Conveners
Quark and Lepton Flavour Physics: Session I - Premiere
- Karim Massri (CERN)
- Carla Gobel Burlamaqui De Mello (Pontificia Universidade Catolica (BR))
- Ruth Van de Water (Fermilab)
Quark and Lepton Flavour Physics: Session II - Premiere
- Ruth Van de Water (Fermilab)
- Karim Massri (CERN)
- Carla Gobel Burlamaqui De Mello (Pontificia Universidade Catolica (BR))
Quark and Lepton Flavour Physics: Session III - Premiere
- Akimasa Ishikawa (KEK)
- Paul Jackson (University of Adelaide)
- Pavel Reznicek (Charles University (CZ))
Quark and Lepton Flavour Physics: Session IV - Premiere
- Pavel Reznicek (Charles University (CZ))
- Akimasa Ishikawa (KEK)
- Paul Jackson (University of Adelaide)
Quark and Lepton Flavour Physics: Session I - Replay
- There are no conveners in this block
Quark and Lepton Flavour Physics: Session IV - Replay
- There are no conveners in this block
Quark and Lepton Flavour Physics: Session III - Replay
- There are no conveners in this block
Quark and Lepton Flavour Physics: Session II - Replay
- There are no conveners in this block
During Run 1 and 2 of the LHC, the LHCb experiment has collected large samples of beauty-hadron decays corresponding to an integrated luminosity of 9/fb at pp centre-of-mass energy of 7, 8 and 13 TeV. Very rare decays are discussed, with an emphasis on Flavour-Changing Neutral-Current processes of the type $B^0_{(s)} \to l^+ l^-$. Anomalies in the branching fractions of these decays are also...
Recent CMS results are reported either for the observation of the B0s to mu+mu- decay and for the search of the B0 to mu+mu- decay by adding the 2016 13TeV data to the Run-I data and for the search of the tau to 3 muons decay, with 2016 13 TeV data, by considering tau leptons coming both from Ds and W decays.
The heavy flavour production and decays are studied with the ATLAS detector, mainly through final states containing muons. This talk will summarise recent results from ATLAS, including measurements on Bc mesons decaying in different final states and of Ds cross-sections. The latest results on the studies of rare processes are also presented. Particular attention will be given to Flavour...
We present the study of $B_{s}$ decays using 121.4 fb$^{-1}$ of data collected at $\Upsilon(5S)$ resonance with the Belle detector at the KEKB asymmetric-energy electron-positron collider. We search for $B_{s}\to \eta^{\prime} \eta$ and $B_{s}\to \eta^{\prime} K^{0}_{S}$, which are suppressed in the standard model (SM) and can receive contribution of physics beyond the SM. We also report the...
Rare $B$-decays are among the most promising indirect probes for the search for New Physics. In recent years there have been several significant hints for physics beyond the SM in semileptonic $b\to s \ell \ell$ transitions. Interestingly, the analysis of these so-called B anomalies indicate a consistent pattern of lepton flavour non-universality.
We present updated global fits of Wilson...
LHCb is playing a crucial role in the study of rare and forbidden decays of charm hadrons, which might reveal effects beyond the Standard Model. We present the latest searches for, and measurements using, rare charm decay processes with two leptons in the final state.
In this talk, we present the latest result on radiative and rare/forbidden decays for D mesons at the BESIII experiment based on 2.92 fb-1 and 3.19 fb-1 data taken at the center-of-mass energy 3.773 4.178 GeV with the BESIII detector, respectively. Based the data at 4.178 GeV, a search for the rare radiative leptonic decay Ds->gamma e+ nu is performed for the first time with negative result...
We report the observation of the rare charm decay $D^0\to K^-\pi^+e^+e^-$, a search for nine lepton-number-violating and three lepton-flavor-violating neutral charm decays of the type $D^0\to h^- h^{'-} \ell^+ \ell^{'+}$, and $D^0\to h^- h^{'+} \ell^+ \ell^{'-}$, and a search for seven lepton-number-violating decays of the type $D^{0}\rightarrow X^{0} e^{\pm} \mu^{\mp}$, where $h$ and...
