scholarly journals QED factorization of non-leptonic B decays

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Martin Beneke ◽  
Philipp Böer ◽  
Jan-Niklas Toelstede ◽  
K. Keri Vos
Keyword(s):  
Weak Interactions ◽  
Branching Fractions ◽  
Form Factors ◽  
New Physics ◽  
Final States ◽  
Final State ◽  
Qcd Factorization ◽  
Factorization Formula ◽  
Qed Effects ◽  
Electrically Charged

Abstract We show that the QCD factorization approach for B-meson decays to charmless hadronic two-body final states can be extended to include electromagnetic corrections. The presence of electrically charged final-state particles complicates the framework. Nevertheless, the factorization formula takes the same form as in QCD alone, with appropriate generalizations of the definitions of light-cone distribution amplitudes and form factors to include QED effects. More precisely, we factorize QED effects above the strong interaction scale ΛQCD for the non-radiative matrix elements $$ \left\langle {M}_1{M}_2\left|{Q}_i\right|\overline{B}\right\rangle $$ M 1 M 2 Q i B ¯ of the current-current operators from the effective weak interactions. The rates of the branching fractions for the infrared-finite observables $$ \overline{B}\to {M}_1{M}_2\left(\gamma \right) $$ B ¯ → M 1 M 2 γ with photons of maximal energy ∆E ≪ ΛQCD is then obtained by multiplying with the soft-photon exponentiation factors. We provide first estimates for the various electromagnetic corrections, and in particular quantify their impact on the πK ratios and sum rules that are often used as diagnostics of New Physics.

scholarly journals RECENT τ LEPTON RESULTS FROM BABAR

2014 ◽  
Vol 35 ◽  
pp. 1460440
Author(s):  
ALBERTO LUSIANI
Keyword(s):  
Standard Model ◽  
Branching Fractions ◽  
Charged Particles ◽  
Babar Collaboration ◽  
Final States ◽  
Final State ◽  
Experimental Knowledge ◽  
Electron Positron ◽  
The Standard Model ◽  
Positron Collisions

We report recent measurements on τ leptons obtained by the BABAR collaboration using the entire recorded sample of electron-positron collisions at and around the Υ(4S) (about 470fb-1). The events were recorded at the PEP-II asymmetric collider at the SLAC National Accelerator Laboratory. The measurements include high multiplicity τ decay branching fractions with 3 or 5 charged particles in the final state, a search for the second class current the τ decay τ → πη′ν, τ branching fractions into final states containing two KS mesons, [Formula: see text], with h = π, K, and preliminary measurements of hadronic spectra of τ decays with three hadrons (τ- → h-h+h-ντ decays, where h = π, K). The results improve the experimental knowledge of the τ lepton properties and can be used to improve the precision tests of the Standard Model.

SEARCH FOR NEW PHYSICS IN eμX DATA AT THE TEVATRON USING SLEUTH: A QUASI-MODEL-INDEPENDENT SEARCH STRATEGY FOR NEW PHYSICS

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 888-890
Author(s):  
◽  
BRUCE KNUTESON
Keyword(s):  
Standard Model ◽  
Search Strategy ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Final States ◽  
Final State ◽  
The Standard Model ◽  
Model Independent

We present a quasi-model-independent search for physics beyond the standard model. We define final states to be studied, and construct a rule that identifies a set of variables appropriate for any particular final state. A new algorithm ("Sleuth") searches for regions of excess in the space of those variables and quantifies the significance of any detected excess. After demonstrating the sensititvity of the method, we apply it to the semi-inclusive channel eμX collected in ≈108 pb -1 of [Formula: see text] collisions at [Formula: see text] at the DØ experiment at the Fermilab Tevatron. We find no evidence of new high pT physics in this sample.

scholarly journals Study of Rare Mesonic Decays Involving Di-Neutrinos in Their Final State

2018 ◽  
Vol 2018 ◽  
pp. 1-20
Author(s):  
Azeem Mir ◽  
Farida Tahir ◽  
Shakeel Mahmood ◽  
Shi- Hai Dong
Keyword(s):  
Branching Fractions ◽  
New Physics ◽  
Supersymmetric Model ◽  
Final State ◽  
Yukawa Couplings ◽  
Leptonic Decays ◽  
Pseudoscalar Mesons ◽  
Theoretical Predictions ◽  
Minimal Supersymmetric Model

We have studied phenomenological implication of R-parity violating (Rp) Minimal Supersymmetric Model (MSSM) via analyses of pure leptonic (M→νν¯) and semileptonic decays of pseudoscalar mesons (M→Xνν¯). These analyses involve comparison between theoretical predictions made by Rp MSSM and the Standard Model (SM) with the experimental results like branching fractions (Br) of the said process. We have found, in general, that Rp contribution dominates over the SM contribution, i.e., by a factor of 10 for the pure leptonic decays of KL,S and by 102 and 104 in case of Bs and Bd, respectively. Furthermore, the limits obtained on Rp Yukawa couplings (λαkβ′λαkγ′⁎) by using Br  (M→Xνν¯) are used to calculate Br  (M→νν¯). This demonstrates the role of Rp MSSM as a viable model for the study of new physics contribution in rare decays at places like Super B factories, KOTO (J-PARC) and NA62 at CERN.

