اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدStudy of the process $e^+e^-toetagamma$ in the center-of-mass energy range 1.07--2.00 GeV
63
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The $e^+e^-toetagamma$ cross section has been measured in the center-of-mass energy range 1.07--2.00 GeV using the decay mode $etato 3pi^0$, $pi^0to gammagamma$. The analysis is based on 36 pb$^{-1}$ of integrated luminosity collected with the SND detector at the VEPP-2000 $e^+e^-$ collider. The measured cross section of about 35 pb at 1.5 GeV is explained by decays of the $rho(1450)$ and $phi(1680)$ resonances.
قيم البحث
اقرأ أيضاً
The process $e^{+}e^{-} rightarrow phieta$ is studied at 22 center-of-mass energy points ($sqrt{s}$) between 2.00 and 3.08 GeV using 715 pb$^{-1}$ of data collected with the BESIII detector. The measured Born cross section of $e^{+}e^{-} rightarrow p
hieta$ is found to be consistent with {textsl{BABAR}} measurements, but with improved precision. A resonant structure around 2.175 GeV is observed with a significance of 6.9$sigma$ with mass ($2163.5pm6.2pm3.0$) MeV/$c^{2}$ and width ($31.1_{-11.6}^{+21.1}pm1.1$) MeV, where the first uncertainties are statistical and the second are systematic.
The dynamics of the process $ e^+e^- to pi^+pi^-pi^0 $ is studied in the energy region from 1.15 to 2.00 GeV using data accumulated with the SND detector at the VEPP-2000 $e^+e^-$ collider. The Dalitz plot distribution and $pi^+pi^-$ mass spectrum ar
e analyzed in a model including the intermediate states $rho(770)pi$, $rho(1450)pi$, and $omegapi^0$. As a result, the energy dependences of the $rho(770)pi$ and $rho(1450)pi$ cross sections and the relative phases between the $rho(770)pi$ amplitude and the $rho(1450)pi $ and $omegapi^0$ amplitudes are obtained. The $rho(1450)pi$ cross section has a peak in the energy region of the $omega(1650)$ resonance (1.55-1.75 GeV). In this energy range the contributions of the $rho(770)pi$ and $rho(1450)pi$ states are of the same order of magnitude. No resonance structure near 1.65 GeV is observed in the $rho(770)pi$ cross section. We conclude that the intermediate state $rho(1450)pi$ gives a significant contribution to the decay of $omega (1650)topi^+pi^-pi^0$, whereas the $rho(770)pi$ mechanism dominates in the decay $omega(1420)topi^+pi^-pi^0$.
The process $e^+e^-toetapi^0gamma$ is studied in the center-of-mass energy range 1.05-2.00 GeV using data with an integrated luminosity of 94.5 pb$^{-1}$ collected by the SND detector at the VEPP-2000 $e^+e^-$ collider. The $e^+e^-toetapi^0gamma$ cro
ss section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $omegaeta$ intermediate state. The measured cross section of the subprocess $e^+e^-toomegaetatoetapi^0gamma$ is consistent with previous measurements in the $e^+e^-topi^+pi^-pi^0eta$ mode. It is found, with a significance of 5.6$sigma$, that the process $e^+e^-toetapi^0gamma$ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $e^+e^-to a_{0}(1450)gamma$, is measured. It is found to be 15-20 pb in the wide energy range from 1.3 to 1.9 GeV.
The cross section for the process e+e- --> omega pi0 --> pi0 pi0 gamma has been measured in the energy range 1.05--2.00 GeV. The experiment has been performed at the e+e- collider VEPP-2000 with the SND detector. The measured e+e- --> omega pi0 cross
section above 1.4 GeV is the most accurate to date. Below 1.4 GeV our data are in good agreement with the previous SND and CMD-2 measurements. Data on the e+e- --> omega pi0 cross section are well described by the VMD model with two excited rho-like states. From the measured cross section we have extracted the gamma^* --> omega pi0 transition form factor. It has been found that the VDM model cannot describe simultaneously our data and data obtained from the omega --> pi0 mu+ mu- decay. We have also tested CVC hypothesis comparing our results on the e+e- --> omega pi0 cross section with data on the tau- --> omega pi- nu_{tau} decay.
In experiment with the SND detector at VEPP-2M $e^+e^-$ collider the $e^+e^-toetagamma$ cross section was measured in the energy range $E$=0.60--1.38 GeV with the integrated luminosity of 27.8 pb$^{-1}$. The measured cross section is well described b
y the vector meson dominance model with contributions from the $rho(770)$, $omega(783)$, $phi(1020)$, $rho^{prime}(1465)$ resonances and agrees with results of previous measurements. The decay probabilities $BR(phitoetagamma)$, $BR(omegatoetagamma)$ and $BR(rhotoetagamma)$ were measured with the accuracies better than or comparable to the world averages.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
