Rare Radiative Bc→Ds1(2460)γB_{c}\rightarrow D_{s1}(2460)\gamma Transition in QCD

We investigate the radiative $B_{c} \to D_{s1} \gamma$ transition in the framework of QCD sum rules. In particular, we calculate the transition form factors responsible for this decay in both weak annihilation and electromagnetic penguin channels using the quark condensate, mixed and two-gluon condensate diagrams as well as propagation of the soft quark in the electromagnetic field as non-perturbative corrections. These form factors are then used to estimate the branching ratios of the channels under consideration. The total branching ratio of the $B_{c} \to D_{s1} \gamma$ transition is obtained to be in order of $10^{-5}$, and the dominant contribution comes from the weak annihilation channel.Comment: 24 Pages and 3 Figure

Reissner-Nordstr\"om Black Holes in Quintic Quasi-topological Gravity

This paper presents a study on charged black holes in quintic quasi-topological gravity, where we construct numerical solutions and investigate their thermodynamics and conserved quantities. We verify the first law of thermodynamics and compare our findings with that of Einstein gravity. We examine the physical properties of the solutions, considering anti-de Sitter, de Sitter, and flat solutions. Our analysis shows that anti-de Sitter solutions exhibit thermal stability, whereas de Sitter and flat solutions do not. Finally, we discuss the implications of our results and possible future research directions.Comment: 27 pages, 9 Figure

Surface terms of quintic quasitopological gravity and thermodynamics of quasi-topological magnetic brane coupled to nonlinear electrodynamics

For the the quintic quasitopological action which has no well-defined variational principle, we introduced a surface term that for a spacetime with flat boundaries make the action well-defined. Moreover, we investigated the numerical solutions of the above-mentioned gravity coupled to the nonlinear logarithmic and exponential electrodynamics. It has no horizon and curvature except one conical singularity at $$r=0$$ with a deficit angle $$\delta \phi$$. Also we found the counterterm which removes non-logarithmic divergences for the static quintic quasitopological gravity. Using this counterterm one can calculate a finite action and conserved quantities for the quintic quasitopological gravity

Rare radiative Bc -> Ds1(2460)gamma transition in QCD

We investigate the radiative B-c -> D-s1 gamma transition in the framework of QCD sum rules. In particular, we calculate the transition form factors responsible for this decay in both weak annihilation and electromagnetic penguin channels using the quark condensate, mixed, and two-gluon condensate diagrams, as well as propagation of the soft quark in the electromagnetic field, as nonperturbative corrections. These form factors are then used to estimate the branching ratios of the channels under consideration. The total branching ratio of the B-c -> D-s1 gamma transition is obtained to be of the order of 10(-5), and the dominant contribution comes from the weak annihilation channel

Strong interaction of doubly heavy spin-3/2 baryons with light vector mesons

We calculate the strong coupling constants among the doubly heavy spin-$$\frac{3}{2}$$ baryons $$\Xi ^*_{QQ}$$ and $$\Omega ^*_{QQ}$$, with Q and $$Q'$$ being c or b quark, with light vector meson by means of the light-cone QCD sum rules. The matrix elements defining these vertices are described by four coupling constants $$g_1$$, $$g_2$$, $$g_3$$, and $$g_4$$. The unwanted pollution coming from the doubly heavy spin-$$\frac{1}{2}$$ baryons are removed by a special ordering of Dirac matrices and selection of appropriate Lorentz structures. The strong coupling constants are basic parameters that carry information on the nature of the strong interaction among hadronic multiplets. Investigation of these parameters may help physicists in the construction of the strong potentials among the doubly heavy baryons and light vector mesons. The values obtained for the strong coupling constants may also help experimental groups in analyses of the data produced at various hadron colliders

Beautiful mathematics for beauty-full and other multi-heavy hadronic systems

In most non-perturbative methods in hadron physics the calculations are started with a correlation function in terms of some interpolating and transition currents in x -space. For simplicity, the calculations are then transformed to the momentum space by a Fourier transformation. To suppress the contributions of the higher states and continuum, and enhance the ground state contribution, the Borel transformation as well as continuum subtraction are applied with the help of quark-hadron duality assumption. In the present study we work out the mathematics required for these processes in the case of light and multi-heavy hadrons. We address a well-known problem in the subtraction of the effects of the higher states and continuum and discuss how we find finite results without any divergence by using an appropriate representation of the modified Bessel functions, appearing in the heavy quark propagator, and successive applications of the Borel transformations, which lead to more suppression of the higher states and continuum contributions. The results obtained can be used in the determination of the spectroscopic and decay properties of the multi-heavy standard and non-conventional (exotic) systems in many non-perturbative methods, especially the QCD sum rules

Strong coupling constants of the doubly heavy Xi(QQ) Baryons with pi Meson

Olamaei, Alireza/0000-0003-3529-3002The doubly charmed Xi(++)(cc) (ccu ) state is the only listed baryon in PDG, which was discovered in the experiment. The LHCb collaboration gets closer to discovering the second doubly charmed baryon Xi(+)(cc) (ccd), hence the investigation of the doubly charmed/bottom baryons from many aspects is of great importance that may help us not only get valuable knowledge on the nature of the newly discovered states, but also in the search for other members of the doubly heavy baryons predicted by the quark model. In this context, we investigate the strong coupling constants among the Xi(+(+))(cc) baryons and pi(0(+/-)) mesons by means of light cone QCD sum rule. Using the general forms of the interpolating currents of the Xi(+(+))(cc) baryons and the distribution amplitudes (DAs) of then meson, we extract the values of the coupling constants g Xi(cc)Xi(cc)pi. We extend our analyses to calculate the strong coupling constants among the partner baryons with pi mesons, as well, and extract the values of the strong couplings g Xi(bb)Xi(bb)pi, and g Xi(bc)Xi(bc)pi. The results of this study may help experimental groups in the analyses of the data related to the strong coupling constants among the hadronic multiplets