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Extreme Multi-label Classification (XMC) methods predict relevant labels for a given query in an extremely large label space. Recent works in XMC address this problem using deep encoders that project text descriptions to an embedding space suitable for recovering the closest labels. However, learning deep models can be computationally expensive in large output spaces, resulting in a trade-off between high performing brute-force approaches and efficient solutions. In this paper, we propose PRIME, a XMC method that employs a novel prototypical contrastive learning technique to reconcile efficiency and performance surpassing brute-force approaches. We frame XMC as a data-to-prototype prediction task where label prototypes aggregate information from related queries. More precisely, we use a shallow transformer encoder that we coin as Label Prototype Network, which enriches label representations by aggregating text-based embeddings, label centroids and learnable free vectors. We jointly train a deep encoder and the Label Prototype Network using an adaptive triplet loss objective that better adapts to the high granularity and ambiguity of extreme label spaces. PRIME achieves state-of-the-art results in several public benchmarks of different sizes and domains, while keeping the model efficient.

The role of asymmetric nuclear medium on the properties of kaon is investigated at zero and finite temperature employing a hybrid approach integrating the light cone quark model (LCQM) and the chiral SU(3) quark mean field (CQMF) model. The in-medium quark masses are calculated within the CQMF model and are used as inputs to study the medium modifications in the kaon properties. In particular, we have analysed the impact of baryonic density, isospin asymmetry and temperature on the weak decay constant, distribution amplitudes (DAs) and parton quark distributions (PDFs) of valence quark structure of kaons. The effects of isospin asymmetry on the kaon doublet $K =\left(\begin{array}{c} K^{+} \\ K^{0} \end{array} \right)$ and antikaon doublet $\bar{K}$= ($K^-, \bar{K}^0$) are also studied. In order to compare with future experiments, we have also evolved the in-medium DAs and PDFs of kaons to $Q^2=16$ GeV$^2$. As compared to the temperature and isospin asymmetry, change in baryonic density of the nuclear medium makes more significant changes to the DAs and PDFs of kaons., Comment: 33 pages, 16 figures

This work comprises the calculations of magnetic moments of $\frac{1}{2}^-$ baryon resonances in the presence of hot and dense hadronic matter. Using the chiral $SU(3)$ quark mean field model, we have taken into account the impact on in-medium scalar meson fields to investigate the density effects on the in-medium baryon masses and their constituent quarks. In light of chiral constituent quark model $\chi$CQM, we have calculated the magnetic moments of $\frac{1}{2}^-$ baryon resonances and scrutinized the explicit contributions coming from the valence quarks, sea quarks and the orbital angular momentum of sea quarks. The effective baryonic magnetic moments have been investigated for the varying values of isospin asymmetry and strangeness fraction., Comment: 45 pages, 7 tables, 13 figures

In this work, we have investigated the transverse and spatial structure of light ($\pi^+ (u\bar d)$, $K^+(u\bar s)$) and heavy ($\eta_c(c\bar c)$, $\eta_b (b\bar b)$, $B$ and $D$) pseudoscalar mesons using the light-cone quark model. The transverse structure of these particles have been studied using the transverse momentum dependent parton distribution (TMDs). The leading twist unpolarized $f_1(x, \mathbf{k}_\perp^2)$ TMD has been solved using the quark-quark correlator. We have predicted the average momenta carried by the quark and antiquark of the considered mesons. For a complete description of mesons, we have also computed the leading twist unpolarized $H(x,0,-t)$ generalized parton distribution (GPD). Further, electromagnetic form factors (EMFFs), along with gravitational form factors (GFFs) have been derived by taking the zeroth and first moments of the unpolarized GPD. These EMFFs are found to be compatible with available lattice simulation results. Further, we have also calculated the parton distribution functions (PDFs) for both the quarks and the antiquarks of these mesons. The PDF sum rule has also been verified., Comment: 32 pages and 17 figures

The realization of fault-tolerant quantum computing requires the execution of quantum error-correction (QEC) schemes, to mitigate the fragile nature of qubits. In this context, to ensure the success of QEC, a protocol capable of implementing both qubit reset and leakage reduction is highly desirable. We demonstrate such a protocol in an architecture consisting of fixed-frequency transmon qubits pair-wise coupled via tunable couplers -- an architecture that is compatible with the surface code. We use tunable couplers to transfer any undesired qubit excitation to the readout resonator of the qubit, from which this excitation decays into the feedline. In total, the combination of qubit reset, leakage reduction, and coupler reset takes only 83ns to complete. Our reset scheme is fast, unconditional, and achieves fidelities well above 99%, thus enabling fixed-frequency qubit architectures as future implementations of fault-tolerant quantum computers. Our protocol also provides a means to both reduce QEC cycle runtime and improve algorithmic fidelity on quantum computers.

