Photofission of heavy nuclei at energies up to 4 GeV.
نویسندگان
چکیده
Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and natPb have been measured simultaneously, using tagged photons in the energy range Egamma=0.17-3.84 GeV. This was the first experiment performed using the Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the photofission cross section for 238U relative to that for 237Np is about 80% over the entire energy range, implying the presence of important processes which compete with fission. If we assume that for 237Np the photofission probability is equal to unity, we observe a significant shadowing effect, starting below 1.5 GeV.
منابع مشابه
Massive Constituent Quarks and Unified Description of Freeze-out Parameters: Does Qgp Form at Low Energies?
The possibility of unified description of hadron multiple production in heavy ion collisions over the wide energy interval, from few hundreds MeV/n at GSI/SIS through 11 GeV/n at BNL/AGS up to 160 GeV/n at CERN/SPS, has been emphasized recently by J. Cleymans and K. Redlich (CR) [1]. They, and somewhat later B. Muller and J. Rafelski [2], treated this fact as an indication that quark-gluon plas...
متن کاملOn the heavy-quark states interactions with nucleons and nuclei
601 The method of multipole expansion in QCD is used to calculate the scattering amplitudes of heavy-quark ( QQ)-states on hadrons. The amplitudes near threshold and the total cross sections for (QQ)hinteractions at different energies are calculated. It is pointed out that these cross sections are small at energies of (QQ)-system E < 50 GeV. This result has serious implications for the models, ...
متن کاملStudy of the Jet Shape at 920 GeV / c in Proton - Nucleus Interactions with HERA - B Detector
We performed a measurement of differential and integral jet shapes in proton-carbon, proton-tungsten and proton-aluminium collisions at 920 GeV/c proton momentum with the HERA-B detector at HERA for the jet transverse energies in the range 4 < ET (jet) < 12 GeV. Jets were identified using the kT-clustering algorithm. The measurements were performed for the hardest jet in the event, directed tow...
متن کاملPhysics Opportunities in Ultraperipheral Heavy Ion Collisions at Lhc
Due to coherence, there are strong electromagnetic fields of short duration in very peripheral heavy ion collisions. They give rise to photon-photon and photon-nucleus collisions with high flux up to an invariant mass region hitherto unexplored experimentally. Photon-photon and photon-hadron physics at various invariant mass scales are discussed. Due to the very strong electromagnetic fields th...
متن کاملتوزیع چندگانگی ذرات باردار در نابودی +e-e در انرژی مرکز جرم GeV54-57 و مقیاس KNO
In this paper, we investigate the multiplicity of charged particles in e+ e– annihilation by using different models. To achieve this we first fit the multiplicity distribution of charged particles in the energy range of 54-57 GeV by using both the Poisson distribution and KNO scaling, then we compare these results with multiplicity distribution at the lower energies. This comparison shows that...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 84 25 شماره
صفحات -
تاریخ انتشار 2000