اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدGasser-Leutwyler coefficients: A progress report
45
0
0.0
(
0
)
تأليف
George T. Fleming
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Last year, we reported our first results on the determination of Gasser-Leutwyler coefficients using partially quenched lattice QCD with three flavors of dynamical staggered quarks. We give an update on our progress in determining two of these coefficients, including an exhaustive effort to estimate all sources of systematic error. At this conference, we have heard about algorithmic techniques to reduce staggered flavor symmetry breaking and a method to incorporate staggered flavor breaking into the partially quenched chiral Lagrangian. We comment on our plans to integrate these developments into our ongoing program.
قيم البحث
اقرأ أيضاً
Some modifications of the Luscher algorithm, which reduce the autocorelation time, are proposed and tested.
We report on progress and future plans for calculating kaon weak matrix elements for epsilon/epsilon using staggered fermions.
We present a report on the status of the GRAL project (Going Realistic And Light), which aims at simulating full QCD with two dynamical Wilson quarks below the vector meson decay threshold, m_ps/m_v < 0.5, making use of finite-size-scaling techniques.
Our progress in computing the spectrum of excited baryons and mesons in lattice QCD is described. Sets of spatially-extended hadron operators with a variety of different momenta are used. A new method of stochastically estimating the low-lying effect
s of quark propagation is utilized which allows reliable determinations of temporal correlations of both single-hadron and multi-hadron operators. The method is tested on the isoscalar mesons in the scalar, pseudoscalar, and vector channels, and on the two-pion system of total isospin I=0,1,2.
MOSARIX is a collaborative project between three research group in Sorbonne University to build a x-ray spectrometer (2-5 keV) portable to large scale facilities with high efficiency and good resolution. X-ray spectroscopy and coincidences experiment
are planned. A prototype with a single HADP crystal with von Hamos geometry has been tested (resolution and efficiency). A fast time and position detector has been realized (patent and publication).We plan to build the spectrometer with 8 HADP (or 4) crystals under Helium atmosphere using a TimePix3 or a CCD camera. MOSARIX is a project of an x-ray spectrometer in the tender x-ray domain (2-5 keV) with high efficiency, allowing performing x-ray emission and coincidences (or covariance mapping) experiments using synchrotron radiation, XFEL, the future installation SPIRAL2/GANIL or CRYRING/FAIR. It involves 2 groups at LCPMR (Francis PENENT and Marc SIMON) and one group at INSP (Dominique VERNHET). The coincidences/covariance measurements will be between x-ray photons and ions or electrons. It would be the first time for such coincidences with energy-resolved photons. The spectrometer will be portable and will be brought to the different large-scale facilities. MOSARIX is a multi-crystal HAPG von Hamos spectrometer optimized for the 2-5 keV photon energy range. Its resolving power E/DE will be 4000. It will be equipped with a fast time and position sensitive detection system, allowing performing coincidences, or with a CCD camera. I. Scientific case and some possible experiments The accelerated development of x-ray sources, as 3 rd generation synchrotrons (and recent upgrades) or free-electron lasers, has opened new opportunities to investigate new phenomena by means of photoelectron and Auger spectroscopy, electron-ion coincidence techniques and x-ray emission. However, several processes of high scientific interests are still hard to measure; some of them require the measurement of photons with high efficiency, high resolution and even sometimes in coincidence mode. This is the purpose of MOSARIX development. As an example, we propose to revisit Resonance-Enhanced X-ray Multiple Ionization (REXMI) 1 with a significant amelioration of the detection of photons, i.e. measuring the photons not only with high efficiency and high resolution but also in coincidence with ions or electrons. This will allow accessing the involved intermediate states and obtaining a clearer image of the dynamic of the multiple ionization process. MOSARIX can also be used for the investigation of very low cross-section phenomena such as attosecond electron dynamics 2 and High-Energy Resolution Off-Resonant Spectroscopy (HEROS) 3,4. X-ray spectroscopy has also proved to be a very powerful tool to investigate quantum dynamics in heavy ions collisions with matter of whatever nature, dilute or condensed 5-7. A
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
