Experimental upper limits on branching fractions for unexpected decay modes of theτlepton

Abstract A data set corresponding to an integrated luminosity of 9 fb−1 of proton-proton collisions collected by the LHCb experiment has been analysed to search for $$ {B}_c^{+}\to {D}_{(s)}^{\left(\ast \right)+}{\genfrac{}{}{0pt}{}{\left(\hbox{---} \right)}{D}}^{\left(\ast \right)0} $$ B c + → D s ∗ + — D ∗ 0 decays. The decays are fully or partially reconstructed, where one or two missing neutral pions or photons from the decay of an excited charm meson are allowed. Upper limits for the branching fractions, normalised to B+ decays to final states with similar topologies, are obtained for sixteen $$ {B}_c^{+} $$ B c + decay modes. For the decay $$ {B}_c^{+}\to {D}_s^{+}{\overline{D}}^0 $$ B c + → D s + D ¯ 0 , an excess with a significance of 3.4 standard deviations is found.

Download Full-text

Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson

Journal of High Energy Physics ◽

10.1007/jhep11(2020)039 ◽

2020 ◽

Vol 2020 (11) ◽

Author(s):

A. M. Sirunyan ◽

◽

A. Tumasyan ◽

W. Adam ◽

F. Ambrogi ◽

...

Keyword(s):

Higgs Boson ◽

Z Boson ◽

Branching Fractions ◽

Proton Collision ◽

Data Set ◽

Proton Proton ◽

Decay Channels ◽

Decay Products ◽

Upper Limits ◽

Z Boson Decays

Abstract Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at $$ \sqrt{s} $$ s = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb−1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04–1.31% and 0.31–0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740–940 and 730–950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.

Download Full-text

Study of nonleptonic B(s)∗→ M1M2 (M = D,Ds,π,K) weak decays with factorization approach

International Journal of Modern Physics A ◽

10.1142/s0217751x15501626 ◽

2015 ◽

Vol 30 (27) ◽

pp. 1550162 ◽

Cited By ~ 6

Author(s):

Qin Chang ◽

Pan-Pan Li ◽

Xiao-Hui Hu ◽

Lin Han

Keyword(s):

Flavor Physics ◽

Branching Fractions ◽

Form Factors ◽

Approximation Formula ◽

Heavy Flavor ◽

Transition Form ◽

Factorization Approach ◽

Decay Modes ◽

Weak Decays ◽

Belle Ii

Motivated by the experiments of heavy flavor physics at running LHC and upgrading SuperKEKB/Belle-II in the future, the nonleptonic [Formula: see text] [Formula: see text] weak decays are studied in this paper. The amplitudes are calculated with factorization approach, and the transition form factors [Formula: see text] are evaluated within BSW model. With the reasonable approximation [Formula: see text], our predictions of branching fractions are presented. Numerically, the CKM-favored tree-dominated [Formula: see text] and [Formula: see text] decays have the largest branching fractions of the order [Formula: see text], and hence will be firstly observed by forthcoming Belle-II experiment. However, most of the other decay modes have the branching fractions [Formula: see text] and thus are hardly to be observed soon. Besides, for the possible detectable [Formula: see text] decays with branching fractions [Formula: see text], some useful ratios, such as [Formula: see text], etc. are presented and discussed in detail.

Download Full-text

MEASUREMENT OF THE $D \bar{D}$ CROSS SECTIONS AND D HADRONIC BRANCHING FRACTIONS

International Journal of Modern Physics A ◽

10.1142/s0217751x05027369 ◽

2005 ◽

Vol 20 (16) ◽

pp. 3701-3703

Author(s):

Guang-Pei Chen

Keyword(s):

Cross Section ◽

Cross Sections ◽

Branching Fractions ◽

Hadronic Decay ◽

Decay Modes ◽

The Cross

Using 57.2 pb-1 of data collected with the CLEO-c detector at the ψ(3770) resonance, we measure absolute branching fractions for three D0 and two D+ Cabibbo-allowed hadronic decay modes, and the cross section for [Formula: see text] at [Formula: see text].

Download Full-text

STATUS OF THE HADRONIC τ DETERMINATION OF Vus

International Journal of Modern Physics A ◽

10.1142/s0217751x08041803 ◽

2008 ◽

Vol 23 (21) ◽

pp. 3191-3195 ◽

Cited By ~ 16

Author(s):

K. MALTMAN ◽

C. E. WOLFE ◽

S. BANERJEE ◽

M. RONEY ◽

I. NUGENT

Keyword(s):

Sum Rules ◽

Branching Fractions ◽

Sum Rule ◽

Slow Convergence ◽

Decay Data ◽

Decay Modes ◽

Good Agreement

We update the extraction of Vus from hadronic τ decay data in light of recent BaBar and Belle results on the branching fractions of a number of important strange decay modes. A range of sum rule analyses is employed, particular attention being paid to those based on “non-spectral weights”, developed previously to bring the slow convergence of the relevant integrated D = 2 OPE series under improved control. Results from the various sum rules are in good agreement with one another, but ~ 3σ below expectations based on 3-family unitarity.