In the present work, we have studied the masses and magnetic moments of spin$-{\frac{1}{2}}^+$ and spin$-{\frac{3}{2}}^+$ singly and doubly charmed baryons in the strange hadronic medium at finite temperature using the chiral SU(3) quark mean field model. The properties of baryons within the framework of chiral SU(3) mean field model are defined in terms of constituent quark masses and energies, which are modified through the exchange of scalar fields $\sigma$, $\zeta$ and $\delta$ and the vector fields $\omega$, $\rho$ and $\phi$. The scalar-isovector field, $\delta$ and the vector-isovector field, $\rho$ contribute when medium has finite isospin asymmetry. We have calculated the effective masses of constituent quarks and charmed baryons in the nuclear and strange matter within the chiral SU(3) quark mean field model and have used these as the input in SU(4) constituent chiral quark model to compute the effective magnetic moments of these baryons. Considering the configuration mixing, the contributions of valence quarks, quark sea and orbital angular momentum of quark sea have been considered explicitly to calculate the in-medium magnetic moments., Comment: 55 pages, 18 figures, 16 tables

We calculate the valence quark transverse momentum-dependent parton distributions (TMDs) of the lightest pseudoscalar meson, pions, in isospin asymmetric nuclear matter at zero temperature by employing a light-cone quark model. The medium modifications in the pion unpolarized TMDs are induced through the effective quark masses computed using the chiral SU($3$) quark mean field model. The spin densities at different momentum fraction ($x$) have also been calculated at different baryonic densities., Comment: 7 pages and 4 figures

We have investigated the unpolarized valence quark generalized parton distribution functions (GPDs) and parton distribution functions (PDFs) for heavy spin-$0$, $B$- and $D$-mesons in the light-front quark model (LFQM). PDFs have been extracted from unpolarized $f_1(x,\textbf{k}^2_{\perp})$ transverse momentum-dependent parton distribution functions (TMDs). We have solved the quark-quark correlation function to have an unpolarized $H(x,\zeta,t)$ GPD. The unpolarized GPDs at zero skewness ($\zeta=0$) lead to describing the electromagnetic form factors (EMFFs) ($F_M(t)$) and gravitational form factors (GFFs)($A_M(t)$) of the mesons., Comment: 4 pages. Presented in the 16th International Conference on Heavy Quarks and Leptons (HQL 2023) held at TIFR, Mumbai, Maharashtra, India

This study investigates the sub-leading twist generalized transverse momentum dependent distributions (GTMDs) of a proton within the light-front quark-diquark model (LFQDM) framework. We solve the parametrization equations for the Dirac matrix structure to yield the explicit GTMD expressions for scalar as well as vector diquark configurations for active $u$ and $d$ quarks. This analysis addresses the multi-dimensional nature of GTMDs by exploring their dependencies on one or two variables while keeping others fixed. Additionally, we extract transverse momentum dependent form factors (TMFFs) from GTMDs by integrating over the longitudinal momentum fraction $x$. The study uses $3$-dimensional plots to illustrate the variation of TMFFs with the quark's transverse momentum $p_{\perp}$ and the transverse momentum transfer to the proton $\Delta_{\perp}$., Comment: 60 pages and 34 figures

We have investigated the ground state ($1S$), radially excited states ($2S$) and ($3S$) along with the orbitally excited state ($1P$) for the heavy charmonia ($c \bar c$) and bottomonia ($b \bar b$) mesons in the light-front quark model (LFQM). The light-front wave functions have been successful in explaining various physical properties of meson states in the past, especially for the $1S$ and $2S$ states. However, studies regarding the radially excited state $3S$ and orbitally excited state $1P$ have hardly been pursued before. In this study, we take up these two excited states and investigate the electromagnetic form factors (EMFFs), charge radii, decay constants, parton distribution functions (PDFs) and the distribution amplitudes (DAs) for the quarkonia system. For the sake of completeness, we have also included the study of the ground and the first excited states of quarkonia mesons. We have also illustrated the 3D wave functions for the radially excited states in order to study their nodal structures., Comment: 28 pages and 7 figures

In this work, we have calculated the photon leading-twist T-even transverse momentum dependent parton distribution functions (TMDs). For these calculations, we have treated photon as a state of quark anti-quark pair and represent the TMDs in explicit form of helicity amplitudes. We have presented all the T-even TMDs for the photon being massless (real) and massive (virtual). We have also compared our longitudinally and transversely polarized TMDs results for different photon masses. The collinear parton distribution functions (PDFs) have been predicted for both the real and virtual photon cases. The results for the unpolarized PDF of our calculations are in good agreement with other model predictions. In addition to this, we have also discussed the spin-spin correlations between the quark and photon., Comment: 30 pages and 10 figures