scholarly journals D * Polarization as an Additional Constraint on New Physics in the b → cτ ν ¯ τ Transition

Particles ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 193-207
Author(s):  
Mikhail A. Ivanov ◽  
Jürgen G. Körner ◽  
Pietro Santorelli ◽  
Chien-Thang Tran
Keyword(s):  
Experimental Data ◽  
Standard Model ◽  
Branching Fractions ◽  
Experimental Studies ◽  
Form Factors ◽  
Unknown Origin ◽  
New Physics ◽  
Constituent Quark Model ◽  
Tensor Operator ◽  
The Standard Model

Measurements of the branching fractions of the semileptonic decays B → D ( * ) τ ν ¯ τ and B c → J / ψ τ ν ¯ τ systematically exceed the Standard Model predictions, pointing to possible signals of new physics that can violate lepton flavor universality. The unknown origin of new physics realized in these channels can be probed using a general effective Hamiltonian constructed from four-fermion operators and the corresponding Wilson coefficients. Previously, constraints on these Wilson coefficients were obtained mainly from the experimental data for the branching fractions. Meanwhile, polarization observables were only theoretically studied. The situation has changed with more experimental data having become available, particularly those regarding the polarization of the tau and the D * meson. In this study, we discuss the implications of the new data on the overall picture. We then include them in an updated fit of the Wilson coefficients using all hadronic form factors from our covariant constituent quark model. The use of our form factors provides an analysis independent of those in the literature. Several new-physics scenarios are studied with the corresponding theoretical predictions provided, which are useful for future experimental studies. In particular, we find that under the one-dominant-operator assumption, no operator survives at 1 σ . Moreover, the scalar operators O S L and O S R are ruled out at 2 σ if one uses the constraint B ( B c → τ ν τ ) ≤ 10 % , while the more relaxed constraint B ( B c → τ ν τ ) ≤ 30 % still allows these operators at 2 σ , but only minimally. The inclusion of the new data for the D * polarization fraction F L D * reduces the likelihood of the right-handed vector operator O V R and significantly constrains the tensor operator O T L . Specifically, the F L D * alone rules out O T L at 1 σ . Finally, we show that the longitudinal polarization P L τ of the tau in the decays B → D * τ ν ¯ τ and B c → J / ψ τ ν ¯ τ is extremely sensitive to the tensor operator. Within the 2 σ allowed region, the best-fit value T L = 0.04 + i 0.17 predicts P L τ ( D * ) = − 0.33 and P L τ ( J / ψ ) = − 0.34 , which are at about 33% larger than the Standard Model (SM) prediction P L τ ( D * ) = − 0.50 and P L τ ( J / ψ ) = − 0.51 .

scholarly journals Measurement of the Quasi-Two-BodyBDecays

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Hossein Mehraban ◽  
Behnam Mohammadi
Keyword(s):  
Branching Fractions ◽  
Final States ◽  
Final State ◽  
Three Body

We study the contributions of theB→ψ(3770)K[ψ(3770)→DD̅],B→K*(1410)π[K*(1410)→Kπ], andB→X(3872)K[X(3872)→J/ψγ,ψ(2S)γ,DD-π,J/ψω,J/ψππ, andDD-*π]quasi-two-body decays. There are no existing previous measurements of the three-body branching fractions for three final states of theX(3872)→J/ψγ,ψ(2S)γ, andDD̅π, but several quasi-two-body modes that can decay to this final state have been seen.

INFRARED RENORMALON EFFECTS ON LIGHT MESONS ELECTROMAGNETIC TRANSITION FORM FACTOR FMγ*(Q2, ω)

2003 ◽  
Vol 18 (07) ◽  
pp. 1023-1050 ◽  
Author(s):  
YEGANA V. MAMEDOVA
Keyword(s):  
Form Factor ◽  
Perturbative Qcd ◽  
Transition Form Factor ◽  
Form Factors ◽  
Transition Form ◽  
Coupling Constant ◽  
Electromagnetic Transition ◽  
Qcd Factorization ◽  
Factorization Formula ◽  
Light Mesons

The light pseudoscalar π0, η and η′ mesons electromagnetic transition γ* + γ* → M form factors FMγ*(Q2,ω) are calculated, applying the perturbative QCD factorization formula and the frozen coupling constant approximation. In the computations the O(αS) order expression for FMγ*(Q2,ω) and the mesons' infrared renormalon corrected distribution amplitudes are used. In the case of the η and η′ mesons, the SUf(3) ordinary octet-singlet mixing scheme is utilized. Comparisons are made with the results obtained, employing the mesons' ordinary distribution amplitudes and with γ + γ* → M transition form factors.

