Nucleon Energy Correlators for the Color Glass Condensate.

We demonstrate the recently proposed nucleon energy-energy correlator (NEEC) f_{EEC}(x,θ) can unveil the gluon saturation in the small-x regime in eA collisions. The novelty of this probe is that it is fully inclusive just like the deep-inelastic scattering (DIS), with no requirements of jets or hadrons but still provides an evident portal to the small-x dynamics through the shape of the θ distribution. We find that the saturation prediction is significantly different from the expectation of the collinear factorization.

Nucleon Energy Correlators.

We introduce the concept of the nucleon energy correlators, a set of novel objects that encode the microscopic details of a nucleon, such as the parton angular distribution in a nucleon, the collinear splitting to all orders, as well as the internal transverse dynamics of the nucleon. The nucleon energy correlators complement the conventional nucleon or nucleus tomography, but without introducing the nonperturbative fragmentation functions or the jet clustering algorithms. We demonstrate how the nucleon energy correlators can be measured in the lepton-nucleon deep inelastic scattering. The predicted distributions display a fascinating phase transition between the perturbative and nonperturbative regime. In the perturbative phase, a polar angle version of the Bjorken scaling behavior is predicted. We discuss its possible applications and expect it to aggrandize the physics content at the electron ion colliders with a far-forward detector.

Analyzing N-Point Energy Correlators inside Jets with CMS Open Data.

Jets of hadrons produced at high-energy colliders provide experimental access to the dynamics of asymptotically free quarks and gluons and their confinement into hadrons. In this Letter, we show that the high energies of the Large Hadron Collider (LHC), together with the exceptional resolution of its detectors, allow multipoint correlation functions of energy flow operators to be directly measured within jets for the first time. Using Open Data from the CMS experiment, we show that reformulating jet substructure in terms of these correlators provides new ways of probing the dynamics of QCD jets, which enables direct imaging of the confining transition to free hadrons as well as precision measurements of the scaling properties and interactions of quarks and gluons. This opens a new era in our understanding of jet substructure and illustrates the immense unexploited potential of high-quality LHC data sets for elucidating the dynamics of QCD.

Extending Precision Perturbative QCD with Track Functions.

Collider experiments often exploit information about the quantum numbers of final state hadrons to maximize their sensitivity, with applications ranging from the use of tracking information (electric charge) for precision jet substructure measurements, to flavor tagging for nucleon structure studies. For such measurements, perturbative calculations in terms of quarks and gluons are insufficient, and nonperturbative track functions describing the energy fraction of a quark or gluon converted into a subset of hadrons (e.g., charged hadrons) must be incorporated. Unlike fragmentation functions, track functions describe correlations between hadrons and therefore satisfy complicated nonlinear evolution equations whose structure has so far eluded calculation beyond the leading order. In this Letter, we develop an understanding of track functions and their interplay with energy flow observables beyond the leading order, allowing them to be used in state-of-the-art perturbative calculations for the first time. We identify a shift symmetry in the evolution of their moments that fixes their structure, and we explicitly compute the evolution of the first three moments at next-to-leading order, allowing for the description of up to three-point energy correlations. We then calculate the two-point energy correlator on charged particles at O(α_{s}^{2}), illustrating explicitly that infrared singularities in perturbation theory are absorbed by moments of the track functions and also highlighting how these moments seamlessly interplay with modern techniques for perturbative calculations. Our results extend the boundaries of traditional perturbative QCD, enabling precision perturbative predictions for energy flow observables sensitive to the quantum numbers of hadronic states.

Dilepton Rapidity Distribution in Drell-Yan Production to Third Order in QCD.

We compute for the first time the lepton-pair rapidity distribution in the photon-mediated Drell-Yan process to next-to-next-to-next-to-leading order in QCD. The calculation is based on the q_{T}-subtraction method, suitably extended to this order for quark-antiquark initiated Born processes. Our results display sizeable QCD corrections at next-to-next-to-next-to-leading order over the full rapidity region and provide a fully independent confirmation of the recent results for the total Drell-Yan cross section at this order.

Optimization of CUT&Tag product recovery and library construction method.