Kaons have played a crucial role in Particle Physics from their early history including some profound discoveries. In this talk I will give account of recent progress on several challenging issues that have been with us for a long time. Seen in the light of this progress what can we learn from many of the flavor anomalies of the past many years will also be discussed.
The purpose of the KOTO experiment, being conducted at J-PARC (Ibaraki Japan), is to search for New Physics
via the rare decay $K_L\rightarrow \pi^0 \nu \bar{\nu}$ using the high intensity $K_L$ beam provided by
the 30~GeV proton synchrotron.
The $K_L\rightarrow \pi^0 \nu \bar{\nu}$ decay is suppressed in the standard model, and
its observation may reveal hints of new physics.
The...
The ultra-rare K+ —> pi+nunu decay benefits from a precisely predicted branching ratio in the SM (8.4 +- 1.0) x 10^{-11}, being almost free from theoretical uncertainties, and most importantly from a very high sensitivity to a variety of beyond-the-standard-model scenarios, making it one of the best candidates to reveal indirect effects of new physics in the flavour sector.
The NA62...
The flavour-changing neutral current decay $K^+\to\pi^+\mu^+\mu^-$ is induced at the one-loop level in the Standard Model, and is well suited to explore its structure and, possibly, its extensions. The NA62 experiment took data in 2016--2018 with the main goal of measuring the $K^+\to\pi^+\nu\bar\nu$ decay. A scaled down di-muon trigger chain was operating along with the main trigger during...
The NA48/2 experiment at CERN reports the first observation of the K± → π± π0 e+ e− decay from an exposure of 1.7×10^11 charged kaon decays recorded in 2003−2004. A sample of 4919 candidates with 4.9% background contamination allows the determination of the branching ratio in the full kinematic region. The study of the kinematic space shows evidence for a structure dependent contribution in...
We selected candidate events for production of the exotic charged charmonium-like states $Z_c^{\pm}(3900)$ decaying to $ J/\psi\pi^{\pm}$ and $X(3872)$ decaying to $J/\psi\pi^{\pm}\pi^{\mp}$. We use 10.4 $\rm fb^{−1}$ of $p\bar p$ collisions recorded by the D0 experiment at the Tevatron collider at $\sqrt s=$1.96 TeV. We measure the $Z_c$ mass and natural width using subsample of candidates...
Novel CMS results in searches for “old" and new quarkonium-like states will be discussed.
Ratios of isospin amplitudes in hadron decays are a useful probe of the interplay between weak and strong interactions, and allow searches for physics beyond the Standard Model. We present results on isospin amplitudes in b-baryon decays using proton-proton collision LHCb data collected at center-of-mass energies of 7, 8 and 13 TeV.
New CMS measurements of the Y(1S) pair production cross section at 13TeV and of the production of Y(nS) mesons in association with an electroweak boson will be discussed.
The associated production of vector boson with quarkonia is a key observable for understanding the quarkonium production mechanisms, including the separation of single and double parton scattering components.
This talk will present the latest measurements from ATLAS on charmonium production at high transverse momentum, and the associated production of a W-boson with a J/psi meson.
BESIII has collected data samples corresponding to luminosities of 2.93 fb-1 and 3.19 fb-1 at center-of-mass energies of 3.773 and 4.178 GeV, respectively. The data set collected at 3.773 GeV contains quantum-correlated D0D0bar pairs that allow access to the phase differences between amplitudes. We report the measurements of strong phase differences in D0 decays, including KS/L pi+ pi-, which...
Using the full data collected with the Belle detector at the KEKB asymmetric-energy $e^{+} e^{-}$ collider, we report the first measurement of charm-mixing $y_{CP}$ in $D^{0}$ decays to the CP-odd final state $K_{S}^{0} \omega$. We present a Dalitz-plot analysis of the three-body decay $D^{0}\to K^{-} \pi^{+} \eta$. Along with these, we present other results related to charm physics at Belle.
New CMS measurements of prompt D*+, D+ and D0 production cross sections at 13TeV are presented together with novel studies of the production of excited Bc states carried out with full Run-II data.
Exclusive semileptonic b-hadron decays are under good theoretical control, which allows for precise determinations of the CKM matrix elements Vcb and Vub. The large production of Bs mesons at the LHC allows LHCb to provide complementary information with respect to the B-factories in this sector. The latest LHCb results on CKM matrix element determination and related measurements are presented.
