameter \(\eta (z)\) does not depend on the cosmological model assumed, but considerably depends on assumptions about mass density distribution profile of the cluster. Maximum likelihood estimates of \(\eta \) might be interpreted as the distance duality violation. However, this effect is more pronounced for isothermal models of clusters than for the models based on hydrostatic equilibrium. This suggests that more sophisticated and accurate modeling of clusters mass density profiles is needed before the X-ray + SZ technique becomes competitive to other methods of measuring distances.


Constraints on Cosmic Equation of State from Joint Analysis of Standard Rulers and Standard Candles

abstract

A key issue of contemporary cosmology is the problem of currently accelerating expansion of the Universe. The nature of this phenomenon is one of the most outstanding problems of physics and astronomy today. Its origin may be attributed to either unknown exotic material component with negative pressure — so-called Dark Energy (DE), to infra red modification of gravity at cosmological scale or requires to relax the assumption of homogeneity of the Universe. The strength of modern cosmology lies in consistency across independent pieces of evidence (like e.g. CMB anisotropies, the large-scale distribution of galaxies, the observed abundances of light elements, etc.) rather than in single one, crucial experiment. In this spirit we performed a joint analysis of two dark energy models using five different tests. These tests will be called diagnostics and include the data coming from supernovae, Gamma Ray Bursts, CMB acoustic peaks, Baryon Acoustic Oscillations and strong lensing systems. Part of the diagnostics makes use of the angular diameter distance, and part of them uses the luminosity distance splitting these probes into two categories: Standard Rules and Standard Candles. It was shown that combined analysis of them had higher restrictive power in the parameter space. The best fits we obtained for the model parameters in joint analysis turned out to prefer cases effectively equivalent to \(\Lambda \)CDM model. Our findings are in agreement with parallel studies performed by other authors on different sets of diagnostic probes.


The Environmental Effects in the Origin of Angular Momenta of Galaxies

abstract

We study the galaxy alignment in the sample of very rich Abell clusters located in and outside superclusters. The statistically significant difference among investigated samples exists. We found that in contrast to the full sample of clusters, where alignment increase with the cluster richness, the clusters belonging to superclusters do not show this effect. Moreover, the alignment decreases with the supercluster richness. One should note however that orientations of galaxies in analyzed clusters are not random, both in the case when we analyzed the full sample of clusters and only clusters belonging to superclusters. The observed trend, dependence of galaxy alignment on both cluster location and supercluster richness clearly supports the idea of influence of environmental effects to the origin of galaxy angular momenta.


Some Observational Aspects of the Orientation of Galaxies

abstract

We investigated the sample of galaxies belonging to the Tully groups of galaxies. We analyzed the orientation of galaxies inside the group. We did not found significant deviation from isotropy both in orientation of position angles or the angles \(\delta _D\) and \(\eta \) giving the spatial orientation of galaxy planes. Moreover, we analyzed consequences of different approximation of “true shape” of galaxies and pointed to possible influence of this problem on the investigation of spatial orientation of galaxies. Implications of the obtained results for the theory of galaxy formation were discussed as well.


Geometries, Quantum Gravity and Quantum Matter in 4-dimensions

abstract

We present arguments that in 4-dimensions quantum matter, geometry and gravity are related in a special, new way. This is based on the geometry of exotic smooth \(\mathbb {R}^4_k\), \(k\) even, which on the one hand underlies the effective states of quantum matter, as in Kondo effect, and on the other, refers to exact superstring backgrounds. This kind of link of geometry and quantum matter allows for quantum treatment of gravity confined to exotic \(\mathbb {R}^4_k\).


New 4D Results from Superstring Theory

abstract

Recent advances in relating superstring theory with dimension 4 via exotic smooth geometries on Euclidean \(\mathbb {R}^4\) are reviewed. The string theory backgrounds and some configurations of Neveu–Schwarz and Dirichlet branes describe exotic open 4-smoothness. This serves as a link to 4D physics.


all authors

G. Cullen, N. Greiner, G. Heinrich, G. Luisoni, P. Mastrolia, G. Ossola, T. Reiter, F. Tramontano

Automation of One-loop Calculations with GoSam: Present Status and Future Outlook

abstract

In this paper, we describe the GoSam (Golem/Samurai) framework for the automated computation of multi-particle scattering amplitudes at the one-loop level. The amplitudes are generated analytically in terms of Feynman diagrams, and can be evaluated using either \(D\)-dimensional integrand reduction or tensor decomposition. GoSam can be used to compute one-loop corrections to Standard Model (QCD and EW) processes, and it is ready to link generic model files for theories Beyond SM. We show the main features of GoSam through its application to several examples of different complexity.


