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Publications
Publications (133)
The azimuthal correlation angle, \(\Delta \phi \), between the scattered lepton and the leading jet in deep inelastic \(e^{\pm }p\) scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of \(\sqrt{s} = 318 {\,\text {Ge}\hspace{-0.66666pt}\text {V}}\), corresponding to an integrated luminosity of...
The first model-independent sensitivity to C P T violation in the top-quark sector is extracted from ATLAS and CMS measurements of the top and antitop kinematical mass difference. We find that the temporal component of a C P T -violating background field interacting with the top-quark vector current is restricted within the interval [ − 0.13 , 0.29...
We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $f_+(0)$ arising in the semileptonic $K \to \pi$ transition at zero mom...
We use vector meson dominance to calculate non-perturbative contributions to the branching ratio of the rare decay $K^\pm \to \pi^\pm \nu\bar \nu$ stemming from matrix elements involving up-quark loops. The importance of this observable as well as of $K^0 \to \pi^0 l^+ l^-$ and of the direct CP violation parameter $\epsilon_K^{\prime}$ is then disc...
The azimuthal correlation angle, $\Delta\phi$, between the scattered lepton and the leading jet in deep inelastic $e^{\pm}p$ scattering at HERA has been studied using data collected with the ZEUS detector at a centre-of-mass energy of $\sqrt{s} = 318 \;\mathrm{GeV}$, corresponding to an integrated luminosity of $326 \;\mathrm{pb}^{-1}$. A measureme...
A new measurement of inclusive-jet cross sections in the Breit frame in neutral current deep inelastic scattering using the ZEUS detector at the HERA collider is presented. The data were taken in the years 2004–2007 at a centre-of-mass energy of $$318\,\,\textrm{GeV}$$ 318 GeV and correspond to an integrated luminosity of $$347\,\,\textrm{pb}^{-1}$...
The hadronic mass spectrum of inclusive $\bar{B} \to X_s \ell^+ \ell^-$ is investigated at next to leading order in the heavy quark expansion. For mild cuts on the hadronic mass, the expansion, which applies when the cut is released, remains convergent. However, the cuts used at BaBar and Belle to reduce backgrounds from charged current semileptoni...
Lorentz and CPT symmetry in the quark sector of the Standard Model are studied in the context of an effective field theory using ZEUS e±p data. Symmetry-violating effects can lead to time-dependent oscillations of otherwise time-independent observables, including scattering cross sections. An analysis using five years of inclusive neutral-current d...
Lorentz and CPT symmetry in the quark sector of the Standard Model are studied in the context of an effective field theory using ZEUS $e^{\pm} p$ data. Symmetry-violating effects can lead to time-dependent oscillations of otherwise time-independent observables, including scattering cross sections. An analysis using five years of inclusive neutral-c...
A bstract
We demonstrate the potential of fully leptonic cascade decays of a heavy neutral Higgs boson through vectorlike leptons as a simultaneous probe for extended Higgs sectors and extra matter particles at the LHC. The processes we explore are unique in that their event topologies lead to di-boson-like leptonic final states with a lepton pair...
This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams,...
This is the Snowmass2021 Energy Frontier (EF) Beyond the Standard Model (BSM) report. It combines the EF topical group reports of EF08 (Model-specific explorations), EF09 (More general explorations), and EF10 (Dark Matter at Colliders). The report includes a general introduction to BSM motivations and the comparative prospects for proposed future e...
We demonstrate the potential of fully leptonic cascade decays of a heavy neutral Higgs boson through vectorlike leptons as a simultaneous probe for extended Higgs sectors and extra matter particles at the LHC. The processes we explore are unique in that their event topologies lead to di-boson-like leptonic final states with a lepton pair which does...
Electron Ion Collider (EIC) is a particle accelerator facility planned for construction at Brookhaven National Laboratory on Long Island, New York by the United States Department of Energy. EIC will provide capabilities of colliding beams of polarized electrons with polarized beams of proton and light ions. EIC will be one of the largest and most s...
In extensions of two Higgs doublet models with vectorlike quarks and leptons the decays of new scalars or fermions can be altered by the presence of the other, depending on the hierarchy of new physics. If new fermions are heavier than Higgses, their decays may be dominated by cascade decays through charged and neutral heavy Higgs bosons. In the op...
We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $f_+(0)$ arising in the semileptonic $K \to \pi$ transition at zero mom...
We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor f+(0) arising in the semileptonic K→π transition at zero momentum transfer,...
