The $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ $(l=\mu,\tau)$ decays are analyzed in the Standar... more The $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ $(l=\mu,\tau)$ decays are analyzed in the Standard Model extended to fourth generation of quarks (SM4). The decay rate, forward-backward asymmetry, lepton polarization asymmetries and the helicity fractions of the final state $K^{*}_{2}(1430)$ meson are obtained using the form factors calculated in the light cone sum rules (LCSR) approach. We have utilized the constraints on different fourth generation parameters obtained from the experimental information on $K$, $B$ and $D$ decays and from the electroweak precision data to explore their impact on the $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ decay. We find that the values of above mentioned physical observables deviate deviate significantly from their minimal SM predications. We also identify a number of correlations between various observables in $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ and $B\rightarrow K^{\ast}(892)l^{+}l^{-}$ decays. Therefore a combined analysis of these two decays will compliment each other in the searches of SM4 effects in flavor physics.
The sensitivity of the zero position of the forward backward asymmetry $\mathcal{A}_{FB}$ for the... more The sensitivity of the zero position of the forward backward asymmetry $\mathcal{A}_{FB}$ for the exclusive $B\rightarrow K_{1}(1270)\mu^{+}\mu^{-}$ decay is examined by using most general non-standard 4-fermion interactions. Our analysis shows that the zero position of the forward backward asymmetry is very sensitive to the sign and size of the Wilson coefficients corresponding to the new vector type interactions, which are the counter partners of the usual Standard Model operators but have opposite chirality. In addition to these, the other significant effect comes from the interference of Scalar-Pseudoscalar and Tensor type operators. These results will not only enhance our theoretical understanding about the axial vector mesons but will also serve as a good tool to look for physics beyond the SM.
We calculate the branching ratios for B→(b1,h1)γ at next-to-leading order (NLO) of αs where b1 an... more We calculate the branching ratios for B→(b1,h1)γ at next-to-leading order (NLO) of αs where b1 and h1 are the corresponding orbitally excited axial vector mesons of ρ and ω respectively. Using the SU(3) symmetry for the form factors, the branching ratio for B→(b1,h1)γ is expressed in terms of the branching ratio of the B→K1γ and it is found to be B(B→b1γ)=0.53×10-6 and B(B→h1γ)=0.51×10-6. We also calculate direct CP-asymmetry for these decays and find that its typical values lies around 11% and is negative like ρ and ω in the standard model. The predicted value of CP-asymmetry, in confirmity with the observations made in the literature, is scale dependent which has also been discussed in detail.
The exclusive weak decay of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}... more The exclusive weak decay of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}$ are investigated in the Applequist-Cheng-Dobrescu model, which is an extension of the standard model in presence of universal extra dimensions. Employing the transition form factors obtained in the light-cone sum rues, we analyze how the invariant mass distribution, forward-backward asymmetry and polarization asymmetry of $\Lambda$ baryon of these decay modes can be used to constrain the only one additional free parameter with respect to the standard model, namely, the radius $R$ of the extra dimension. Our results indicate that the Kaluza-Klein modes can lead to approximately 25% suppression of the branching ratio of $\Lambda_b \to \Lambda \gamma$, however, their contributions can bring about 10% enhancement to the decay rate of $\Lambda_b \to \Lambda l^{+} l^{-}$. It is shown that the zero-position of forward-backward asymmetry of $\Lambda_b \to \Lambda \mu^{+} \mu^{-}$ is sensitive to the compactification parameter $R$ in this scenario, while the measurement of polarizations of $\Lambda$ baryon in the $\Lambda_b$ decays is not suitable to provide some valuable information for the universal extra dimension model.
