Strong and electromagnetic decays of the radially excited $$D_s$$ and $$B_s$$ mesons in light cone QCD sum rules

Recently, LHCb Collaboration announced the discovery of radial excitations of $$D_s$$ D s and $$B_s$$ B s mesons. In present work, we calculate the most promising strong and electromagnetic decay widths of radially excited $$D_s(2S)$$ D s ( 2 S ) and $$B_s(2S)$$ B s ( 2 S ) mesons within the light cone QCD sum rules method.

P-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ scheme

We compute P-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme based on nonrelativistic effective field theories. We include nonperturbative effects from the long-distance behaviors of the potential, while the short-distance behaviors are determined from perturbative QCD. We obtain $$ \overline{\mathrm{MS}} $$ MS ¯ -renormalized P-wave quarkonium wavefunctions at the origin that have the correct scale dependences that are expected from factorization formalisms, so that the dependences on the scheme and scale cancel in physical quantities. This greatly reduces the theoretical uncertainties associated with scheme and scale dependences in predictions of decay and production rates. Based on the calculation of the P-wave wavefunctions at the origin in this work, we make first-principles predictions of electromagnetic decay rates and exclusive electromagnetic production rates of P-wave charmonia and bottomonia, and compare them with measurements.

Production and electromagnetic decay of hyperons: a feasibility study with HADES as a phase-0 experiment at FAIR

A feasibility study has been performed in order to investigate the performance of the HADES detector to measure the electromagnetic decays of the hyperon resonances $$\Sigma (1385)^{0}$$ Σ ( 1385 ) 0 , $$\Lambda (1405)$$ Λ ( 1405 ) and $$\Lambda (1520)$$ Λ ( 1520 ) as well as the production of double strange baryon systems $$\Xi ^{-}$$ Ξ - and $$\Lambda $$ Λ $$\Lambda $$ Λ in p + p reactions at a beam kinetic energy of $$4.5\,{\mathrm{GeV}}$$ 4.5 GeV . The existing HADES detector will be upgraded by a new Forward Detector, which extends the detector acceptance into a range of polar angles that plays a crucial role for these investigations. The analysis of each channel is preceded by a consideration of the production cross-sections. Afterwards the expected signal count rates using a target consisting of either liquid hydrogen or polyethylene are summarized.

Application of the Oscillation Symmetry to the Electromagnetic Interactions of Some Particles, Nuclei, and Atoms

The oscillation symmetry is first applied to electromagnetic interactions of particles and nuclei. It is shown that the differences between successive masses plotted versus their mean values and the electromagnetic decay widths Γee of 0^−(1^−−) b¯b and c¯c mesons, plotted versus their masses, agree with such symmetry. Then it is shown that the variation of the energy differences between different levels of several nuclei from 8Be to 20Ne, corresponding to given electric or magnetic transitions, display also oscillating behaviours. The electromagnetic widths of the electric and magnetic transitions between excited levels of these nuclei, plotted versus the corresponding differences between energies agree also with this property. The oscillating periods describe also an oscillation, the same for E1, M1, and E2 transitions. It is also the case for the multiplicative factor used β, and for ratios between these parameters. The oscillation symmetry is then applied to atomic energy levels of several neutral atoms from hydrogen to phosphorus. The data exhibit nice oscillations when plotted in the same way as before. The oscillations in various nuclear and atomic periods of different elements (A) exhibit the same shape and can be fitted by the same distribution.

MS renormalization of S-wave quarkonium wavefunctions at the origin

We compute S-wave quarkonium wavefunctions at the origin in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme based on nonrelativistic effective field theories. We include the effects of nonperturbative long-distance behaviors of the potentials, while we determine the short-distance behaviors of the potentials in perturbative QCD. We obtain $$ \overline{\mathrm{MS}} $$ MS ¯ -renormalized quarkonium wavefunctions at the origin that have the correct scale dependences that are expected from perturbative QCD, so that the scale dependences cancel in physical quantities. Based on the calculation of the wavefunctions at the origin, we make model-independent predictions of decay constants and electromagnetic decay rates of S-wave charmonia and bottomonia, and compare them with measurements. We find that the poor convergence of perturbative QCD corrections are substantially improved when we include corrections to the wavefunctions at the origin in the calculation of decay constants and decay rates.

Decay properties of high spin states in Mn

The electromagnetic decay properties of high spin states in 52Mn have been studied through various experiments with the GASP and EUROBALL arrays plus the ISIS charged-particle detector, the Neutron-Wall and the Recoil Filter Detector. From 7-7-particles coincidence measurements, spins and parities of these states have been determined and using the Doppler-shift attenuation method the mean life of some of these states have been determined. These results are compared with large scale shell-model calculations in the full fp shell.

Feasibility studies of production and electromagnetic decay studies of hyperons for HADES

The spectrum of excited states of single and double strange hyperons is only poorly known. Their internal structure is controversially discussed within quark, bag and molecular models. The most famous example is Λ(1405). In this context radiative decays are predicted to be an ideal tool to discriminate between various predictions. Moreover, Ξ− production yield measured by HADES in [email protected] GeV and [email protected] GeV experiments strongly overshoots theory predictions and calls for more detailed studies in elementary collisions. In our poster we show results of the feasibility studies for the HADES detector of the cascade production close to the threshold and also the radiative decays of the excited hyperon states. Three bench mark channels: $pp \to \Lambda (15020){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, $pp \to \Lambda (1405){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$ and $pp \to \Sigma (1385){K^ + }p \to \Lambda {e^ + }{e^ - }{K^ + }p$, at beam energy Ek = 4.5 GeV have been put into extensive simulation studies together with the most significant background channels. We will show the results including expected count rates and signal to background ratios.

Electromagnetic decay of Monopole–Antimonopole pair

A Monopole–Antimonopole pair could annihilate producing a photon shower: Some aspects of the shower like the multiplicity distribution and angular correlations are investigated within a model suitable for processes with high multiplicities and therefore difficult to deal with standard perturbative treatment. The possible production of electron–positron pairs is also considered.