Conveners
Parallel - Flavour: Session 1
- Divya Sachdeva
Parallel - Flavour: Session 2
- Saurabh Sandilya
Parallel - Flavour: Session 3
- Seema Bahinipati
The left-handed chiral structure of the W boson in the Standard Model implies that CP violation parameters measured in radiative penguin decays of B mesons should be close to zero due to the suppression of right-handed polarised photon in the final state. Hence these decays are sensitive to physics beyond the standard model through new particles in the loop that can enhance the right-handed...
We analyze the exclusive two-body nonleptonic decays of $B_s^0$ meson to ground as well as radially ecited $2S$ charmonium states and a light meson $K_s$, induced by the $b\to c\bar{c}d$ transition. Within the framework of relativistic independent quark (RIQ) model based on a flavor-independent interaction potential in scalar-vector harmonic form, we calculate the weak form factors from the...
The rare decays $K \to \pi \nu \bar \nu$ are crucial for exploring physics beyond the Standard Model. Our investigation focuses on these decays in the context of scalar leptoquarks, exploring both lepton flavor conserving and violating channels. Furthermore, we explore the potential to detect lepton number violating operators in $K \to \pi \nu \bar \nu$ decays.
The Belle and Belle$~$II experiment have collected samples of $e^+e^-$ collision data at centre-of-mass energies near the $\Upsilon(nS)$ resonances. These data have constrained kinematics and low multiplicity, which allow searches for dark sector particles in the mass range from a few MeV to 10~GeV. Latest results are presented.
In this study, we investigate the new physics effects in semileptonic decay $\bar{B}_s \to K^{*+}(\to K \pi) l^- \bar{\nu}_l$ which is induced by the $b \to u l\nu$ quark level transition. This decay process serves as an important probe for testing the Standard Model predictions and searching deviations that might indicate new physics. The new physics wilson coefficients are constrained by...
In this work, we focus on the angular observables such as longitudinal polarization of final leptons, $\tau$-polarization, and forward-backward asymmetry, also including the study of the lepton flavor violating observables, the $\mathcal{R}$ Ratios in the decay channels $B_c \rightarrow \eta_c(J/\psi)\tau \nu_{\tau}$ & $B_c \rightarrow D(D^*)\tau \nu_{\tau}$ in the entire $q^2$ region. Our...
The $SU(2)_L\times U(1)_Y$ invariance of the Standard Model Effective Field Theory (SMEFT) predicts multiple restrictions in the space of Wilson coefficients of $U(1)_{em}$ invariant effective lagrangians such as the Low-energy Effective Field Theory (LEFT), used for low-energy flavor-physics observables, or the Higgs Effective Field Theory (HEFT) in unitary gauge, appropriate for...
We study the purely leptonic decays of heavy-flavored charged pseudoscalar (P) and vector (V) mesons ($D_{(s)}^{(*)+}$, $B_{(c)}^{(*)+}$) in the relativistic independent quark (RIQ) model based on an average flavor-independent confining potential in equally mixed scalar-vector harmonic form. We first compute the mass spectra of the ground-state-mesons and fix the model parameters necessary for...
The decay D โ KSKS is among the most interesting modes for the understanding of CP violation in charm decays. It is a singly Cabibbo suppressed transition that involves the interference between cu (bar) โ ss (bar) and cu (bar) โ dd (bar) amplitudes, mediated by the exchange of a W boson at the tree level, that can generate CP asymmetries at the 1% level, even if the...
The Belle-II has recently presented the evidence for $B^+ \to K^+ \bar{\nu} \nu$ decay for the first time. The result is in excess of the Standard Model prediction and could be a hint for physics beyond the Standard Model. In this work, we explore the implications of the Belle-II results on the $\Lambda_b \to \Lambda^{(\ast)} \nu \bar{\nu}$ decays. We make Standard Model predictions of the...
We make a correlative study of B-meson anomalies and fermionic dark matter in an extended standard model framework with $U(1)_{L_e-L_\mu}$ gauge symmetry. With three heavy neutral fermions and scalar double leptoquark $\tilde{R}_2$, we realize the $b\to s$ transition. On top, an additional singlet spontaneously breaks the new $U(1)$ and an inert scalar doublet to obtain neutrino mass at one...
