Ivan Nišandžić

activity

20122026

most citedOn the B to D* tau nu Sensitivity to New Physics

437 citations · 1.6k across the 23 of their papers we have counts for

collaborators

24 papers

hep-ph2026

New Predictions for the Lifetimes of Doubly Heavy Baryons and the $B_{c}$ Meson

Lovro Dulibić, Blaženka Melić, Ivan Nišandžić

We present updated predictions for the lifetimes of all weakly decaying doubly heavy baryons, including $bb$ , $cc$ , and $b c$ baryons, as well as for the $B_{c}$ meson. The analysis i…

hep-ph2025

Nonperturbative Parameters of Inclusive $Λ_{b}$ Decays from Small Velocity Sum Rules

Blaženka Melić, Ivan Nišandžić

We investigate the nonperturbative parameters entering the heavy quark expansion for the inclusive decay rates of the $Λ_{b}$ baryon, focusing on the kinetic term $μ^_{π}^{2}$ and the…

hep-ph2024

Revisiting the Higgs Boson Decay into a Photon and a Neutrino Pair

Aliaksei Kachanovich, Ivan Nišandžić

We present new calculations of the leading-order one-loop amplitude and the decay rate for $H \to ν ν ˉ γ$ within the standard model, employing reduction to a set of basic Passarin…

hep-ph2023★ 10 cited

Revisiting lifetimes of doubly charmed baryons

Lovro Dulibić, James Gratrex, Blaženka Melić +1

We present updated predictions for lifetimes of doubly charmed baryons, within the heavy quark expansion, including available NLO $α_{s}$ contributions and newly-computed terms in th…

hep-ph2023

Charmed hadron lifetimes

James Gratrex, Blaženka Melić, Ivan Nišandžić

We provide updated predictions of the lifetimes of singly charmed baryons and mesons within the heavy quark expansion, with all known corrections included. A special attention is d…

hep-ph2023★ 11 cited

Quark-hadron duality at work: lifetimes of bottom baryons

James Gratrex, Alexander Lenz, Blaženka Melić +3

In the 1990s, very low experimental values for the lifetime ratio $τ (Λ_{b}) / τ (B_{d})$ triggered a considerable amount of doubt in the applicability of the heavy quark expansion (HQE),…

hep-ph2022★ 31 cited

Lifetimes of singly charmed hadrons

James Gratrex, Blaženka Melić, Ivan Nišandžić

We provide an extensive study of the lifetimes of singly charmed baryons and mesons, within the heavy quark expansion with all known corrections included. A special attention is de…

hep-ph2021★ 13 cited

Higgs decay into a lepton pair and a photon: a roadmap to $H \to Z γ$ discovery and probes of new physics

Aliaksei Kachanovich, Ulrich Nierste, Ivan Nišandžić

The decay $H \to ℓ^{+} ℓ^{-} γ$ , $ℓ = e, μ$ , receives contributions from $H \to Z [\to ℓ^{+} ℓ^{-}] γ$ and a non-resonant contribution, both of which are loop-induced. We describe h…

hep-ph2021★ 19 cited

Flavorful leptoquarks at the LHC and beyond: Spin 1

Gudrun Hiller, Dennis Loose, Ivan Nišandžić

Evidence for electron-muon universality violation that has been revealed in $b \to s ℓℓ$ transitions in the observables $R_{K, K^{*}}$ by the LHCb Collaboration can be explained…

hep-ph2020★ 32 cited

Higgs decay into a lepton pair and a photon revisited

Aliaksei Kachanovich, Ulrich Nierste, Ivan Nišandžić

We present new calculations of the differential decay rates for $H \to ℓ^{+} ℓ^{-} γ$ with $ℓ = e$ or $μ$ in the Standard Model. The branching fractions and forward-backward asymm…

hep-ph2019★ 20 cited

Lepton Flavor Universality tests through angular observables of $B \to D^{(*)} ℓ ν$ decay modes

Damir Becirevic, Marco Fedele, Ivan Nisandzic +1

We discuss the possibility of using the observables deduced from the angular distribution of the $B \to D^{(*)} ℓ ν ˉ$ decays to test the effects of lepton flavor universalit…

hep-ph2018★ 39 cited

Soft-Photon Corrections to $B ˉ \to D τ^{-} ν ˉ_{τ}$ Relative to $B ˉ \to D μ^{-} ν ˉ_{μ}$