A bstract
We study 4 b + 2 τ and 4 b + 1 τ signatures of heavy neutral and charged Higgs bosons originating from cascade decays of pair-produced new quarks. Decays of vectorlike quarks through heavy Higgses can easily dominate in the two Higgs doublet model of type-II, and the studied signatures are common to many possible decay chains. We design s...
We study $4b+2\tau$ and $4b+1\tau$ signatures of heavy neutral and charged Higgs bosons originating from cascade decays of pair-produced new quarks. Decays of vectorlike quarks through heavy Higgses can easily dominate in the two Higgs doublet model of type-II, and the studied signatures are common to many possible decay chains. We design search st...
A bstract
Quark-sector Lorentz violation is studied in the context of Drell-Yan dilepton production including effects from Z -boson exchange. We show the chiral nature of the weak interactions enables parity-violating and spin-dependent effects to be studied using unpolarized initial states. Constraints are placed on dimensionless and CPT-even coef...
This report describes the physics case, the resulting detector requirements, and the evolving detector concepts for the experimental program at the Electron-Ion Collider (EIC). The EIC will be a powerful new high-luminosity facility in the United States with the capability to collide high-energy electron beams with high-energy proton and ion beams,...
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may be easily dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top quark decays also contain bottom quarks, the 6 bottom quarks in final states is a common signature to a large...
Quark-sector Lorentz violation is studied in the context of Drell-Yan dilepton production including effects from $Z$-boson exchange. We show the chiral nature of the weak interactions enables parity-violating and spin-dependent effects to be studied using unpolarized initial states. Estimated constraints are placed on dimensionless and CPT-even coe...
A bstract
With the first data being recorded at Belle II, we are at the brink of a new era in quark flavour physics. The many exciting new opportunities for Belle II include a full angular analysis of inclusive $$ \overline{B}\to {X}_s{\mathrm{\ell}}^{+}{\mathrm{\ell}}^{-} $$ B ¯ → X s ℓ + ℓ − which has the potential to reveal new physics, in parti...
The two lower panels of figure 1 are mildly modified while all other numerical results are unaffected. In tables 3–5 we adopt a more useful parameterization for the branching ratios in the case of a vectorlike quark doublet with couplings to H u and H d .
Two of the elements of the Cabibbo–Kobayashi–Maskawa quark mixing matrix, $$|V_{ub}|$$ | V ub | and $$|V_{cb}|$$ | V cb | , are extracted from semileptonic B decays. The results of the B factories, analysed in the light of the most recent theoretical calculations, remain puzzling, because for both $$|V_{ub}|$$ | V ub | and $$|V_{cb}|$$ | V cb | the...
With the first data being recorded at Belle II, we are at the brink of a new era in quark flavour physics. The many exciting new opportunities for Belle~II include a full angular analysis of inclusive ${\bar B \to X_{s} \, \ell^+\ell^-}$ which has the potential to reveal new physics, in particular by its interplay with the exclusive $b \to s \ell^+...
A bstract
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may easily be dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top quark decays also contain bottom quarks, a common signature for many possible decay chains is 6 bot...
Two of the elements of the Cabibbo-Kobayashi-Maskawa quark mixing matrix, $|V_{ub}|$ and $|V_{cb}|$, are extracted from semileptonic B decays. The results of the B factories, analysed in the light of the most recent theoretical calculations, remain puzzling, because for both $|V_{ub}|$ and $|V_{cb}|$ the exclusive and inclusive determinations are i...
In extensions of two Higgs doublet models with vectorlike quarks, the decays of vectorlike quarks may easily be dominated by cascade decays through charged or neutral Higgs bosons leading to signatures with 6 top or bottom quarks. Since top quark decays also contain bottom quarks, a common signature for many possible decay chains is 6 bottom quarks...
A bstract
A framework is presented for the factorization of high-energy hadronic processes in the presence of Lorentz and CPT violation. The comprehensive effective field theory describing Lorentz and CPT violation, the Standard-Model Extension, is used to demonstrate factorization of the hadronic tensor at leading order in electroweak interactions...
A bstract
We study cascade decays of heavy neutral Higgs bosons through vectorlike quarks. We focus on scenarios where decay modes into pairs of vectorlike quarks are not kinematically open which extends the sensitivity of the LHC to larger masses. Assuming only mixing with the third family of standard model quarks the new decay modes of heavy Higg...
We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor \(f_+(0)\) arising in the semileptonic \(K \rightarrow \pi \) transition at...
