Model-independent description of nonleptonic decays of charmed mesons is a challenging task due to large nonperturbative effects of strong interactions on the transition amplitudes. We discuss the equivalence of two different... more
Model-independent description of nonleptonic decays of charmed mesons is a challenging task due to large nonperturbative effects of strong interactions on the transition amplitudes. We discuss the equivalence of two different flavor-SU(3)-based descriptions of Cabibbo-favored non-leptonic decays of charmed mesons to two-pseudoscalars final states including the η and η′ mesons.
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Standard Model Neutrino Effective Field Theory (SMNEFT) is an effective theory with Standard Model (SM) gauge-invariant operators constructed only from SM and right-handed neutrino fields. For the full set of dimension-six SMNEFT... more
Standard Model Neutrino Effective Field Theory (SMNEFT) is an effective theory with Standard Model (SM) gauge-invariant operators constructed only from SM and right-handed neutrino fields. For the full set of dimension-six SMNEFT operators, we present the gauge coupling terms of the one-loop anomalous dimension matrix for renormalization group evolution (RGE) of the Wilson coefficients between a new physics scale and the electroweak scale. We find that the SMNEFT operators can be divided into five subsets which are closed under RGE. Our results apply for both Dirac and Majorana neutrinos. We also discuss the operator mixing pattern numerically and comment on some interesting phenomenological implications.
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The Standard Model Neutrino Effective Field Theory (SMNEFT) is the Standard Model Effective Field Theory (SMEFT) augmented with right-handed neutrinos. Building on our previous work, arXiv:2010.12109, we calculate the Yukawa coupling... more
The Standard Model Neutrino Effective Field Theory (SMNEFT) is the Standard Model Effective Field Theory (SMEFT) augmented with right-handed neutrinos. Building on our previous work, arXiv:2010.12109, we calculate the Yukawa coupling contributions to the one-loop anomalous dimension matrix for the 11 dimension-six four-fermion SMNEFT operators. We also present the new contributions to the anomalous dimension matrix for the 14 four-fermion SMEFT operators that mix with the SMNEFT operators through the Yukawa couplings of the right-handed neutrinos.
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At present, the measurements of $$ {R}_{D^{\left(\ast \right)}} $$ R D ∗ and RJ/ψ hint at new physics (NP) in $$ b\to c{\tau}^{-}\overline{v} $$ b → c τ − v ¯ decays. The angular distribution of $$ \overline{B}\to {D}^{\ast}\left(\to D\pi... more
At present, the measurements of $$ {R}_{D^{\left(\ast \right)}} $$ R D ∗ and RJ/ψ hint at new physics (NP) in $$ b\to c{\tau}^{-}\overline{v} $$ b → c τ − v ¯ decays. The angular distribution of $$ \overline{B}\to {D}^{\ast}\left(\to D\pi \right){\tau}^{-}{\overline{v}}_{\tau } $$ B ¯ → D ∗ → Dπ τ − v ¯ τ would be useful for getting information about the NP, but it cannot be measured. The reason is that the three-momentum $$ {\overrightarrow{p}}_{\tau } $$ p → τ cannot be determined precisely since the decay products of the τ− include an undetected ντ. In this paper, we construct a measurable angular distribution by considering the additional decay τ−→ π−ντ. The full process is $$ \overline{B}\to {D}^{\ast}\left(\to D{\pi}^{\prime}\right){\tau}^{-}\left(\to {\pi}^{-}{v}_{\tau}\right){\overline{v}}_{\tau } $$ B ¯ → D ∗ → D π ′ τ − → π − v τ v ¯ τ , which includes three final-state particles whose three-momenta can be measured: D, π′, π−. The magnitudes and relative phases of all the ...