The weak decays of $\Lambda_b \to \Lambda l^{+} l^{-}$ ($l=e, \mu$) are investigated in Minimal S... more The weak decays of $\Lambda_b \to \Lambda l^{+} l^{-}$ ($l=e, \mu$) are investigated in Minimal Supersymmetric Standard Model (MSSM) and also in Supersymmetric (SUSY) SO(10) Grand Unified Models. In MSSM the special attention is paid to the Neutral Higgs Bosons (NHBs) as they make quite a large contribution in exclusive $B \to X_{s} l^{+} l^{-}$ decays at large $\tan{\beta}$ regions of parameter space of SUSY models, since part of SUSY contributions is proportional to $\tan^{3}{\beta}$. The analysis of decay rate, forward-backward asymmetries, lepton polarization asymmetries and the polarization asymmetries of $\Lambda $ baryon in $\Lambda_b \to \Lambda l^{+} l^{-}$ show that the values of these physical observables are greatly modified by the effects of NHBs. In SUSY SO(10) GUT model, the new physics contribution comes from the operators which are induced by the NHBs penguins and also from the operators having chirality opposite to that of the corresponding SM operators. SUSY SO(10) effects show up only in the decay $\Lambda_b \to \Lambda +\tau^{+} \tau^{-}$ where the longitudinal and transverse lepton polarization asymmetries are deviate significantly from the SM value while the effects in the decay rate, forward-backward asymmetries and polarization asymmetries of final state $\Lambda$ baryon are very mild. The transverse lepton polarization asymmetry in $\Lambda_b \to \Lambda +\tau^{+} \tau^{-}$ is almost zero in SM and in MSSM model. However, it can reach to -0.1 in SUSY SO(10) GUT model and could be seen at the future colliders; hence this asymmetry observable will provide us useful information to probe new physics and discriminate between different models.
] on the processes $e^+ e^- \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ near the pe... more ] on the processes $e^+ e^- \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ near the peak of the $\Upsilon(5S)$ resonance, which are found to be anomalously large in rates compared to similar dipion transitions between the lower $\Upsilon$ resonances. Assuming these final states arise from the production and decays of the $J^{PC}=1^{--}$ state $Y_b(10890)$, which we interpret as a bound (diquark-antidiquark) tetraquark state $[bq][\bar{b}\bar{q}]$, a dynamical model for the decays $Y_b \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ is presented. Depending on the phase space, these decays receive significant contributions from the scalar $0^{++}$ states, $f_0(600)$ and $f_0(980)$, and from the $2^{++}$ $q\bar{q}$-meson $f_2(1270)$. Our model provides excellent fits for the decay distributions, supporting $Y_b$ as a tetraquark state.
section I. Synchroton radiation and applications. 1. Physics and biology: applications of synchro... more section I. Synchroton radiation and applications. 1. Physics and biology: applications of synchroton radiation in biology / Louise N. Johnson. 2. Sesame - a project to foster science and peace and its relevance for the region / Herwig Schopper. 3. The impact of synchroton light sources on science and society in developing countries / Herman Winick -- section II. Quantum physics and quantum information. 1. Discrimination of quantum states with selected applications / János A. Bergou. 2. Physical problems of brain-computer interfacing / Peter Fromherz. 3. NMR implementation of exponential sums for integer factorization / M. Stefanák ... [et al.] -- section III. Nonlinear phenomena and plasma physics. 1. Complexity and hydrodynamic turbulence / K. R. Sreenivasan. 2. Nonlinear interactions in quantum systems / P. K. Shukla and B. Eliasson. 3. Vortex in plasmas - topology, singularity and scale hierarchy / Z. Yoshida -- section IV. Nanophysics and applications. 1. Symmetry and novelty in the electronic and geometric structure of nanoalloys: the case of Ag[symbol]Cu[symbol] / M. Alcántara Ortigoza and T. S. Rahman. 2. New approaches to photovoltaic and photoelectrochemical energy conversion / S. Ismat Shah ... [et al.] -- section V. Particle physics, gravity and cosmology. 1. Theoretical interest in B-meson physics at the B factories, tevatron and the LHC / Ahmed Ali. 2. Quantum gravity and black holes / Viqar Husain. 3. Constraints on alternative theories of gravity and cosmology / Alexander F. Zakharov.
