118679403
Comments on Baryon Melting in Quark Gluon Plasma with Gluon Condensation
We consider a black hole solution with a non-trivial dilaton from IIB super gravity which is expected to describe a strongly coupled hot gauge plasma with non-vanishing gluon condensation present. We construct a rotating and moving baryon to probe the screening and phases of the plasma. Melting of the baryons in hot plasma in this background had been studied previously, however, we show that baryons melt much lower temperature than has been suggested previously.
14612850
Holographic melting of heavy baryons in plasma with gluon condensation
We propose a Dirac-Born-Infeld (DBI) D5 vertex brane plus N(c) fundamental strings configuration to describe a baryon probe in strongly coupled gauge theory with gluon condensation at finite temperature via AdS/CFT correspondence. We investigate properties of this configuration in a dilaton deformed AdS(5) x S(5) background, in which IIB string theory is dual to super Yang-Mills theory in a state with a constant self-dual gauge field (F(mn) = F(mn)*) background. We find that for most values of temperature T and gluon condensation parameter q (q = pi(2) ), there always exists a screening length L(s). The relation L(s) similar to 1/T has been checked. We give the q dependence of L(s). We calculate the boost velocity nu(nu = - tanh eta) and angular velocity omega dependence of L(s) for a baryon probe, and obtain L(s) = L(0)* (1-nu(2))(1/4) for large nu and L(s) similar to omega(-1), which are consistent with those dependence relations in the point brane plus strings case, and find that the usual relations have been modified by q. We also calculate the mass of baryon and find T dependence of baryon mass.
204003965
Textures and hierarchies in quark mass matrices with four texture-zeros
A systematic analysis on the phenomenologically allowed textures in Hermitian quark mass matrices with four texture-zeros is presented. The current data allow a full determination of the mass matrix elements, provided that the actual number of the parameters in the matrices is less than or equal to ten. Besides the standard texture with zeros located in (1,1) and (1,3) positions, we find four new type of parallel mass matrices. All of them are found to have similar hierarchical structures: three of the nonzero matrix elements are at the same order of magnitude with a small geometric hierarchy, while the remaining one is relatively much smaller. These textures show a possibility that a realistic quark mass matrix may have an approximate flavor $S(2)_{L}\otimes S(2)_{R}$ symmetry, i.e. a partial flavor democracy. The absolute values of the CP violating phases in the matrix elements are found to be either close to their maximum ($\approx 90^\circ$) or very small ($\leq 10^{\circ}$). We also find twenty-six quasi-parallel and seventeen non-parallel textures allowed by the experimental data.
119257921
Geometry of the effective Majorana neutrino mass in the $0\nu\beta\beta$ decay
The neutrinoless double-beta (0 nu beta beta) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass (ee). We put forward a novel 'coupling-rod' diagram to describe (ee) in the complex plane, by which the effects of the neutrino mass ordering and CP-violating phases on (ee) are intuitively understood. We show that this geometric language allows us to easily obtain the maximum and minimum of vertical bar (ee)vertical bar. It remains usable even if there is a kind of new physics contributing to (ee), and it can also be extended to describe the effective Majorana masses (e mu), (e tau), (mu mu), (mu tau), and (tau tau) which may appear in some other lepton-number violating processes.
123787607
The Contribution of Reggeon in charge exchange processes
We discuss in this paper The experimental results on maximum psedo-rapidity $\eta_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS Collaboration at HERA. We calculate the contributions of \regg ($\rho$-Reggeon associated with $\rho$ meson) from regge phenomenology and $\pi^{+}$-exchange from pion cloud model. The results show that neither the \regg-exchange nor the pion cloud model alone can explain the experimental data well, but after considering both these two processes together, by using Monte Carlo simulation, a good agreement between theoretical results and experimental data is found. This means that in discussing the large rapidity gap phenomena in deep inelastic scattering, both of the two processes play substantial role.
119355833
Isospin relation and SU(3) breaking effects of strong phases in charmless B decays
Isospin and flavor SU(3) relations in charmless hadronic B decays B→ ππ, πK are investigated in detail with paying attention to the SU(3) symmetry breaking effects in both amplitudes and strong phases. In general, the isospin and the flavor SU(3) structure of the effective Hamiltonian provide several relations among the amplitudes and strong phases. Whereas a global fit to the latest data shows that some relation seems not to be favorable for a consistent explanation to the current data within the standard model (SM). By considering several patterns of SU(3) breaking, the amplitudes and the corresponding strong phases are extracted and compared with the theoretical estimations. It is found that in the case of SU(3) limits and also the case with SU(3) breaking only in amplitudes, the fitting results lead to an unexpected large ratio between two isospin amplitudes ac3/2/au3/2, which is about an order of magnitude larger than the SM prediction. The results are found to be insensitive to the weak phase γ. By including SU(3) breaking effects on the strong phases, one is able to obtain a consistent fit to the current data within the SM, which implies that the SU(3) breaking effect on strong phases may play an important role in understanding the observed charmless hadronic B decay modes B→ ππ and πK. It is possible to test those breaking effects in the near future from more precise measurements of direct CP violation in B factories. PACS: 13.25.Hw – 11.30.Er – 12.15.Hh – 12.60.Fr
119286757
Dirac neutrinos with S"4 flavor symmetry in warped extra dimensions
We present a warped extra dimension model with the custodial symmetry SU(2)(L) x SU(2)(R) x U(1)(X) x P-LR based on the flavor symmetry S-4 X Z(2) x Z(2)', and the neutrinos are taken to be Dirac particles. At leading order, the democratic lepton mixing is derived exactly, and the high-dimensional operators introduce corrections of order lambda(c) to all the three lepton mixing angles such that agreement with the experimental data can be achieved. The neutrino mass spectrum is predicted to be of the inverted hierarchy and the second octant of theta(23) is preferred. We suggest the modified democratic mixing, which is obtained by permuting the second and the third rows of the democratic mixing matrix, should be a good first order approximation to understanding sizable theta(13) and the first octant of theta(23). The constraints on the model from the electroweak precision measurements are discussed. Furthermore, we investigate the lepton mixing patterns for all the possible residual symmetries G(nu) and G(l) in the neutrino and charged lepton sectors, respectively. (C) 2013 Elsevier B.V. All rights reserved.