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In order to explain the observed anomalies in the measurements of $$ {R}_{D^{\left(\ast \right)}} $$ R D ∗ and R J/ψ , a variety of new-physics (NP) models that contribute to $$ b\to c{\tau}^{-}\overline{\nu} $$ b → c τ − ν ¯ have been... more
In order to explain the observed anomalies in the measurements of $$ {R}_{D^{\left(\ast \right)}} $$ R D ∗ and R J/ψ , a variety of new-physics (NP) models that contribute to $$ b\to c{\tau}^{-}\overline{\nu} $$ b → c τ − ν ¯ have been proposed. In this paper, we show how CP-violating observables can be used to distinguish these NP models. Because $$ {\overrightarrow{p}}_{\tau } $$ p → τ cannot be measured (the decay products of the τ include the undetected ν τ ), obtaining the angular distribution of $$ {\overline{B}}^0\to {D}^{\ast +}{\tau}^{-}{\overline{\nu}}_{\tau } $$ B ¯ 0 → D ∗ + τ − ν ¯ τ is problematic. Instead, we focus here on $$ {\overline{B}}^0\to {D}^{\ast +}\left(\to {D}^0{\pi}^{+}\right){\mu}^{-}{\overline{\nu}}_{\mu } $$ B ¯ 0 → D ∗ + → D 0 π + μ − ν ¯ μ . This process may also receive contributions from the same NP, and LHCb intends to measure the CP-violating angular asymmetries in this decay. There are two classes of NP models that contribute to $$ b\to c{\mu}^{-...
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We examine current constraints on and the future sensitivity to the strength of couplings between quarks and neutrinos in the presence of a form factor generated from loop effects of hidden sector particles that interact with quarks via... more
We examine current constraints on and the future sensitivity to the strength of couplings between quarks and neutrinos in the presence of a form factor generated from loop effects of hidden sector particles that interact with quarks via new interactions. We consider models associated with either vector or scalar interactions of quarks and leptons generated by hidden sector dynamics. We study constraints on these models using data from coherent elastic neutrino-nucleus scattering and solar neutrino experiments and demonstrate how these new interactions may be discovered by utilizing the recoil spectra. We show that our framework can be naturally extended to explain the lepton universality violating neutral current B decay anomalies, and that in a model framework the constraints from neutrino scattering can have implications for these anomalies.
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We study the implication of the recent $\Delta m_s$ measurement on $ b \to s \bar{q} q$ transitions. We show that it is possible, in the presence of a flavour symmetry, that the phase in $B_s$ mixing may be unobservable even with new CP... more
We study the implication of the recent $\Delta m_s$ measurement on $ b \to s \bar{q} q$ transitions. We show that it is possible, in the presence of a flavour symmetry, that the phase in $B_s$ mixing may be unobservable even with new CP odd phases in $b \to s$ transitions. These phases may then produce new CP odd effects in certain $b \to s \bar{q} q $ transitions like $ B \to K \pi$ but not in others like $ B_d \to \phi K_s$. Working in a two higgs doublet model of new physics we discuss the allowed NP contribution to $B \to K \pi$ and $ B_d \to \phi K_s$ decays with the new $ Delta m_s$ measurement.
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Radial mixing in the pseudoscalar ηη′ systems can be generated from hyperfine interactions and annihilation terms. For the ηη′ system we find the effects of radial mixing are appreciable and seriously affect the decay branching ratios... more
Radial mixing in the pseudoscalar ηη′ systems can be generated from hyperfine interactions and annihilation terms. For the ηη′ system we find the effects of radial mixing are appreciable and seriously affect the decay branching ratios for B→η(η′)K(K * ), mainly by modifying ...
