High Energy Elastic p and p p Differential Cross Sections

<正>(Updated September 2013.COMPAS group.IHEP,Protvino)Using new results from FNAL-COLLIDER-D0 experiment in pp elastic collisions at s~(1/2)=1.96 TeV[1],CERN-LHC-TOTEM experiment in p p elastic collisions at s~(1/2)=7,8 TeV[2-3]and PAO experiment in proton-air collisions at 57 TeV[4]the amplitudes of the elastic p p and p p collisions are investigated in a most broad region in s~(1/2)and t via three observables da/dt(s,t).σ~(tot)(s),and p(s).The summary of the database for dσ/dt(s,t)is presented in Figure 50.10.where projection of the dσ/dt(s~(1/2),t)to the(da/dt,—t)plane orthogonal to the s~(1/2)axis is displayed.     

On the reactions p + p↦p + Λ + K+ and p + p↦p + Σ0 + K+ near thresholds

The cross-sections for the reactions of the strange production p + p ↦ p + Λ + K⁺ and p + p ↦ p + Σ⁰ + K⁺ near thresholds of the final states pΛK⁺ and pΣ⁰K⁺ are calculated in the effective Lagrangian approach. Our approach is based on the dominant contribution of the one-pion exchange and strong interaction of the colliding protons in the initial state. The theoretical values of the cross-sections agree reasonably well with the experimental data. The polarization properties of the Λ- and Σ⁰-hyperons are discussed.     

On polarization of strange baryons in reactions p + p↦p + Λ0 + K+ and p + p↦p + Σ0 + K+ near thresholds

Polarization properties of strange baryons produced in pp reactions, p + p↦p + Λ⁰ + K⁺ and p + p↦p + Σ⁰ + K⁺, near thresholds of the final states pΛ⁰K⁺ and pΣ⁰K⁺ are analysed relative to polarizations of colliding protons. The cross-sections for pp reactions are calculated within the effective Lagrangian approach accounting for strong pp rescattering in the initial state of colliding protons with a dominant contribution of the one-pion exchange and strong final-state interaction of daughter hadrons (Eur. Phys. J. A 9, 425 (2000)). Received: 22 October 2001 / Accepted: 14 November 2001     

Deuteron fragmentationd+p→p+p+n at 9 GeV/c

Gamma-ray energy correlations have been measured for several reactions leading to light-mass Hf isotopes with 160 ?A?166. The correlation spectra show ridge-valley structures up to high rotational frequencies from which a drop in J _c ⁽²⁾ is deduced at high frequencies. This drop suggests that a large portion of the angular momentum is generated by aligning particles. It may also be explained by the theoretically predicted triaxial states with large deformation.     

精确计算在π0重整化链图传播下p(p)→p(p)'微分截面

本文采用中性介子π0与核子N-反核子(N)强相互作用的Lorentz不变耦合模型,对质子p-反质子(p)在中性介子π0重整化链图传播下的散射微分截面,作了严格解析计算后获得了"精确"理论结果;进而,又对该计算结果与π0树图传播下的微分截面作了对比分析,获得了相关辐射修正的重要结果.这对于深入研究质子p-摊贩质子(p)在高、中、低能区中的弹性碰撞及其描述强相互作用的Lorentz不变耦合模型理论,都将提供某些值得借鉴与参考的理论研究价值.     

Study of the p and p Identification at BES Ⅱ

Based on three methods of particle identification (PID) of BES,we study the identification of p and p in momentum range from 0.3 to 1.2 GeV using real particle samples of e,μ,π,K,p and p which were collected in 2-5GeV R scan,J/(ψ) and ψ′ data taking periods. The paper presents the optimized method of PID:p(p) is identified by dE/dx only if momentum below 0.6GeV,and by TOF or the combination of dE/dx and TOF for higher momentum.The PID efficiency of p, p and contamination from the other charged particles are also given.     

类钴Pd19+离子3p63d9-3p53d10,3p63d9-3p83d84p跃迁的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Pd19+离子3p63d9-3p53d10,3p63d9-3p83d84p跃迁和振子强度,并与实验符合得较好。     

Drell-Yan Process in p–p Collisions from a Holographic Model

We study Drell-Yan process in proton–proton collisions through the exchange of vector mesons using the holographic hard wall model to describe the dynamics and interactions of vector mesons and baryons. We estimate the angular parameters λ,?μ, ν of the produced dileptons in a region of ${q_{T}^2 << Q^{2}}$ , where the effective coupling of perturbative QCD is large due to logarithm corrections.     

类钴Ag20+离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁光谱的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴Ag20 离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁和振子强度,并与实验符合得较好.     

