In recent times, several discrepancies at the level of $(2-3)σ$ have been observed in the decay processes mediated by flavour changing neutral current (FCNC) transitions $b \to s \ell^+ \ell^-$, which may be considered as the smoking-gun signal of New Physics (NP). These intriguing hints of NP have attracted a lot of attention and many attempts are made to look for the possible NP signature in other related processes, which are mediated through the same quark-level transitions. In this work, we perform a comprehensive analysis of the FCNC decays of $B$ meson to axial vector mesons $ K_1(1270)$ and $ K_1(1400)$, which are admixture of the $1^3P_1$ and $1^1P_1$ states $K_{1A}$ and $K_{1B}$, in a model independent framework. Using the $ B \to K_1$ form factors evaluated in the light cone sum rule approach, we investigate the rare exclusive semileptonic decays $ B \to K_1(1270) μ^+ μ^-$ and $ B \to K_1(1400) μ^+ μ^-$. Considering all the possible relevant operators for $b \to s \ell^+ \ell^-$ transitions, we study their effects on various observables such as branching fractions, lepton flavor universality violating ratio ($R_{K_1})$, forward-backward asymmetries, and lepton polarization asymmetries of these processes. These results will not only enhance the theoretical understanding of the mixing angle but also serve as a good tool for probing New Physics.
This paper has been temporarily withdrawn by the author. A modified version will be resubmitted. One of the trivial solutions was missed with crucial bearing on conclusions.
I give a brief review of final state interactions (FSI) in heavy meson decays, paying particular attention to B-meson physics. Available theoretical methods for dealing with the effects of FSI are discussed.
Combined analysis of recent measured $\bs$ mixing and $B \to X_s γ$ decays provides constraints on the anomalous $\bar{t}sW$ couplings. We discuss the perspectives to examine the anomalous $\bar{t}sW$ couplings through CKM-suppressed $ t \to s W$ decays at the LHC.
The recent measurement of $ΔA_{CP}$ by the LHCb collaboration requires an ${\cal O}(10)$ enhancement coming from hadronic physics in order to be explained within the SM. We examine to what extent can NP models explain $ΔA_{CP}$ without such enhancements. We discuss the implications in terms of a low energy effective theory as well as in the context of several explicit NP models.
We discuss the effects of the gravitino on the big-bang nucleosynthesis (BBN), paying particular attention to the hadronic decay mode of the gravitino. We will see that the hadronic decay of the gravitino significantly affect the BBN and, for the case where the hadronic branching ratio is sizable, very stringent upper bound on the reheating temperature after inflation is obtained.
We explore the exclusive $ B^0 \to ρ^0 γ$ decay to obtain the time-dependent CP asymmetry in $b \to d γ$ decay process. We find that the complex RL and RR mass insertion to the squark sector in the MSSM can lead to a large deviation of CP asymmetry from that predicted in the Standard Model.
The consequences of CP- and CPT-invariance for production and subsequent decay of Majorana fermions are analytically studied. We derive general symmetry relations for the spin density matrix for production of Majorana fermions by polarized fermion-antifermion annihilation which allow to distinguish Majorana from Dirac fermions. We discuss the influence of the spin correlations on energy and angular distributions of the decay products. Numerical results are shown for the production of neutralinos and charginos with subsequent leptonic decay at a future linear collider with longitudinally polari…
We analyze the effect of the non-universal $Z$ boson in the rare decays $B_s \to l^+ l^- $, $B_s \to l^+ l^- γ$ and $Z \to b \bar s$ decays. These decays involve the FCNC mediated $ b \to s $ transitions, and are found to be very small in the standard model. The smallness of these decays in the standard model makes them sensitive probe for new physics. We find an enhancement of at least an order in these branching ratios because of the non-universal $Zbs$ coupling.
Grand unified theories (GUTs) can lead to non-universal gaugino masses at the unification scale. We study the implications of such non-universal gaugino masses for the composition of the lightest neutralino in supersymmetric (SUSY) theories based on SU(5) gauge group. We also consider the phenomenological implications of non-universal gaugino masses for the phenomenology of Higgs bosons in the context of Large Hadron Collider.
