scholarly journals RPV SUSY effects in $\tau^- \to e^-(\mu^-) K\bar{K}$ decays

2014 ◽  
Vol 29 (11n12) ◽  
pp. 1450063 ◽  
Author(s):  
Wenjun Li ◽  
Xiao-Qin Nie ◽  
Ying-Ying Fan ◽  
Ming-Qiang Lu ◽  
Yu-Wei Guo
Keyword(s):  
Scalar Meson ◽  
Branching Ratios ◽  
Product Formula ◽  
Tree Level ◽  
Matrix Elements ◽  
Experiment Data ◽  
Order Of Magnitude ◽  
Resonant Contribution ◽  
Susy Model

In this paper, we investigate [Formula: see text] decays in the framework of the RPV SUSY model. We discuss the tree-level contribution of the sparticles [Formula: see text] and [Formula: see text] to these decay branching ratios. In the two channels, the [Formula: see text]-mediated channel is more sensitive to the parameter product [Formula: see text] than the [Formula: see text]-mediated channel to [Formula: see text]. And the parameter product [Formula: see text] is severely constrained to the order of [Formula: see text] by the experiment data with [Formula: see text], which is one order of magnitude more stringent than before. In the calculation of hadronic matrix elements, the resonant effects are large than those of nonresonant terms. Especially, the resonant contribution of scalar meson f(980) plays a dominate role in [Formula: see text]-mediated channel.

WEAK DECAYS OF B−, $\bar{B}^0$ MESONS TO A PSEUDOSCALAR AND A SCALAR MESON IN THE FINAL STATE

1996 ◽  
Vol 11 (01) ◽  
pp. 129-139 ◽  
Author(s):  
A.C. KATOCH ◽  
R.C. VERMA
Keyword(s):  
Quark Model ◽  
Pseudoscalar Meson ◽  
Scalar Meson ◽  
Form Factors ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Final State ◽  
Factorization Scheme ◽  
Weak Decays

Using the factorization scheme, we study two-body exclusive weak decays of B– and [Formula: see text] mesons to a pseudoscalar meson and a scalar meson in the final state. Employing the Isgur-Scora-Grinstein-Wise quark model to obtain the form factors involved in the decay matrix elements, we calculate the branching ratios for the decays involving b→c transition.

scholarly journals Another SMEFT story: Z′ facing new results on ε′/ε, ∆MK and K → $$ \pi \nu \overline{\nu} $$

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Jason Aebischer ◽  
Andrzej J. Buras ◽  
Jacky Kumar
Keyword(s):  
Renormalization Group ◽  
Mass Difference ◽  
Branching Ratios ◽  
New Physics ◽  
Matrix Elements ◽  
Isospin Breaking ◽  
Left Handed ◽  
The Standard Model ◽  
First Time ◽  
Group Effects

Abstract Recently the RBC-UKQCD lattice QCD collaboration presented new results for the hadronic matrix elements relevant for the ratio ε′/ε in the Standard Model (SM) albeit with significant uncertainties. With the present knowledge of the Wilson coefficients and isospin breaking effects there is still a sizable room left for new physics (NP) contributions to ε′/ε which could both enhance or suppress this ratio to agree with the data. The new SM value for the K0 − $$ {\overline{K}}^0 $$ K ¯ 0 mass difference ∆MK from RBC-UKQCD is on the other hand by 2σ above the data hinting for NP required to suppress ∆MK. Simultaneously the most recent results for K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ from NA62 and for KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ from KOTO still allow for significant NP contributions. We point out that the suppression of ∆MK by NP requires the presence of new CP-violating phases with interesting implications for K → $$ \pi \nu \overline{\nu} $$ πν ν ¯ , KS → μ+μ− and KL → π0ℓ+ℓ− decays. Considering a Z′-scenario within the SMEFT we analyze the dependence of all these observables on the size of NP still allowed by the data on ε′/ε. The hinted ∆MK anomaly together with the εK constraint implies in the presence of only left-handed (LH) or right-handed (RH) flavour-violating Z′ couplings strict correlation between K+ → $$ {\pi}^{+}\nu \overline{\nu} $$ π + ν ν ¯ and KL → $$ {\pi}^0\nu \overline{\nu} $$ π 0 ν ν ¯ branching ratios so that they are either simultaneously enhanced or suppressed relative to SM predictions. An anticorrelation can only be obtained in the presence of both LH and RH couplings. Interestingly, the NP QCD penguin scenario for ε′/ε is excluded by SMEFT renormalization group effects in εK so that NP effects in ε′/ε are governed by electroweak penguins. We also investigate for the first time whether the presence of a heavy Z′ with flavour violating couplings could generate through top Yukawa renormalization group effects FCNCs mediated by the SM Z-boson. The outcome turns out to be very interesting.

