We present a phenomenological study of the $γγ^*\to K\bar{K}^*(892)$ process by including the $s$-channel production of the $η(1475)$ and $f_1(1420)$ resonances. The non-resonant channel via $K$- and $K^*$-exchanges is investigated carefully by performing the Lorentz tensor decomposition and is constructed to yield a correct high-energy Regge behavior. The transition form factor of $f_1(1420)$ is adjusted to achieve a reasonable description of the existing L3 data in the $f_1(1420)$ resonance region. This model is intended to serve as a Monte Carlo generator for the analysis currently being performed by the BESIII Collaboration. We also estimate the polarized $γγ^*\to K\bar{K}^*(892)$ cross sections and demonstrate how to extract the transition form factors of $f_1(1420)$ from the polarized cross sections.
We point out that the variance of net-baryon distribution normalized by the Skellam distribution baseline, $κ_2[B-\bar{B}]/\langle B+\bar{B}\rangle$, is sensitive to the possible modification of (anti)baryon yields due to $B\bar{B}$ annihilation in the hadronic phase. The corresponding measurements can thus place stringent limits on the magnitude of the $B\bar{B}$ annihilation and its inverse reaction. We perform Monte Carlo simulations of the hadronic phase in Pb-Pb collisions at the LHC via the recently developed subensemble sampler + UrQMD afterburner and show that the effect survives in ne…
Constraining the top quark effective field theory using the top quark pair production in association with a jet at future lepton colliders
本文的主要目的是通过$e^{-} e^{+} \rightarrow t \bar{t}+$喷注过程约束描述顶夸克耦合的有效场论。该分析是在考虑500和3000 GeV两种不同质量中心能量的情况下进行的,包括对探测器响应和背景过程的主要来源的真实模拟。对于使用双轻子$t \bar{t}$终态的每个基准方案,在新物理耦合(如$t \bar t γ$、$t \bar t Z$和$t \bar t g$)上推导出95\% CL的预期限值。我们表明,在本分析中考虑的无量纲Wilson系数$\bar{c}_i$的95% CL极限可以被探测到$10^{-4}$。
We simultaneously incorporate two common extensions of the hadron resonance gas model, namely the addition of extra, unconfirmed resonances to the particle list and the excluded volume repulsive interactions. We emphasize the complementary nature of these two extensions and identify combinations of conserved charge susceptibilities that allow to constrain them separately. In particular, ratios of second-order susceptibilities like $χ_{11}^{BQ}/χ_2^B$ and $χ_{11}^{BS}/χ_2^B$ are sensitive only to the baryon spectrum, while fourth-to-second order ratios like $χ_4^B/χ_2^B$, $χ_{31}^{BS}/χ_{11}^{B…
Hadron spectroscopy is a powerful tool for testing the standard model and for the search of new physics. In this work, we create a tetraquark model from a di-meson interaction inspired by Jacobi coordinates. We consider mesons as thick points and quantify their interaction with the quark-antiquark interaction through a factor k (that takes approximately the value 2) in a central phenomenological potential, reducing the four-body problem finally to a one body equivalent problem. The eigenproblem is solved using a combination of the DVR method and perturbation theory in a C++ code. We obtain a m…
Constraining non-standard interactions in nu_e e or bar{nu}_e e scattering
对ν e e和\bar ν e e散射中的非普适和变味非标准中微子相互作用(NSI)进行了新的分析.我们对这些过程的全球分析包括所有相关实验,例如最近的MUNU反应堆中微子测量,无论是在标准模型的背景下,还是在NSI存在的情况下。我们还比较了我们对非通用和风味变化NSI的约束与以前的分析结果。我们强调中微子和反中微子数据相结合的重要性,在所产生的限制电弱参数,以及未来的低能量太阳中微子实验可以发挥重要作用,在提高现有的灵敏度。
We study the processes $pp \to t\bar{t}Z$ and $pp \to tZj$ in the framework of Standard Model Effective Field Theory (SMEFT), employing conventional cut-and-count as well as machine learning techniques to take advantage of kinematic information in complex final states involving multiple leptons and $b$ jets. We explore the projected sensitivity for two SMEFT operators, $\mathcal{O}_{tZ}$ and $\mathcal{O}_{tW}$, that induce electroweak dipole moment interactions for top quarks, through direct searches in these electroweak top production processes at the HL-LHC. New physics modifications to domi…
Phenomenological extraction of fragmentation functions in a $p\bar{p}$ environment
Facultad de Ciencias Físico-Matemáticas, Universidad Autónoma de Sinaloa(西那罗亚自治大学物理数学科学学院);Facultad de Ciencias de la Tierra y el Espacio, Universidad Autónoma de Sinaloa(西那罗亚自治大学地球与空间科学学院);Instituto de Física Corpuscular, Universitat de Valencia - Consejo Superior de Investigaciones Científicas(瓦伦西亚大学-西班牙高等科学研究理事会粒子物理研究所)
Within the quasi-two-body decay model, we study the localized $CP$ violation and branching fraction of the four-body decay $\bar{B}^0\rightarrow [K^-π^+]_{S/V}[π^+π^-]_{V/S} \rightarrow K^-π^+π^-π^+$ when $K^-π^+$ and $π^-π^+$ pair invariant masses are $0.35<m_{K^-π^+}<2.04 \, \mathrm{GeV}$ and $0<m_{π^-π^+}<1.06\, \mathrm{GeV}$, with the pairs being dominated by the $\bar{K}^*_0(700)^0$, $\bar{K}^*(892)^0$, $\bar{K}^*(1410)^0$, $\bar{K}^*_0(1430)$ and $\bar{K}^*(1680)^0$, and $f_0(500)$, $ρ^0(770)$ , $ω(782)$ and $f_0(980)$ resonances, respectively. When dealing with the dynamical functions o…