A framework is presented for the factorization of high-energy hadronic processes in the presence of Lorentz and CPT violation. The comprehensive effective field theory describing Lorentz and CPT violation, the Standard-Model Extension, is used to demonstrate factorization of the hadronic tensor at leading order in electroweak interactions for deep...
A bstract
Rare inclusive B decays such as $$ \overline{B} $$ B ¯ → X s ( d ) ℓ ⁺ ℓ − are interesting probes for physics beyond the Standard Model. Due to the complementarity to their exclusive counter- parts, they might shed light on the anomalies currently seen in exclusive b → s transitions. Distinguishing new-physics effects from the Standard Mo...
Rare inclusive $B$ decays such as $\bar{B}\to X_{s(d)} \ell^+\ell^-$ are interesting probes for physics beyond the Standard Model. Due to the complementarity to their exclusive counterparts, they might shed light on the anomalies currently seen in exclusive $b \to s$ transitions. Distinguishing new-physics effects from the Standard Model requires p...
We study cascade decays of heavy neutral Higgs bosons through vectorlike quarks. We focus on scenarios where decay modes into pairs of vectorlike quarks are not kinematically open which extends the sensitivity of the LHC to larger masses. Assuming only mixing with the third family of standard model quarks the new decay modes of heavy Higgs bosons a...
A bstract
We analyze decays of vectorlike quarks in extensions of the standard model and a two Higgs doublet model. We identify several typical patterns of branching ratios of the lightest new up-type quark, t 4 , and down-type quark, b 4 , depending on the structure of Yukawa couplings that mix the vectorlike and standard model quarks (we assume o...
We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $f_+(0)$ arising in the semileptonic $K \to \pi$ transition at zero mom...
We analyze decays of vectorlike quarks in extensions of the standard model and a two Higgs doublet model. We identify several typical patterns of branching ratios of the lightest new up-type quark, $t_4$, and down-type quark, $b_4$, depending on the structure of Yukawa couplings that mix the vectorlike and standard model quarks (we assume only mixi...
This is the third out of five chapters of the final report [1] of the Workshop on Physics at HL-LHC, and perspectives on HE-LHC [2]. It is devoted to the study of the potential, in the search for Beyond the Standard Model (BSM) physics, of the High Luminosity (HL) phase of the LHC, defined as $3$ ab$^{-1}$ of data taken at a centre-of-mass energy o...
We investigate the prospects for detecting violations of Lorentz symmetry in unpolarized deep inelastic electron-proton scattering in the context of the future electron-ion collider. Simulated differential cross-section data are used to place expected bounds on a class of quark-sector coefficients for Lorentz violation that induce sidereal time dep...
We investigate the prospects for detecting violations of Lorentz symmetry in unpolarized deep inelastic electron-proton scattering in the context of the future electron-ion collider. Simulated differential cross-section data are used to place expected bounds on a class of quark-sector coefficients for Lorentz violation that induce sidereal time dep...
Rare $B$, $D$, and $K$ decays offer unique opportunities to probe for evidence of new particles from physics beyond the Standard Model at mass scales extending from the electroweak scale to well above those directly accessible at the LHC. We review a selection of theoretical and experimental results on rare $B$, $D$, and $K$ decays illustrating the...
We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle-physics community. More specifically, we report on the determination of the light-quark masses, the form factor \(f_+(0)\), arising in the semileptonic \(K \rightarrow \pi \) transition at zero momentum transfer, as...
Lorentz violation in the quark sector induces a sidereal time dependence in electron-proton, proton-antiproton and proton-proton cross sections. At high energies nonperturbative effects are buried in universal nucleon parton distribution functions and Lorentz violating effects are calculable in perturbation theory. We focus on deep inelastic electr...
The effects of quark-sector Lorentz violation on deep inelastic electron-proton scattering are studied. We show that existing data can be used to establish first constraints on numerous coefficients for Lorentz violation in the quark sector at an estimated sensitivity of parts in a million.
The effects of quark-sector Lorentz violation on deep inelastic electron-proton scattering are studied. We show that existing data can be used to establish first constraints on numerous coefficients for Lorentz violation in the quark sector at an estimated sensitivity of parts in a million.
One of the cleanest signatures of a heavy Higgs boson in models with vectorlike leptons is $H\to e_4^\pm \ell^\mp \to h\ell^+\ell^-$ which, in two Higgs doublet model type-II, can even be the dominant decay mode of heavy Higgses. Among the decay modes of the standard model like Higgs boson, $h$, we consider $b \bar b$ and $\gamma \gamma$ as represe...