scholarly journals Magnetic HexadecapoleγTransitions and Neutrino-Nuclear Responses in Medium-Heavy Nuclei

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Lotta Jokiniemi ◽  
Jouni Suhonen ◽  
Hiroyasu Ejiri
Keyword(s):  
Nuclear Matrix ◽  
Wave Functions ◽  
Matrix Elements ◽  
Heavy Nuclei ◽  
Magnetic Quadrupole ◽  
Order Of Magnitude ◽  
Nuclear Responses ◽  
Beta Decays ◽  
Gamow Teller ◽  
Phonon Model

Neutrino-nuclear responses in the form of squares of nuclear matrix elements, NMEs, are crucial for studies of neutrino-induced processes in nuclei. In this work we investigate magnetic hexadecapole (M4) NMEs in medium-heavy nuclei. The experimentally derived NMEs,MEXP(M4), deduced from observed M4γtransition half-lives are compared with the single-quasiparticle (QP) NMEs,MQP(M4), and the microscopic quasiparticle-phonon model (MQPM) NMEsMMQPM(M4). The experimentally derived M4 NMEs are found to be reduced by a coefficientk≈0.29with respect toMQP(M4) and byk≈0.33with respect toMMQPM(M4). The M4 NMEs are reduced a little by the quasiparticle-phonon correlations of the MQPM wave functions but mainly by other nucleonic and nonnucleonic correlations which are not explicitly included in the MQPM. The found reduction rates are of the same order of magnitude as those for magnetic quadrupoleγtransitions and Gamow-Teller (GT) and spin-dipole (SD)βtransitions. The impacts of the found reduction coefficients on the magnitudes of the NMEs involved in astroneutrino interactions and neutrinoless double beta decays are discussed.

CP Violation in SU(3) × U(1) Electroweak Model

1997 ◽  
Vol 12 (24) ◽  
pp. 4411-4424 ◽  
Author(s):  
Tae Hoon Lee ◽  
Dae Sung Hwang
Keyword(s):  
Cp Violation ◽  
Mass Matrix ◽  
Neutral Current ◽  
Tree Level ◽  
Additional Contribution ◽  
Matrix Elements ◽  
Mixing Angle ◽  
Mixing Matrix ◽  
Electroweak Model ◽  
New Phase

We study the charged and the neutral current interactions of quarks in an SU (3)L × U (1)X electroweak model. Based on the assumption that u-type quarks coincide with their mass eigenstates, we obtain a new mixing angle θ′ and another CP violating phase δ′ in the extra heavy quark sector besides the usual Kobayashi–Maskawa mixing matrix. This new phase δ′ does not effect a change in the mass matrix elements of the [Formula: see text] systems when θ′ is small, but extra heavy quarks and gauge bosons give rise to additional contribution to the real part of the off-diagonal mass matrix elements and then the CP violation parameter ε is modified. By requiring that the tree level FCNC does not have an important effect on the [Formula: see text] and [Formula: see text] mixings in this model, we obtain a new lower bound on the mass of the extra heavy neutral gauge boson as 1.8 TeV.