Form factors parametrizing radiative leptonic decays of heavy mesons (B+ → γl+νl) for photon ener... more Form factors parametrizing radiative leptonic decays of heavy mesons (B+ → γl+νl) for photon energy are computed in the language of dispersion relations. The contributing states to the absorptive part in the dispersion relation are the multiparticle continuum, estimated by the quark triangle graph, and resonances with quantum numbers 1- and 1+ which include B* and B*A and their radial excitations, which model the higher state contributions. Constraints provided by the asymptotic behavior of the structure dependent amplitude, Ward Identities and gauge invariance are used to provide useful information for parameters needed. The couplings gBB*γ and fBBA* γ are predicted if we restrict to the first radial excitation; otherwise using these as an input the radiative decay coupling constants for radial excitations are predicted. The value of the branching ratio for the process B+ → γμ+νμ is found to be in the range 0.5 × 10-6. A detailed comparison is given with other approaches.
ABSTRACT The exclusive weak decay ofb → �γ andb → �l+l are investigated in the Applequist- Cheng-... more ABSTRACT The exclusive weak decay ofb → �γ andb → �l+l are investigated in the Applequist- Cheng-Dobrescu model, which is an extension of the standard model in presence of universal extra dimensions. Employing the transition form factors obtained in the light-cone sum rues, we analyze how the invariant mass distribution, forward-backward asymmetry and polarization asymmetry ofbaryon of these decay modes can be used to constrain the only one additional free parameter with respect to the standard model, namely, the radius R of the extra dimension. Our results indicate that the Kaluza-Klein modes can lead to approximately 25% suppression of the branching ratio ofb → �γ, however, their contributions can bring about 10% enhancement to the decay rate ofb → �l+l . It is shown that the zero- position of forward-backward asymmetry ofb → �� +� is sensitive to the compactification parameter R in this scenario, while the measurement of polarizations ofbaryon in theb decays is not suitable to provide some valuable information for the universal extra dimension model.
... Page 2. Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes Muhammad JamilAslam ... more ... Page 2. Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes Muhammad JamilAslam Department of Physics and ... studies. I also wish to acknowledge the financial support provided by Dr. Riazud-din during my research work. Muhammad Jamil Aslam Page 10. . ...
The $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ $(l=\mu,\tau)$ decays are analyzed in the Standar... more The $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ $(l=\mu,\tau)$ decays are analyzed in the Standard Model extended to fourth generation of quarks (SM4). The decay rate, forward-backward asymmetry, lepton polarization asymmetries and the helicity fractions of the final state $K^{*}_{2}(1430)$ meson are obtained using the form factors calculated in the light cone sum rules (LCSR) approach. We have utilized the constraints on different fourth generation parameters obtained from the experimental information on $K$, $B$ and $D$ decays and from the electroweak precision data to explore their impact on the $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ decay. We find that the values of above mentioned physical observables deviate deviate significantly from their minimal SM predications. We also identify a number of correlations between various observables in $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ and $B\rightarrow K^{\ast}(892)l^{+}l^{-}$ decays. Therefore a combined analysis of these two decays will compliment each other in the searches of SM4 effects in flavor physics.
The sensitivity of the zero position of the forward backward asymmetry $\mathcal{A}_{FB}$ for the... more The sensitivity of the zero position of the forward backward asymmetry $\mathcal{A}_{FB}$ for the exclusive $B\rightarrow K_{1}(1270)\mu^{+}\mu^{-}$ decay is examined by using most general non-standard 4-fermion interactions. Our analysis shows that the zero position of the forward backward asymmetry is very sensitive to the sign and size of the Wilson coefficients corresponding to the new vector type interactions, which are the counter partners of the usual Standard Model operators but have opposite chirality. In addition to these, the other significant effect comes from the interference of Scalar-Pseudoscalar and Tensor type operators. These results will not only enhance our theoretical understanding about the axial vector mesons but will also serve as a good tool to look for physics beyond the SM.
We calculate the branching ratios for B→(b1,h1)γ at next-to-leading order (NLO) of αs where b1 an... more We calculate the branching ratios for B→(b1,h1)γ at next-to-leading order (NLO) of αs where b1 and h1 are the corresponding orbitally excited axial vector mesons of ρ and ω respectively. Using the SU(3) symmetry for the form factors, the branching ratio for B→(b1,h1)γ is expressed in terms of the branching ratio of the B→K1γ and it is found to be B(B→b1γ)=0.53×10-6 and B(B→h1γ)=0.51×10-6. We also calculate direct CP-asymmetry for these decays and find that its typical values lies around 11% and is negative like ρ and ω in the standard model. The predicted value of CP-asymmetry, in confirmity with the observations made in the literature, is scale dependent which has also been discussed in detail.