A key ingredient to searches for new physics in the flavor sector are precise theoretical predictions derived from the Standard Model. Due to its large mass and long lifetime processes involving $b$ quarks are of particular interest. Focusing at the nonperturbative QCD contributions, we carry out lattice QCD simulations with the focus on semileptonic $B_{(s)}$ decays. We present results on our...
Precision measurements of $V_{ub}$ and $V_{cb}$ play a central role in precision tests of the CKM sector of the Standard Model and complement direct measurements of CP violation of B meson decays. In this talk, we present first studies for measuring $V_{ub}$ and $V_{cb}$ with semileptonic decays using collision events recorded at the $\Upsilon(4S)$ resonance by the Belle II experiment. Belle...
We present results on the first full 4-dimensional angular analysis of the $B -> D^* l \nu$ and $B -> D l \nu$ decays, using the $e^+e^-$ collision dataset collected by the $BABAR$ experiment at the $\Upsilon(4S)$resonance. One $B$ meson from the $\Upsilon(4S)\to B\bar{B}$ decay is fully reconstructed in a hadronic decay mode which constrains the kinematics and provides a precise...
Flavour physics represents a unique test bench for the Standard Model (SM). New analyses performed at the LHC experiments are now providing unprecedented insights into CKM metrology and new results for rare decays. The CKM picture can provide very precise SM predictions through global analyses.
We present here the results of the latest global SM analysis performed by the UTfit collaboration...
Recent hints of lepton-universality violation in b->clnu and anomalies observed in b->sll transitions could imply the existence of lepton-flavour violating B decays. The LHCb experiment is well suited to search for these decays thanks to its large acceptance and trigger efficiency, as well as its excellent invariant mass resolution and particle identification capabilities. Recent results on...
Charged Lepton Flavor Violation (LFV) is a very clean probe of New Physics since it is forbidden in the Standard Model (SM). The observation of neutrino oscillation implies nonzero LFV rates, which however are highly suppressed by the smallness of neutrino masses. This makes LFV an appealing target of experimental searches, as its observation would unambiguously point to New Physics.
In...
In the Standard Model, the three charged leptons are identical copies of each other, aside from differences in mass. Experimental tests of this principle in semileptonic decays of b-hadrons are highly sensitive to New Physics particles which couple differently among the leptonic families. This talk reports the most recent lepton universality tests in semileptonic b->c transitions at LHCb.
The NA62 experiment at CERN collected a large sample of charged kaon decays into final states with multiple charged particles in 2016-2018. This sample provides sensitivities to rare decays with branching ratios as low as 10^{-11}. Searches for lepton flavour and lepton number violating decays of the charged kaon into final states containing a lepton pair based on this data set are presented.
In the past some years many indications of Lepton-flavor universality violations [LFUV] have emerged, here we’ll first voice some reservations for these. Assuming they stand further scrutiny a general theoretical framework will be used to analyze these. Then the consequences for the “Intensity Frontier (IF)” precision experiments and for the “Energy Frontier (EF)” collider experiments will...
We report on a precision measurement of the ratio $R_{\tau\mu} = BF(\Upsilon(3S)\to\tau^+\tau^-)/BF(\Upsilon(3S)\to\mu^+\mu^-)$ using data collected with the BABAR detector at the SLAC PEP-II $e^+e^-$ collider. The measurement is based on a 28 ${\mathrm{fb^{-1}}}$ data sample collected at a center-of-mass energy of 10.355 ${\mathrm{GeV}}/c^2$ which corresponds to a sample 122 million...
The Minimal Supersymmetric Standard Model (MSSM) can be extended to include non-holomorphic trilinear soft supersymmetry (SUSY) breaking interactions that may have distinct signatures. We consider non-vanishing off-diagonal entries of the coupling matrices associated with holomorphic (of MSSM) and non-holomorphic trilinear terms corresponding to sleptons with elements $A^l_{ij}$ and $A^{\prime...