Recently BABAR and Belle have measured anomalous large transverse polarizations in some pure penguin $B \to VV$ decays, which might be inconsistent with the Standard Model expectations. We try to explore its implications for R-parity violating (RPV) supersymmetry. The QCD factorization approach is employed for the hadronic dynamics of B decays. We find that it is possible to have parameter spaces solving the anomaly. Furthermore, we have derived stringent bounds on relevant RPV couplings from the experimental data, which is useful for further studies of RPV phenomena.
Recent reports of the observation of the decay $τ\rarrow ν_τ + K + π+ π$ raise interesting questions. The $u-s$ quark mass difference can induce an effective second-class current in the strange sector and enhance decays to helicity-suppressed scalar states. This suggests searches for scalar strange mesons in the $τ\rarrow ν_τ + K + η' $ and $τ\rarrow ν_τ + K + π$ decay modes. $τ$ decays to axial vector final states may clarify strange meson spectroscopy by analogy with the clarification of the $a_1$ problem in the nonstrange sector. Open questions include mixing effects in the strange axial ve…
Taken by itself, the interference with the etaprime appears to strongly affect the amplitude of the transition eta->3 pi. I point out that this effect is fictitious and also occurs in the mass spectrum of the pseudoscalars. Chiral symmetry implies that the same combination of effective coupling constants which determines the small deviations from the Gell-Mann-Okubo formula also specifies the symmetry breaking effects in the decay amplitude and thus ensures that these are small.
The B-meson system is an interesting probe for the exploration of strong interactions, the quark-flavour sector of the Standard Model, and the search for new physics. In this programme, non-leptonic B decays, which are particularly challenging from the point of view of QCD, play a key role. After discussing strategies to deal with the corresponding hadronic matrix elements of four-quark operators and popular avenues for new physics to manifest itself in B decays, we focus on puzzling patterns in the B-factory data for B -> pi pi, pi K decays; we explore their implications for hadron physics, n…
We examine the implications of the hypothesis that the decays of the b-quark occur via pure right-handed couplings. We show that the existing lower limits on neutrinoless double beta decay imply that any gauge model realizing this idea must have either an $L_e-L_μ$ or $L_e-L_τ$ symmetry. We then show that constraints of cosmology together with observations from SN1987A imply that the right-handed neutrinos in this model must be heavier than about 100 MeV in general. In one special case with the $L_e-L_μ$ symmetry, the $ν_{τ_R}$ is heavier than 2 GeV so that this particular version of the model…
In left-right models the gluonic penguin contribution to b --> s s-bar s transition is enhanced by m_t/m_b due to the presence of (V+A) currents and by the larger values of loop functions than in the Standard Model. Together those may completely overcome the suppression due to small left-right mixing angle xi <~ 0.013. Two independent new phases in the B --> phi K_S decay amplitude appearing in a large class of left-right models may therefore modify the time dependent CP asymmetry in this decay mode by O(1) and explain the recent BaBar and Belle CP asymmetry measurements in this channel. This …
We study constraints and implications of the recent LHCb measurement of ${\cal B}(B_s \to μ^+μ^-)$ for tree-level Higgs-mediated flavor-changing neutral current (FCNC) interactions. Combined with experimental data on $B_s$ mass difference $Δm_s$, the $h \to μτ$, and the $h \to τ^+τ^-$ decay branching ratios from the LHC, we find that the Higgs FCNC couplings are severely constrained. The allowed regions for $B_s \to μτ$, $ττ$ and $h \to sb$ decays are obtained. Current data allow large CP violation in the $h \to τ^+ τ^-$ decay. Consequences of the Cheng-Sher ansatz for the Higgs Yukawa couplin…