Stefan de Boer, Teppei Kitahara, Ivan Nisandzic

We evaluate long-distance electromagnetic (QED) contributions to $B ˉ^{0} \to D^{+} τ^{-} ν ˉ_{τ}$ and $B^{-} \to D^{0} τ^{-} ν ˉ_{τ}$ relative to $B ˉ^{0} \to D^{+} μ^{-} ν ˉ_{μ}$ …

hep-ph2018★ 92 cited

Flavorful leptoquarks at hadron colliders

Gudrun Hiller, Dennis Loose, Ivan Nisandzic

$B$ -physics data and flavor symmetries suggest that leptoquarks can have masses as low as few ${\cal{O}}(\mbox{TeV})$, predominantly decay to third generation quarks, and highlight…

hep-ph2017★ 188 cited

$R_{K}$ and $R_{K^{*}}$ beyond the Standard Model

Gudrun Hiller, Ivan Nisandzic

Measurements of the ratio of $B \to K^{*} μμ$ to $B \to K^{*} ee$ branching fractions, $R_{K^{*}}$ , by the LHCb collaboration strengthen the hints from previous studies with pseudoscal…

hep-ph2017★ 11 cited

Revisiting $B \to K^{*} (\to K π) ν ν ˉ$ decays

Diganta Das, Gudrun Hiller, Ivan Nisandzic

The rare decay $B \to K^{*} (\to K π) ν ν ˉ$ is expected to play an important role in searches for physics beyond the Standard Model at the near future $B$ -physics experiments. We…

hep-ph2016★ 17 cited

Zooming in on $B \to K^{*} ℓℓ$ decays at low recoil

Simon Braß, Gudrun Hiller, Ivan Nisandzic

We analyse $B \to K^{*} ℓℓ$ decays in the region of low hadronic recoil, where an operator product expansion (OPE) in $1/ m_{b}$ applies. Using a local model for charm contribut…

hep-ph2016★ 26 cited

Angular distributions of $B ˉ \to D^{(*)} ℓ ν ˉ_{ℓ}$ decays and search of New Physics

Damir Becirevic, Svjetlana Fajfer, Ivan Nisandzic +1

We derive the expressions for the full angular distributions of $B ˉ \to D ℓ ν ˉ_{ℓ}$ and $B ˉ \to D^{*} ℓ ν ˉ_{ℓ}$ decays and discuss the spectra on each angle s…

hep-ph2015★ 66 cited

LHC diphoton 750 GeV resonance as an indication of $S U (3)_{c} \times S U (3)_{L} \times U (1)_{X}$ gauge symmetry

A. E. Cárcamo Hernández, Ivan Nisandzic

The LHC collaborations ATLAS and CMS recently reported on the excess of the events in the diphoton final states at the invariant mass of about $750 GeV$ . In this article we…

hep-ph2015★ 52 cited

Discerning new physics in charm meson leptonic and semileptonic decays

Svjetlana Fajfer, Ivan Nisandzic, Ursa Rojec

Current experimental information on the charm meson decay observables in which the $c \to s ℓ ν_{ℓ}$ transitions occur is well compatible with the Standard Model predictions. Rece…

hep-ph2015★ 89 cited

New Physics Models Facing Lepton Flavor Violating Higgs Decays at the Percent Level

Ilja Dorsner, Svjetlana Fajfer, Admir Greljo +3

We speculate about the possible interpretations of the recently observed excess in the $h \to τ μ$ decay. We derive a robust lower bound on the Higgs boson coupling strength to a ta…

hep-ph2013★ 145 cited

Minimally flavored colored scalar in $B ˉ \to D^{(*)} τ ν ˉ$ and the mass matrices constraints

Ilja Dorsner, Svjetlana Fajfer, Nejc Kosnik +1

The presence of a colored scalar that is a weak doublet with fractional electric charges of $∣ Q ∣ = 2/3$ and $∣ Q ∣ = 5/3$ with mass below 1,TeV can provide an explanation of the observed…

hep-ph2013

Theory of $B \to τ ν$ and $B \to D^{(*)} τ ν$

Svjetlana Fajfer, Ivan Nisandzic

We review possible impact of beyond Standard Model physics in the third generation leptonic and semileptonic B decays.

hep-ph2012★ 298 cited

Implications of lepton flavor universality violations in B decays

Svjetlana Fajfer, Jernej F. Kamenik, Ivan Nisandzic +1

Present measurements of b->c tau nu and b->u tau nu transitions differ from the standard model predictions of lepton flavor universality by almost 4sigma. We examine new physics in…

hep-ph2012★ 437 cited

On the B to D* tau nu Sensitivity to New Physics

Svjetlana Fajfer, Jernej F. Kamenik, Ivan Nisandzic

B physics has played a prominent role in investigations of new physics effects at low-energies. Presently, the largest discrepancy between a standard model prediction and experimen…

New Predictions for the Lifetimes of Doubly Heavy Baryons and the Bc​ Meson

Nonperturbative Parameters of Inclusive Λb​ Decays from Small Velocity Sum Rules