The exclusive weak decay of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}... more The exclusive weak decay of $\Lambda_b \to \Lambda \gamma$ and $\Lambda_b \to \Lambda l^{+} l^{-}$ are investigated in the Applequist-Cheng-Dobrescu model, which is an extension of the standard model in presence of universal extra dimensions. Employing the transition form factors obtained in the light-cone sum rues, we analyze how the invariant mass distribution, forward-backward asymmetry and polarization asymmetry of $\Lambda$ baryon of these decay modes can be used to constrain the only one additional free parameter with respect to the standard model, namely, the radius $R$ of the extra dimension. Our results indicate that the Kaluza-Klein modes can lead to approximately 25% suppression of the branching ratio of $\Lambda_b \to \Lambda \gamma$, however, their contributions can bring about 10% enhancement to the decay rate of $\Lambda_b \to \Lambda l^{+} l^{-}$. It is shown that the zero-position of forward-backward asymmetry of $\Lambda_b \to \Lambda \mu^{+} \mu^{-}$ is sensitive to the compactification parameter $R$ in this scenario, while the measurement of polarizations of $\Lambda$ baryon in the $\Lambda_b$ decays is not suitable to provide some valuable information for the universal extra dimension model.
The weak decays of $\Lambda_b \to \Lambda l^{+} l^{-}$ ($l=e, \mu$) are investigated in Minimal S... more The weak decays of $\Lambda_b \to \Lambda l^{+} l^{-}$ ($l=e, \mu$) are investigated in Minimal Supersymmetric Standard Model (MSSM) and also in Supersymmetric (SUSY) SO(10) Grand Unified Models. In MSSM the special attention is paid to the Neutral Higgs Bosons (NHBs) as they make quite a large contribution in exclusive $B \to X_{s} l^{+} l^{-}$ decays at large $\tan{\beta}$ regions of parameter space of SUSY models, since part of SUSY contributions is proportional to $\tan^{3}{\beta}$. The analysis of decay rate, forward-backward asymmetries, lepton polarization asymmetries and the polarization asymmetries of $\Lambda $ baryon in $\Lambda_b \to \Lambda l^{+} l^{-}$ show that the values of these physical observables are greatly modified by the effects of NHBs. In SUSY SO(10) GUT model, the new physics contribution comes from the operators which are induced by the NHBs penguins and also from the operators having chirality opposite to that of the corresponding SM operators. SUSY SO(10) effects show up only in the decay $\Lambda_b \to \Lambda +\tau^{+} \tau^{-}$ where the longitudinal and transverse lepton polarization asymmetries are deviate significantly from the SM value while the effects in the decay rate, forward-backward asymmetries and polarization asymmetries of final state $\Lambda$ baryon are very mild. The transverse lepton polarization asymmetry in $\Lambda_b \to \Lambda +\tau^{+} \tau^{-}$ is almost zero in SM and in MSSM model. However, it can reach to -0.1 in SUSY SO(10) GUT model and could be seen at the future colliders; hence this asymmetry observable will provide us useful information to probe new physics and discriminate between different models.
] on the processes $e^+ e^- \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ near the pe... more ] on the processes $e^+ e^- \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ near the peak of the $\Upsilon(5S)$ resonance, which are found to be anomalously large in rates compared to similar dipion transitions between the lower $\Upsilon$ resonances. Assuming these final states arise from the production and decays of the $J^{PC}=1^{--}$ state $Y_b(10890)$, which we interpret as a bound (diquark-antidiquark) tetraquark state $[bq][\bar{b}\bar{q}]$, a dynamical model for the decays $Y_b \to \Upsilon(1S)\; \pi^+\pi^-, \Upsilon(2S)\; \pi^+\pi^-$ is presented. Depending on the phase space, these decays receive significant contributions from the scalar $0^{++}$ states, $f_0(600)$ and $f_0(980)$, and from the $2^{++}$ $q\bar{q}$-meson $f_2(1270)$. Our model provides excellent fits for the decay distributions, supporting $Y_b$ as a tetraquark state.
