We report on a major milestone in the construction of logarithmically accurate final-state parton showers, achieving next-to-next-to-leading-logarithmic (NNLL) accuracy for wide class observables known as event shapes. The key to this advance lies identification relation between critical NNLL analytic resummation ingredients and their parton-shower counterparts. Our discussion is supplemented with numerical tests logarithmic three shower variants more than dozen distinct event-shape <a:math...

We propose a new class of infrared-collinear (IRC) and Sudakov safe observables with an associated jet grooming technique that removes dynamically soft large angle branches. It is based on identifying the hardest branch in Cambridge/Aachen re-clustering sequence discarding prior splittings occur at larger angles. This leads to generated cut-off phase space tagged splitting encoded form factor. In this exploratory study we focus mass momentum sharing distributions which analyze analytically...

We explore the ability of a recently proposed jet substructure technique, Dynamical Grooming, to pin down properties Quark-Gluon Plasma formed in ultra-relativistic heavy-ion collisions. In particular, we compute, both analytically and via Monte-Carlo simulations, opening angle $\theta_g$ hardest splitting as defined by Grooming. Our calculation, grounded perturbative QCD, accounts for factorization time between vacuum-like medium-induced processes double logarithmic approximation. observe...

A bstract We formulate PanScales parton showers for hadron collisions so as to achieve next-to-leading logarithmic (NLL) accuracy across a broad set of observables. do specifically colour singlet production. Relative the existing final-state showers, main new question is that how redistribute momentum imbalances from initial-state branching remainder event. present tests at fixed order, including treatment full soft-collinear emissions and spin correlations in both soft collinear domains....

A bstract We investigate the collinear limit of energy-energy correlator (EEC) in a heavy-ion context. First, we revisit leading-logarithmic (LL) resummation this observable vacuum following diagrammatic approach. argue that route allows to naturally incorporate medium-induced effects into all-orders structure systematically. As an example, show how phase-space constraints imposed by static medium on vacuum-like emissions can be incorporated LL result modifying anomalous dimensions. On...

We present a dynamical explanation of the hollowness effect observed in proton-proton scattering at $\sqrt s\!=\!7$ TeV. This phenomenon, not lower energies, consists depletion inelasticity density zero impact parameter collision. Our analysis is based on three main ingredients: we rely gluonic hot spots inside proton as effective degrees freedom for description process. Next assume that some non-trivial correlation between transverse positions exists. Finally build amplitude from multiple...

We reconsider the problem of transverse momentum broadening a highly-energetic parton suffering multiple scatterings in dense colored media, such as thermal Quark-Gluon plasma or large nuclei. In framework Moli\`ere's theory scattering we re-derive simple analytic formula, to be used jet quenching phenomenology, that accounts for both soft and hard Rutherford regimes. Further, discuss sensitivity modeling non-perturbative infrared sector by presenting detailed numerical comparison between...

A bstract We calculate the fully differential medium-induced radiative spectrum at next-to-leading order (NLO) accuracy within Improved Opacity Expansion (IOE) framework. This scheme allows us to gain analytical control of low and high gluon frequencies simultaneously. The frequency regime can be obtained in standard opacity expansion framework which resulting power series diverges characteristic ω c ∼ $$ \hat{q} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover>...

A bstract We carry out extensive tests of the next-to-leading logarithmic (NLL) accuracy PanScales parton showers, as introduced recently for colour-singlet production in hadron collisions. The include comparisons to (semi-)analytic NLL calculations a wide range hadron-collider observables: boson transverse momentum distribution; global and non-global hadronic energy flow variables related jet vetoes analogues jettiness distributions; (sub)jet multiplicities; observables sensitive DGLAP...

In this article, we document version 0.1 of the PANSCALES code for parton shower simulations. With help a few examples, discuss basic usage code, including tests logarithmic accuracy showers. We expose some numerical techniques underlying and include description how users can implement their own showers within framework. Some simpler be performed in minutes on modern laptop. As an early step towards phenomenology, also outline aspects preliminary interface to PYTHIA 8.3, access its hard...

A bstract We revisit the calculation of soft gluon emission probability off a colour-singlet $$ q\overline{q} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>q</mml:mi> <mml:mover> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> system that evolves in quark-gluon plasma. The antenna is created presence medium and then emits outside. modified with respect to vacuum baseline due interactions during formation its propagation. Previous studies disregarded former effect found...

The unambiguous observation of a Chiral Magnetic Effect (CME)-driven charge separation is the core aim isobar program at RHIC consisting ${^{96}_{40}}$Zr+${^{96}_{40}}$Zr and ${^{96}_{44}}$Ru+${^{96}_{44}}$Ru collisions $\sqrt {s_{\rm NN}}\!=\!200$ GeV. We quantify role spatial distributions nucleons in isobars on both eccentricity magnetic field strength within relativistic hadronic transport approach (SMASH, Simulating Many Accelerated Strongly-interacting Hadrons). In particular, we...

We explore the possibility of using dead cone heavy quarks as a region Lund plane where medium-induced gluon radiation can be isolated and characterized. The filling by gluons is expected to result interplay between minimum angle such due transverse momentum broadening dead-cone angle. Since measurement fully corrected in heavy-ion collisions currently challenging, we propose use jet grooming techniques identify particular splitting tree that both perturbative sensitive effect. To end, new...

