A theoretical study of $\bar{p}p \to \bar{p}n π^+ $ reaction for anti-proton beam energy from 1 to 4 GeV is made by including contributions from various known $N^*$ and $Δ^*$ resonances. It is found that for the beam energy around 1.5 GeV, the contribution of the Roper resonance $N^*_{(1440)}$ produced by the t-channel $σ$ exchange dominates over all other contributions. Since such reaction can be studied in the forthcoming $\bar{P}$ANDA experiment at Facility of Antiproton and Ion Research (FAIR), the reaction will be realistically the cleanest place for studying the properties of the Roper resonance and the best place for looking for other "missing" $N^*$ resonances with large coupling to $Nσ$.
With accumulation of high statistics data at BESIII, one may study many new interesting channels. Among them, J/ψ\to B^*\bar B + \bar{B^*}B \to γB\bar B processes may provide valuable information of the radiative decays of the excited baryons (N^*,Λ^*,Σ^*,Ξ^*), and may shed light on their internal quark-gluon structure. Our estimation for the branching ratios of the nucleon excitations N^*(1440), N^*(1535) and N^*(1520) from the reaction J/ψ\to N^*\bar p + \bar N^* p \to γp\bar p, indicates that these processes can be studied at BESIII with 10^{10} J/ψevents. Explicit theoretical formulae for …
In this work, we study the $B\bar{K}$ molecule in the Bethe-Salpeter (BS) equation approach. With the kernel containing one-particle-exchange diagrams and introducing two different form factors (monopole form factor and dipole form factor) in the vertex, we solve the BS equation numerically in the covariant instantaneous approximation. We investigate the isoscalar and isovector $B\bar{K}$ systems, and we find $X(5568)$ cannot be a $B\bar{K}$ molecule.
Studying the Triple Higgs Self-Coupling Via e+e- --> b bar b HH, t bar t HH at Future Linear e+e- Colliders
我们研究了三重希格斯自耦合在未来的$e^{+}e^{-}$对撞机能量，与反应$e^{+}e^{-}\to b \bar b HH$和$e^{+}e^{-}\to t \bar t HH$。我们评估了$b\bar bHH$，$t\bar tHH$的总截面，并计算了事件的总数考虑在树级的费曼图的完整集合。三重希格斯耦合的灵敏度被认为是在希格斯质量范围110-190 $GeV$，预计将在一个可能的下一个线性$e^{+}e^{-}$对撞机与质心能量$800, 1000, 1500$ $GeV$和光度1000 $fb^{-1}$的能量。
The color connection of the parton system is an important bridge to connect the perturbative process and the hadronization one. The special color connection of four-heavy-quark system in $e^+e^-$ annihilation, which is the necessary one for the doubly heavy baryon and tetraquark productions is revisited. The hadronization effects, investigated with the help of the Quark Combination Model are compared with the corresponding results employing the Lund String Model in our previous work. The global properties related to a certain color connection are not sensitive to various hadronization models.
We interpret the $X_1(2900)$ as an $S$-wave $\bar{D}_1K$ molecular state in the Bethe-Salpeter equation approach with the ladder and instantaneous approximations for the kernel. By solving the Bethe-Salpeter equation numerically with the kernel containing one-particle-exchange diagrams and introducing three different form factors (monopole, dipole, and exponential form factors) in the verties, we find the bound state exists. We also study the decay width of the decay $X_1(2900)$ to $D^-K^+$.
It is proposed to clear some of the puzzles of B decay to the broad $\bar{D}^{\ast\ast}$ states by studying the corresponding decay with strange states $B_s^0 \to D_{s0}^{\ast -} π^+$ at LHCb. Interpretation of the results should be easier due to the narrowness of the $D_{s0}^{\ast -}$ state.