We have calculated the valence quark distributions of the lightest pseudoscalar meson, pions, in the isospin asymmetric nuclear matter at zero and finite temperature employing a light-cone quark model. The medium modifications in the pion properties have been stimulated through the effective quark masses computed using the chiral SU($3$) quark mean field model. We have primarily focused on the impact of isospin asymmetric medium on the distribution amplitudes (DAs) and parton distribution functions (PDFs) of a valence quark for different baryon density and temperature values. Also, the DAs and PDFs have been evolved to $Q^2=10$ GeV$^2$ and $Q^2=16$ GeV$^2$ for different densities of nuclear medium and results have been compared with the available experimental data. The DAs and PDFs are found to modify substantially as a function of baryon density as compared to temperature and isospin asymmetry of the medium., Comment: 26 pages and 10 figures

We have performed the structural analysis of low-lying octet baryon members by assuming charge-isospin symmetry among quark flavors in transverse and longitudinal space. Using the light-cone spectator diquark model, we have investigated the electromagnetic form factors of the octet baryons and have compared them with the available data. Model scale has been estimated by comparing the valence $u$ quark's parton distribution function (PDF) of proton with the result of CTEQ5L parameterization. A comparative analysis of PDFs and generalized parton distributions (GPDs) for non-zero skewness among octet baryons has also been demonstrated. Fourier transform of the deeply virtual Compton scattering amplitude with respect to skewness has been further applied to study the diffraction patterns in the boost-invariant longitudinal position space., Comment: 28 pages and 11 figures

We investigate quantum chromodynamics (QCD) in this study by computing chiral-even generalized parton distributions (GPDs) at twist-$3$ using the light-front quark-diquark model (LFQDM), particularly when the longitudinal momentum transfer is zero. We provide a detailed analysis of the twist-$3$ chiral-even GPD's dependence on the longitudinal momentum fraction ($x$) and the momentum transfer ($t$) by illustrating their behavior through extensive two-dimensional ($2$-D) and three-dimensional ($3$-D) visualizations. Our investigation also reveals the intricate relationships between these GPDs and other distribution functions (DFs) such as generalized transverse-momentum dependent distributions (GTMDs), transverse momentum-dependent parton distributions (TMDs), and parton distribution functions (PDFs). Our study also includes the connected form factors (FFs) which are crucial in understanding the internal structure of hadrons. Additionally, we provide impact parameter GPD plots to offer insights into the spatial distribution of partons., Comment: 30 pages and 8 figures

Coherent phonons, light-induced coherent lattice vibrations in solids, provide a powerful route to engineer structural and electronic degrees of freedom using light. In this manuscript, we formulate an ab initio theory of the displacive excitation of coherent phonons (DECP), the primary mechanism for light-induced structural control in semimetals. Our study - based on the ab initio simulations of the ultrafast electron and coherent-phonon dynamics in presence of electron-phonon interactions - establishes a predictive computational framework for describing the emergence of light-induced structural changes and the ensuing transient band-structure renormalization arising from the DECP mechanism. We validate this framework via a combined theoretical and experimental investigation of coherent phonons in the elemental semimetal antimony. Via a Fourier analysis of time- and angle-resolved photoemission spectroscopy (tr-ARPES) measurements, we retrieve information about transient spectral features and quasiparticle renormalization arising from the coherent A1g phonon as a function of momentum, energy, time, and fluence. The qualitative and quantitative agreement between experiment and theory corroborates the first-principles approach formulated in this study. Besides advancing the fundamental understanding of electron-phonon interactions mediated by coherent phonons, this study opens new opportunities for predictively engineering structural and electronic degrees of freedom in semimetals via the DECP mechanism.

The deviations of the recent measurements of the muon magnetic moment and the $W-$boson mass from their SM predictions hint to new physics beyond the SM. In this article, we address the observed discrepancies in the $W$-boson mass and muon anomalous magnetic moment in the Inert Two Higgs Doublet Model (I2HDM) extended by a complex scalar field singlet under the SM gauge group. The model is constrained from the existing LEP data and the measurements of partial decay widths to gauge bosons at LHC. It is shown that a large subset of this constrained parameter space of the model can simultaneously accommodate the $W$-boson mass and also explain the muon $g-2$ anomaly., Comment: 15 pages, 5 figures

This work shows the development of a volume-produced negative ion source that consists of annular parallel plates driven by a 13.56 MHz capacitively coupled radio frequency in a push-pull configuration. This source shows advantages in controlling plasma conditions by varying the pressure, power, and applied axial magnetic field. It is found that the push-pull configuration allows the plasma potential to remain in the range of 20 to 40 Volts. Conversely, the application of a magnetic field helps serves to augment the production of negative ions in the central hollow part of the annular plate. Further, a plausible explanation to the obtained experimental results is presented., Comment: 5 pages, 7 figures

