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\Large
\centerline{\bf The DSS Global QCD Analysis of Fragmentation Functions}

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\centerline{Daniel de Florian$^1$, Rodolfo Sassot$^1$, and 
{\underline{Marco Stratmann}}$^2$}

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\noindent
$^1$ Departamento de Fisica, Universidad de Buenos Aires, 
Buenos Aires, Argentina\newline
$^2$ Radiation Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama, Japan

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\noindent
We present new sets fragmentation functions for pions, kaons \cite{ref:dss1}, 
protons, and unidentified charged hadrons \cite{ref:dss2} obtained in NLO combined 
analyses of single-inclusive hadron production in electron-positron annihilation, 
proton-proton collisions, and deep-inelastic lepton-proton scattering. 
At variance with previous fits, the present analyses take into 
account data where hadrons of different electrical charge are identified, 
which allow to discriminate quark from anti-quark fragmentation functions 
without the need of non-trivial flavor symmetry assumptions.
The resulting sets are in good agreement with all data analyzed.
The success of the global analysis performed here, 
including observables other than $e^+e^-$ annihilation, stands
for an explicit check of factorization, universality, and the underlying 
framework of perturbative QCD.

Increasingly accessible hadron production data from proton-proton collisions 
and ha\-dron multiplicities coming from semi-inclusive DIS should not be disregarded as they
offer a crucial piece of complementary information that reduces
significantly the uncertainties of the resulting fragmentation functions. 
For instance, we find that the new DIS pion and kaon multiplicities provided 
by the HERMES experiment effectively constrain the separation between favored 
and unfavored distributions, a separation that was either not implemented in previous 
sets or it was based on certain assumptions.
The most recent RHIC results provide stringent constraints on the
gluon fragmentation function and, in general, on the large $z$ behavior
of the other distributions.

The implementation of the $\chi^2$ minimization in our global analysis is
numerically fast and efficient and can be straightforwardly expanded to any
future set of hadron production data. With the help of the Mellin moment technique
\cite{ref:mellin}, the entire analysis was consistently performed at NLO accuracy without
resorting to often used approximations for NLO hard scattering cross sections.
For completeness we also provide LO sets.
An extensive use of the Lagrange multiplier technique \cite{ref:lagrange} is made in order to
assess the typical uncertainties in the extraction of the fragmentation functions and
the synergy from the complementary data sets in our global analysis.

\begin{thebibliography}{99}
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\small
\bibitem{ref:dss1} D.\ de Florian, R.\ Sassot, and M.\ Stratmann,
Phys. Rev. {\bf D75}, 114010 (2007).
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\bibitem{ref:dss2} D.\ de Florian, R.\ Sassot, and M.\ Stratmann,
Phys. Rev. {\bf D76}, 074033 (2007).
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\bibitem{ref:mellin} M.\ Stratmann and W.\ Vogelsang, Phys. Rev. {\bf D64},
114007 (2001).
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\bibitem{ref:lagrange} See, e.g., D.\ Stump {\em et al.},
Phys. Rev. {\bf D65}, 014012 (2002).
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