Effects of pH and Uranium Valence State on the Aqueous Dissolution of Brannerite

2003 ◽  
Vol 807 ◽  
Author(s):  
Y. Zhang ◽  
E. Loi ◽  
M. Blackford ◽  
T. McLeod ◽  
H. Li ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Valence State ◽  
Ph Dependence ◽  
Aqueous Media ◽  
Matrix Elements ◽  
Atmospheric Conditions ◽  
Ph Values ◽  
Surface Alteration ◽  
Effects Of Ph ◽  
Order Of Magnitude

ABSTRACTThe dissolution of the thorium analogue of brannerite (ThTi2O6-I) and U(IV)/U(V) doped Th-brannerite (Th0.97U0.03Ti2O6-II and Th0.955U0.03Ca0.015Ti2O6-III) in aqueous media under atmospheric conditions has been studied to elucidate the effects of pH and uranium valence state on the dissolution rate.The dissolution of I is nearly stoichiometric but slightly preferential release of U occurs for II and preferential release of Ca and U occur for III. The V-shape pH dependence previously observed for U-brannerite only occurs for U (not other matrix elements) for II, indicating that the pH dependence is related to the U oxidation state upon dissolution. The normalised U dissolution rates of III are nearly an order of magnitude higher than those of II for pH values over 3, suggesting brannerite is less durable with U(V) doping. TEM examination of specimens after leaching revealed few surface alteration products, which is consistent with the nearly stoichiometric dissolution of thorium brannerite.

NEW RESULT OF DIRECT CP VIOLATION IN B → π+π-π+π-

2011 ◽  
Vol 26 (17) ◽  
pp. 2899-2912 ◽  
Author(s):  
GANG LÜ ◽  
ZHEN-HUA ZHANG ◽  
XIU-YING LIU ◽  
LI-YING ZHANG
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Invariant Mass ◽  
Branching Ratios ◽  
Effective Parameter ◽  
Matrix Elements ◽  
Strong Constraint ◽  
Ckm Matrix ◽  
First Order ◽  
Isospin Violation

In the framework of factorization, based on the first-order of isospin violation, we study direct CP violation in the decay of [Formula: see text] including the effect of ρ–ω mixing. The CP violation depends strongly on Cabibbo–Kobayashi–Maskawa (CKM) matrix elements and the effective parameter, Nc. Recently, the experimental data for the branching ratios of [Formula: see text] are accurate and we can give the strong constraint on the range of Nc. We find that the CP violating asymmetry is large and ranges from -82% to -98% via ρ–ω mixing mechanism when the invariant mass of the π+π- pair is in the vicinity of the ω resonance. We also discuss the possibility to observe the predicted CP violating asymmetries at the LHC.

scholarly journals Study on branching ratios and direct CP asymmetries of D → PV decays

2014 ◽  
Vol 29 ◽  
pp. 1460209 ◽  
Author(s):  
Qin Qin ◽  
Hsiang-Nan Li ◽  
Cai-Dian Lü ◽  
Fu-Sheng Yu
Keyword(s):  
Experimental Data ◽  
Pseudoscalar Meson ◽  
Short Distance ◽  
D Mesons ◽  
Branching Ratios ◽  
Matrix Elements ◽  
Long Distance ◽  
Global Fit ◽  
Belle Ii ◽  
Cp Asymmetries

We study the non-leptonic two-body decays of D mesons decaying into one pseudoscalar meson (P) and one vector meson (V) in the factorization-asisted topological-amplitude approach. In this approach, the decay amplitudes are factorized into two parts, the short-distance contribution (Wilson coefficients) and the long-distance contribution (hadronic matrix elements). We predict the branching ratios of D → PV decays using a global fit with the non-perturbative parameters. Our results agree well with the experimental data. We also predict the direct CP asymmetries by combining short-distance dynamics associated with penguin operators and long-distance hadronic matrix elements determined by branching ratios. The large asymmetries in D+ → π+ρ0 and [Formula: see text] may be measurable in the LHCb and future Belle II experiments.

scholarly journals THE EXCLUSIVE $\bar B \to\pi e^+ e^-$ AND $\bar B\to \rho e^+ e^-$ DECAYS IN THE TWO HIGGS DOUBLET MODEL WITH FLAVOR CHANGING NEUTRAL CURRENTS

1999 ◽  
Vol 14 (27) ◽  
pp. 4365-4393 ◽  
Author(s):  
E. O. ILTAN
Keyword(s):  
Branching Ratio ◽  
Higgs Doublet ◽  
Branching Ratios ◽  
New Physics ◽  
Tree Level ◽  
Efficient Tool ◽  
Flavor Changing ◽  
The Matrix ◽  
Doublet Model ◽  
Two Higgs Doublet Model

