Multiparton scattering at the LHC

The large parton flux at high energy gives rise to events where different pairs of partons interact contemporarily with large momentum exchange. A main effect of multiple parton interactions is to generate events with many jets at relatively large transverse momenta. The large value of the heavy quarks production cross section may however give also rise a sizable rate of events with several $b$-quarks produced. We summarize the main features of multiparton interactions and make some estimate of the inclusive cross section to produce two $b{\bar b}$ pairs within the acceptance of the ALICE detector.Comment: 10 pages, 4 figures, contribution to ALICE PP

b \bar b b\bar b production in proton-nucleus collisions at the LHC

A sizable rate of events, with several pairs of $b$-quarks produced contemporarily by multiple parton interactions, may be expected at very high energies as a consequence of the large parton luminosities. The production rates are further enhanced in hadron-nucleus reactions, which may represent a convenient tool to study the phenomenon. We compare the different contributions to $b{\bar b}b{\bar b}$ production, due to single and double parton scatterings, in collisions of protons with nuclei at the CERN-LHC.Comment: 13 pages, 4 figure

The Nature and Function of Languages

Several studies in philosophy, linguistics and neuroscience have tried to define the nature and functions of language. Cybernetics and the mathematical theory of communication have clarified the role and functions of signals, symbols and codes involved in the transmission of information. Linguistics has defined the main characteristics of verbal communication by analyzing the main tasks and levels of language. Paleoanthropology has explored the relationship between cognitive development and the origin of language in Homo sapiens. According to Daniel Dor, language represents the most important technological invention of human beings. Seemingly, the main function of language consists of its ability to allow the sharing of the mind’s imaginative products. Following language’s invention, human beings have developed multiple languages and cultures, which, on the one hand, have favored socialization within communities and, on the other hand, have led to an increase in aggression between different human groups

Effects of Mindfulness Training on School Teachers\u2019 Self-Reported Personality Traits As Well As Stress and Burnout Levels

Among a sample of only female school teachers, we compared a mindfulness meditation (MM) training group (n = 19) with a waiting-list control group (n = 20) on several participant-completed questionnaires: the Five Facet Mindfulness Questionnaire, the Big Five Personality Inventory, the Teacher Stress Inventory, and the Maslach Burnout Inventory. With these measures, we assessed the participants\u2019 dispositional mindfulness, personality styles, and their stress and burnout. Following mindfulness training, teachers in the MM group showed higher trait mindfulness and conscientiousness and lower neuroticism and stress and burnout levels than teachers in the waiting-list control group. These results support the beneficial role of MM in individuals\u2019 effective management of stressful conditions in the workplace

Double parton distributions in the leading logarithm approximation of perturbative QCD

Recent CDF measurements of the inclusive cross section for a double parton scattering attach a great importance to any theoretical calculations of two-particle distribution functions. Using a parton interpretation of the leading logarithm diagrams of perturbative QCD theory, generalized Lipatov-Altarelli-Parisi-Dokshitzer equations for the two-parton distributions are re-obtained. The solutions of these equations are not at all the product of two single-parton distributions what is usually applied to the current analysis as ansatz.Comment: 8 pages, LaTe

Scale Factor in Double Parton Collisions and Parton Densities in Transverse Space

The scale factor $\sigma_{eff}$, which characterizes double parton collisions in high energy hadron interactions, is a direct manifestation of the distribution of the interacting partons in transverse space, in such a way that different distributions give rise to different values of $\sigma_{eff}$ in different double parton collision processes. We work out the value of the scale factor in a few reactions of interest, in a correlated model of the multi-parton density of the proton recently proposed.Comment: 10 pages, 2 figure

Production and detection of doubly charmed tetraquarks

The feasibility of tetraquark detection is studied. For the cc\bar{u}\bar{d} tetraquark we show that in present (SELEX, Tevatron, RHIC) and future facilities (LHCb, ALICE) the production rate is promising and we propose some detectable decay channels.Comment: 6 pages, 5 figure

Fractional momentum correlations in multiple production of W bosons and of b-anti_b pairs in high energy pp collisions

Multiple parton collisions will represent a rather common feature in pp collisions at the LHC, where regimes with very large momentum transfer may be studied and events rare in lower energy accelerators might occur with a significant rate. A reason of interest in large p_t regimes is that, differently from low p_t, evolution will induce correlations in x in the multiparton structure functions. We have estimated the cross section of multiple production of W bosons with equal sign, where the correlations in x induced by evolution are particularly relevant, and the cross section of b-bar_b b-bar_b production, where the effects of evolution are much smaller. Our result is that, in the case of multiple production of W bosons, the terms with correlations may represent a correction of the order of 40% of the cross sections, for pp collisions at 1 TeV c.m. energy, and a correction of the order of 20% at 14 TeV. In the case of b-bar_b pairs the correction terms are of the order of 10-15% at 1 TeV and of the order of 5% at 14 TeV.Comment: Submitted to Phys. Rev.