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Top physics provides a fertile ground for new-physics searches. At present, most top observables appear to be in good agreement with the respective Standard Model predictions. However, in the case of decay modes that are suppressed in the…

High Energy Physics - Phenomenology · Physics 2014-12-01 Pratishruti Saha

We discuss the possibilities of extracting the constraints on New Physics by using the current data on the leptonic and semileptonic decays of pseudoscalar mesons. In doing so we use a general low energy Lagrangian that besides the vector…

High Energy Physics - Phenomenology · Physics 2021-05-20 Damir Bečirević , Florentin Jaffredo , Ana Peñuelas , Olcyr Sumensari

Recently hints of lepton flavor non-universality emerged when the BaBar Collaboration observed deviations from the standard model predictions in $R(D^{(*)}) \equiv {\cal B}({\bar B} \to D^{(*)+} \tau^- {\bar\nu}_\tau) / {\cal B}({\bar B}…

High Energy Physics - Phenomenology · Physics 2015-06-10 Shanmuka Shivashankara , Wanwei Wu , Alakabha Datta

Physics beyond the Standard Model could be measured indirectly, through its effects on Standard Model observables. One place to look for such effects is in the semileptonic decays of B mesons. In order to constrain the possible role of new…

High Energy Physics - Phenomenology · Physics 2007-05-23 Walter D. Goldberger

The latest BaBar measurements of the ratios ${\cal R}(D^{(*)})=\displaystyle{\frac{{\cal B}(B \to D^{(*)} \tau {\bar \nu}_\tau)}{{\cal B}(B \to D^{(*)} \mu {\bar \nu}_\mu)}}$ deviate from the Standard Model predictions at the global level…

High Energy Physics - Phenomenology · Physics 2014-11-07 Fulvia De Fazio

The increasing number of flavour anomalies motivates the investigation of new processes where tensions similar to the observed ones may emerge. It is necessary to identify observables sensitive to physics beyond the Standard Model. The…

High Energy Physics - Phenomenology · Physics 2022-09-20 Francesco Loparco

We propose two different and complementary observables for singling out possible signals of physics beyond the standard model in the semi-leptonic decays $\Lambda_b \to \Lambda_c \ell{\bar \nu}_{\ell}$, both with the $\tau$ lepton and with…

High Energy Physics - Phenomenology · Physics 2017-03-21 Elvio Di Salvo , Ziad J. Ajaltouni

We present, for the first time, the six-fold differential decay density expression for $\Lambda^0_b\to\Lambda^+_{c} l^- \bar{\nu}_{l}$, taking into account the polarisation of the $\Lambda^0_b$ baryon and a complete basis of new physics…

High Energy Physics - Phenomenology · Physics 2020-01-22 Martina Ferrillo , Abhijit Mathad , Patrick Owen , Nicola Serra

Recent measurements of exclusive $B^{-} \to \tau^{-}\,\nu$ and $B^0 \to \pi^{+}\,l^{-}\,\bar{\nu}_l$ decays via the $b \to u\,l\,\nu$ transition process differ from the standard model expectation and, if they persist in future $B$…

High Energy Physics - Phenomenology · Physics 2013-12-30 Rupak Dutta , Anupama Bhol , Anjan K Giri

Recent experimental results of ${\cal R}(D^{(*)})$ deviate from the standard model (SM) by $3.1\sigma$, suggesting a new physics (NP) that affects the $b\to c \tau \bar\nu_\tau$ transition. Motivated by this, we investigate the possible NP…

High Energy Physics - Phenomenology · Physics 2019-12-18 Xiao-Long Mu , Ying Li , Zhi-Tian Zou , Bin Zhu

The new angular analysis of the decay $B \to K^* \ell^+ \ell^-$ recently presented by the LHCb Collaboration still indicates some tensions with the Standard Model predictions. There are several ongoing analyses to solve the problem of…

High Energy Physics - Phenomenology · Physics 2021-06-03 T. Hurth , F. Mahmoudi , S. Neshatpour

We analyze the new physics effects in semileptonic $\bar{B_s} \to K^{*+}(\to K\pi) \ell^- \bar{\nu}_\ell$ decay induced by the $b \to u \ell \nu_{\ell}$ quark level transition. We consider the vector, scalar and tensor new physics Lorentz…

High Energy Physics - Phenomenology · Physics 2025-10-30 Shabana Khan , Dinesh Kumar

We examine the new physics sensitivity of the rare decay $\Lambda_b \to \Lambda \nu\bar\nu$ which can be accessible at future $Z$-pole machines like FCC-ee and CEPC. We find that the longitudinal polarization of $\Lambda_b$ baryons produced…

High Energy Physics - Phenomenology · Physics 2025-03-11 Wolfgang Altmannshofer , Sri Aditya Gadam , Kevin Toner

The recent measurements on $R_D$, $R_{D^*}$ and $R_{J/\psi}$ by three pioneering experiments, BaBar, Belle and LHCb, indicate that the notion of lepton flavour universality is violated in the weak charged-current processes, mediated through…

High Energy Physics - Phenomenology · Physics 2021-08-06 Aishwarya Bhatta , Atasi Ray , Rukmani Mohanta

Motivated by the first observation of $\Lambda_b\to\Lambda_c~\tau\bar{\nu}$ by LHCb, we discuss various observables that can be derived from angular distribution of this decay which, if measured, could be essential for explanation of the…

High Energy Physics - Phenomenology · Physics 2022-10-24 Damir Becirevic , Florentin Jaffredo

Disentangling New Physics effects from the Standard Model requires a good understanding of all pieces that stem from the latter, especially the uncertainties that might plague the theoretical estimations within the Standard Model. In the…

High Energy Physics - Phenomenology · Physics 2016-11-16 Marco Ciuchini , Marco Fedele , Enrico Franco , Satoshi Mishima , Ayan Paul , Luca Silvestrini , Mauro Valli

In this paper we discuss the Standard Model and new physics sensitivity of the $\Lambda_b\to\Lambda^\ast(1520)(\to N\!\bar{K})\ell^+\ell^-$ decay at low-recoil, where $\ell^\pm$ are massive leptons and $N\!\bar{K}=\{pK^-, n\bar{K}^0 \}$. We…

High Energy Physics - Phenomenology · Physics 2020-07-15 Diganta Das , Jaydeb Das

Motivated by deviations with respect to Standard Model predictions in $b\to s\ell^+\ell^-$ decays, we evaluate the global significance of the new physics hypothesis in this system by including the {\it look-elsewhere effect} for the first…

High Energy Physics - Phenomenology · Physics 2021-09-28 Gino Isidori , Davide Lancierini , Patrick Owen , Nicola Serra

Inspired by various updated tantalizing results of LHCb on baryonic sector we study the {\Lambda}_b decays into {\Lambda}^* (1520)l^+ l^- decay in non-universal Z^' model. We present the four-fold angular distributions of the decay in terms…

High Energy Physics - Phenomenology · Physics 2023-10-17 S. Biswas , S. Mahata , B. P. Nayak , S. Sahoo

The experimental studies of the observables associated with the $b \rightarrow c$ transitions in the semileptonic $B-$ meson decays at BaBar, Belle and LHCb have shown some deviations from the Standard Model (SM) predictions, consequently,…

High Energy Physics - Phenomenology · Physics 2024-06-24 Tahira Yasmeen , Ishtiaq Ahmed , Saba Shafaq , Muhammad Arslan , Muhammad Jamil Aslam