The emerging cleavage under target and tagment (CUT&Tag) technology uses Tn5 transposase to cleavage near the DNA binding site of target protein and study the generated DNA fragments by the next-generation sequencing. It can quickly identify protein-DNA interactions, which greatly simplifies the experimental process of ChIP-Seq. After CUT&Tag tagment reaction, DNA recovery or other post-processing is required to perform library construction PCR. Different recovery methods have significant impact respectively. By establishing Streptavidin beads recovery CUT&Tag(srCUT&Tag), we can quickly and conveniently complete the product recovery of CUT&Tag. We carried out CUT&Tag assay of H3K4me3, RNA Polymerase II (RNA polymerase II, RNAPII), transcription factor CTCF and HMGA1 in K562 cells with different recovery methods, including ethanol precipitation, fragment separation magnetic beads (SPRI) Magnetic bead recovery, direct PCR method, as well as our srCUT&Tag recovery method. The results show that among the CUT&Tag results of four different targets, the SPRI magnetic bead recovery and our srCUT&Tag methods have higher recovery efficiency than the direct PCR method and ethanol precipitation method. All CUT&Tag results showed that the recovery of SPRI magnetic beads would lose most of the product fragments less than 150 bp. In the recovery of CTCF and HMGA1, direct PCR lost most of the fragments larger than 300 bp and has significant difference from result of other recovery method. This enables srCUT&Tag to provide more real and higher-resolution information than other recovery method. In summary, the newly established srCUT&Tag recovery method can improve the efficiency of CUT&Tag library construction and obtain better data quality compared with the existing CUT&Tag product recovery method, providing a better technical choice for epigenetics research.

Quantum Interference in Jet Substructure from Spinning Gluons.

Collimated sprays of hadrons, called jets, are an emergent phenomenon of quantum chromodynamics (QCD) at collider experiments, whose detailed internal structure encodes valuable information about the interactions of high energy quarks and gluons and their confinement into color-neutral hadrons. The flow of energy within jets is characterized by correlation functions of energy flow operators, with the three-point correlator being the first correlator with nontrivial shape dependence, playing a special role in unraveling the dynamics of QCD. In this Letter, we initiate a study of the three-point energy correlator to all orders in the strong coupling constant, in the limit where two of the detectors are squeezed together. We show that, by rotating the two squeezed detectors with respect to the third by an angle ϕ, a cos(2ϕ) dependence arising from the quantum interference between intermediate virtual gluons with +/- helicity is imprinted on the detector. This can be regarded as a double slit experiment performed with jet substructure, and it provides a direct probe of the ultimately quantum nature of the substructure of jets and of transverse spin physics in QCD. To facilitate our all-orders analysis, we adopt the operator product expansion (OPE) for light-ray operators in conformal field theory and develop it in QCD. Our application of the light-ray OPE in real world QCD establishes it as a powerful theoretical tool with broad applications for the study of jet substructure.

Quark Transverse Parton Distribution at the Next-to-Next-to-Next-to-Leading Order.

We report a calculation of the perturbative matching coefficients for the transverse-momentum-dependent parton distribution functions for quark at the next-to-next-to-next-to-leading order in QCD, which involves calculation of nonstandard Feynman integrals with rapidity divergence. We introduce a set of generalized integration-by-parts equations, which allows an algorithmic evaluation of such integrals using the machinery of modern Feynman integral calculation.

Precision QCD Event Shapes at Hadron Colliders: The Transverse Energy-Energy Correlator in the Back-to-Back Limit.

We present an operator-based factorization formula for the transverse energy-energy correlator (TEEC) hadron collider event shape in the back-to-back (dijet) limit. This factorization formula exhibits a remarkably symmetric form, being a projection onto a scattering plane of a more standard transverse momentum dependent factorization. Soft radiation is incorporated through a dijet soft function, which can be elegantly obtained to next-to-next-to-leading order (NNLO) due to the symmetries of the problem. We present numerical results for the TEEC resummed to next-to-next-to-leading logarithm (NNLL) matched to fixed order at the LHC. Our results constitute the first NNLL resummation for a dijet event shape observable at a hadron collider, and the first analytic result for a hadron collider dijet soft function at NNLO. We anticipate that the theoretical simplicity of the TEEC observable will make it indispensable for precision studies of QCD at the LHC, and as a playground for theoretical studies of factorization and its violation.

Analytical Computation of Energy-Energy Correlation at Next-to-Leading Order in QCD.