We explore the possibility of lepton number violation (LNV) manifesting in the rare kaon decay $K\toπνν$, and its consequences for radiative neutrino mass generation and the washout of Lepton asymmetry in high-scale leptogenesis scenarios. We perform the analysis in a model-independent framework, the Standard Model effective field theory (SMEFT), and discuss the possible LNV nature of the rare kaon decay in the context of the currently operating NA62 experiment at CERN. We find that, in case of a LNV interaction, its detection would put high-scale leptogenesis under tension and would hint to s…
The production of the excited charmed baryon doublet $Λ_c^*$ via fragmentation is studied. An analysis of the subsequent hadronic decays of the doublet within the framework of heavy hadron chiral perturbation theory produces expressions for both the angular distribution of the decay products and the polarization of the final state heavy baryon in terms of various nonperturbative fragmentation parameters. Future experimental investigation of this system will determine these parameters. In addition, recent experimental results are shown to fix one of the parameters in the heavy hadron chiral Lag…
When studying B decays within the Standard Model, it is customary to use the unitarity of the CKM matrix in order to write the decay amplitudes in terms of only two of the three weak phases which appear in the various diagrams. Occasionally, it is mentioned that those two weak phases can be used in order to describe any decay amplitude, even beyond the Standard Model. Here we point out that, when describing a generic decay amplitude, the two weak phases can be chosen completely at will, and we study the behavior of the decay amplitudes under changes in the two weak phases chosen as a basis. Of…
We point out that combinations of parameters that predict large counting rates in experiments searching for supersymmetric dark matter often tend to predict a very large branching ratio for the inclusive decay \bsg. The recent measurement of this branching ratio, therefore, indicates that searches for supersymmetric dark matter might be even more difficult than previously anticipated.
The experimental measurements of flavor-changing neutral-current B-meson decays governed by b --> s + (gamma, l^+ l^-) transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B -->K^(*) l^+ l^- and B_s --> mu^+ mu^- decays are used in model-(in)dependent analyses to test the Standard Model predictions and to derive stronger constraints on nonstandard contributions. While in agreement with the Standard Model, they still leave sizable room for new physics.
The observation that the $b \rightarrow sγ$ decay rate is close to the Standard Model value implies a large mass for the charged-Higgs boson in the Minimum Supersymmetric Standard Model, that nearly closes the $t \rightarrow b H^+$ decay channel. For $m_t = 150$ GeV, the parameter region $m_A \ltap 130$ GeV is excluded; this largely pre-empts LEP II searches and also partially excludes a region that would be inaccessible to MSSM Higgs boson searches both at LEP II and at SSC/LHC.
The decay $b\to sν\barν$ is discussed in the minimal supersymmetric standard model with general flavor mixing for squarks, at large $\tanβ$. In this case, in addition to the chargino loop contributions which were analyzed in previously studies, $\tanβ$-enhanced contributions from the gluino and charged Higgs boson loops might become sizable compared with the standard model contribution, at least in principle. However, it is demonstrated that the experimental bounds on the new physics contributions to the radiative decay $b\to sγ$ should strongly constrain these contributions to $b\to sν\barν$,…
The $Z\to γγ$ and $H\to γγγ$ decays are strictly forbidden in the Standard Model, but they can be induced by theories that violate Lorentz symmetry or the CPT theorem. By assuming that a nonvanishing $Zγγ$ vertex is induced in some context of new physics, and by analyzing the reaction $H\to γZ^*\to γγγ$ in the $Z$ resonance, we obtain an estimation for the branching ratio of the $H\to γγγ$ decay. Specifically, it is found that $BR(H\to γγγ)\lesssim BR(H\to γZ)BR_{Exp}(Z\to γγ)$, which is of the order of $10^{-7}$.