Mu2e experiment aims to find charged lepton flavor violation (CLFV) by measuring the monochromatic electrons from $\mu^{-}N \rightarrow e^- N$ conversion with an unprecedented single event sensitivity of $3 \times10^{-17}$. When completed the experiment will improve the current limit by 10$^4$ and make a previously unexplored phase space available for the search for beyond the standard model...
The tree-level determination of the CKM angle gamma is a standard candle measurement of CP violation in the Standard Model. The latest LHCb results from time-integrated measurements of CP violation using beauty to open charm decays are presented. These include updates to previous Run 1 measurements using the full LHCb Run 1+2 data sample and the latest LHCb gamma combination.
The latest time-dependent CP violation measurements using beauty to open charm decays from LHCb are presented. These decays provide sensitivity to important CKM parameters such as the angles beta and gamma from the unitarity triangle. Measurements include the latest results from new decay channels, analysed for the first time, including data from both LHCb Run 1 and Run 2.
In the Standard Model of particle physics, CP violation arises due to a single complex phase in the Cabibbo–Kobayashi–Maskawa (CKM) quark mixing matrix. Precise measurements of the CKM parameters therefore constrain the Standard Model, and may reveal new physics effects. The measurement of the time–dependent decay rates of B0s—>J/psi phi provides a theoretically clean method for extracting...
A new CMS measurement of CP Violation in B0s to J/psi phi decay with 2017 and 2018 13TeV data will be presented.
Measurements of mixing-induced and direct CP violation in charmless 2-body B decays provide stringent tests of the Standard Model. In addition to new phases that may enter the mixing loop, charmless B decays have an additional opportunity for unknown particles to induce deviations from the Standard Model expectation due to the sizeable contribution to these decays from penguin topologies. We...
Short and long-distance dynamics along with a sizeable effective weak phase caused by the interference between tree and penguin topologies in charmless 3-body B decays leads to a rich structure of CP violation as a function of the phase space. We present the latest studies with charmless B -> 3h decays at LHCb, including CP asymmetries and branching fractions.
The violation of CP symmetry is now very well established in the meson sector. However, CP violation has yet to be observed in the baryonic sector. Charmless b-baryon decays represent a promising opportunity in this respect since their amplitudes receive contributions from a b -> u tree diagram carrying the sizeable phase gamma. We present the most recent measurements of charmless b-baryon...
Magnetic and electric dipole moments of fundamental particles are powerful probes for physics within and beyond the Standard Model. These have not been experimentally accessible to date for the case of short-lived particles, due to the difficulties imposed by their short lifetimes.
In the recent years, direct measurements of electromagnetic dipole moments of heavy baryons and ultimately the...
Rare b->sll decays are Flavour-Changing Neutral-Current processes that are forbidden at the lowest perturbative order in the Standard Model (SM). As a consequence, new particles in SM extensions may affect the branching fractions of these decays and their angular distributions. The LHCb experiment is ideally suited for the analysis of these decays due to its high trigger efficiency, as well as...
New CMS results in the measurement of observables sensitive to New Physics by exploiting b --> s l+ l- transitions with Run-II data will be discussed.
Rare b-hadron decays are sensitive probes of New Physics through the study of branching fractions, angular observables, CP asymmetries. Moreover, the LHCb experiment has the opportunity to study the rare decays of heavy b-quark hadrons such as Bc mesons or Lambda_b baryons, which cannot be explored at the B factories. Recent results from the LHCb experiment are presented and their...
In the recent years, several measurements of $B$-decays with flavor changing neutral currents, i.e.
$b\to s$ transitions hint at deviations from the Standard Model (SM) predictions.These decays are
forbidden at tree-level in the SM and can only proceed via suppressed loop level diagrams. Rare
decays of $B$ mesons are an ideal probe to search for phenomena beyond the SM, since...
Radiative, rare, b-hadron decays are sensitive probes of New Physics through the study of branching fractions, angular observables, CP asymmetries and measurements of the polarisation of the photon emitted in the decay. The LHCb experiment is ideally suited for the analysis of these decays due to its high trigger efficiency, as well as excellent tracking and particle identification...
Searches for, and measurements of exotic states are studied with the ATLAS detector. The latest results from ATLAS on studies of pentaquark structures in the decays of heavy flavour are presented.
In addition, recent results from heavy flavour spectroscopy are reported.