The energy-energy correlation (EEC) between two detectors in e^{+}e^{-} annihilation was computed analytically at leading order in QCD almost 40 years ago, and numerically at next-to-leading order (NLO) starting in the 1980s. We present the first analytical result for the EEC at NLO, which is remarkably simple, and facilitates analytical study of the perturbative structure of the EEC. We provide the expansion of the EEC in the collinear and back-to-back regions through next-to-leading power, information which should aid resummation in these regions.

Bootstrapping Rapidity Anomalous Dimensions for Transverse-Momentum Resummation.

A soft function relevant for transverse-momentum resummation for Drell-Yan or Higgs production at hadron colliders is computed through to three loops in the expansion of strong coupling, with the help of the bootstrap technique and supersymmetric decomposition. The corresponding rapidity anomalous dimension is extracted. An intriguing relation between anomalous dimensions for transverse-momentum resummation and threshold resummation is found.

Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD.

We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.

Locked nucleic acid couples with Fok I nucleases to target and cleave hepatitis B virus's gene in vitro.

Hepatitis B virus (HBV) is a dented double-stranded DNA virus. After infecting human hepatic cells, it forms cccDNA that replicates persistently and integrates randomly into the host's genome during the process of reserve transcription. On average, in each cell with chronic HBV infection, there are about 33 copies of cccDNA with a half of 35-57 days, which can be difficult to eradicate. A new strategy is to inhibit HBV transcription by using locked nucleic acid (LNA). Besides, cleaving HBV genome by targeted genome editing technologies could potentially cure patients. In this study, we explored new genome editing tools for HBV treatment. Based on LNA's ability to form triple helix by binding to duplex DNA, its stability towards nuclease and polymerase, and its sensitivity to single base mismatches, we designed LNA-modified oligonucleotides as DNA binding domain to effectively increase the specificity of target gene recognition. Meanwhile, by utilizing the small molecular weight and dimerization dependent activity of nuclease Fok I, we used Fok I recombinant dimer protein as DNA cleavage domain. Here, we established a method by chemical coupling of LNA-oligonucleotide with Fok I cleavage domain, and also validated the targeted cleavage of HBV genes with our new tools in vitro. These results provide new possibilities for future in vivo anti-virus gene therapy with high specificity and no integration risk.

Top quark forward-backward asymmetry in e+ e- annihilation at next-to-next-to-leading order in QCD.

We report on a complete calculation of electroweak production of top-quark pairs in e+ e- annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential in phase space and can be used to calculate any infrared-safe observable. Especially we calculated the next-to-next-to-leading-order corrections to the top-quark forward-backward asymmetry and found sizable effects. Our results show a large reduction of the theoretical uncertainties in predictions of the forward-backward asymmetry, and allow for a precision determination of the top-quark electroweak couplings at future e+ e- colliders.

Transverse-momentum resummation for top-quark pairs at hadron colliders.

We develop a framework for a systematic resummation of the transverse momentum distribution of top-quark pairs produced at hadron colliders based on effective field theory. Compared to Drell-Yan and Higgs production, a novel soft function matrix is required to account for the soft gluon emissions from the final states. We calculate this soft function at the next-to-leading order, and perform the resummation at the next-to-next-to-leading logarithmic accuracy. We compare our results with parton shower programs and with the experimental data at the Tevatron and the LHC. We also discuss the implications for the top quark charge asymmetry.

Top-quark decay at next-to-next-to-leading order in QCD.

We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and W boson width effects. In particular, we also show the first results of the fully differential decay rates for the top-quark semileptonic decay t → W(+)(l(+)ν)b at next-to-next-to-leading order in QCD. Our method is based on the understanding of the invariant mass distribution of the final-state jet in the singular limit from effective field theory. Our result can be used to study arbitrary infrared-safe observables of top-quark decay with the highest perturbative accuracy.

Next-to-leading QCD effect on the quark compositeness search at the LHC.

We present the exact next-to-leading order (NLO) QCD corrections to the dijet production induced by the quark contact interactions at the CERN Large Hadron Collider. We show that, as compared to the exact calculation, the scaled NLO QCD prediction adopted by the ATLAS Collaboration has overestimated the new physics effect on some direct observables by more than 30% and renders a higher limit on the quark compositeness scale. The destructive contribution from the exact NLO correction will also lower the compositeness scale limit set by the CMS Collaboration.