We have studied the two-body production and decay of a heavy, right-handed neutrino to two light states using the full Boltzmann equation instead of the usual integrated Boltzmann equation which assumes kinetic equilibrium of all species. Decays and inverse decays are inefficient for thermalising the distribution function of the heavy neutrino and in some parameter ranges there can be very large deviations from kinetic equilibrium. This leads to substantial numerical differences between the two approaches. Furthermore we study the impact of this difference on the lepton asymmetry production du…
I review the implications of recent measurements of CP violation in D meson decays in the context of standard model extensions. Using effective theory methods, one can derive significant constraints on the possible non-standard contributions from measurements of neutral D meson mixing and direct CP violation in kaon decays. Due to an approximate universality of CP violation in new physics scenarios which only break the SU(3)_Q flavor symmetry of the standard model kinetic Lagrangian, such contributions are particularly constrained by epsilon'/epsilon. Explanations of the observed effect within…
For a Standard Model Higgs boson with mass between 115 GeV and 150 GeV, the two-photon decay mode is important for discovery at the Large Hadron Collider (LHC). We describe the interactions of a light Higgs boson in a more model-independent fashion, and consider the parameter space where there is no two-photon decay mode. We argue from generalities that analysis of the $t\bar t h$ discovery mode outside its normally thought of range of applicability is especially needed under these circumstances. We demonstrate the general conclusion with a specific example of parameters of a type I two-Higgs …
The recently observed mass difference of the $D^0-\overline{D^0}$ mixing is used to predict the branching ratios of the rare top quark decays $t\to uγ$ and $t\to ug$ in a model independent way using the effective Lagrangian approach. It is found that $Br(t\to uγ)<4\times 10^{-4}$ and $Br(t\to ug)<2\times 10^{-3}$, which still may be within reach of the LHC collider.
We demonstrate that supersymmetric decays, as typified by the predictions of several GUT-scale boundary condition choices, do not prevent detection of $Z^* \to H^0A^0,H^+H^-$, at a $1-4$ TeV $e^+e^-$ or $μ^+μ^-$ collider operating at anticipated luminosity. For much of parameter space the relative branching ratios for various SUSY and non-SUSY decays can be measured with sufficient accuracy that different GUT-scale boundary condition choices can be distinguished from one another at a very high confidence level.
The study of $B \to τ^+ τ^- (X)$ decays can provide us with a better understanding of the third generation, and can be a useful probe of physics beyond the standard model. We present a model independent analysis of these decays. We classify new physics that can largely enhance the decay rates and we discuss the constraints implied by other processes. Experimentally, flavor changing neutral current $B$ decays into final state $τ$'s are still unconstrained. Searches for $B$ decays with large missing energy at LEP provide the first limits. We estimate that existing data already imply bounds on th…
The recent results on the CP violating parameters Re(e'/e) and Δϕ= ϕ_{00}-ϕ_{+-} reported by the KTeV Collaboration are analyzed with a view to constrain CP, T and CPT violations in a decay process. Combining with some relevant data compiled by the Particle Data Group, we find Re(e_2-e_0) = (0.85 +- 3.11)*10^{-4} and Im(e_2-e_0) = (3.2 +- 0.7)*10^{-4}, where Re(e_I) and Im(e_I) represent respectively CP/CPT and CP/T violations in decay of K^0 and \bar{K^0} into a 2πstate with isospin I.
