CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces （246°〈 φ 〈 263°） we find that this anomaly can be easily explained; at the same time, the branching ratio of B→φKs decay can also be in agreement with experimental measurements.     

CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces (246°<φ<263°) we find that this anomaly can be easily ex-plained; at the same time, the branching ratio of B →φKs decay can also be in agreement with experimental measurements.     

Probing new physics through B→Kl + l − decays in R-parity violating minimal supersymmetric standard model

We study the decay rate of the process B→Kl ⁺ l ^? (l=e,μ) and some of its other related observables, like the forward–backward asymmetry (A _FB), polarization asymmetry (PA), double branching ratio and CP asymmetry (A _CP) in the R-parity violating Minimal Supersymmetric Standard Model ( $\not \!{R}_{p}$ MSSM). We have performed an error analysis of the differential branching fraction, A _FB and CP asymmetry. The analysis shows that theoretical results based on $\not \!{R}_{p}$ MSSM as an additional effect are compatible with the standard model. A _FB is found to be zero, in agreement with SM. The average A _CP is not only found to be significant in comparison with SM, but it is also compatible with the measured value within errors.     

The CMSSM and NUHM1 in light of 7 TeV LHC, B s →μ + μ − and XENON100 data

We make a frequentist analysis of the parameter space of the CMSSM and NUHM1, using a Markov Chain Monte Carlo (MCMC) with 95 (221) million points to sample the CMSSM (NUHM1) parameter spaces. Our analysis includes the ATLAS search for supersymmetric jets?+? signals using ～5/fb of LHC data at 7 TeV, which we apply using PYTHIA and a Delphes implementation that we validate in the relevant parameter regions of the CMSSM and NUHM1. Our analysis also includes the constraint imposed by searches for BR(B _s →μ ⁺ μ ^?) by LHCb, CMS, ATLAS and CDF, and the limit on spin-independent dark matter scattering from 225 live days of XENON100 data. We assume M _h ～125 GeV, and use a full set of electroweak precision and other flavour-physics observables, as well as the cold dark matter density constraint. The ATLAS_5/fb constraint has relatively limited effects on the 68 and 95 % CL regions in the (m ₀,m _1/2) planes of the CMSSM and NUHM1. The new BR(B _s →μ ⁺ μ ^?) constraint has greater impacts on these CL regions, and also impacts significantly the 68 and 95 % CL regions in the (M _A ,tanβ) planes of both models, reducing the best-fit values of tanβ. The recent XENON100 data eliminate the focus-point region in the CMSSM and affect the 68 and 95 % CL regions in the NUHM1. In combination, these new constraints reduce the best-fit values of m ₀,m _1/2 in the CMSSM, and increase the global χ ² from 31.0 to 32.8, reducing the p-value from 12 % to 8.5 %. In the case of the NUHM1, they have little effect on the best-fit values of m ₀,m _1/2, but increase the global χ ² from 28.9 to 31.3, thereby reducing the p-value from 15 % to 9.1 %.     

Searching for physics beyond the Standard Model in the decay B+ → K+K+ π−

The observation potential of the decay B⁺ K⁺K^+– with the ATLAS detector at LHC is described in this paper. In the Standard Model this decay mode is highly suppressed, while in models beyond the Standard Model it could be significantly enhanced. To improve the selection of the K⁺K^+– final state, a charged hadron identification using Time-over-Threshold measurements in the ATLAS Transition Radiation Tracker was developed and used.     

Effects of final-state interactions in pure annihilation decay of B s 0 → π+π −

The hadronic decay of B _s ⁰ → π ⁺ π ^? is analyzed by using “QCD factorization” (QCDF) method and final-state interaction (FSI). First, the B _s ⁰ → π ⁺ π ^? decay is calculated via QCDF method and the annihilation graphs only exist in this method. Hence, the FSI must be seriously considered to solve the B _s ⁰ → π ⁺ π ^? decay and the K ^+(*) K ^?(*) and \(K^{0(*)} K^{\bar 0(*)}\) via the exchange of K ^0(*) and K ^?(*) mesons are chosen for the intermediate states. To estimate the intermediate state amplitudes, the QCDF method is again used. These amplitudes are used in the absorptive part of the diagrams. The experimental branching ratio of B _s ⁰ → π ⁺ π ^? decay is less than 1.2 × 10^?6 and our results according to the QCDF method and FSI are 0.68 × 10^?8 and 1.18 × 10^?6, respectively.     

