Inclusive spectra of the kaons produced in $Ar Sc$ collisions as functions of their transverse momentum $p_T$ at mid-rapidity have been calculated within the approach based on the assumption of the similarity of inclusive spectra of the hadrons produced in nucleus-nucleus collisions at their small transverse momenta in the mid-rapidity region taking into account the quark-gluon dynamics in nucleon-nucleon interactions. This article gives a satisfactory description of NA61/SHINE data on $p_T$-spectra of the $K^\pm$ mesons produced in $ArSc$ collisions at the mid-rapdity ($y\simeq$ 0).
We report an extension of charged kaon transverse momentum ($p_T$) spectra at mid-rapidity ($\mid y\mid <$ 0.5) up to 15 GeV/$c$, neutral kaon $p_T$ spectra up to 12 GeV/$c$ using events triggered by the Barrel Electro-Magnetic Calorimeter (BEMC) from p+p collisions at $\sqrt{s_{NN}}$ = 200 GeV. The $K^{\pm}/π^{\pm}$ and $K^{0}/π^{\pm}$ at high $p_T$ are compared in p+p and Au+Au collisions, and nuclear modification factor ($R_{AA}$)for pion, kaon, proton and rho are discussed. The $R_{AA}$ for kaon in central collisions are consistent with theory calculation having jet conversion in a plasma …
The magnitude of four independent amplitudes are determined in charged kaon photoproduction in the energy range of 1500 to 2300MeV incident photon. Differential cross section and three polarization parameters are required for such amplitudes reconstruction at different kaon scattering angles. This analysis has indicated that the magnitudes of spin-flip amplitudes of the target nucleon dominate over the non-flip ones in all energies and scattering angles. The results have been compared with the solution of phase shift analysis sp98 at all energies. This analysis indicates that here is a good ag…
A completely relativistic quark model in the Bethe-Salpter framework is employed to calculate the exclusive production ratio of the neutral over charged Kaon pair in $e^+e^-$ annihilation continuum region for center of mass energies smaller than the $J/Ψ$ mass. The valence quark charge plays the key rôle. The cancellation of the diagrams for the same charge case (in $K_S + K_L$) and the non-cancellation of the diagrams for the different charge case (in $K^-+K^+$) lead to the ratio as $(m_s-m_d)^2/M_{Kaon}^2 \sim 1/10$.
The higher-twist (HT) contribution to the charged kaon pair production in the high energy proton-antiproton collisions at large transverse momentum $p_T$ is investigated by using the frozen coupling constant approach for various kaon distribution amplitudes (DAs), which are predicted by light-cone formalism, the light-front quark model, the nonlocal chiral quark model and the light-front holographic AdS/CFT approach. In the numerics the dependencies of the HT contribution on the transverse momentum $p_T$, the rapidity $y$, and the variable $x_T$ are discussed with special emphasis put on DAs. …
An expression for the Dalitz plot of the semileptonic decay of a charged kaon, including radiative corrections to order O[απ)(q/M_1)], where q is the four-momentum transfer and M_1 is the mass of the decaying kaon, is obtained. Contributions of both the three- and four-body regions are accounted for. Besides, the emitted muon is considered to be polarized so the analysis is also focused on evaluating the radiative corrections to the longitudinal, transverse, and normal polarization components of the muon. The final formulas, with the triple integration of the bremsstrahlung photon variables re…
A model with $L_μ -L_τ$ gauge symmetry is the least constrained model as a resolution to the disagreement of the muon anomalous magnetic moment between the theoretical predictions and the experimental results. In this paper, we discuss how well the $L_μ - L_τ$ model can be constrained by looking for decays of the charged kaon associated with a $L_μ-L_τ$ gauge boson. More concretely, we consider searches for single muon tracks from the decays of stopped charged kaon as in the E949 experiment. In our conservative estimation, we find that the favored parameter region for the muon anomalous magnet…
The inclusive spectra of pions and kaons produced in $Be Be$ collisions as functions of their transverse momentum $p_t$ at mid-rapidity are calculated within the self-similarity approach. A satisfactory description of NA61/SHINE data on these spectra and the ratio of $K^\pm$ to $π^\pm$ meson production cross sections in $Be Be$ collisions as a function of $\sqrt{s}$ are presented. The similarity of these observables to the ones for $pp$ collisions at mid-rapidity and in the wide range of initial energies is illustrated.