Present measurements of b->c tau nu and b->u tau nu transitions differ from the standard model predictions of lepton flavor universality by almost 4sigma. We examine new physics interpretations of this anomaly. An effective field theory analysis shows that minimal flavor violating models are not preferred as an explanation, but are also not yet excluded. Allowing for general flavor violation, right-right vector and right-left scalar quark currents are identified as viable candidates. We discuss explicit examples of two Higgs doublet models, leptoquarks as well as quark and lepton compositeness…
Meson decays offer a good opportunity to probe new physics. The rare kaon decay $K^+ \rightarrow π^+ ν\barν$ is one of the cleanest of them and, for this reason, is rather sensitive to new physics, in particular, vector mediators. NA62 collaboration, running a fixed-target experiment at CERN, recently reported an unprecedented sensitivity to this decay, namely a branching fraction of $BR(K^+ \rightarrow π^+ ν\barν) = (11^{+4.0}_{-3.5})\times 10^{-11}$ at 68\% C.L. Vector mediators that couple to neutrinos may yield a sizeable contribution to this decay. Motivated by the new measurement, we int…
The considerable influx of new data on B decays offers opportunities to determine some of the smaller contributions to the decay process, such as suppressed diagrams, and to test the relations between decay amplitudes implied by (broken) SU(3) symmetry. The graphical decomposition of decay amplitudes, corrected here for the contribution of electroweak penguins following Gronau, Rosner et al, implies bounds not only on the size of diagram contributions but also on the relevant complex phases due to Cabbibo-Kobayashi-Maskawa matrix factors. The available data on B decays to two charmless pseudos…
Recently a positive indication of the neutrinoless double beta decay has been announced. We study the implications of this result taking into consideration earlier results on atmospheric neutrinos and solar neutrinos. We also include in our discussions the recent results from SNO and K2K. We point out that on the confidence level given for the double beta signal, the neutrino mass matrices are now highly constrained. All models predicting Dirac masses are ruled out and leptogenesis becomes a natural choice. Only the degenerate and the inverted hierarchical solutions are allowed for the three g…
Recent experiments suggest that certain data of $B \to ππ,πK$ decays are inconsistent with the standard model expectations. We try to explain the discrepancies with R-parity violating suppersymmetry. By employing the QCD factorization approach, we study these decays in the minimal supersymmetric standard model with R-parity violation. We show that R-parity violation can resolve the discrepancies in both $B \to ππ$ and $B \to πK$ decays, and find that in some regions of parameter spaces all these requirements, including the CP averaged branching ratios and the direct CP asymmetries, can be sati…
Encouraged by a recent observation of the B_c^+ -> B_s^0 + pi^+ decay by the LHCb collaboration we present the meson dominance predictions for other weak decays of the B_c^+ into B_s^0 or B^0 in the form of branching ratios to the observed decay.
Rare B meson decays mediated by flavour changing neutral current (FCNC) transition play interesting role to probe the flavour sector of the standard model (SM). Generally at the tree level, FCNC processes are not allowed in the SM but occurs at the loop levels. This gives an excellent hunting ground for new physics (NP). From various experimental studies it is found that the FCNC processes having quark level transition $b \to s$ are challenging. Here, we investigate different kinematic observables like forward-backward asymmetry, differential branching ratio and lepton polarization asymmetry f…
We discuss the production of radiation and dark matter assuming a time-dependent inflaton decay rate during the reheating period. It is shown that the time dependence of the inflaton decay rate can substantially modify the reheating dynamics. As an illustration, a leading interaction between the inflaton $ϕ$ and the Higgs doublet ${\boldsymbol h}$ of the form $ϕ|{\boldsymbol h}|^2$ was adopted. In the presence of such interaction, the Higgs doublet acquires a $ϕ$-dependent mass which generates vacuum-expectation-value due to inflaton oscillations and breaks the Standard Model gauge symmetry. T…
The very rare Bd0 --> mu+ mu- decay may be the last chance for New Physics in flavor sector at the LHC, before the 13 TeV run in 2015. Partially motivated by the known tension in sin(2beta/phi_1), enhancement beyond (3-4) x 10^-10 would likely imply the effect of a fourth generation of quarks. If observed at this level, the 126 GeV boson may not be the actual Higgs boson, while the b --> d quadrangle (modulo m_t') would jump out. The 2011-2012 data is likely not sensitive to values below 3 x 10^-10, and the mode should continue to be pursued with the 13 TeV run.
