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Related papers: Probing new physics effects in $\Lambda_b \to \Lam…

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We present the prospects of an angular analysis of the $\Lambda_b \to \Lambda(1520)\ell^+\ell^-$ decay. Using the expected yield in the current dataset collected at the LHCb experiment, as well as the foreseen ones after the LHCb upgrades,…

High Energy Physics - Phenomenology · Physics 2021-08-17 Yasmine Amhis , Sébastien Descotes-Genon , Carla Marin Benito , Martín Novoa-Brunet , Marie-Hélène Schune

Recently, the LHCb Collaboration provided updated measurements for the lepton flavour ratios $R_K$ and $R_{K^*}$. The currently observed values align with the predictions of the standard model. In light of these recent updates, our…

High Energy Physics - Phenomenology · Physics 2024-10-04 Juhi Vardani , Ria Sain

Recent experimental data on several observables in semileptonic $B$-meson decays are found to be in tension with the corresponding Standard Model predictions. Most of these deviations are related to $b \to c$ and $b \to s$ flavour changing…

High Energy Physics - Phenomenology · Physics 2020-07-27 Aleksey V. Rusov

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

Motivated by recent anomalies in observables associated with flavor-changing neutral current (FCNC) transitions, specifically $b \rightarrow s \ell^+ \ell^-$ processes, we present a comprehensive analysis of lepton flavor-violating (LFV)…

High Energy Physics - Phenomenology · Physics 2025-05-09 Aishwarya Bhatta , Dhiren Panda , Rukmani Mohanta

We consider new-physics (NP) contributions to the decay t -> b \bar{b} c. We parameterize the NP couplings by an effective Lagrangian consisting of 10 Lorentz structures. We show that the presence of NP can be detected through the…

High Energy Physics - Phenomenology · Physics 2013-05-29 Ken Kiers , Tal Knighton , David London , Matthew Russell , Alejandro Szynkman , Kari Webster

We propose to investigate the effects of new physics in the semi-leptonic sequential decay $\Lambda_b \to \Lambda_c (\to \Lambda \pi) \tau{\bar \nu}_{\tau}$. Firstly, we write the general, model independent, non-covariant expression of the…

High Energy Physics - Phenomenology · Physics 2023-04-04 E. Di Salvo , Z. J. Ajaltouni

Latest measurement of the ratio of branching ratios $R_D = \mathcal B(B \to D\,\tau\,\nu)/\mathcal B(B \to D\,l\,\nu)$ and $R_{D^{\ast}} = \mathcal B(B \to D^{\ast}\,\tau\,\nu)/\mathcal B(B \to D^{\ast}\,l\,\nu)$, where $l$ is either an…

High Energy Physics - Phenomenology · Physics 2017-08-30 Rupak Dutta , Anupama Bhol

In this work, we study the decays $\Lambda_c \to (\Lambda, n) \ell^+ \nu_\ell$ ($\ell = \mu, e$) within a model-independent framework. We calculate the helicity amplitudes for all possible four-fermion operators, including the interactions…

High Energy Physics - Phenomenology · Physics 2025-01-23 Zhi-Hua Zhang , Ying Li

Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable processes for probing the flavour structure of the Standard Model, with outstanding sensitivity to new (pseudo)-scalar contributions. While the branching ratio of…

High Energy Physics - Phenomenology · Physics 2018-05-16 Robert Fleischer

Recent anomalies in decays induced by $b\to c \ell^- \bar\nu_\ell$ transitions raise the question about such phenomena in the $D$ decays induced by $c\to (s,d)\ell^+\nu_\ell$ transitions. In the experimental side, current measurements on…

High Energy Physics - Phenomenology · Physics 2021-07-07 Xue Leng , Xiao-Long Mu , Zhi-Tian Zou , Ying Li

The search for New Physics (NP) beyond the Standard Model (SM) has been a central focus of particle physics, including in the context of $B$-meson decays involving $b \to s \ell \ell$ transitions. These transitions, mediated by…

High Energy Physics - Phenomenology · Physics 2024-08-08 F. Mahmoudi , Y. Monceaux

We discuss possible new physics (NP) effects beyond the standard model (SM) in the exclusive decays $\bar{B}^0 \to D^{(\ast)} \tau^- \bar{\nu}_{\tau}$. Starting with a model-independent effective Hamiltonian including non-SM four-Fermi…

High Energy Physics - Phenomenology · Physics 2017-02-23 Chien-Thang Tran , Mikhail A. Ivanov , Jürgen G. Körner

We revisit the decay $\Lambda_b^0\to \Lambda_c^+ \ell^-\bar\nu$ ($\ell = e,\mu,\tau$) with a subsequent two-body decay $\Lambda_c^+ \to \Lambda^0 \pi^+$ in the Standard Model and in generic New Physics models. The decay's joint…

High Energy Physics - Phenomenology · Physics 2022-08-01 Philipp Böer , Ahmet Kokulu , Jan-Niklas Toelstede , Danny van Dyk

The measurements of several lepton flavor universality (LFU) violating observables in the decays induced by the quark level transition $b \to c \tau \bar{\nu}$ provide an inkling of plausible physics beyond the standard model of electroweak…

High Energy Physics - Phenomenology · Physics 2023-05-17 Shabana Khan , Neetu Raj Singh Chundawat , Dinesh Kumar

The di-leptons and di-neutrinos observed in the final states of flavor-changing neutral b decays provide an ideal platform for probing physics beyond the standard model. Although the latest measurements of $R_{K^{(*)}}$ agree well with the…

High Energy Physics - Phenomenology · Physics 2023-07-10 Nilakshi Das , Rupak Dutta

It is generally believed that the decay mode $B\to K^*\ell^+\ell^-$ is one of the best modes to search for physics beyond the standard model. The angular distribution enables the independent measurement of several observables as a function…

High Energy Physics - Phenomenology · Physics 2014-11-18 Rusa Mandal , Rahul Sinha , Diganta Das

The $B$ meson semileptonic modes to $\rho(770)$ and $a_1 (1260)$ are useful to pin down possible non Standard Model effects. The 4d differential $\bar B \to \rho(\pi \pi) \ell^- \bar \nu_\ell$ and $ \bar B \to a_1 (\rho \pi) \ell^- \bar…

High Energy Physics - Phenomenology · Physics 2019-11-06 P. Colangelo , F. De Fazio , F. Loparco

The rare decays {$B^- \to \tau \bar\nu$}, \mbox{$B \to \tau^+ \tau^-$}, {$b \to X \nu \bar\nu$} and \mbox{$b \to X \tau^+ \tau^-$} all contain third generation leptons in the final state, and hence are sensitive to new physics that couples…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dafne Guetta , Enrico Nardi

We perform a comprehensive study of the impact of new-physics operators with different Lorentz structures on decays involving the b -> s mu+ mu- transition. We examine the effects of new vector-axial vector (VA), scalar-pseudoscalar (SP)…

High Energy Physics - Phenomenology · Physics 2015-05-19 Ashutosh Kumar Alok , Alakabha Datta , Amol Dighe , Murugeswaran Duraisamy , Diptimoy Ghosh , David London