We investigate the single transverse-spin asymmetry with a $\sin (ϕ_h-ϕ_S)$ modulation in the charged Kaon produced and in $Λ$ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $D_1$ for the produced hadron. The parametrization for the proton Qiu-Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kine…
Kinetic Freeze-Out Properties from Transverse Momentum Spectra of kaon, Pion, and (anti-)proton production in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV
Estimates for parameters and characteristics of the confining SU(3)-gluonic field in charged pions and kaons from leptonic decays and chiral symmetry breaking
Hadron spectra measured in high-energy collisions present distributions which can be derived from the non-extensive statistical and thermodynamical phenomena. Based on earlier theoretical developments, it seems, the methods are very applicable for jets hadronization processes in electron-positron, proton-proton, and even in heavy-ion collisions. Here, we present what can was learnt from the recent theoretical and phenomenological developments: transverse momentum spectra and azimuthal anisotropy ($v_2$) of charge averaged pions, kaons and protons stemming from central Pb+Pb collisions at $\sqr…
A calculation of the inclusive spectra of pions and kaons produced in $pp$ collisions as functions of their transverse momentum $p_t$ at mid-rapidity is presented within the self-similarity approach. A satisfactory description of the data within a wide range of initial energies is presented. We focus mainly on the ratio of cross-sections of $K^\pm$ to $π^\pm$ mesons produced in $pp$ collisions as a function of $\sqrt{s}$. A fast rise of this ratio, when the initial energy increases starting from the kaon production threshold up to $\sqrt{s}\simeq$ 20-30 Gev, is revealed together with its very …
In this study, we have investigated the two-body hadronic decay of the charged kaon, $ K^{+}\rightarrowπ^{+}+π^{0} $, in the presence of a laser field with circular polarization. We have derived, by analytical techniques, the laser-assisted decay width and the branching ratio of the charged kaon decay via the two-body hadronic channel. We have also taken into consideration the impressive results obtained for the laser-assisted charged kaon decay via the leptonic mode in order to understand more clearly the effect of the laser field on the quantities related to the charged kaon decay such as th…
Identical-particle (pion and kaon) femtoscopy in Pb$-$Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with Therminator2 modeled with (3+1)D viscous hydrodynamics
Indian Institute of Technology Bombay（印度理工学院孟买分校）；University of Tsukuba（筑波大学）
利用 (3+1)D 粘性流体动力学和 THERMINATOR 2 代码研究 Pb-Pb 碰撞中介子和 K 介子的费米简缩，发现半径随对偶动量增加而减小，表明强集体性。
We study single kaon production off the nucleon induced by electrons (positrons) i.e. $e^-(e^+) + N \rightarrow ν_e (\bar ν_e) + \bar K (K) + N^\prime$ at low energies. The possibility of observing these processes with the high luminosity beams available at TJNAF and Mainz is discussed, taking into account that the strangeness conserving electromagnetic reactions have a higher energy threshold for $\bar K (K)$ production. The calculations are done using a microscopic model that starts from the SU(3) chiral Lagrangians, includes background terms and the resonant mechanisms associated to the low…
We investigate the results of the charged kaon multiplicities off the deuteron target from HERMES and COMPASS experiments. The discrepancy of the two data sets cannot be explained by different $Q^2$ values. Furthermore we examine the empirical parametrization of the fragmentation functions, DSS2017, and find that the agreement between the theoretical predictions and the HERMES data is less satisfactory as claimed.
With the aim of achieving a better and more complete understanding of neutrino interactions with nuclear targets, the coherent production of charged kaons induced by neutrinos and antineutrinos is investigated in the energy range of some of the current neutrino experiments. We follow a microscopic approach which, at the nucleon level, incorporates the most important mechanisms allowed by the chiral symmetry breaking pattern of QCD. The distortion of the outgoing (anti)kaon is taken into account by solving the Klein-Gordon equation with realistic optical potentials. Angular and momentum distrib…
Measurements of the dynamical correlations between neutral and charged kaons in central Pb-Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV by the ALICE Collaboration display anomalous behavior relative to conventional heavy-ion collision simulators such as AMPT, EPOS, and HIJING. We consider other conventional statistical models, none of which can reproduce the magnitude and centrality dependence of the correlations. The data can be reproduced by coherent emission from domains which grow in number and volume with increasing centrality. We show that the energy released by condensation of strange qu…
Large Hadron Collider (LHC) had produced a vast amount of high precision data for high energy heavy ion collision. We attempt here to study (i) transverse momenta spectra, (ii) $K/π$, $p/π$ ratio behaviours, (iii)rapidity distribution, and (iv) the nuclear modification factors of the pion, kaon and antiproton produced in $p+p$ and $Pb+Pb$ collisions at energy $\sqrt{s_{NN}}$ = 2.76 TeV, on the basis of Sequential Chain Model (SCM). Comparisons of the model-based results with the measured data on these observables are generally found to be modestly satisfactory.