We present a complete study of R-parity violating supersymmetric effects in thirteen exclusive and inclusive semi-leptonic $b \to (s,d) ν\barν$ decays, including $B^+_u\to K^{(*)+}ν\barν$, $B^0_d\to K^{(*)0}ν\barν$, $B^0_s\to ϕν\barν$, $B^0_d\to π^0(ρ^0)ν\barν$, $B^+_u\to π^+(ρ^+)ν\barν$, $B^0_s\to K^{(*)0}ν\barν$ and $B \to X_{s,d} ν\barν$ decay modes, and we find those thirteen modes are very sensitive to the constrained R-parity violating couplings. We derive stringent bounds on relevant R-parity violating couplings, which are based on all existent experimental upper limits of involved semi…
Studying the Top Quark via the W-Gluon Fusion Process
研究$W$ -胶子融合过程中的单顶夸克产生，可以提供以下方面的信息：（i）测量衰变宽度$\width$，（ii）通过测量~ \tbW的形状因子来探索对称性破缺机制，（iii）在超级对撞机前检验有效的~ $W$近似，（iv）在超对撞机前检验有效的~ $W$近似，（iv）在超对撞机前检验有效的~ $W$近似。（iv）通过观察$\bar p p \ra t X $和$\bar p p \ra \bar t X$的不同产生率来检验CP破坏;（v）除了测量顶夸克质量外，还从几乎百分之百的纵向极化顶夸克衰变中检验CP破坏。与R. K. Ellis和S.帕克，我们证明了这个过程在Tevatron上非常有用。
In this work, we make a theoretical study on the $p \bar p \rightarrow Λ\barΛη$ reaction for antiproton beam energy from threshold to 4GeV within an effective Lagrangian approach and isobar model. By assuming this reaction is dominated by the excitation of $Λ$ and $\bar Λ$ resonances in intermediate states, we calculate the total cross sections and give the predictions of the angular distribution and invariant mass spectrum of final particles. In particular, we discuss the possibility to verify the existence of a narrow $Λ$ resonance found in the process of $K^- p\to ηΛ$ in the present reactio…
In this work, we study the localized $CP$ violation and the branching fraction of the four-body decay $\bar{B}^0\rightarrow K^-π^+π^-π^+$ by employing a quasi-two-body QCD factorization approach. Considering the interference of $\bar{B}^0\rightarrow \bar{K}_0^*(700)ρ^0(770)\rightarrow K^-π^+π^-π^+$ and $\bar{B}^0\rightarrow \bar{K}^*(892)f_0(500)\rightarrow K^-π^+π^-π^+$ channels, we predict $\mathcal{A_{CP}}(\bar{B}^0\rightarrow K^-π^+π^-π^+)\in[0.15,0.28]$ and $\mathcal{B}(\bar{B}^0\rightarrow K^-π^+π^-π^+)\in[1.73,5.10]\times10^{-7}$, respectively, which shows that this two channels' interf…
Using the gauge/gravity duality, we investigate the string breaking and dissolution of two heavy quarks coupled to a light quark at finite temperature. It is found that there exist three configurations of QQq with the increase of separate distance for heavy quarks in the confined phase. Besides, the string breaking occurs at the distance $L_{\rm{QQq}} = 1.27 \rm{fm}$($T = 0.1 \rm{GeV}$) for the decay mode $\rm{Q Q q \rightarrow Q q q+Q \bar{q}}$. In the deconfined phase, QQq will melt at a certain distance then becomes free quarks. At last, we compare the potential of QQq with that of $\rm{Q\b…
Improved method for CKM constraints in charmless three-body B and B_s decays
最近，Ciuchini，Pierini和Silvestrini提出了一种通过相位测量I=3/2 K*pi末态的振幅来约束B->K pi pi和B_s-> K pi pi的CKM参数的方法。通过研究Delta I=1 B->（K*pi）_{I=1/2}，B_s->（K* \bar K）_{I =1}和B_s->（\bar K* K）_{I=1}振幅的相位，可以得到CKM参数的补充信息。用味SU（3）研究了电弱企鹅算符O_9和O_10的这些约束的强子不确定性，结果表明在B->K pi pi和B_s->K pi pi中很小，而在B_s-> K \bar K pi中稍大。第一个过程意味着\bar rho和\bar eta之间存在精确的线性关系，在\bar eta=0处具有可测量的斜率和截距，理论误差为0.03。衰变B_s-> K π π允许测量γ，理论误差小于一度。我们注意到，当研究B^0衰变在4S轨道上时，时间依赖性是必需的，而当研究B_s衰变在强子对撞机上时，时间依赖性可能不是必需的。
