Cutoff rigidity and particle trajectories online calculator

Over the years, many authors have developed unique software packages for calculating the geomagnetic cut- off rigidities and the asymptotic directions of particle arrival. Such programs are used for mass calculations and require some skill. However, it is often necessary to carry out single calculations with the same accu- racy. For this purpose, calculator programs have been created on the basis of already developed software packages. One of such programs, a calculator, is described in this work

Evidence of a J/ψΛJ/\psi\Lambda structure and observation of excited Ξ−\Xi^- states in the Ξb−→J/ψΛK−\Xi^-_b \to J/\psi\Lambda K^- decay

First evidence of a structure in the $J/\psi{\Lambda}$ invariant mass distribution is obtained from an amplitude analysis of $\Xi_b^-{\rightarrow}J/\psi{\Lambda}K^-$ decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of $3.1\sigma$ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be $4458.8\pm2.9^{+4.7}_{-1.1}$ MeV and $17.3\pm6.5^{+8.0}_{-5.7}$ MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited $\Xi^-$ states, $\Xi(1690)^-$ and $\Xi(1820)^-$, are seen for the first time in a $\Xi^-_b$ decay, and their masses and widths are measured with improved precision. The analysis is performed using $pp$ collision data corresponding to a total integrated luminosity of 9 fb$^{-1}$, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV

Observation of the suppressed Λb0→DpK- decay with D→K+π- and measurement of its CP asymmetry

International audienceA study of Λb0 baryon decays to the DpK- final state is presented based on a proton-proton collision data sample corresponding to an integrated luminosity of 9  fb-1 collected with the LHCb detector. Two Λb0 decays are considered, Λb0→DpK- with D→K-π+ and D→K+π-, where D represents a superposition of D0 and D¯0 states. The latter process is expected to be suppressed relative to the former, and is observed for the first time. The ratio of branching fractions of the two decays is measured, and the CP asymmetry of the suppressed mode, which is sensitive to the Cabibbo-Kobayashi-Maskawa angle γ, is also reported

Branching Fraction Measurements of the Rare Bs0→ϕμ+μ−B^0_s\rightarrow\phi\mu^+\mu^- and Bs0→f2′(1525)μ+μ−B^0_s\rightarrow f_2^\prime(1525)\mu^+\mu^-- Decays

International audienceThe branching fraction of the rare Bs0→ϕμ+μ- decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6  fb-1, respectively. The branching fraction is reported in intervals of q2, the square of the dimuon invariant mass. In the q2 region between 1.1 and 6.0  GeV2/c4, the measurement is found to lie 3.6 standard deviations below a standard model prediction based on a combination of light cone sum rule and lattice QCD calculations. In addition, the first observation of the rare Bs0→f2′(1525)μ+μ- decay is reported with a statistical significance of 9 standard deviations and its branching fraction is determined

Measurement of prompt charged-particle production in pp collisions at s \sqrt{\mathrm{s}} = 13 TeV

International audienceThe differential cross-section of prompt inclusive production of long-lived charged particles in proton-proton collisions is measured using a data sample recorded by the LHCb experiment at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV. The data sample, collected with an unbiased trigger, corresponds to an integrated luminosity of 5.4 nb$^{−1}$. The differential cross-section is measured as a function of transverse momentum and pseudorapidity in the ranges p$_{T}$ ∈ [80, 10 000) MeV/c and η ∈ [2.0, 4.8) and is determined separately for positively and negatively charged particles. The results are compared with predictions from various hadronic-interaction models.[graphic not available: see fulltext

Precise measurement of the fs/fdf_s/f_d ratio of fragmentation fractions and of Bs0B^0_s decay branching fractions

International audienceThe ratio of the Bs0 and B0 fragmentation fractions, fs/fd, in proton-proton collisions at the LHC, is obtained as a function of B-meson transverse momentum and collision center-of-mass energy from the combined analysis of different B-decay channels measured by the LHCb experiment. The results are described by a linear function of the meson transverse momentum or with a function inspired by Tsallis statistics. Precise measurements of the branching fractions of the Bs0→J/ψϕ and Bs0→Ds-π+ decays are performed, reducing their uncertainty by about a factor of 2 with respect to previous world averages. Numerous Bs0 decay branching fractions, measured at the LHCb experiment, are also updated using the new values of fs/fd and branching fractions of normalization channels. These results reduce a major source of systematic uncertainty in several searches for new physics performed through measurements of Bs0 branching fractions

Observation of excited Ωc0\Omega_c^0 baryons in Ωb−→Ξc+K−π−\Omega_b^- \to \Xi_c^+ K^-\pi^-decays

International audienceThe first observation of the Ωb-→Ξc+K-π- decay is reported using p p collision data at center of mass energies of 7, 8, and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb-1. Four excited Ωc0 baryons are observed in the Ξc+ K- mass projection of the Ωb-→Ξc+K-π- decays with the significance of each exceeding five standard deviations. They coincide with the states previously observed in prompt pp and e+e- production. Relative production rates, masses, and natural widths of the states are measured, and a test of spin hypotheses is performed. Moreover, the branching ratio of Ωb-→Ξc+K-π- is measured relative to the Ωb-→Ωc0π- decay mode and a precise measurement of the Ωb- mass of 6044.3±1.2±1.1-0.22+0.19  MeV is obtained