For understanding the hierarchies of fermion masses and mixing, we extend the standard model gauge group with $U(1)_X$ and $Z_N$ symmetry. The field content of the Standard model is augmented by three heavy right-handed neutrinos and two new scalar singlets. $U(1)_X$ charges of different fields are considered after satisfying anomaly cancellation conditions. In this scenario, the fermion...
Recent results on the rare b โ sll decays are presented by the CMS experiment at 13 TeV. The individual branching fraction results of Bยฑ โ Kยฑฮผ+ฮผโ and Bยฑ โ Kยฑe+eโ decays are shown along with the lepton flavor universality (LFU). The effective lifetime of B0s โ J/ฯK0S decay is discussed. Finally, the CP averaged (Fl) and CP Asymmetry (A6) angular observables of Bs0 to phi mu mu decay is...
We discuss a mechanism in which the masses of the third, second, and first generation charged fermions are generated at tree level, 1-loop, and 2-loop levels, respectively. In this mechanism, loop-generated masses are obtained through fermionic self-energy corrections induced by heavy gauge bosons of a new flavorful $U(1)_F$ symmetry, which have flavor-violating interactions with Standard...
Leptoquarks, hypothesized as particles of scalar or vector nature, interact with both quarks and leptons. Building on recent measurements from $B$ factories, we investigate how leptoquark couplings influence the rare decays of $B$ mesons involving missing energy. We systematically explore all possible scalar and vector leptoquarks that are invariant under the Standard Model gauge group,...
The Belle and Belle$~$II experiments have collected a 1.1$~$ab$^{-1}$ sample of $e^+ e^-\to B\bar{B}$ collisions at the $\Upsilon(4S)$ resonance. These data, with low particle multiplicity and constrained initial state kinematics, are an ideal environment to search for rare $B$ meson decays proceeding via electroweak and radiative penguin processes. Results include those of the decay $B\to...
The Belle and Belle II B-factories have collectively gathered an extensive 1.1~ab$^{-1}$ dataset of $e^+ e^-$ collisions at the $\Upsilon(4S)$ resonance, resulting in the production of numerous $B\bar{B}$ pairs. This allows for precise measurements of hadronic $B$ decays, which is essential to test Quantum Chromodynamics (QCD) and refine theoretical models. This also helps improve simulation...
The first observation of the concurrent production of two $\rm{J}/\psi$ mesons in proton-nucleus collisions will be presented. The analysis is performed using a dataset recorded by the CMS experiment at the LHC with the nucleon-nucleon center-of-mass collision energy at 8.16 TeV. The integrated luminosity is 174.6 $\rm{nb}^{-1}$. The measured inclusive fiducial cross section $\sigma(\rm{pPb}...
The study of weak radiative decays of charmed mesons is still in its developing stage. The weak decays of $D$ mesons pose challenges due to significant final-state interactions. However, decays mediated by $c \rightarrow u \gamma$ transitions can be affected by potential contributions coming from the non-minimal supersymmetry, which is an new physics scenario. The ratio of branching fractions...
We study the interrelation among the $B$ decays mediated by $b \to c \ell \nu_{\ell}$, $b \to s \nu _\ell \nu _\ell$ and $b \to s\ell \ell$ ($\ell = e, \mu, \tau$) quark level transitions in the context of six-dimesional SMEFT operators such as $\mathcal{Q}_{\ell q}^{(3)}$,~$\mathcal{Q}_{\ell ed q}$, $\mathcal{Q}_{\ell e qu}^{(1)}$, $\mathcal{Q}_{\ell e qu}^{(3)}$, $\mathcal{Q}_{\phi...
We investigate the flavour and collider phenomenology of the flavon of the novel and unique $\mathcal{Z}_{\rm N} \times \mathcal{Z}_{\rm M}$ flavour symmetry, which is capable of addressing the flavour problem of the standard model through the Froggatt-Nielsen (FN) mechanism. In addition to the conventional approach relying on soft-symmetry breaking of the $\mathcal{Z}_{\rm N} \times...
In the universal framework of simplified t-channel dark matter models, the relic abundance is dominated by mediator annihilation in most of parameter space, which gets considerably enhanced by the Sommerfeld effect and bound state formation. We provide an intuitive and easy to use add-on package to micrOMEGAs, allowing for an automated inclusion of these effects for a generic t-channel dark...