In 2017 LHCb made the first observation of the doubly-charged, doubly-charmed baryon Xicc++. This has prompted significant experimental and theoretical work to predict and measure the properties of the new baryon, and search for other doubly-charmed baryons Xicc+ and Omegacc+. Here we present several searches for, and studies of, these new states. We also present several measurements using...
Recent CMS results concerning the observation of a Lambda_b rare decay and of four excited Lambda_b baryons, by using 13TeV data, are presented.
The latest results of beauty meson decays to final states with charmonium resonances from LHCb are presented. This includes measurements of time-dependent CP violation parameters and branching fractions.
The latest studies of beauty-meson decays to open-charm final states from LHCb are presented. Several branching fraction measurements using Run 1 and Run 2 data samples are shown, including first observations. These decay modes will provide important inputs to other analyses and to studies of spectroscopy.
With large branching fractions and controllable theoretical uncertainties, semileptonic B decays are excellent tools for measuring B hadron properties as well as testing QCD calculations. The large samples of Bs mesons and b-baryons uniquely available at LHCb extend the experimental reach into this sector, allowing differential decay rates of these hadrons to be probed for the first time. The...
Semileptonic $B$ meson decays allow to determine the magnitudes of the Cabibbo-Kobayashi-Maskawa matrix elements $|V_{cb}|$ and $|V_{ub}|$. $B$ decays with a heavy $\tau$ lepton in the final state constitute a powerful probe for physics beyond the standard model as well as a test for lepton flavour universality. Finally, $B$ decays with leptonic final states enable us to search for lepton...
BESIII has collected data samples corresponding to luminosities of 2.93 fb-1 and 3.19 fb-1 at center-of-mass energies of 3.773 and 4.178 GeV, respectively. In addition, data samples with a luminosity of about 3 fb-1 at center-of-mass energies between 4.19 and 4.23GeV are used to study Ds decays in some analyses. We report recent measurements that include the decays D(s)+ -> l+ nu (l=mu, tau),...
The physics of charmless B decays is an essential portion of the Belle II program.
The expected large yields of charmless B decays will enable significant advancements in the
understanding of quark dynamics, including a world-leading determination of the CKM phase
alpha/phi_2, a conclusive understanding of the so-called K-pi CP-puzzle, and a deeper insight into
phenomenological models of...
The Charm sector provides a unique environment for the searches of Physics Beyond the Standard
Model. Recent observation of CP violation in the D0 decays by the LHCb collaboration has renewed
this interest and calls for confirmation in other channels and by other experiments. As we will discuss in
this talk, Belle II will play a crucial role in measuring CP violation in many decay channels,...
The CMD-3 experiment at VEPP-2000 collider in Novosibirsk carries out a comprehensive study of the of $e^+e^-$ annihilation into hadrons in the center-of-mass energy range from the threshold, 0.32 GeV, to 2E<2 GeV. The energy scan of the whole energy range was performed in 2011-2013 and, after detector and collider upgrade and increase of luminosity, was resumed in 2017-2019 and continue in...
Many heavy-flavour measurements involve studies or searches for decays of hadrons into final states with neutral particles that are difficult or impossible to reconstruct with collider detectors, such as neutrinos, neutrons, $K^0_L$ mesons, or various dark-matter candidates. These decays are difficult to deal with, especially in the hadronic environment, such as at LHCb.
We propose a novel...
Present data sample of 8 fb$^{-1}$ collected by KLOE and KLOE-2 experiments at the upgraded DA$\Phi$NE collider of the INFN Laboratori Nazionali di Frascati corresponds to the largest sample ever collected at the $\phi$(1020) meson peak at an $e^+e^-$ collider - $2.4\times10^{10}$ $\phi$-mesons produced.
The lepton charge asymmetry measured in $K_S$ semileptonic decays with 1.7 fb$^{−1}$ of...
In 2019 the LHCb experiment published the first observation of CP violation in charmed particles, using decay channels D0->pi+pi- and D0->K+K-. Further measurements in different decay modes are essential in order to understand whether this effect can be explained by the Standard Model, or if new sources of CPV are needed. Here we present the latest searches for direct CP violation in several...
