Soft Gluon Logarithmic Resummation and Hadron Mass Effects in Single Hadron Inclusive Production

We define a general scheme for the evolution of fragmentation functions which resums soft gluon logarithms in a manner consistent with fixed order evolution. We present an explicit example of our approach in which double logarithms are resummed using the Double Logarithmic Approximation. We show that this scheme reproduces the Modified Leading Logarithm Approximation in certain limits, and find that after using it to fit quark and gluon fragmentation functions to experimental data,a good description of the data from the largest x values to the peak region in ln (1/x) is obtained. In addition, we develop a treatment of hadron mass effects which gives additional improvements at small x.Comment: Prepared for Ringberg Workshop: New Trends in HERA Physics 2005, October 2 - 7, 200

Quark and lepton masses and mixing from a gauged SU(3)_F family symmetry with a light O(eV) sterile Dirac neutrino

In the framework of a complete vector-like and universal gauged SU(3)_F family symmetry, we report a global region in the parameter space where this approach can account for a realistic spectrum of quark masses and mixing in a 4 x 4 non-unitary V_{CKM}, as well as for the known charged lepton masses and the squared neutrino mass differences reported from neutrino oscillation experiments. The $SU(3)_F$ family symmetry is broken spontaneously in two stages by heavy SM singlet scalars, whose hierarchy of scales yield and approximate SU(2)_F global symmetry associated to the almost degenerate boson masses of the order of the lower scale of the SU(3)_F SSB. The gauge symmetry, the fermion content, and the transformation of the scalar fields, all together, avoid Yukawa couplings between SM fermions. Therefore, in this scenario ordinary heavy fermions, top and bottom quarks and tau lepton, become massive at tree level from Dirac See-saw mechanisms, while light fermions, including light neutrinos, obtain masses from radiative corrections mediated by the massive gauge bosons of the SU(3)_F family symmetry. The displayed fit parameter space region solution for fermion masses and mixing yield the vector-like fermion masses: M_D \approx 3.2 \,TeV, M_U \approx 6.9 \,TeV, M_E \approx 21.6 \,TeV, SU(2)_F family gauge boson masses of $\mathcal{O} (2 TeV)$, and the squared neutrino mass differences: m_2^2-m_1^2 \approx 7.5 x 10^{-5}\;eV^2, m_3^2-m_2^2 \approx 2.2 x 10^{-3}\;eV^2, m_4^2-m_1^2 \approx 0.82\;eV^2.Comment: 19 pages, 1 figure, Contribution to Proceedings of the 19th Workshop "What Comes Beyond the Standard Models", July 11-19, Bled, Slovenia. arXiv admin note: substantial text overlap with arXiv:1602.08212, arXiv:1212.457

The industrial symbiosis approach: A classification of business models

Industrial symbiosis is a collaborative approach concerning physical exchange of materials, energy, and services among different firms: accordingly, wastes produced by a given firm are exploited as inputs by other firms. This approach is able to generate remarkable environmental benefits, since it allows to reduce the amount of wastes disposed of in the landfill and the amount of primary inputs used by the industrial sector. It has been proved that the economic logic is the basis of symbiotic exchanges. Through industrial symbiosis, firms are interested to achieve competitive advantage coming from lower production costs and revenue increase. Therefore, the first requirement for the establishment of a symbiotic relationship is its economic sustainability for all the firms involved. In this paper, from the analysis of actual cases of industrial symbiosis, we develop a classification of business models oriented to the symbiotic approach. The classification is based on the different ways in which industrial symbiosis is able to generate economic benefits for the firm that implements it. Six different business models oriented to industrial symbiosis have been identified. The proposed classification could be useful at the company level, in order to promote the implementation of the symbiotic approach, providing a guide about how to integrate it within its current business models

The non-singlet kaon fragmentation function from e^+e^- kaon production

We perform fits to the available charged and neutral kaon production data in $e^++e^-\to K+X$, $K=K^\pm and K^0_S$, and determine the non-singlet combination of kaon fragmentation functions $D_u^{K^\pm}-D_d^{K^\pm}$ in a model independent way and without any correlations to the other fragmentation functions. Only nuclear isospin invariance is assumed. Working with non-singlets allows us to include the data at very low momentum fractions, which have so far been excluded in global fits, and to perform a first NNLO fit to fragmentation functions. We find that the kaon non-singlet fragmentation function at large $z$ is larger than that obtained by the other collaborations from global fit analysis and differs significantly at low $z$

Fully double-logarithm-resummed cross sections

We calculate the complete double logarithmic contribution to cross sections for semi-inclusive hadron production in the modified minimal-subtraction scheme by applying dimensional regularization to the double logarithm approximation. The full double logarithmic contribution to the coefficient functions for inclusive hadron production in electron-positron annihilation is obtained in this scheme for the first time. Our result agrees with all fixed order results in the literature, which extend to next-next-to-leading order.Comment: To appear in Nuclear Physics