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ABSTRACT We examine CP violation in the Delta S=0 decays tau -> omega pi nu_tau and tau -> a_1 pi nu_tau and the Delta S=1 decay tau -> K pi pi nu_tau. We assume that the new physics is a charged Higgs. We show that... more
ABSTRACT We examine CP violation in the Delta S=0 decays tau -> omega pi nu_tau and tau -> a_1 pi nu_tau and the Delta S=1 decay tau -> K pi pi nu_tau. We assume that the new physics is a charged Higgs. We show that sizeable CP-violating effects are possible in tau -> a_1 pi nu_tau (polarization-dependent rate asymmetry) and tau -> omega pi nu_ tau (triple-product asymmetry). The Delta S=1 decay tau -> K pi pi nu_tau can proceed via several resonances. We construct two modified rate asymmetries and a triple product asymmetry for this decay and discuss the potential sensitivities of these asymmetries.
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Many extensions of the Standard Model(SM) generate contributions to Flavor Changing Neutral Current(FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with... more
Many extensions of the Standard Model(SM) generate contributions to Flavor Changing Neutral Current(FCNC) processes that must have sufficient flavor suppression to be consistent with experiments, if the new physics (NP) is associated with a scale of a TeV. Here we present a mechanism for suppressing the NP effects to FCNC processes. We consider the possibility that the source of NP contributions to FCNC processes share the same flavor symmetry underlying the SM source of FCNC processes which are the quark and lepton mass matrices. We call this the principle of shared flavor symmetry. In the flavor symmetric limit, the quark and lepton mixing matrices have fixed forms and there are no NP FCNC processes. In the flavor symmetric limit, we take the quark mixing matrix to be the identity matrix and the lepton mixing matrix to be given by tri-bimaximal mixing. Realistic mixing matrices are obtained by the small breaking of the flavor symmetry. New contributions to FCNC processes arise because of non universal breaking of the flavor symmetry in the quark and lepton mass matrices and the NP sources of FCNC processes. In particular, we will focus on new FCNC effects that arise due to the breaking of flavor symmetry only in the quark and charged lepton mass matrices but not in the NP sector. In this scenario, NP contributions to FCNC processes is linked to the source of flavor symmetry breaking in the quark and charged lepton mass matrices. To demonstrate the mechanism we use a two higgs doublet model as an example of beyond the SM physics though one should be able to adapt this mechanism to other models of new physics.
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We consider the new-physics (NP) solution to the polarization puzzle in B -> phi K* decays. We note that any such solution must reproduce the data in B -> phi Ks, where there are disagreements with the standard model in CP-asymmetry... more
We consider the new-physics (NP) solution to the polarization puzzle in B -> phi K* decays. We note that any such solution must reproduce the data in B -> phi Ks, where there are disagreements with the standard model in CP-asymmetry measurements. We examine 10 NP operators, of S/P, V/A and T variety. We find that, as long as B -> phi Ks exhibits large CP-violating effects, no single operator can explain the observations in both B -> phi K* and B -> phi Ks. For 2-NP-operator solutions, there are four possibilities, all of S/P type, which are presently allowed. We discuss ways of distinguishing among these solutions in the future. Models which contain only V/A operators, such as those with supersymmetry or extra Z' bosons, cannot explain both B -> phi Ks and B -> phi K* data. On the other hand, the two-Higgs-doublet model, which has only S/P operators, is favored.}
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Supersymmetric contributions to time independent asymmetry in $B^0_s \to J/\psi \phi$ process are analyzed in the view of the recent Tevatron experimental measurements. We show that the experimental limits of the mass difference $\Delta... more
Supersymmetric contributions to time independent asymmetry in $B^0_s \to J/\psi \phi$ process are analyzed in the view of the recent Tevatron experimental measurements. We show that the experimental limits of the mass difference $\Delta M_{B_s}$ and the mercury EDM significantly constrain the SUSY contribution to $B^0_s -\bar{B}^0_s$ mixing, so that $\sin 2 \beta_s \lsim 0.1$. We also point out that the one loop SUSY contribution to $B^0_s \to J/\psi \phi$ decay can be important and can lead to large indirect CP asymmetries which are different for different polarization states. These new physics effects in the decay amplitude can be consistent with CP measurements in the $B_d$ system.