We study the semileptonic decays of the $B_c$ meson into final charmonium states within the standard model and beyond. The relevant hadronic transition form factors are calculated in the framework of the covariant confined quark model developed by us. We focus on the tau mode of these decays, which may provide some hints of new physics effects. We extend the standard model by assuming a general effective Hamiltonian describing the $b\to cτν$ transition, which consists of the full set of the four-fermion operators. We then obtain experimental constraints on the Wilson coefficients corresponding…
The flavor changing decays of heavy bottom quarks to the corresponding lighter quarks ($u$, $c$ and $s$) in various $B$-meson decays via charged current and neutral current semileptonic transitions have emerged as promising candidates to explore the physics beyond the standard model. Experimentally the lepton flavor universality violation in $b \to (c,u)\,l\,ν$ and $b \to s\,l^+ l^-$ transitions have been reported to a higher precision. The measurements of the lepton flavor violating ratios such as $R_{D^{(*)}}$, $R_{J/Ψ}$ and $R_{K^{(*)}}$ are observed to deviate from the standard model expec…
Adopting the 3 neutrino framework, we present an updated determination of the oscillation parameters. We perform a global analysis and develope simple arguments that give essentially the same result. We also discuss determinations of solar neutrino fluxes, capabilities of future experiments, tests of CPT, implications for neutrino-less double-beta decay, beta decay, cosmology.
Neutrinoless double beta decay is a sensitive probe of the patterns of neutrino masses and mixings if the neutrinos are Majorana particles as well as other new physics scenarios beyond the standard model. In this talk, the present experimental lower bound on the lifetime for $ββ_{0ν}$ is used to constrain the neutrino mixings and set limits on the parameters of the new physics scenarios such as the left-right symmetric models, R-parity violating SUSY models etc which lead to this process. We also discuss proposed high precision searches for $ββ_{0ν}$ decay that can provide extremely valuable i…
The strong decays of $D_1(2420)^0$, $D_2^*(2460)^0$, $D_2^*(2460)^+$, $D_2^*(2460)^-$, $D(2550)^0$, $D_J^*(2600)^0$, $D(2740)^0$, $D_3^*(2750)^0$, $D_3^*(2750)^+$, $D_3^*(2750)^-$, $D_J(3000)^0$, $D{_{J}^*}(3000)^0$ and $D_2^*(3000)^0$ resonance states are analyzed in the heavy quark mass limit of Heavy Quark Effective Theory (HQET). The individual decay rates and the branching ratios among the strong decays determine their spin and parity. From such states the Regge trajectories are constructed in $(J, M^2)$ and $(n_r, M^2)$ planes and further predict the masses of higher excited states (1$^1…
We discuss neutrino parameters in addition with the effects of a Higgs boson of mass $\sim$ 125 GeV in Split Supersymmetry with Bilinear R-Parity Violation. This model allows for the explanation of neutrino masses and mixing angles, and has the gravitino as Dark Matter candidate. We find constraints on the parameters in the neutrino sector of the model by performing a numerical study of the parameter space, and by fitting neutrino oscillation observables and the Higgs mass. In addition, we study in detail the decay of the lightest neutralino in this model and we realize the importance of the e…
We discuss the implications of assuming a four-zero Yukawa texture for the charged Higgs decay $H^+ \to W^+ γ$ at one-loop level, within the context of the general 2-Higgs Doublet Model of Type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting effects on its decays. In particular, we present the possible enhancement of the decay $H^+ \to W^+ γ$, whose branching ratio could be of the order $\sim 10^{-1}$, for charged Higgs mass of the order 180 GeV. These parameters can still avoid the $B \to X_s γ$ constraint and the pertur…
We analyze the unconventional top quark decay mode t -> H^+ b at the quantum level within the context of general Two-Higgs-Doublet models by including the full electroweak effects from the Yukawa couplings. The results are presented in the on-shell renormalization scheme with a physically well motivated definition of tan(beta). While the QCD corrections have been taken into account in the current experimental analyses of that decay, the electroweak effects have always been neglected. However, we find that they can be rather large and could dramatically alter the interpretation of the present d…
