Semi-inclusive hadron production at DESY HERA: The effect of QCD gluon resummation

Abstract

We present a formalism that improves the applicability of perturbative QCD in the current region of semi-inclusive deep inelastic scattering. The formalism is based on all-order resummation of large logarithms arising in the perturbative treatment of hadron multiplicities and energy flows in this region. It is shown that the current region of semi-inclusive DIS is similar to the region of small transverse momenta in vector boson production at hadron colliders. We use this resummation formalism to describe transverse energy flows and charged particle multiplicity measured at the electron-proton collider HERA. We find good agreement between our theoretical results and experimental data for the transverse energy flows.

Extraction of partonic transverse momentum distributions from semi-inclusive deep-inelastic scattering, Drell-Yan and Z-boson production

“…[76] the authors fitted Hermes and Compass multiplicities separately (576 and 6284 points respectively), without TMD evolution and introducing an ad-hoc normalization for Compass data. A fit of SIDIS data including TMD evolution was performed on measurements by the H1 collaboration of the so-called transverse energy flow [55,94].…”

A New Micromachined Bandpass Filter on a Quartz Substrate

“…[4] that effects due to small-x enhancements that were suggested by phenomenological studies [6] for semi-inclusive DIS (SIDIS) Q t distributions, could be very significant (especially in the context of massive vector-boson production) when extrapolated to the smaller x values that will be important at the LHC. It was also suggested in ref.…”

“…This is also a different quantity from the resummed z flow studied in refs. [4,6] while also being directly related to the Drell-Yan Q t spectra and thus should provide an independent probe of small-x broadening effects.…”

“…If discrepancies are visible at low x then one may consider a small-x enhanced smearing function as was the case in refs. [4,6]. This is certainly not a substitute for a detailed treatment based on a physical understanding of the small-x region but merely a phenomenological investigation into how such effects may be parameterised if present in the first place.…”

SIDIS cross sections: perturbative and non-perturbative aspects

“…The CSS resummation scheme was originally developed for DY processes, but can be applied to SemiInclusive Deep Inelastic Scattering (SIDIS) reactions as well. For unpolarized SIDIS processes, N → hX, the following CSS expression [7,8] holds…”