Recent issues in hadron spectroscopy

A brief survey is presented of recently discovered hadrons, some of them presumably demonstrating a new kind of internal structure. This includes : spin-singlet quarkonium, mesons with unexpected mass or width, baryons with two heavy quarks, and pentaquark candidates. Flavour configurations with a combination of light and heavy quarks appear as particularly promising.Comment: Based on an invited talk at the session on Subnucleon degrees of freedo

Historical Survey of the Quasi-Nuclear Baryonium

We review ideas and speculations concerning possible bound states or resonances of the nucleon--antinucleon system.Comment: 12 pages, Talk at the Workshop on Hadron Spectroscopy, Frascati, Italy, march 199

Safe domain and elementary geometry

A classical problem of mechanics involves a projectile fired from a given point with a given velocity whose direction is varied. This results in a family of trajectories whose envelope defines the border of a 'safe' domain. In the simple cases of a constant force, harmonic potential and Kepler or Coulomb motion, the trajectories are conic curves whose envelope in a plane is another conic section which can be derived either by simple calculus or by geometrical considerations. The case of harmonic forces reveals a subtle property of the maximal sum of distances within an ellipse.Comment: Also available from http://democrite.in2p3.fr/democrite-0002317

Positivity domains for pairs of triples of spin observables

Positivity restrains the allowed domains for pairs or triples of spin observables in polarised reactions. Various domain shapes in ${1\over2}+{1\over2}\to{1\over2}+{1\over2}$ reactions are displayed. Some methods to determine these domains are mentioned and a new one based on the anticommutation between two observables is presented.Comment: Talk given by Xavier Artru at "DSPIN-07", XII Workshop on High-Energy Spin Physics, Dubna, Sept. 3-7, 2007, to appear in the Proceeding

Spiritual Well-Being, Self-Esteem and Intimacy Among Couples Using Natural Family Planning

Making decisions about achieving and avoiding pregnancy and the methods used to attain those ends are some of the most central decisions during a couple\u27s reproductive life. Health professionals (especially professional nurses) are often consulted to aid couples in their reproductive decisions and provide couples with choices of reproductive control. Information provided on family planning choices, however, is often limited and usually involves issues of effectiveness to avoid pregnancy, convenience, health risks, and life-style preferences.1,2 Little information is provided on how family planning methods compare on psychological, spiritual, and social well-being variables. One method of family planning that needs further study on these variables is Natural Family Planning (NFP). The purpose of this study was to describe how NFP influenced the intimacy, self-esteem, and the spiritual well-being of couples who used NFP to avoid pregnancy for at least a one year period. A secondary purpose was to describe and compare the intimacy, self-esteem and spiritual well-being of couples who stopped using NFP and who have used contraception for at least a year

Stability of multiquarks in a simple string model

A simple string model inspired by the strong-coupling regime of Quantum ChromoDynamics is used as a potential for studying the spectrum of multiquark systems with two quarks and two antiquarks, with a careful treatment of the four-body problem. It is found that the ground state is stable, lying below the threshold for dissociation into two isolated mesons.Comment: 4 pages, 2 figures, Refs. added, typos corrected, discussion improved, to appear in Phys. Rev.

Comments on "Observation of Long-Range, Near-Side Angular Correlations in Proton-Proton Collisions at the LHC" by the CMS collaboration(arXiv:1009.4122v1 [hep-ex])"

It is the purpose of this note to point out that the CMS observation is in line with previous observations in particle physics at large transverse momenta and/or high multiplicities at lower energies, which were interpreted as possible evidence for quark-gluon plasma (QGP), and to suggest other features of the QGP observed in A+A collisions such as radial flow and jet quenching, which should be investigated in p-p collisions in order to provide further evidence for QGP production

Evaluation of Pit-trap Transects With Varied Trap Spacing in a Northern Michigan Forest

The study compared effects of four distances between traps (range 0.5-4.0 m) on arthropod captures. Twelve traps were aligned in each of four transects, and 20 samples. trap were obtained during summer and fall in a northern Michigan deciduous forest. Catches proved to be unaffected by trap spacing. Rather, they reflected local within-site differences in abundance of dominant species

Graph Laplacians and Stabilization of Vehicle Formations

Control of vehicle formations has emerged as a topic of significant interest to the controls community. In this paper, we merge tools from graph theory and control theory to derive stability criteria for formation stabilization. The interconnection between vehicles (i.e., which vehicles are sensed by other vehicles) is modeled as a graph, and the eigenvalues of the Laplacian matrix of the graph are used in stating a Nyquist-like stability criterion for vehicle formations. The location of the Laplacian eigenvalues can be correlated to the graph structure, and therefore used to identify desirable and undesirable formation interconnection topologies

Relation between Tcc,bbT_{cc,bb} and Xc,bX_{c,b} from QCD

We have studied, using double ratio of QCD (spectral) sum rules, the ratio between the masses of $T_{cc}$ and X(3872) assuming that they are respectively described by the $D-{D}^*$ and $D-\bar{D}^*$ molecular currents. We found (within our approximation) that the masses of these two states are almost degenerate. Since the pion exchange interaction between these mesons is exactly the same, we conclude that if the observed X(3872) meson is a $D\bar{D}^*+c.c.$ molecule, then the $DD^*$ molecule should also exist with approximately the same mass. An extension of the analysis to the $b$-quark case leads to the same conclusion. We also study the SU(3) breakings for the $T^s_{QQ}/T_{QQ}$ mass ratios. Motivated by the recent Belle observation of two $Z_b$ states, we revise our determination of $X_b$ by combining results from exponential and FESR sum rules.Comment: revised version to appear on Phys. Lett.