A bstract We revisit the calculation of average jet multiplicity in high-energy collisions. First, we introduce a new definition (sub)jet based on Lund declusterings obtained using Cambridge algorithm. develop systematic resummation approach. This allows us to compute both and multiplicities next-to-next-to-double (NNDL) logarithmic accuracy electron-positron annihilation, an order higher than previous works literature. match our resummed exact NLO ( $$ \mathcal{O} <mml:math...

Energetic jets that traverse the quark-gluon plasma created in heavy-ion collisions serve as excellent probes to study this new state of deconfined QCD matter. Presently, however, our ability achieve a crisp theoretical interpretation crescent number jet observables measured experiments is hampered by presence selection biases. The aim work minimise those biases associated modification quark- vs. gluon-initiated fraction order assess other medium-induced effects, namely color decoherence,...

We compute the average Lund multiplicity of high-energy QCD jets. This extends an earlier calculation, done for event-wide in $e^+e^-$ collisions [arxiv:2205.02861], to large energy range available at LHC. Our calculation achieves next-to-next-to-double logarithmic (NNDL) accuracy. results are split into a universal collinear piece, common and non-universal large-angle contribution. The latter amounts 10-15% total multiplicity. provide accurate LHC predictions by matching our resummed...

We define a new strategy to scan jet substructure in heavy-ion collisions. The scope is multifold: (i) test the dominance of vacuum dynamics at early times, (ii) capture transition from coherent incoherent energy loss, and (iii) study elastic scatterings medium, which are either hard perturbative or soft responsible for thermalization. To achieve that, we analyze angular distribution hardest splitting, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"...

We present a quantitative study of the $\ensuremath{\nu}N$ cross section in neutrino energy range ${10}^{4}<{E}_{\ensuremath{\nu}}<{10}^{14}\text{ }\text{ }\mathrm{GeV}$ within two transversal QCD approaches: next-to-leading-order Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution using different sets parton distribution functions and Balitsky-Kovchegov (BK) small-$x$ with running coupling kinematical corrections. show that nonlinear effects embodied BK equation yield slower raise...

We present a systematic study of the normalized symmetric cumulants, NSC(n,m), at eccentricity level in proton-proton interactions $\sqrt s\!=\! 13$ TeV within wounded hot spot approach. focus our attention on influence spatial correlations between proton constituents, case gluonic spots, this observable. notice that presence short-range repulsive spots systematically decreases values NSC(2,3) and NSC(2,4) mid-to-ultra central collisions while increases them peripheral interactions. In we...

We investigate the effect of non-trivial spatial correlations between proton constituents, considered in this work to be gluonic hot spots, on initial conditions proton-proton collisions from ISR LHC energies, i.e. $\sqrt s\!=\!52.6,7000,13000$ GeV. The inclusion these is motivated by their fundamental role description a recently observed new feature $pp$ scattering at s\!=\!7$ TeV, hollowness effect. Our analysis relies Monte-Carlo Glauber approach including fluctuations spot positions and...

A bstract In this work, we analyse the all-orders resummation structure of momentum sharing fraction, z g , opening angle, θ and relative transverse momentum, k t,g splitting tagged by Dynamical Grooming procedure in hadronic collisions. We demonstrate that their does non-exponentiate it is free clustering logarithms. Then, analytically compute probability distributions ( ) up to next-to-next-to-double logarithm accuracy (N 2 DL) narrow jet limit, including a matching leading order α s . On...

We evaluate the phenomenological applicability of dynamical grooming technique, introduced by Y. Mehtar-Tani, A. Soto-Ontoso, and K. Tywoniuk [Phys. Rev. D 101, 034004 (2020)], to boosted $W$ top tagging at LHC conditions. An extension our method intended for multiprong decays with an internal mass scale, such as quark decay, is presented. First, we tackle reconstruction distribution jets quantifying smearing due pileup. When compared state-of-the-art algorithms like SoftDropand its...

We study the production of $J/\psi$ vector mesons as a function charged hadron multiplicity in p+p and p+Pb collisions at LHC energies. employ color glass condensate framework, using running coupling Balitsky-Kovchegov evolved dipole amplitudes, to compute gluon $c\bar{c}$-pair production. use fragmentation functions obtain hadrons, explore two different hadronization schemes for $J/\psi$: non-relativistic quantum chromodynamics improved evaporation model. In our event-by-event fluctuations...

Multiparton interactions are a fascinating phenomenon that occur in almost every high-energy hadron-hadron collision yet remarkably difficult to study quantitatively. In this Letter, we present strategy optimally disentangle multiparton from the primary scattering collision. That enables probes of significantly beyond state art, including their characteristic momentum scale, interconnection between and secondary scatters, pattern three potentially even more simultaneous hard scatterings....

In this article, we document version 0.1 of the PANSCALES code for parton shower simulations. With help a few examples, discuss basic usage code, including tests logarithmic accuracy showers. We expose some numerical techniques underlying and include description how users can implement their own showers within framework. Some simpler be performed in minutes on modern laptop. As an early step towards phenomenology, also outline aspects preliminary interface to PYTHIA 8.3, access its hard...