We present the first measurement of $CP$-violation parameters in a time-dependent angular analysis of the decay channel $B^0\to D^{*\pm} \rho^{\mp}$. Thanks to the angular analysis of the vector-vector final state, all the information necessary to extract $2\phi_1 + \phi_3$ can be determined from this decay. This is in contrast to $B^0\to D^{(*)\pm} \pi^{\mp}$, where SU(3) flavour assumptions...
The CKM angle $\gamma$ is the least well known of the angles of the unitarity triangle and the only one that is accessible with tree-level decays in a theoretically clean way. The key method to measure $\gamma$ is through the interference between $B^+\to D^0 K^+$ and $B^+ \to \bar D^0 K^+$ decays which occurs if the final state of the charm-meson decay is accessible to both the $D^0$ and $\bar...
With the help of the generalized Wolfenstein parametrization of quark flavor mixing and CP violation, we calculate fine differences between the twin $b$-flavored unitarity triangles defined by $V^{*}_{ub} V^{}_{ud} + V^{*}_{cb} V^{}_{cd} + V^{*}_{tb} V^{}_{td} = 0$ and $V^{*}_{ud} V^{}_{td} + V^{*}_{us} V^{}_{ts} + V^{*}_{ub} V^{}_{tb} = 0$ in the complex plane. We find that apexes of the...
Four-fermion effective interactions have played a major role in the formulation of the Standard Model (SM) of particle physics. Nowadays, they are of fundamental importance in establishing the viability of extensions of the SM, since this category of operators is sensitive to the flavor structure of New Physics (NP), including new sources of CP violation. Following the renormalization of...
Lepton flavor violating decay of muon is one of the best probes for physics beyond the Standard Model (bSM). A golden channel, $\mu \to e \gamma$, will be searched by the MEG II experiment. MEG II aims to search $\mu \to e \gamma$ with ten times better branching ratio sensitivity than MEG, $6 \times 10^{-14}$ (90% C.L.). Many well motivated bSM theories predict sizable branching ratio of this...
The COMET Experiment at J-PARC aims to search for the lepton-flavour violating process of muon to electron conversion in a muonic atom, $\mu^{-}N\rightarrow\mathrm{e}^{-}N$, with a 90% confidence level branching-ratio sensitivity of $6\times10^{-17}$, in order to explore the parameter region predicted by most well-motivated theoretical models beyond the Standard Model. The need for this...
Muon-electron conversion in a nuclear field ($\mu^- + A \rightarrow e^- + A$) is a charged-lepton flavor violation (CLFV) process. It is possible that CLFV signals are present just under the current experimental limits.
DeeMe project aims to perform an experimental search for muon-electron conversion by utilizing muonic atoms copiously produced in a primary proton target. If muon-electron...
Quark-lepton SU(4) symmetry is an appealing paradigm, a step towards grand unification. It has been identified decades ago that the minimal potentially realistic models with the quark-lepton symmetry have the $SU(4) \times SU(2) \times U(1)$ gauge structure and naturally contain both gauge and scalar leptoquarks. Such models have been thoroughly studied by several authors.
In recent years,...
The coupling of the electroweak gauge bosons of the Standard Model (SM) to leptons is flavour universal. Extensions of the SM do not necessarily have this property. Rare decays of heavy flavour are suppressed in the SM and new particles may give sizeable contributions to these processes, therefore, their precise study allows for sensitive tests of lepton flavour universality. Of particular...
The lepton flavor universality violation has been reported in the various flavor ratios such as $R_K$, $R_{K^*}$, and $P_{5}^{\prime}$ in $B\, \to\, K^{(*)}\, \mu^+ \,\mu^-$ decays. In this context, we perform an angular analysis of the four-body differential decay of $B_s\, \to\, f_{2}^{\prime}\,(1525)\,(\to K^+\,K^-)\,\mu^+ \,\mu^-$ in a model independent effective field theory formalism and...
The electroweak penguin $B$ decays mediated by $b\to s \ell^{+} \ell^{-}$ transitions are flavour-changing neutral current processes, and are thus sensitive to new physics because of possible contributions of heavy particles in the quantum loop. Recently, Belle and LHCb obtained interesting results, where the lepton flavour universality violation (LFUV) effects might be seen. We report new...