We present the leading logarithmic QCD corrections to the matrix element of the decay b→de+e- in the two Higgs doublet model with tree level flavor changing currents (model III). We continue studying the differential branching ratio and the CP-violating asymmetry for the exclusive decays B→πe+e- and B→ρe+e- and analysing the dependencies of these quantities on the selected model III parameters, ξU,D, including the leading logarithmic QCD corrections. Further, we present the forward–backward asymmetry of dileptons for the decay B→ρe+e- and discuss the dependencies to the model III parameters. We observe that there is a possibility to enhance the branching ratios and suppress the CP-violating effects for both decays in the framework of the model III. Therefore, the measurements of these quantities will be an efficient tool to search the new physics beyond the SM.

SPIN CORRELATION EFFECTS IN THE HADROPRODUCTION AND DECAY OF VERY HEAVY TOP QUARK PAIRS

1989 ◽  
Vol 04 (03) ◽  
pp. 617-625 ◽  
Author(s):  
V. BARGER ◽  
J. OHNEMUS ◽  
R. J. N. PHILLIPS
Keyword(s):  
Top Quark ◽  
Spin Correlation ◽  
Weak Decay ◽  
Tree Level ◽  
Matrix Elements ◽  
Correlation Effects ◽  
Quark Pairs ◽  
Quark Spin ◽  
Dilepton Events ◽  
Top Quark Pairs

Density matrix techniques in the helicity basis allow us to write down explicitly the squared matrix elements for tree-level hadroproduction and weak decay of very heavy top quark pairs, that decay before hadronization. This treatment includes the full effects of quark spin correlation. We illustrate the effects of spin correlation on physical distributions in [Formula: see text] dilepton events, [Formula: see text], [Formula: see text], [Formula: see text], for the case mt =120 GeV at [Formula: see text], the energy of the Tevatron collider. The effects of spin correlation are quantitatively small compared to calculations that ignore them, giving corrections of order 10% or less in the physical distributions studied.

Electron capture branching ratios for the odd–odd intermediate nuclei in double-beta decay using the TITAN ion trap facility

2007 ◽  
Vol 85 (1) ◽  
pp. 57-75 ◽  
Author(s):  
D Frekers ◽  
J Dilling ◽  
I Tanihata
Keyword(s):  
Electron Capture ◽  
Nuclear Matrix ◽  
Ion Trap ◽  
Ion Traps ◽  
Branching Ratios ◽  
Double Beta Decay ◽  
Radioactive Beam ◽  
X Rays ◽  
Matrix Elements ◽  
Exchange Reactions

We suggest a measurement of the electron capture (EC) branching ratios for the odd–odd intermediate nuclei in double-beta (β– β–) decay using the new ion trap facility TITAN at the TRIUMF radioactive beam facility. The EC branching ratios are important for evaluating the nuclear matrix elements involved in the β– β– -decay for both, the 2ν and the 0ν-decay mode. Especially the neutrinoless (0νββ) mode is presently at the center of attention, as it probes the Majorana character of the neutrino, and if observed unambiguously, knowledge of the nuclear matrix elements are the key for determining the neutrino mass. The EC branches are in most cases suppressed by several orders of magnitude relative to their β– -counterparts owing to much lower decay energies, and are, therefore, either poorly known or not known at all. Here, the traditional methods of producing the radioactive isotope through irradiation of a suitable target and then measuring the K-shell X-rays have reached a limit of sensitivity. In this note, we will describe a novel technique to measure the EC branching ratios, where the TITAN ion traps and the ISAC radioactive beam facility at TRIUMF are the central components. This approach will increase the sensitivity limit because of significantly reduced background levels. Seven cases will be discussed in detail and connections to hadronic charge-exchange reactions will be made. For most of these, the daughter isotopes are β– β– -decay nuclei that are presently under intense experimental investigations. These are [Formula: see text]PACS Nos.: 23.40.–s, 23.40.Hc, 29.30.Kv, 29.25.Rm, 14.60.Pq

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