Computational Tools for Hard Scattering Processes

abstract

Some issues related to the computation of hard scattering processes with several particles in the final state at NLO QCD are addressed, along with their solutions.


Simplifying 5-point Tensor Reduction

abstract

The \(5\)-point tensors have the property that after insertion of the metric tensor \(g^{\mu \nu }\) in terms of external momenta, all \(g^{\mu \nu }\)-contributions in the tensor decomposition cancel. If furthermore the tensors are contracted with external momenta, the inverse \(5\)-point Gram determinant \(\left ( \right )_5\) cancels automatically. If the remaining \(4\)-point sub-Gram determinant \(\binom {s}{s}_5\) is not small then this approach appears to be particularly efficient in numerical calculations. We also indicate how to deal with small \(\binom {s}{s}_5\). Explicit formulae for tensors of degree \(2\) and \(3\) are given for large and small (sub-) Gram determinants.


Search for Sterile Neutrinos at Reactors with a Small Core

abstract

The sensitivity to the sterile neutrino mixing at very short baseline reactor neutrino experiments is investigated. If the reactor core is relatively large as in the case of commercial reactors, then the sensitivity is lost for \(\Delta m^2 \gtrsim \) 1 eV\(^2\) due to smearing of the reactor core size. If the reactor core is small as in the case of the experimental fast neutron reactor Joyo, the ILL research reactor or the Osiris reactor, on the other hand, then sensitivity to \(\sin ^22\theta _{14}\) can be as good as 0.03 for \(\Delta m^2 \sim \) several eV\(^2\) because of its small size.


The T2K Experiment: First Results and Future Plans

abstract

T2K is the first off-axis long-baseline neutrino oscillation experiment. It aims at the measurement of the \(\theta _{13}\) mixing angle by the observation of the muon neutrinos into electron neutrinos oscillations. The experiment started to take data in January 2010 and accumulated \(1.43 \times 10^{20}\) protons on target. Six candidates for the \(\nu _e\) appearance have been found, with the expected background of \(1.5 \pm 0.3\). The statistical significance of this observation is \(2.5\sigma \).


Underground Operation of the ICARUS T600 Detector in Gran Sasso Laboratory

abstract

The multipurpose ICARUS T600 detector, with its large sensitive volume, high granularity, excellent tracking and particle identification capabilities, is an ideal device for searching for phenomena beyond the Standard Model. The ICARUS T600 addresses a wide physics program. It is simultaneously collecting a wide variety of “self-triggered” events of different nature, such as cosmic ray events (atmospheric and solar neutrino interactions), and neutrino interactions associated with the CNGS neutrino beam. It will also search for rare events, like a proton decay.


Parametrizing the Neutrino Sector

abstract

The original Standard Model has massless neutrinos, but the observation of neutrino oscillations requires that neutrinos are massive. The simple extension of adding gauge singlet fermions to the particle spectrum allows normal Yukawa mass terms for neutrinos. The seesaw mechanism then suggests an explanation for the observed smallness of the neutrino masses. After reviewing the framework of the seesaw we suggest a parametrization that directly exhibits the smallness of the mass ratios in the seesaw for an arbitrary number of singlet fermions and we present our plans to perform calculations for a process that might be studied at the LHC.


Phenomenological Studies of Top Pair Production at Next-to-Leading Order

abstract

The calculation of NLO QCD corrections to the \(t\bar {t}\to W^{+}W^{-}b\bar {b}\to e^{+}\nu _e \mu ^{-}\bar {\nu }_{\mu }b\bar {b}\) process with complete off-shell effects, is briefly summarized. Besides the total cross-section and its scale dependence, a few differential distributions at the Tevatron Run II and LHC are given. All results presented in this contribution have been obtained with the help of the Helac-NLO Monte Carlo framework.