类钴pd19+离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁的理论计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高离化态类钴3p63d9-3p53d10,3p63d9-3p63d84p跃迁和振子强度,并与实验符合得较好.     

高能p+p(p)碰撞中J/ψ和γ的硬衍射产生

讨论从ISR到SSC能区p+p(p)→p+J/ψ(Υ)+X过程.假定Pomeron(p)的结构以胶子为主且在小x处有的行为后,在QCD最低阶计算了两个主要子过程的硬衍射截面和作为背景项的Drell-Yan模式的相应截面.与背景项在高能时随Ins增加不同,硬衍射项基本上随(InS)²增加,因而在TeV能区以上时后者将大大超过前者.这种性质对其它硬衍射过程具有普适性.因此如果关于P的上述假定正确,在准确地测定P的结构后,选择适当的硬衍射过程,可能在超高能时提供探测物理粒子的新实验方法.     

Photoproduction of J/ψ in non-single-diffractive p+p collisions

Significant enhancements of J/ψ production at very low transverse momenta were recently observed by the ALICE and STAR collaborations in peripheral hadronic A+A collisions. The anomalous excess points to coherent photon-nucleus interactions in violent hadronic heavy-ion collisions, which were conventionally studied only in ultra-peripheral collisions. Assuming that the coherent photoproduction is the underlying mechanism responsible for the excess observed in peripheral A+A collisions, its contribution in p+p collisions with nuclear overlap, i.e. nonsingle-diffractive collisions, is of particular interest. In this paper, we perform a calculation of exclusive J/ψ photoproduction in non-single-diffractive p+p collisions at the RHIC and LHC energies based on the pQCD motivated parametrization using the world-wide experimental data, which could be further employed to improve the precision of the phenomenological calculations for photoproduction in A+A collisions. The differential rapidity and transverse momentum distributions of J/ψ from photoproduction are presented. In comparison with the J/ψ production from hadronic interactions, we find that the contribution of photoproduction is negligible.     

Λ(Λ)production in p(p) collisions

We describe the production of (AA) in p(p) collisions using a constituent quark model which has been successfully applied to the N(N)system.     

p,p在北京谱仪(Ⅱ)中的行为研究

从Monte Calor模拟和北京谱仪(BESⅡ)所取的实验数据入手,分析了p和p产生次级带电径迹和中性径迹的几率以及好径迹选择条件对这些次级径迹的去除情况、p在探测器中的能量损失和p的湮没、p和p在桶部簇射计数器中沉积能量的分布以及3种不同的粒子鉴别方法的优劣.给出了BES目前可以正确重建出的p和p的动量的最小值和利用TOF和dE?dx的联合信息鉴别p和p的优越性.     

44≤Z≤48类钴离子3p63d9,3p53d10,3p63d84p组态原子参数的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,系统计算了高离化态44≤Z≤48类钴等电子序列离子3p63d9,3p53d10,3p63d84p,组态的能级跃迁波长和振子强度,并与实验符合得较好。     

高能p+p(p)碰撞中双重Pomeron交换和J/ψ、γ产生过程

讨论高能双衍射硬产生过程.假定Pomeron(P)中以胶子分布为主且小x处有的行为后,计算了截面随能量的变化,比较了它们与单衍射(单个P交换)硬过程和非衍射Drell-Yan相应过程的截面随的变化.得出双衍射硬过程与单衍射时相似,在超高能(TeV以上)区截面基本上都是以(lnS)2增加,指出了这在实验中可能具有的意义.     

高Z类钴Te25+离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁及振子强度的计算

用多组态自洽场方法,结合我们提出的半经验拟合公式,计算了高Z类钴Te25+离子3p63d9-3p53d10,3p63d9-3p63d84p跃迁和振子强度,与实验符合得较好。     

Molecular two-centre integrals between 2 pπ and 3 pπ atomic orbitals

The evaluation of two-centre Coulomb-penetration and exchange-penetration integrals is discussed. All possible penetration integrals between 2pπ and 3pπ atomic orbitals exponent α are reduced analytically and tabulated for α = 1·00 (0·25) 10·00.     

Double Pomeron Exchange and J/ψ,γ Production Processes in High Energy p＋p(p)Collisions

The double diffractive J/ψ, hard production processes is discussed. Assuming that Pomeron has parton distributions and dominated by gluons with behavior as 1/x when x is small, the energy dependance of the cross section, for above processes is calculated and compared with both the cross section of single diffractive hard scattering and of Drell-Yan processes . It is shown that the is similar with and increases as (lnS)2 at superhigh energies. It is emphasized that this character may provide a new method for detecting physical particles at energy ranges of SSC.