Observed since the 1950's, the seasonal effect on underground muons is a well studied phenomenon. The interaction height of incident cosmic rays changes as the temperature of the atmosphere changes, which affects the production height of mesons (mostly pions and kaons). The decay of these mesons produces muons that can be detected underground. The production of muons is dominated by pion decay, and previous work did not include the effect of kaons. In this work, the methods of Barrett and MACRO are extended to include the effect of kaons. These efforts give rise to a new method to measure the …
A microscopic approach has been employed to study the kaon and $Λ$ productions in heavy ion collisions. The productions of $K^+$ and $Λ$ have been studied within the framework of Boltzmann transport equation for various beam energies. We find a non-monotonic horn like structure for $K^+/π^+$ and $Λ/π$ when plotted against centre of mass energies ($\sqrt s_{\mathrm NN}$) with the assumption of initial partonic phase for $\sqrt s_{\mathrm NN}$ beyond a certain threshold. However, the ratio $K^+/π^+$ shows a monotonic nature when a hadronic initial state is considered for all $\sqrt s_{\mathrm NN…
A sample of more than one million Ke4 decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003-2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of radiative Ke4gamma decays, is measured to be BR(Ke4) = (4.257 +/- 0.016_exp +/- 0.031_ext) x 10-5 with a total relative error of 0.8%. This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the pio…
The CMS experiment at the Large Hadron Collider has recently presented data on the average transverse momentum of protons, kaons and pions as a function of particle multiplicity. We relate the particle multiplicity to saturation momentum using recently published computations of the interaction radius determined from the theory of the Color Glass Condensate. We show that the pp and the pA experimental data scale in terms of these saturation momenta. Computing transverse momentum spectra for identified particles using Boltzmann-type distributions and relating different associated multiplicities …
We calculate the cumulants and correlation functions of net-kaon multiplicity distributions in Au+Au collisions at $\sqrt{s_{NN}} = 7.7$ GeV using a multiphase transport model (AMPT) with both a new coalescence mechanism and all charge conservation laws. The AMPT model can qualitatively describe the centrality dependences of the net-kaon cumulants and cumulant ratios measured by the STAR experiment. By focusing on the stage evolution of the cumulants, cumulant ratios, and correlation functions, we reveal several key effects on the fluctuations and correlations of strangeness during the dynamic…
The main aim of this paper is a new determination of transverse momentum dependence of unpolarized fragmentation function (TMD FFs) in single inclusive hadron production in electron-positron annihilation (SIA) process. Motivated by the need for a reliable and consistent determination of TMD FFs, we use the most recent TMD production cross sections of charged pions ($π^\pm$), kaons ($K^\pm$) and protons/antiprotons ($p/\bar{p}$) measured in inclusive $e^+e^-$ collisions by Belle Collaboration. These datasets are the first transverse momentum dependence of identified light charged hadron measure…
A simple method for the extraction of the times of maximal emission for kaons and pions using the combined fitting of their transverse momentum spectra and the longitudinal interferometry radii dependencies on the pair transverse mass $m_T$ is applied to Pb+Pb collisions at the LHC energy $\sqrt{s_{NN}}=5.02$ TeV. The method is based on the analytical formulas, that were earlier successfully utilized in the studies of Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV. To test the method, the spectra, radii and particle radiation picture are calculated within the integrated hydrokinetic model (iHKM)…
We provide, within the hydrokinetic model, a detailed investigation of kaon interferometry in $Pb+Pb$ collisions at LHC energy ($\sqrt{s_{NN}} = 2.76$ TeV). Predictions are presented for 1D interferometry radii of $K^0_SK^0_S$ and $K^{\pm}K^{\pm}$ pairs as well as for 3D femtoscopy scales in out, side and long directions. The results are compared with existing pion interferometry radii. We also make predictions for full LHC energy.
CP asymmetries have been measured recently by the LHCb collaboration in three-body $B^+$ decays to final states involving charged pions and kaons. Large asymmetries with opposite signs at a level of about 60% have been observed in $B^\pm\to π^\pm({\rm or} K^\pm)π^+π^-$ and $B^\pm \to π^\pm K^+K^-$ for restricted regions in the Dalitz plots involving $π^+π^-$ and $K^+K^-$ with low invariant mass. U-spin is shown to predict corresponding $ΔS=0$ and $ΔS=1$ asymmetries with opposite signs and inversely proportional to their branching ratios, in analogy with a successful relation predicted thirteen…
