J.H. Vossebeld

Measurement of the proton structure function F-2 at very low Q(2) at HERA

A measurement of the proton structure function F_2(x,Q^2) is presented in the kinematic range 0.045 GeV^2<Q^2<0.65 GeV^2 and 6*10^{-7}<x<1*10^{-3}. The results were obtained using a data sample corresponding to an integrated luminosity of 3.9pb^-1 in e^+p reactions recorded with the ZEUS detector at HERA. Information from a silicon-strip tracking detector, installed in front of the small electromagnetic calorimeter used to measure the energy of the final-state positron at small scattering angles, together with an enhanced simulation of the hadronic final state, has permitted the extension of the kinematic range beyond that of previous measurements. The uncertainties in F_2 are typically less than 4%. At the low Q^2 values of the present measurement, the rise of F_2 at low x is slower than observed in HERA data at higher Q^2 and can be described by Regge theory with a constant logarithmic slope. The dependence of F_2 on Q^2 is stronger than at higher Q^2 values, approaching, at the lowest Q^2 values of this measurement, a region where F_2 becomes nearly proportional to Q^2.A measurement of the proton structure function F-2(x, Q(2)) is presented in the kinematic range 0.045 GeV2 lt Q(2) lt 0.65 GeV2 and 6 . 10(-7) lt x lt 1 . 10(-3). The results were obtained using a data sample corresponding to an integrated luminosity of 3.9 pb(-1) in e(+)p reactions recorded with the ZEUS detector at HERA. Information from a silicon-strip tracking detector, installed in front of the small electromagnetic calorimeter used to measure the energy of the final-state positron at small scattering angles, together with an enhanced simulation of the hadronic final state, has permitted the extension of the kinematic range beyond that of previous measurements. The uncertainties in F-2 are typically less than 4%. At the low Q(2) values of the present measurement, the rise of F-2 at low x is slower than observed in HERA data at higher Q(2) and can be described by Regge theory with a constant logarithmic slope partial derivative lnF(2)/partial derivative ln(1/x). The dependence of F-2 on Q(2) is stronger than at higher Q(2) values, approaching, at the lowest Q(2) values of this measurement, a region where F-2 becomes nearly proportional to Q(2).

Measurement of D*(+/-) production and the charm contribution to F-2 in deep inelastic scattering at HERA

Abstract. The production of n

Exclusive electroproduction of \(\rho^0\) and \(J/\psi\) mesons at HERA

D^{ast pm}

Elastic and proton-dissociative \(\rho^0\) photoproduction at HERA

(2010) mesons in deep inelastic scattering has been measured in the ZEUS detector at HERA using an integrated luminosity of 37 pbn

Measurement of elastic

^{-1}

\phi

. The decay channels n

photoproduction at HERA

D^{ast +}rightarrow D^0 pi^+

Measurement of the F-2 structure function in deep inelastic e(+)p scattering using 1994 data from the ZEUS detector at HERA

(+ c.c.), with n

D* Production in deep inelastic scattering at HERA

D^0 rightarrow K^- pi^+

Measurement of open beauty production in photoproduction at HERA

or n