We review lattice results related to pion, kaon, D- and B-meson physics with the aim of making them easily accessible to the particle physics community. More specifically, we report on the determination of the light-quark masses, the form factor f+(0), arising in the semileptonic K -> pi transition at zero momentum transfer, as well as the decay co...
In models with extended Higgs sector and additional matter fields, the decay
modes of heavy Higgs bosons can be dominated by cascade decays through the new
fermions rendering present search strategies ineffective. We investigate new
decay topologies of heavy neutral Higgses in two Higgs doublet model with
vectorlike leptons. We also discuss constra...
We study the exclusive semileptonic $B$-meson decays $B\to
K(\pi)\ell^+\ell^-$, $B \to K(\pi)\nu\bar\nu$, and $B\to\pi\tau\nu$, computing
observables in the Standard model using the recent lattice-QCD results for the
underlying form factors from the Fermilab Lattice and MILC Collaborations.
These processes provide theoretically clean windows into p...
The rare decay B→πℓ+ℓ- arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present the first ab initio QCD calculation of the B→π tensor form factor fT. Together with the vector and scalar form factors f+ and f0 from our companion work [J.A. Bailey et al., Phys. Rev. D 92, 014024 (2...
We study a two Higgs doublet model extended by vectorlike leptons mixing with one family of standard model leptons. Generated flavor violating couplings between heavy and light leptons can dramatically alter the decay patterns of heavier Higgs bosons. We focus on pp → H → ν
4ν
μ
→ W μν
μ
, where ν
4 is a new neutral lepton, and study possible effec...
We study contributions to (Formula presented.) in models with a new Higgs boson, H, and a neutral lepton, ν4, with couplings H (Formula presented.) and W (Formula presented.) through the process (Formula presented.). Contrary to naive expectations, we find that contributions to pp → W W can be very large while satisfying constraints from standard H...
It has been clear for past many years that in low energy observables new
physics can only appear as a perturbation. Therefore precise theoretical
predictions and precise experimental measurements have become mandatory. Here
we draw attention to the significant advances that have been made on the
lattice in recent years in $K\to \pi \pi$, $\Delta M_...
With the discovery of the Higgs boson the Standard Model has become a
complete and comprehensive theory, which has been verified with unparalleled
precision and in principle might be valid at all scales. However, several
reasons remain why we firmly believe that there should be physics beyond the
Standard Model. Experiments such as the LHC, new $B$...
The rare decay $B\to\pi\ell^+\ell^-$ is sensitive to $b\to d$ flavor-changing
neutral currents, which could arise from physics beyond the Standard Model.
Here, we present the first $ab$-$initio$ QCD calculation of the $B\to\pi$
tensor form factor $f_T$. Together with the vector and scalar form factors
$f_+$ and $f_0$ from our companion work [J. A....
We investigate logarithmically enhanced electromagnetic corrections of all angular observables in inclusive \( \overline{B}\to {X}_s{\ell}^{+}{\ell}^{-} \). We present analytical results, which are supplemented by a dedicated Monte Carlo study on the treatment of collinear photons in order to determine the size of the electromagnetic logarithms. We...
The excess in $pp\to W^+W^- \to \ell\nu\ell\nu$ measurements observed by
ATLAS and CMS can be explained by the existence of a new Higgs boson, $H$, and
one or two neutral leptons, $\nu_{4(5)}$, with couplings
$H-\nu_{4(5)}-\nu_{\mu(e)}$ and $W-\nu_{4(5)}-\mu(e)$. The kinematic
distributions of observed events can be nicely fit and constraints from...
We investigate logarithmically enhanced electromagnetic corrections of all
angular observables in inclusive B -> X_s l^+ l^-. We present analytical
results, which are supplemented by a dedicated Monte Carlo study on the
treatment of collinear photons in order to determine the size of the
electromagnetic logarithms. We then give the Standard Model p...
We consider extensions of the Standard Model by vectorlike leptons and set
limits on a new charged lepton, $e_4^\pm$, using the ATLAS search for anomalous
production of multi-lepton events. It is assumed that only one Standard Model
lepton, namely the muon, dominantly mixes with vectorlike leptons resulting in
possible decays $e_4^\pm \to W^\pm \nu...