We analyse the new physics implications of theoretically clean $b \to s$ observables in a model-independent approach and compare their coherence with the implications of other rare $B$-decays. A statistical comparison is done between the New Physics explanation and hadronic contributions as the source of the anomalies in angular observables of the $B\to K^*μμ$ decay. We make projections for future measurements that indicate that LHCb will be in the position to discover lepton non-universality via a single observable using the Run 3 data. The global fit of rare $B$-decays is given within a mult…
We study the decay modes of a new, light spin-0 particle, arguing that if the mass of the (pseudo)scalar is ~11-15 GeV, it can have an appreciable branching ratio into bottomonium, in particular the rare eta's. Using non-relativistic QCD (NRQCD), we calculate its decay rate to bottomonia for mass splittings greater than the typical momentum transfer within the bound state. It can exceed that of decays to other Standard Model fermions under the assumption of couplings proportional to those of the Standard Model. At smaller splittings, where our computational methods break down, we estimate the …
We calculate, in the framework of QCD sum rules and to next-to-leading order in perturbation theory, the universal function $ξ_3(v\cdot v')$ which appears at order $1/m_Q$ in the heavy quark expansion of meson weak decay form factors. We find that radiative corrections of order $α_s$ are very important. Over the kinematic range accessible in semileptonic decays, $ξ_3(v\cdot v')$ is proportional to the leading-order Isgur-Wise function $ξ(v\cdot v')$ to very good accuracy. Taking into account all sources of uncertainty, we estimate $ξ_3/ξ=(0.6\pm 0.2)$. This reduces the theoretical uncertainty …
The alternative $SU(4) \otimes SU(2)_L \otimes SU(2)_R$ gauge model, which allows unification of the quarks and leptons at the TeV scale, is studied in detail. We discuss the implications for nucleon decay, B and K rare meson decays and neutrino masses. We also explain how this model solves the gauge hierarchy problem without using supersymmetry or extra large dimensions.
The recently observed color suppressed B0bar to D0 pi0, D0 eta, D0 eta', Ds+ K-and D0 K0bar decay modes all have rates larger than expected, hinting at the presence of final state interactions. We study rescattering effects in Bbar to D P, D Kbar and Dbar Kbar modes in the quasi-elastic approach, which is extended to accommodate D0 eta' without using U(3) symmetry. The D0bar Kbar modes are of interest in the determination of the unitarity angle phi3/gamma. The updated DP data are used to extract the effective Wilson coefficients a_1^{eff} ~ 0.92, a_2^{eff} ~ 0.22, three strong phases delta ~ 6…
In this work we study the implication of the fourth generation standard model (SM4) to the single and double lepton polarization asymmetries in the $B\rightarrow K^{\ast}\ell^{+}\ell^{-}$, $(l=μ,τ)$ decay. To see the variation in the values of lepton polarization asymmetries from the standard model values, we have taken lower bound values of CMS and ATLAS for $m_{t^\prime}=404$GeV and 552GeV respectively whereas $ϕ_{sb}$ is vary in two allowed regions $75^\circ-115^\circ$ and $240^\circ-290^\circ$ while for the numerical values of these asymmetries $|λ_{t^\prime}|$ is set to be $6\times10^{-3}…
The Large Hadron Collider has recently discovered a Higgs-like particle having a mass around 125 GeV and also indicated that there is an enhancement in the Higgs to diphoton decay rate as compared to that in the standard model. We have studied implications of these discoveries in the bilinear R-parity violating supersymmetric model, whose main motivation is to explain the non-zero masses for neutrinos. The R-parity violating parameters in this model are $ε$ and $b_ε$, and these parameters determine the scale of neutrino masses. If the enhancement in the Higgs to diphoton decay rate is true, th…
From the tau-lepton analysis of the charged Higgs decay of the top quark at the Tevatron, t -> H+ b -> tau+ nu_{tau} b, it is possible to set rather stringent bounds on the (tan(beta),M_{H+})-plane, if one assumes that H+ is a charged member of a generic two-Higgs-doublet model. However, if we consider the possibility that H+ is supersymmetric, then we find that the allowed region in the (tan(beta),M_{H+})-plane can be significantly modified by the MSSM quantum corrections. Throughout our analysis we correlate the top quark results with the limits imposed by radiative and semileptonic B-meson …
