اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدEvidence of strong higher twist effects in diffractive DIS at HERA at moderate Q2
133
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We study a twist decomposition of diffractive structure functions in the diffractive deep inelastic scattering (DDIS) at HERA. At low Q2 and at large energy the data exhibit a strong excess, up to about 100%, above the twist 2 NLO DGLAP description. The excess in consistent with higher twist effects. It is found, that complementing the DGLAP fit by twist 4 and 6 components of the GBW saturation model leads to a good description of data at low Q2. We conclude that the DDIS at HERA provides the first, strong evidence of higher twist effects in DIS.
قيم البحث
اقرأ أيضاً
HERA data on diffractive DIS show deviations from twist 2 DGLAP predictions below $Q^2sim 5$ GeV$^2$ at low pomeron $xi$, which may reach up to 100%. These deviations are consistent with higher twists effects extracted from the saturation model. It i
s a first direct evidence for the higher twists in DIS. This finding affects determination of the diffractive parton densities that are used for the predictions at the LHC.
A recent H1 measurement of triple differential dijet cross sections in electron-proton interactions in the region of photon virtualities 2<Q2<80 GeV is presented and compared to LO and NLO QCD predictions. Effects that go beyond the fixed-order NLO QCD calculations are identified.
In this letter we report the direct perturbative QCD evaluation of twist-4 effects in diffractive DIS. They are large and have a strong impact on the $Q^2$ dependence of diffractive structure functions at large $beta$. Based on the AGK rules, we comm
ent on the possible contribution from diffractive higher twists to $propto {1 over Q^{2}}$ corrections to proton structure function at small $x$. These corrections to the longitudinal structure function $F_{L}$ may be particularly large.
The higher twist corrections $h^N(x)/Q^2$ to the spin dependent proton and neutron $g_1$ structure functions are extracted from the world data on $g_1(x,Q^2)$ in a model independent way and found to be non-negligible. Their role in determining the po
larized parton densities in the nucleon is discussed. It is also considered how the results are influenced by the recent JLab and HERMES/d inclusive DIS data.
We present a NLO calculation of prompt photon production in DIS. The calculation involves direct, fragmentation and resolved contributions. It is performed in the virtual-photon proton center-of-mass system. A comparison of the theoretical results with HERA data is carried out.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