A bottom-up approach has been adopted to identify a flavour model that agrees with present experimental measurements. The charged fermion mass hierarchies suggest that only the top Yukawa term should be present at the renormalisable level. The flavour symmetry of the Lagrangian including the fermionic kinetic terms and only the top Yukawa is then a combination of U(2) and U(3) factors. ...
Charged lepton flavour violating processes are unobservable in the standard model, but they are predicted to be enhanced in several new physics extensions. We present a search for electron-muon flavour violation in $\Upsilon(3{\mathrm{S}})$ and $\Upsilon(2{\mathrm{S}})$ decays to the $e^{\pm}\mu^{\mp}$ final state. The search was conducted using data samples consisting of 118 million...
Within the framework of the Standard Model effective field theory, with operators up to dimension 6, we perform a model-independent analysis of the lepton-flavour-violating processes involving tau leptons. Namely, we study $\ell$-$\tau$ conversion in nuclei and hadronic tau decays. Based on available experimental limits, we establish bounds on the Wilson coefficients of the operators...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate
at the SuperKEKB energy-asymmetric e+e− collider. The design luminosity of the machine
is 8 × 1035 cm−2s−1 and the Belle II experiment aims to record 50 ab−1 of data, a factor
of 50 more than its predecessor. From February to July 2018, the machine has completed a
commissioning run and main operation of...
We discuss the four-fold angular distribution for the semileptonic decay $\bar{B}\to D_2^*(\to D \pi)\,\ell \bar{\nu}$ where $D_2^*$(2460) is a tensor meson. We start with the most general beyond the Standard Model (SM) dimension-six effective Hamiltonian which comprises (axial)vector, (pseudo)scalar and tensor operators for both quark and lepton currents, and it also includes the right-handed...
Recent measurements of $R_D$-$R_{D^*}$ by Belle collaboration are in agreement with the Standard Model predictions. After inclusion of these measurements, the tension between global average and the SM prediction has reduced to $3.1\sigma$. Assuming the new physics Wilson coefficients to be complex, we do a global fit to present $b\rightarrow c\,\tau\,\bar{\nu}$ data. We find that there are...
The lepton flavour universality predicted by the Standard Model is challenged by various measurements of b-hadron decays involving tau and light leptons. The Belle II experiment started recording first collision data in Spring 2019 and offers a unique laboratory to study lepton flavour universality in leptonic and semileptonic decays of B mesons at high precision. In this talk, we report the...
In this talk I will elaborate on two of the most intriguing puzzles of the Universe, viz. the dark puzzle and the flavour anomaly puzzle, and try to correlate them by considering an extension of the Inert Higgs doublet model with SU(2)_L singlet vector like fermions. This model is capable of addressing some interesting anomalous results in b → sll decays (like R(K), R(K*)) and in muon (g − 2)...
An attractive solution to the problem of B-anomalies is to combine two O(1 TeV) scalar leptoquarks in a coherent renormalizable scenario. We show that the combination of S3 and R2 leptoquarks provide such a framework that satisfies all of the low energy and high energy experimental constraints. Similarly, one can combine S1 and S3 leptoquarks but with more Yukawa couplings. The advantage of...
Current lattice determinations of the hadronic contribution to the muon anomalous magnetic moment a_mu have uncertainties of a few percent. This translates into an overall error on the Standard Model prediction of a_mu which is one order of magnitude larger than the expected final uncertainty from the ongoing E989 experiment. The bottleneck is the large statistical error in the Monte Carlo...
The muon g-2/EDM experiment at J-PARC aims to measure the anomalous magnetic moment (g-2) and electric dipole moment (EDM) of the positive muon with a novel technique utilizing a reaccelerated thermal muon beam and a 66 cm-diameter compact muon storage ring without focusing electric field. This experiment will be complementary to the previous BNL E821 experiment and ongoing Fermilab E989...
Flavor violation is an established fact for the quark sector of the Standard Model (SM) as it is for the neutral sector of leptons. But in charged sector this phenomenon has not been observed yet. We shall study the lepton flavor violation (LFV) processes from $Z$ boson decays (LFVZD), $Z\rightarrow l_il_j$. For this we shall extend the SM with higher-dimensional gauge-invariant operators...