Analysis of B0 → Ds−∗K+ decay

2015 ◽  
Vol 30 (36) ◽  
pp. 1550222
Author(s):  
Amin Asadi ◽  
Hossein Mehraban
Keyword(s):  
Vector Meson ◽  
Pseudoscalar Meson ◽  
Final State Interaction ◽  
Branching Ratio ◽  
State Interaction ◽  
Final States ◽  
Final State ◽  
Phenomenological Parameter ◽  
Qcd Factorization ◽  
Intermediate States

In this paper, we analyzed the decay [Formula: see text] within QCD factorization (QCDF) and final state interaction (FSI) methods. At first, we consider the QCDF approach, where the final states are a pseudoscalar meson and vector meson. Then, we consider the FSI method where the intermediate states are [Formula: see text] and [Formula: see text] via the exchange of [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] to improve the branching ratio. The above intermediate states are calculated by using the QCDF method. In the FSI effects, the results of our calculations depend on [Formula: see text] as the phenomenological parameter. The experimental branching ratio of this decay is [Formula: see text]. Our results in QCDF approach is [Formula: see text], and with [Formula: see text], the improved branching ratio is [Formula: see text].

scholarly journals Test of QCD at large Q2 with exclusive hadronic processes

2014 ◽  
Vol 31 ◽  
pp. 1460304
Author(s):  
Chengping Shen ◽  
Keyword(s):  
Perturbative Qcd ◽  
Cross Sections ◽  
Branching Fractions ◽  
Center Of Mass ◽  
Axial Vector ◽  
Hadronic Decays ◽  
Final States ◽  
Final State ◽  
The Cross ◽  
Using Data

My report consists of two parts: (1). Using samples of 102 million ϒ(1S) and 158 million ϒ(2S) events at Belle, we study 17 exclusive hadronic decays of these two bottomonium resonances to some Vector-Pseudoscalar (VP), Vector-Tensor (VT) and Axial-vector-Pseudoscalar (AP) processes and their final states. Branching fractions are measured for all the processes. The ratios of the branching fractions of ϒ(2S) and ϒ(1S) decays into the same final state are used to test a perturbative QCD (pQCD) prediction for OZI-suppressed bottomonium decays. (2). Using data samples of 89 fb-1, 703 fb-1, and 121 fb-1 collected at center-of-mass (CMS) energies 10.52, 10.58, and 10.876 GeV, respectively, we measure the cross sections of e+e- → ωπ0, [Formula: see text], and [Formula: see text]. The energy dependence of the cross sections is presented.

scholarly journals Parametrizations of three-body hadronic B- and D-decay amplitudes

2019 ◽  
Vol 202 ◽  
pp. 06014
Author(s):  
Benoît Loiseau ◽  
Diogo Boito ◽  
Jean-Pierre Dedonder ◽  
Bruno El-Bennich ◽  
Rafel Escribano ◽  
...  
Keyword(s):  
Recent Work ◽  
Form Factors ◽  
Short Review ◽  
Model Description ◽  
Final States ◽  
Hadronic Final State ◽  
Final State ◽  
Factorization Approach ◽  
Final State Interactions ◽  
Three Body

A short review of our recent work on amplitude parametrizations of three-body hadronic weak B and D decays is presented. The final states are here composed of three light mesons, namely the various charge πππ, Kππ and KK$ \bar K $ states. These parametrizations are derived from previous calculations based on a quasi-two-body factorization approach where the two-body hadronic final state interactions are fully taken into account in terms of unitary S- and P-wave ππ, πK and K$ \bar K $ form factors. They are an alternative to the isobar-model description and can be useful in the interpretation of CP asymmetries.

scholarly journals ANALYSIS OF B± → K+K-K± DECAYS

2011 ◽  
Vol 26 (03n04) ◽  
pp. 542-544 ◽  
Author(s):  
L. LEŚNIAK ◽  
A. FURMAN ◽  
R. KAMIŃSKI ◽  
P. ŻENCZYKOWSKI
Keyword(s):  
Form Factors ◽  
Weak Decay ◽  
Vector Form ◽  
Final State ◽  
Scalar Form ◽  
Mass Distributions ◽  
Qcd Factorization ◽  
Final State Interactions ◽  
Coupled Channel ◽  
Low K

Rare B± decays to three charged kaons are analysed. The weak decay amplitudes are derived in the QCD factorization approach. The strong final state interactions between pairs of kaons are described using the kaon scalar and vector form factors. The scalar form factors at low K+K- effective mass distributions are constrained by chiral symmetry and are related to the coupled channel meson-meson amplitudes describing all the transitions between three channels consisting of two kaons, two pions and four pions. The vector form factors are fitted to the data on e+e- collisions. The model results are compared with the Belle and BaBar data.

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