Related papers: Hyperon Radiative Decays in the 1/N_c Expansion
We study the neutrinoless double beta decays of spin-1/2 hyperons, $B_1^- \to B_2^+ \ell^- \ell^-$ with $B_1^-\in \{\Sigma^-,\Xi^-\}$ and $B_2^+\in\{p,\Sigma^+\}$, which violate lepton number by two units. The decay amplitudes are computed…
We present measurements of the masses and widths of four bottom baryon resonances, Sigma_b(*)+-, reconstructed in the Lambda_b pi+- hadron decay modes. The isospin mass splittings for the Sigma_b and Sigma_b* multiplets are extracted as…
We present the method of calculation of radiative decays of composite quark-antiquark systems with different J^{PC}: (Q\bar Q)_{in} -> gamma (Q\bar Q)_{out}. The method is relativistic invariant, it is based on the double dispersion…
Radiative muon decay in the kinematics similar to the neutrinoless decay $\mu\to e\gamma$ is considered. Radiative corrections due to 1-loop virtual photons and emission of additional soft or hard photons are taken into account. Analytical…
Motivated by recent experimental advancements in the study of radiative decays of charmed mesons, we investigate the magnetic (transition) moments of vector mesons by applying the effective mass scheme, obtained from the one-gluon exchange…
It is shown that, in the bound state picture, the $\Lambda_c(2593) \to\Lambda_c\gamma$ and $\Lambda_c(2625)\to\Lambda_c\gamma$ decays are severely suppressed. On the other hand, for their bottom counterparts, which are predicted to have…
The hadronic decays of non-strange negative parity baryons are analyzed in the framework of the 1/Nc expansion. A complete basis of spin-flavor operators for the pseudoscalar meson S and D partial wave amplitudes is established to order…
The strong and radiative decays of the low-lying $\lambda$-mode $D$-wave $\Lambda_{c(b)}$, $\Sigma_{c(b)}$, $\Xi_{c(b)}$, $\Xi_{c(b)}'$, and $\Omega_{c(b)}$ baryons are studied in a constituent quark model. Our calculation shows the…
The two-particle hadronic decays of B_c meson into S-wave and P-wave charmonium states X_cc are considered in the framework of hard gluon exchange model. It is shown that decay width of B_c meson into S-wave charmonium states doubly exceeds…
From a picture of the X(3872) where the resonance is a bound state of $\bar{D}D^*-c.c.$, we evaluate the decay width into the $J/\psi \gamma$ channel, which is sensitive to the internal structure of this state. For this purpose we evaluate…
The sums k(E1)+k(M1) of radiative strength functions of dipole primary gamma-transitions were approximated with high precision in the energy region of $0.5 < E_1 < B_n-0.5$ MeV for nuclei: 40K, 60Co, 71,74Ge, 80Br, 114Cd, 118Sn, 124,125Te,…
The electromagnetic form factors of the Xi baryons and the semileptonic decay process Xi_c->Xi e^+nu_e are investigated in the frame work of the light-cone QCD sum rule method with Ioffe-type interpolating currents. Our estimates on the…
Using the calculated values of the strong coupling constants of the heavy sextet spin-3/2 baryons to sextet and antitriplet heavy spin-1/2 baryons with light mesons within the light cone QCD sum rules method, and vector meson dominance…
Within an extended chiral constituent quark model, three- and five-quark structure of the $S_{01}$ resonance $\Lambda(1405)$ is investigated. Helicity amplitudes for the electromagnetic decays ($\Lambda(1405) \to \Lambda(1116)\gamma$,…
We analyze the radiative decays of the the 1$P$, 1$D$, 2$S$, and 2$P$ $\Lambda_c$ and 1$D$, 2$S$, and 2$P$ $\Xi_c$ charmed baryons, which belong to the flavor anti-triplet ($\bf {\bar 3}_{\rm F}$), using the constituent quark model. We…
The "g_{Delta N gamma}" coupling for the "Delta -> N gamma" decay is calculated in framework of the light cone QCD sum rules and is found to be g_{Delta N gamma} = (1.6 pm 0.2) GeV^(-1). Using this value of g_{Delta N gamma} we estimate the…
Motivated by concerns regarding possible two-body contributions to the recently-measured inclusive Upsilon(nS)->gamma+X (n=1, 2, 3) direct photon spectra, we report on a new study of exclusive radiative decays of these narrow Upsilon(nS)…
We compute the O(alpha_s) corrections to the Wilson coefficients of the dimension five operators emerging from the Operator Product Expansion of inclusive radiative B decays. We discuss the impact of the resulting O(alpha_s…
The baryon magnetic and transition magnetic moments are computed in heavy baryon chiral perturbation theory in the large-N_c limit, where N_c is the number of colors. One-loop nonanalytic corrections of orders m_q^{1/2} and m_q ln m_q are…
This work is an extension of our previous work in \cite{bhatnagar20} to calculate M1 transitions, $0^{-+}\rightarrow 1^{--} \gamma$, and E1 transitions involving axial vector mesons such as, $1^{+-} \rightarrow 0^{-+}\gamma$, and…