Phenomenology of \(R\)-symmetric Supersymmetry

abstract

Salient features of the Minimal \(R\)-symmetric Supersymmetric Standard Model and its distinct phenomenological implications at colliders are discussed.


all authors

M. Skrzypek, S. Jadach, A. Kusina, W. Płaczek, M. Slawinska, O. Gituliar

Fully NLO Parton Shower in QCD

abstract

The project of constructing a complete NLO-level Parton Shower Monte Carlo for the QCD processes developed in IFJ PAN in Kraków is reviewed. Four issues are discussed: (1) the extension of the standard inclusive collinear factorization into a new, fully exclusive scheme; (2) reconstruction of the LO Parton Shower in the new scheme; (3) inclusion of the exclusive NLO corrections into the hard process and (4) inclusion of the exclusive NLO corrections into the evolution (ladder) part.


The Effect of Extra Matter on Unification of Yukawa Couplings in MSSM

abstract

In this paper we investigate the effect of extra matter on unification of the third Yukawa couplings in the context of the Minimal Supersymmetric Standard Model using two-loop \(\beta \)-functions.


Universality Violation in Leptonic \(W\) Decays: An Effective Field Theory Approach

abstract

We analyse the deviation from universality in leptonic \(W\) decays suggested by current PDG data within a general effective field theory approach. Considering the constraints to the New Physics effects coming from Electroweak precision observables we are able to set limits on the amount of universality violation that can be accounted for in a broad class of New Physics models. Our approach starts from a usual Single Operator analysis and extends up to considering the interplay of all the effective operators defined by our EFT.


all authors

L. Barzè, G. Balossini, C. Bignamini, C.M. Carloni Calame, G. Montagna, O. Nicrosini, F. Piccinini

Probing Dark Forces at GeV-scale Colliders

abstract

Since the 1980s a broad class of new physics models has postulated the existence of a light, weakly coupled neutral gauge boson (dark photon). In recent years, a wealth of astrophysical anomalies has been explained in terms of this idea, without contradicting existing particle physics data. Because these new GeV-scale bosons communicate with the Standard Model particles, they can be produced in a controlled laboratory environment and low-energy experiments with high luminosity are the prime place to look for such states. Here we focus on the process of associated production of a photon and a dark photon at GeV-scale high-luminosity \(e^+ e^-\) colliders. We present the experimental sensitivity to a dark photon signal of current experiments like KLOE-2 at DA\(\phi \)NE and at a future super\(B\) factory. Our calculation is implemented in an upgraded version of the generator BabaYaga@NLO, available for data analysis in these new physics searches.


A Theoretical Progress on the Calculation of NNLO Leptonic and Hadronic Corrections to Bhabha Scattering and Their Implementation into BabaYaga Monte Carlo Generator

abstract

Tests of the accuracy of NNLO corrections in BabaYaga MC generator are presented for real experimental event selections at meson factories.


New Developments in carlomat

abstract

New developments in carlomat, a program for automatic computation of the lowest order cross-sections, are presented. They include improvements of the phase integration routines and implementation of extensions of the Standard Model, such as scalar electrodynamics or the anomalous \(Wtb\) coupling including operators of dimension up to five.


Scalar Gluons at the LHC

abstract

We investigate phenomenology of scalar gluons (sgluons), as appear in e.g. a hybrid \(N=1/N=2\) or \(R\)-symmetric supersymmetric extension of the Standard Model. Prospects for their discovery at the 7 TeV LHC are discussed.


Physics Beyond Standard Model in Neutron Beta Decay

abstract

Limits from neutron beta decay on parameters describing physics beyond the Standard Model are presented. New Physics is described by the most general Lorentz invariant effective Hamiltonian involving vector, scalar and tensor operators and Standard Model fields only. Two-parameter fits to the decay parameters measured in free neutron beta decay have been done, in some cases indicating rather big dependence of the results on \(g_{\rm A}\)/\(g_{\rm V}\) ratio of nucleon form factors at zero four-momentum transfer.


Non-standard Interactions, Density Matrix and Neutrino Oscillations

abstract

We present an analysis of a neutrino production and detection processes, necessary in order to describe the oscillation phenomena in any model of neutrino interaction. We derive an oscillation probability in the presence of neutrino non-standard interactions and compare the result with the standard approach. Our results are applicable in a very wide class of New Physics models.


Majorana Neutrino Mass Matrix with CP Symmetry Breaking

abstract

From the new existing data with not vanishing \(\theta _{13}\) mixing angle we determine the possible shape of the Majorana neutrino mass matrix. We assume that CP symmetry is broken and all Dirac and Majorana phases are taken into account. Two possible approaches “bottom–up” and “top–down” are presented. The problem of unphysical phases is examined in detail.


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