section I. Synchroton radiation and applications. 1. Physics and biology: applications of synchro... more section I. Synchroton radiation and applications. 1. Physics and biology: applications of synchroton radiation in biology / Louise N. Johnson. 2. Sesame - a project to foster science and peace and its relevance for the region / Herwig Schopper. 3. The impact of synchroton light sources on science and society in developing countries / Herman Winick -- section II. Quantum physics and quantum information. 1. Discrimination of quantum states with selected applications / János A. Bergou. 2. Physical problems of brain-computer interfacing / Peter Fromherz. 3. NMR implementation of exponential sums for integer factorization / M. Stefanák ... [et al.] -- section III. Nonlinear phenomena and plasma physics. 1. Complexity and hydrodynamic turbulence / K. R. Sreenivasan. 2. Nonlinear interactions in quantum systems / P. K. Shukla and B. Eliasson. 3. Vortex in plasmas - topology, singularity and scale hierarchy / Z. Yoshida -- section IV. Nanophysics and applications. 1. Symmetry and novelty in the electronic and geometric structure of nanoalloys: the case of Ag[symbol]Cu[symbol] / M. Alcántara Ortigoza and T. S. Rahman. 2. New approaches to photovoltaic and photoelectrochemical energy conversion / S. Ismat Shah ... [et al.] -- section V. Particle physics, gravity and cosmology. 1. Theoretical interest in B-meson physics at the B factories, tevatron and the LHC / Ahmed Ali. 2. Quantum gravity and black holes / Viqar Husain. 3. Constraints on alternative theories of gravity and cosmology / Alexander F. Zakharov.
Form factors parametrizing radiative leptonic decays of heavy mesons (B+ → γl+νl) for photon ener... more Form factors parametrizing radiative leptonic decays of heavy mesons (B+ → γl+νl) for photon energy are computed in the language of dispersion relations. The contributing states to the absorptive part in the dispersion relation are the multiparticle continuum, estimated by the quark triangle graph, and resonances with quantum numbers 1- and 1+ which include B* and B*A and their radial excitations, which model the higher state contributions. Constraints provided by the asymptotic behavior of the structure dependent amplitude, Ward Identities and gauge invariance are used to provide useful information for parameters needed. The couplings gBB*γ and fBBA* γ are predicted if we restrict to the first radial excitation; otherwise using these as an input the radiative decay coupling constants for radial excitations are predicted. The value of the branching ratio for the process B+ → γμ+νμ is found to be in the range 0.5 × 10-6. A detailed comparison is given with other approaches.
ABSTRACT The exclusive weak decay ofb → �γ andb → �l+l are investigated in the Applequist- Cheng-... more ABSTRACT The exclusive weak decay ofb → �γ andb → �l+l are investigated in the Applequist- Cheng-Dobrescu model, which is an extension of the standard model in presence of universal extra dimensions. Employing the transition form factors obtained in the light-cone sum rues, we analyze how the invariant mass distribution, forward-backward asymmetry and polarization asymmetry ofbaryon of these decay modes can be used to constrain the only one additional free parameter with respect to the standard model, namely, the radius R of the extra dimension. Our results indicate that the Kaluza-Klein modes can lead to approximately 25% suppression of the branching ratio ofb → �γ, however, their contributions can bring about 10% enhancement to the decay rate ofb → �l+l . It is shown that the zero- position of forward-backward asymmetry ofb → �� +� is sensitive to the compactification parameter R in this scenario, while the measurement of polarizations ofbaryon in theb decays is not suitable to provide some valuable information for the universal extra dimension model.
... Page 2. Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes Muhammad JamilAslam ... more ... Page 2. Studying Bounds on Lepton Flavor Violating (LFV) Decay Processes Muhammad JamilAslam Department of Physics and ... studies. I also wish to acknowledge the financial support provided by Dr. Riazud-din during my research work. Muhammad Jamil Aslam Page 10. . ...
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