Properties of the B-meson light-cone wavefunction up to next-to-leading order Fock state expansion are studied by a comparative study of the B → π, K form factors within the kT factorization approach and the light-c...Properties of the B-meson light-cone wavefunction up to next-to-leading order Fock state expansion are studied by a comparative study of the B → π, K form factors within the kT factorization approach and the light-cone sum rule analysis. The form factors F＋,0,T^B→ π and F＋,0,T^B→ K are carefully re-calculated up to O（1/mb^2） within the kT factorization approach in the large recoil region. The QCD light-cone sum rule is applicable in the large and intermediate energy regions, and the QCD light-cone sum rule results in Ref. [12] are adopted for such a comparative study. It is found that when the two phenomenological parameters ∧^-∈ [0.50, 0.55] and δ∈ [0.25, 0.30], the results of F＋,0,T^B→ π （Q^2 ） and F＋,0,T^B→ K（Q ^2） from these two approaches are consistent with each other in the large recoil energy region.展开更多
A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products o...A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis, modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC). The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel elec- trophoresis, there was no observable product in the range of 1,000 ? 30,000 (m/q) using MALDI-TOF, and small bio- molecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.展开更多
We present a short review on the properties of heavy and light mesons’light-cone wavefunctions(LCWFs),and their distribution amplitudes(DAs).The B meson LCWFs can be treated by taking the heavy quark limit(mb!1)and b...We present a short review on the properties of heavy and light mesons’light-cone wavefunctions(LCWFs),and their distribution amplitudes(DAs).The B meson LCWFs can be treated by taking the heavy quark limit(mb!1)and by using the heavy quark effective theory.Furthermore,we propose a simple model for the B meson wavefunctions with 3-particle Fock states’contributions,whose behaviors are controlled by two parameters K and d.Using such model,the form factors FB!p t;0;Tand FB!K t;0;Tin large recoil region are studied up to Oe1=m2bT within the kTfactorization approach.On the other hand,we adopt BrodskyHuang-Lepage(BHL)prescription for constructing the WFs of the lighter pseudoscalars as gc;D-meson,pion,kaon,ge0T and etc.Such BHL-like model can be conveniently extended to construct the LCWFs for light scalar or vector mesons.Within such model the longitudinal distributions of those WFs are basically determined by a parameter B,whose value can be determined via a global fit of experimental data.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10805082, and the Natural Science Foundation of Zhongqing City under Grant No 2008BB0298.
文摘Properties of the B-meson light-cone wavefunction up to next-to-leading order Fock state expansion are studied by a comparative study of the B → π, K form factors within the kT factorization approach and the light-cone sum rule analysis. The form factors F＋,0,T^B→ π and F＋,0,T^B→ K are carefully re-calculated up to O（1/mb^2） within the kT factorization approach in the large recoil region. The QCD light-cone sum rule is applicable in the large and intermediate energy regions, and the QCD light-cone sum rule results in Ref. [12] are adopted for such a comparative study. It is found that when the two phenomenological parameters ∧^-∈ [0.50, 0.55] and δ∈ [0.25, 0.30], the results of F＋,0,T^B→ π （Q^2 ） and F＋,0,T^B→ K（Q ^2） from these two approaches are consistent with each other in the large recoil energy region.
文摘A study of the fragments of DNA irradiated with MeV ions is important for the understanding of the DNA damage mechanism and the subsequent biological effects (induced by heavy ions). In this experiment, the products of calf thymus DNA (CT DNA) irradiated with MeV fluorine ions were analyzed using agarose gel electrophoresis, modified time-of-flight mass spectrometer (MALDI-TOF), and high-performance liquid chromatography (HPLC). The results showed that the molecular mass of the fragments were concentrated around 831 bp with agarose gel elec- trophoresis, there was no observable product in the range of 1,000 ? 30,000 (m/q) using MALDI-TOF, and small bio- molecules were separated from the products. The results of this study indicated that the strand breaks of calf thymus DNA induced by MeV fluorine ions were nonrandom.
基金supported in part by the National Natural Science Foundation of China (11075225,11275280 and 11235005)the Program for New Century Excellent Talents in University (NCET-10-0882)the Fundamental Research Funds for the Central Universities (CQDXWL-2012-Z002)
文摘We present a short review on the properties of heavy and light mesons’light-cone wavefunctions(LCWFs),and their distribution amplitudes(DAs).The B meson LCWFs can be treated by taking the heavy quark limit(mb!1)and by using the heavy quark effective theory.Furthermore,we propose a simple model for the B meson wavefunctions with 3-particle Fock states’contributions,whose behaviors are controlled by two parameters K and d.Using such model,the form factors FB!p t;0;Tand FB!K t;0;Tin large recoil region are studied up to Oe1=m2bT within the kTfactorization approach.On the other hand,we adopt BrodskyHuang-Lepage(BHL)prescription for constructing the WFs of the lighter pseudoscalars as gc;D-meson,pion,kaon,ge0T and etc.Such BHL-like model can be conveniently extended to construct the LCWFs for light scalar or vector mesons.Within such model the longitudinal distributions of those WFs are basically determined by a parameter B,whose value can be determined via a global fit of experimental data.
