اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدNeutral pion form factor measurement at NA62
62
0
0.0
(
0
)
تأليف
Evgueni Goudzovski
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The NA62 experiment at CERN collected a large sample of charged kaon decays with a highly efficient trigger for decays into electrons in 2007. The kaon beam represents a source of tagged neutral pion decays in vacuum. A measurement of the electromagnetic transition form factor slope of the neutral pion in the time-like region from $1.05times10^6$ fully reconstructed $pi^0$ Dalitz decay is presented. The limits on dark photon production in $pi^0$ decays from the earlier kaon experiment at CERN, NA48/2, are also reported.
قيم البحث
اقرأ أيضاً
The update of the e^+e^-topi^+pi^- process cross section, measured in the energy region sqrt{s}<1 GeV with SND detector at VEPP-2M collider is presented.
We report the first measurement of the parity-violating asymmetry in elastic electron scattering from the proton. The asymmetry depends on the neutral weak magnetic form factor of the proton which contains new information on the contribution of stran
ge quark-antiquark pairs to the magnetic moment of the proton. We obtain the value $G_M^Z= 0.34 pm 0.09 pm 0.04 pm 0.05$ n.m. at $Q^2=0.1$ (GeV/c)${}^2$.
The electromagnetic form factor of the pion in the space-like region, and at finite temperature, $F_{pi}(Q^{2},T)$, is obtained from a QCD Finite Energy Sum Rule. The form factor decreases with increasing T, and vanishes at some critical temperature,
where the pion radius diverges. This divergence may be interpreted as a signal for quark deconfinement.
The pion electromagnetic form factor and two-pion production in electron-positron collisions are simultaneously fitted by a vector dominance model evolving to perturbative QCD at large momentum transfer. This model was previously successful in simult
aneously fitting the nucleon electromagnetic form factors (spacelike region) and the electromagnetic production of nucleon-antinucleon pairs (timelike region). For this pion case dispersion relations are used to produce the analytic connection of the spacelike and timelike regions. The fit to all the data is good, especially for the newer sets of time-like data. The description of high-$q^2$ data, in the time-like region, requires one more meson with $rho$ quantum numbers than listed in the 2014 Particle Data Group review.
We report a measurement of the process gamma gamma* --> pi0 with a 759 fb^{-1} data sample recorded with the Belle detector at the KEKB asymmetric-energy e+e- collider. The pion transition form factor, F(Q^2), is measured for the kinematical region 4
GeV^2 <~ Q^2 <~ 40 GeV^2, where -Q^2 is the invariant mass squared of a virtual photon. The measured values of Q^2|F(Q^2)| agree well with the previous measurements below Q^2 ~= 9 GeV^2 but do not exhibit the rapid growth in the higher Q^2 region seen in another recent measurement, which exceeds the asymptotic QCD expectation by as much as 50%.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