The dielectric constant of a sheath, whether ionic or electronic, formed around the cylindrical limbs of a hairpin probe, is often considered the same as that of a vacuum. However, this assumption does not hold true for electron sheaths and electron-permeating ionic sheaths, resulting in a deviation of the sheath dielectric constant from that of a vacuum. This deviation significantly influences the effective dielectric between the cylindrical limbs. As a result, it impacts the theoretically estimated resonance frequency characteristic curve of a DC-biased hairpin probe. In this study, we investigate the influence of electron temperature on the sheath dielectric and, consequently, on the resonance frequency characteristic curve. The findings shows that electron temperature primarily determines the resonance frequency characteristic curve. With increasing electron temperature, the peak in the resonance frequency characteristic curve shifts towards higher positive probe bias values and exhibits a broadening near the maxima instead of a sharp peak. This broadening near the maxima has also been validated with an experimentally measured resonance frequency characteristic curve in a capacitively coupled argon discharge., Comment: 9 pages, 13 figures

In this study, we have investigated the production of negative ions by mixing electronegative oxygen gas with electropositive argon gas in a geometrically asymmetric cylindrical capacitively coupled radio frequency plasma discharge. The plasma parameters such as density (electron, positive and negative ion), negative ion fraction, and electron temperature are investigated for fixed gas pressure and increasing axial magnetic field strength. The axisymmetric magnetic field creates an ExB drift in the azimuthal direction, leading to the confinement of high-energy electrons at the radial edge of the chamber, resulting in decreased species density and negative ion fraction in the plasma bulk. However, the electron temperature increases with the magnetic field. It is concluded that low magnetic fields are better suited for negative ion production in such devices. Furthermore, in addition to the percentage ratio of the two gases, the applied axial magnetic field also plays a vital role in controlling negative ion fraction., Comment: 18 Pages

In this work, we have established the relations between the T-even proton transverse momentum-dependent parton distributions (TMDs) at all twist levels up to twist-4 using the light-front quark diquark model (LFQDM). From the parameterization equations of TMDs, we have found that there are multiple ways by which a particular TMD can be expressed in terms of the helicities of the proton in the initial and final states. For the first time, we have presented a parameterization table that can be applied to the derivation and recognition of proton TMDs based on their helicity. We have constructed the linear and quadratic relationships of TMDs at the intra-twist and inter-twist levels within the same model. We have also looked at the inequality relations that TMDs follow. Additionally, to provide an easy access to the calculations, amplitude matrices have been expressed in the form of TMDs over all the possible helicities of the diquark., Comment: 40 pages and 3 tables

Being the fountainhead of transverse distortion and asymmetries in accordance to $``SSA=GPD \ast FSI\,"$, we study the spin flip generalized parton distribution. We demonstrate this transverse deformation by using the quark-scalar diquark model and unveil a comparison among the low-lying strange baryons for distinct feasible combinations of quark-diquark pairs. Final-state interaction originating the correlation of a target spin and a virtual photon to the generated pion plane in semi-inclusive deep inelastic scattering has also been analyzed., Comment: 21 pages, 12 figures and 2 tables

We have investigated the spin-orbital angular momentum correlations for the active quark inside the light and heavy mesons for both the spin-0 and spin-1 cases. These correlations can be derived from the generalised transverse momentum dependent distributions (GTMDs) as well as the generalised parton distributions (GPDs). We employ the overlap representation of light-front wave functions in the light-front quark model (LFQM) to calculate our analytical results. The dependence of spin-orbit correlations (SOCs) on the longitudinal momentum fraction $x$ as well as the transverse momentum dependence $\mathbf{k}_{\perp}$ has been graphically presented. Even though the SOCs have already been studied for the spin-0 pions and kaons in other approaches, no calculations for the other light and heavy spin-0 mesons have been reported in literature. Further, the correlations for any of the light and heavy spin-1 mesons have been studied for the first time in the present work., Comment: 23 pages, 4 figures and 3 tables

Using the standard parametrization of the dipole form, we have studied the vulnerability of $Q^2$ on the vector form factors ($f_i^{B_iB_f}(Q^2)$) and axial-vector form factors ($g_i^{B_iB_f}(Q^2)$), $i=1,2,3$ computed for the semileptonic $B_i \rightarrow B_f l \bar{\nu}$ decays for hyperons in the framework of chiral constituent quark model ($\chi$CQM). Both, strangeness changing as well as strangeness conserving decays have been examined. We also present the dependence of the ratio of hyperon semileptonic decay constants $g_1(Q^2)/f_1(Q^2)$ for these decays. Further, we calculate the CKM matrix elements $V_{ud}$ from strangeness conserving and $V_{us}$ from strangeness changing hyperon decays., Comment: 21 pages, 5 figures and 9 tables