b→cτ■ decay in supersymmetry with R-parity violation

In past years,several hints of lepton flavor universality(LFU)violation have emerged from the b→ct■,and b→sl~+l-data.More recently,the Belle Collaboration has reported the first measurement of the D* longitudinal polarization fraction in the B→D*τV decay.Motivated by this intriguing result,along with the recent measurements of RJ/Ψand τ polarization,we present the study of b→ct■ decays in supersymmetry(SUSY)with R-parity violation(RPV).We consider B→D(*)t■,Bc→ηct■,Bc→J/ψt■ and ∧b→∧ct■ modes and focus on the branching ratios,LFU ratios,forward-backward asymmetries,polarizations of daughter hadrons,and the τ lepton.The RPV SUSY was capable of explaining the RD(*) anomalies at the 2σ level,after taking into account various flavor constraints.In the allowed parameter space,the differential branching fractions and LFU ratios are largely enhanced by the SUSY effects,especially in the large dilepton invariant mass region.Moreover,a lower bound B(B~+→K~+vv)7.37×10~(-6) is obtained.These observables could provide testable signatures at the high-luminosity LHC and SuperKEKB,and correlate with direct searches for SUSY.     

Final state interaction effects in the B + → D + K 0 decay

The exclusive decay of B ⁺ → D ⁺ K ⁰ is calculated by the QCD factorization method (QCDF) and final state interaction (FSI). First, the B ⁺ → D ⁺ K ⁰ decay is calculated via QCDF method. The result that is found by using the QCDF method is less than the experimental result. So FSI is considered to solve the B ⁺ → D ⁺ K ⁰ decay. For this decay, the D _s ⁺ π⁰, D _s ⁺ *ρ⁰, D _s ⁺ *? via the exchange of \(\bar K^0\) , \(\bar K^{0*} \) , D ^?, and D ^?* mesons are chosen for the intermediate states. The above intermediate states are calculated by using the QCDF method. In the FSI effects, the results of our calculations depend on η as the phenomenological parameter. The range of this parameter is selected from 2 to 2.4. It is found that if η = 2.4 is selected, the numbers of the branching ratio are placed in the experimental range. The experimental branching ratio of this decay is less than 2.9 × 10^?6 and our results calculated by QCDF and FSI are (0.16 ± 0.04) × 10^?6 and (2.8 ± 0.09) × 10^?6, respectively.     

Search for the decay τ− → vτηπ−

We have searched for the decay τ⁻ → v_τηπ⁻ using data accumulated by the ARGUS detector at the e⁺e⁻ storage ring DORIS II at DESY. No η signal was found in the π⁺π⁻π⁰ subsystems of the decay τ⁻ →v_τπ⁻π⁻π⁺ π⁰. We obtain an upper limit for the branching ratio of the decay τ⁻ → v_τηπ⁻ of 1.3% at the 95% confidence level.     

Is there a puzzle in the π0→e + e − decay?

We show the importance of precise experimental cuts in π⁰→e ⁺ e ^? decay measurements. Similar cuts have little effect in η(K _L ⁰ )→μ⁺μ^? decays.     

Constraining new physics with B→K ∗ μ + μ − in the early LHC era

We investigate the observables available in the angular distribution of B→K ^? μ ⁺ μ ^? to identify those suitable for measurements in the first few years of LHC data taking. There are three observables that may be extracted by counting signal events as a function of one or two decay angles and correspond to large features of the full angular distribution in the Standard Model: A _FB, F _L, and S ₅. Two of these are well known in the experimental community; however, we show that measuring S ₅ adds complementary sensitivity to physics beyond the Standard model. Like A _FB, it features a zero-crossing point with reduced hadronic uncertainties at leading order and in the large recoil limit. Due to the high gradient of S ₅ at this point, we find it would be possible for LHCb to measure it to high precision. Current experimental model independent constraints on parameter space are presented and predictions made for the values of the A _FB and S ₅ zero-crossing points. The relative impact of early LHCb measurements of A _FB, F _L, and S ₅ is assessed. These issues are explored with a new model of the decay that can be used with standard simulation tools such as EvtGen.     

τ− → π−π0ντ decay in the extended NJL model

The width of the decay τ^? → π^?π⁰ν_τ was calculated in the extended NJL model. Contact interaction of W boson with a pion pair as well as the contribution of the ρ mesons in the ground and first radialexcited states are taken into account. The sum of the contact diagram and diagram with intermediate ρ meson in the ground state leads to the result which coincides with the result of the vector-dominance model. Our results are in satisfactory agreement with experimental data.     

Study of the K − → e − νπ 0 decay

The decay K ^? → e ^? νπ ⁰ has been studied using in-flight decays detected with the ISTRA₊ setup working at the 25-GeV negative secondary beam of the U-70 PS. About 130K events were used for the analysis. The λ ₊ parameter of the vector form factor has been measured: λ ₊=0.0293±0.0015(stat.)±0.002(syst.). The limits on the possible tensor and scalar couplings have been derived: f _T/f ₊(0)=?0.045±0.060(stat.) and f _S/f ₊(0)=?0.019 _?0.016 ^+0.025 (stat.).