We recall and update, both theoretically and phenomenologically, our (nearly) forty-years-old proposal of a string-junction as a necessary complement to the conventional classification of hadrons based just on their quark-antiquark constituents. In that proposal single (though in general metastable) hadronic states are associated with "irreducible" gauge-invariant operators consisting of Wilson lines (visualized as strings of color flux tubes) that may either end on a quark or an antiquark, or annihilate in triplets at a junction $J$ or an anti-junction $\bar{J}$. For the junction-free sector …
Recent results from CDF and DØ collaborations favor a large CP asymmetry in B_s^0-\bar{B}_s^0 mixing, while the standard model prediction is very small. Such a large phase may imply sizable new physics effects in B_s^0-\bar{B}_s^0 mixing. We compute the gluino-mediated supersymmetry contributions to B_s^0-\bar{B}_s^0 mixing, B_s->K^{(*)-}K^{(*)+} and B->X_sγdecays in the frame of the mass insertion approximation. Combining the constraints of \DeltaM_s, ΔΓ_s, ϕ^{J/ψϕ}_s, B(B_s->K^{-}K^{+}) and B(B->X_s γ), we find that the effects of the constrained LL and RR insertions in B_s->K^{(*)-}K^{(*)+}…
Several proposals for studying neutrinos with large detectors are currently under discussion. We suggest that they could provide a precise measurement of the electroweak mixing angle as well as a probe for new physics, such as non-standard neutrino interactions (NSI), and the electroweak gauge structure. We illustrate this explicitly for the case of the LENA proposal, either with an artificial radioactive source or by using the solar neutrino flux.
Studying baryon number transport dynamics via hyperon-kaon correlations in $p + \mathrm{Au}$ collisions at $\sqrt{s_{_{\rm NN}}}=20$, $39$ and $62$ GeV
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University（核物理与离子束应用教育部重点实验室，复旦大学）
Studying minijets via the $p_T$ dependence of two-particle correlation in azimuthal angle $ϕ$
在我以前的建议，两个粒子的关联函数可以用来解决的最小偏置事件的高能强子相互作用的粒子产生的微喷流的贡献，我研究的$p_T$和能量依赖的相关性。利用HIJING Monte Carlo模型，发现在高碰撞能量下，由于微喷流的产生，两粒子与$p_T>p_T^{cut}$之间的方位角$ϕ$的关联$c(ϕ_1,ϕ_2)$类似于两个背靠背的喷流，随着$p_T^{cut}$的增加.结果表明，$c(0,0)-c(0,π)$，这是有关的相对分数的颗粒从微型射流，增加与能量。固定$p_T^{cut}$的相关性的背景也随着能量的增加而增加，这是由于多个微型喷气式飞机生产的增加。本文还讨论了这一分析在超相对论重离子碰撞喷注猝灭研究中的应用。
Implication of the observed $ψ(3770)\to p\bar{p}π^0$ for studying the $p\bar{p}\to ψ(3770)π^0$ process
Lanzhou University（兰州大学）；Institute of Modern Physics, Chinese Academy of Sciences（中国科学院近代物理研究所）；School of Physical Science and Technology, Lanzhou University（兰州大学物理科学与技术学院）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）
We sketch a novel method to search for light di-leptonic resonances by exploiting precision measurements of Drell-Yan production. Motivated by the recent hints of lepton flavour universality violation in $B \to K^{\ast} \ell^+ \ell^-$, we illustrate our proposal by studying the case of spin-1 resonances that couple to muons and have masses in the range of a few GeV. We show that the existing LHC data on $pp \to Z/γ^\ast \to μ^+ μ^-$ put non-trivial constraints on light di-muon resonance interpretations of $B$ decay anomalies in a model-independent fashion. The impact of our proposal on the lon…