Download Full-text

Charmed $$\Omega _c$$ weak decays into $$\Omega $$ in the light-front quark model

The European Physical Journal C ◽

10.1140/epjc/s10052-020-08619-y ◽

2020 ◽

Vol 80 (11) ◽

Author(s):

Yu-Kuo Hsiao ◽

Ling Yang ◽

Chong-Chung Lih ◽

Shang-Yuu Tsai

Keyword(s):

Quark Model ◽

Recent Observation ◽

Branching Fractions ◽

Form Factors ◽

Weak Decay ◽

Current Data ◽

Light Front ◽

Transition Form ◽

Decay Modes ◽

Weak Decays

AbstractMore than ten $$\Omega _c^0$$ Ω c 0 weak decay modes have been measured with the branching fractions relative to that of $$\Omega ^0_c\rightarrow \Omega ^-\pi ^+$$ Ω c 0 → Ω - π + . In order to extract the absolute branching fractions, the study of $$\Omega ^0_c\rightarrow \Omega ^-\pi ^+$$ Ω c 0 → Ω - π + is needed. In this work, we predict $${{\mathcal {B}}}_\pi \equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-\pi ^+)=(5.1\pm 0.7)\times 10^{-3}$$ B π ≡ B ( Ω c 0 → Ω - π + ) = ( 5.1 ± 0.7 ) × 10 - 3 with the $$\Omega _c^0\rightarrow \Omega ^-$$ Ω c 0 → Ω - transition form factors calculated in the light-front quark model. We also predict $${{\mathcal {B}}}_\rho \equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-\rho ^+)=(14.4\pm 0.4)\times 10^{-3}$$ B ρ ≡ B ( Ω c 0 → Ω - ρ + ) = ( 14.4 ± 0.4 ) × 10 - 3 and $${{\mathcal {B}}}_e\equiv {{\mathcal {B}}}(\Omega _c^0\rightarrow \Omega ^-e^+\nu _e)=(5.4\pm 0.2)\times 10^{-3}$$ B e ≡ B ( Ω c 0 → Ω - e + ν e ) = ( 5.4 ± 0.2 ) × 10 - 3 . The previous values for $${{\mathcal {B}}}_\rho /{{\mathcal {B}}}_\pi $$ B ρ / B π have been found to deviate from the most recent observation. Nonetheless, our $${{\mathcal {B}}}_\rho /{{\mathcal {B}}}_\pi =2.8\pm 0.4$$ B ρ / B π = 2.8 ± 0.4 is able to alleviate the deviation. Moreover, we obtain $${{\mathcal {B}}}_e/{{\mathcal {B}}}_\pi =1.1\pm 0.2$$ B e / B π = 1.1 ± 0.2 , which is consistent with the current data.

Download Full-text

New Measurements of B → PV and VV Decays at Belle

International Journal of Modern Physics A ◽

10.1142/s0217751x0502700x ◽

2005 ◽

Vol 20 (15) ◽

pp. 3569-3577

Author(s):

Kai-Feng Chen

Keyword(s):

Storage Ring ◽

Branching Fractions ◽

Belle Detector ◽

Polarization Study ◽

Upper Limits

We present measurements of B → PV and VV decays based on 140 fb-1 of data recorded at the ϒ(4S) resonance with the Belle detector at the KEKB e+e- storage ring. Branching fractions of B → ηK*, ηρ+, ρπ0, and ρ+K* are measured; while upper limits of B → ηρ0 and ρ0K* decays are given. The polarization study of B → ϕK* is also updated.

Download Full-text

Study of $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ decays to charmonia and three light hadrons

Journal of High Energy Physics ◽

10.1007/jhep01(2022)065 ◽

2022 ◽

Vol 2022 (1) ◽

Author(s):

◽

R. Aaij ◽

A. S. W. Abdelmotteleb ◽

C. Abellán Beteta ◽

F. J. Abudinen Gallego ◽

...

Keyword(s):

Branching Fractions ◽

Theoretical Description ◽

Proton Collision ◽

Proton Proton ◽

Decay Modes ◽

Charged Hadrons ◽

Lhcb Detector ◽

Proton Proton Collision ◽

First Time ◽

Integrated Luminosity

Abstract Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1 collected with the LHCb detector, seven decay modes of the $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + meson into a J/ψ or ψ(2S) meson and three charged hadrons, kaons or pions, are studied. The decays $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + → (ψ(2S) → J/ψπ+π−)π+, $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + → ψ(2S)π+π−π+, $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + → J/ψK+π−π+ and $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + → J/ψK+K−K+ are observed for the first time, and evidence for the $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + → ψ(2S)K+K−π+, decay is found, where J/ψ and ψ(2S) mesons are reconstructed in their dimuon decay modes. The ratios of branching fractions between the different $$ {\mathrm{B}}_{\mathrm{c}}^{+} $$ B c + decays are reported as well as the fractions of the decays proceeding via intermediate resonances. The results largely support the factorisation approach used for a theoretical description of the studied decays.

Download Full-text

TAU LEPTON HADRONIC DECAYS AT BABAR AND BELLE

Modern Physics Letters A ◽

10.1142/s0217732313600079 ◽

2013 ◽

Vol 28 (24) ◽

pp. 1360007

Author(s):

G. D. LAFFERTY

Keyword(s):

Quark Mass ◽

Branching Fractions ◽

Mass Difference ◽

Total Sample ◽

Tau Lepton ◽

Hadronic Decays ◽

Decay Modes ◽

Systematic Uncertainties ◽

Lepton Decays ◽

Lower Limits

The BaBar and Belle experiments together recorded a total sample of some 3 ×109 tau lepton decays between the years 2000 and 2010. This enabled many new and improved measurements of tau hadronic decays to be made, and resulted in lower limits for branching fractions to rare and forbidden hadronic modes, such as those mediated by second-class weak currents which are sensitive to the u–d quark mass difference. Better measurements of strange decays have contributed to more precise data on the CKM matrix element, |Vus|. However, only limited progress has been made in measurements that feed into knowledge of the value of the strong coupling constant, αs, and the strange quark mass. This is largely due to the dominance of systematic uncertainties on branching fractions and shapes of mass spectra (spectral functions) for some of the important hadronic tau decay modes.

Download Full-text