Current searches for the charged Higgs at the LHC focus only on the
$\tau\nu$, $cs$, and $tb$ final states. Instead, we consider the process $pp\to
\Phi\to W^\pm H^\mp \to W^+ W^- A$ where $\Phi$ is a heavy neutral Higgs boson,
$H^\pm$ is a charged Higgs boson, and $A$ is a light Higgs boson, with mass
either below or above the $b\bar{b}$ threshold...
We review lattice results related to pion, kaon, D- and B-meson physics with
the aim of making them easily accessible to the particle physics community.
More specifically, we report on the determination of the light-quark masses,
the form factor f+(0), arising in semileptonic K -> pi transition at zero
momentum transfer, as well as the decay consta...
In singlet extensions of the two Higgs doublet model, a light CP-odd Higgs
boson (A) can significantly modify decay modes of the charged Higgs, without
necessarily affecting decay modes of the standard model-like Higgs boson. These
effects can be sizable even if the doublet component of the light CP-odd Higgs
is small, so that constraints from Upsi...
We discuss the present status of global fits to the CKM unitary triangle
using the latest experimental and theoretical constraints. For the required
nonperturbative weak matrix elements, we use three-flavor lattice QCD averages
from www.latticeaverages.org; these have been updated from Ref. [1] to reflect
all available lattice calculations as of th...
Using firmly established experimental inputs such as ϵKϵK, ΔMdΔMd, ΔMsΔMs, Br(B→τν)Br(B→τν), γ, VcbVcb along with corresponding lattice matrix elements which have been well studied and are in full QCD such as BKBK, SU(3) breaking ratio ξ, BBsBBs and in particular without using VubVub or the pseudoscalar decay constants fBdfBd or fBsfBs from the lat...
We perform a global fit to the CKM unitarity triangle using the latest
experimental and theoretical constraints. We present results for three
different sets of constraints: the standard inputs used by CKMfitter and UTFit,
the standard inputs minus |Vub|, and the standard inputs minus both |Vub| and
|Vcb|. For the required nonperturbative weak matri...
We study the decay B → K
∗ℓ+ℓ−in the QCD factorization approach and propose a new integrated observable whose dependence on the form factors is almost negligible, consequently the non-perturbative error is significantly reduced and indeed its overall theoretical error is dominated by perturbative scale uncertainties. The new observable we propose i...
Using primarily experimental inputs for S(Bd→ψKs), ΔMBs, ΔMBd, BR(B→τν) and ϵK along with necessary inputs from the lattice, we find that the measured value of sin(2β) is smaller than expectations of the Standard Model by as much as 3.3σ, and also that the measured value of the BR(B→τν) seems to be less than the predicted value by about 2.8σ. Howev...
In the past decade, one of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor.In this time frame, measurements and the theoretical interpretation of their results have advanced tremendously. A much broader understanding of flavor particles has been achieved, apart from their masses and qu...
The use of semileptonic decays has become standard in constraining the unitarity triangle. Since precise calculations of these are very challenging, we propose an entirely new approach. The epsilon(K) constraint, which depends extremely sensitively on vertical bar V(cb)vertical bar, is replaced by the interplay between epsilon(K), BR(B --> tau nu),...
We perform a global fit to the CKM unitarity triangle using the latest experimental and theoretical constraints. Our emphasis is on the hadronic weak matrix elements that enter the analysis, which must be computed using lattice QCD or other nonperturbative methods. Realistic lattice QCD calculations which include the effects of the dynamical up, do...
One of the major challenges of particle physics has been to gain an in-depth understanding of the role of quark flavor and measurements and theoretical interpretations of their results have advanced tremendously: apart from masses
and quantum numbers of flavor particles, there now exist detailed measurements of the characteristics of their interact...
We consider several hints for new physics involving CP-asymmetries in B-decays and interpret them in terms of generic contributions to effective Wilson coefficients. The effects we focus on are: the differences in the fitted value of sin(2 beta) versus the ones directly measured via the time dependent CP asymmetries in B -> J/psi K or via B -> (phi...
Modern cosmology has sharpened questions posed for millennia about the origin of our cosmic habitat. The age-old questions have been transformed into two pressing issues primed for attack in the coming decade: How did the Universe begin? and What physical laws govern the Universe at the highest energies? The clearest window onto these questions is...
We study logarithmically enhanced electromagnetic corrections to the decay rate in the high dilepton invariant mass region as well as corrections to the forward–backward asymmetry (FBA) of the inclusive rare decay View the MathML source. As expected, the relative effect of these corrections in the high dilepton mass region is around −8% for the muo...