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1. Transverse energy-energy correlator for vector boson-tagged hadron production in $pp$ and $pA$ collisions

   https://doi.org/10.1103/1djw-8zrh  

   Kang, Zhong-Bo; Lee, Sookhyun; Penttala, Jani; Zhao, Fanyi; Zhou, Yiyu (July 2025, Physical Review D)

   We investigate the transverse energy-energy correlator (TEEC) event-shape observable for back-to-back $\gamma +h$and $Z+h$production in both $pp$and $pA$collisions. Our study incorporates nuclear modifications into the transverse-momentum dependent (TMD) factorization framework, with resummation up to next-to-leading logarithmic accuracy, for TEEC as a function of the variable $\tau =(1+\cos \varphi )/2$, where $\varphi$is the azimuthal angle between the vector boson and the final hadron. We analyze the nuclear modification factor $R_{pA}$in $p\mathrm{Au}$collisions at Relativistic Heavy Ion Collider and $p\mathrm{Pb}$collisions at the Large Hadron Collider. Our results demonstrate that the TEEC observable is a sensitive probe for nuclear modifications in TMD physics. Specifically, the changes in the $\tau$-distribution shape provide insights into transverse momentum broadening effects in large nuclei, while measurements at different rapidities allow us to explore nuclear modifications in the collinear component of the TMD parton distribution functions in nuclei. 

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2. Determination of the Relative Sign of the Higgs Boson Couplings to $W$ and $Z$ Bosons Using $WH$ Production via Vector-Boson Fusion with the ATLAS Detector

   https://doi.org/10.1103/PhysRevLett.133.141801  

   Aad, G; Abbott, B; Abeling, K; Abicht, N J; Abidi, S H; Aboulhorma, A; Abramowicz, H; Abreu, H; Abulaiti, Y; Acharya, B S; et al (October 2024, Physical Review Letters)

   The associated production of Higgs and $W$bosons via vector-boson fusion is highly sensitive to the relative sign of the Higgs boson couplings to $W$and $Z$bosons. In this Letter, two searches for this process are presented, using $140{\mathrm{fb}}^{-1}$of proton-proton collision data at $\sqrt{s}=13\mathrm{TeV}$recorded by the ATLAS detector at the LHC. The first search targets scenarios with opposite-sign couplings of the $W$and $Z$bosons to the Higgs boson, while the second targets standard model-like scenarios with same-sign couplings. Both analyses consider Higgs boson decays into a pair of $b$quarks and $W$boson decays with an electron or muon. The data exclude the opposite-sign coupling hypothesis with a significance beyond $5\sigma$, and the observed (expected) upper limit set on the cross section for vector-boson fusion $WH$production is 9.0 (8.7) times the standard model value at 95% confidence level. © 2024 CERN, for the ATLAS Collaboration2024CERN 

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3. Measurement of ${\mathrm{\Lambda }}_b^0$ , ${\mathrm{\Lambda }}_c^{+}$ , and $\mathrm{\Lambda }$ Decay Parameters Using ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}$ Decays

   https://doi.org/10.1103/PhysRevLett.133.261804  

   Aaij, R; Abdelmotteleb, A_S W; Abellan_Beteta, C; Abudinén, F; Ackernley, T; Adefisoye, A A; Adeva, B; Adinolfi, M; Adlarson, P; Agapopoulou, C; et al (December 2024, Physical Review Letters)

   A comprehensive study of the angular distributions in the bottom-baryon decays ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}(h=\pi ,K)$, followed by ${\mathrm{\Lambda }}_c^{+}\to \mathrm{\Lambda }{h}^{+}$with $\mathrm{\Lambda }\to p{\pi }^{-}$or ${\mathrm{\Lambda }}_c^{+}\to p{K}_{\mathrm{S}}^0$decays, is performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of $9{\mathrm{fb}}^{-1}$collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The decay parameters and the associated charge-parity ( $CP$) asymmetries are measured, with no significant $CP$violation observed. For the first time, the ${\mathrm{\Lambda }}_b^0\to {\mathrm{\Lambda }}_c^{+}{h}^{-}$decay parameters are measured. The most precise measurements of the decay parameters $\alpha$, $\beta$, and $\gamma$are obtained for ${\mathrm{\Lambda }}_c^{+}$decays and an independent measurement of the decay parameters for the strange-baryon $\mathrm{\Lambda }$decay is provided. The results deepen our understanding of weak decay dynamics in baryon decays. © 2024 CERN, for the LHCb Collaboration2024CERN 

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4. Search for production of a single vectorlike quark decaying to $tH$ or $tZ$ in the all-hadronic final state in $pp$ collisions at $\sqrt{s}=13\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevD.110.072012  

   Hayrapetyan, A; Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Hussain, P S; Jeitler, M; et al (October 2024, Physical Review D)

   A search for electroweak production of a single vectorlike $T$quark in association with a bottom ( $b$) quark in the all-hadronic decay channel is presented. This search uses proton-proton collision data at $\sqrt{s}=13\mathrm{TeV}$collected by the CMS experiment at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of $138{\mathrm{fb}}^{-1}$. The $T$quark is assumed to have charge $2/3$and decay to a top ( $t$) quark and a Higgs ( $H$) or $Z$boson. Hadronic decays of the $t$quark and the $H$or $Z$boson are reconstructed from the kinematic properties of jets, including those containing $b$hadrons. No deviation from the standard model prediction is observed in the reconstructed $tH$and $tZ$invariant mass distributions. The 95% confidence level upper limits on the product of the production cross section and branching fraction of a $T$quark produced in association with a $b$quark and decaying via $tH$or $tZ$range from 1260 to 68 fb for $T$quark masses of 600–1200 GeV. © 2024 CERN, for the CMS Collaboration2024CERN 

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5. Investigating strangeness enhancement in jet and medium via $\varphi \left(1020\right)$ production in $p$ -Pb collisions at $\sqrt{s_{NN}}=5.02\mathrm{TeV}$

   https://doi.org/10.1103/PhysRevC.110.064912  

   Acharya, S; Adamová, D; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; et al (December 2024, Physical Review C)

   This work aims to differentiate strangeness produced from hard processes (jetlike) and softer processes (underlying event) by measuring the angular correlation between a high-momentum trigger hadron ( $h$) acting as a jet proxy and a produced strange hadron [ $\varphi \left(1020\right)$meson]. Measuring $h\text{−}\varphi$correlations at midrapidity in $p$-Pb collisions at $\sqrt{s_{NN}}=5.02\mathrm{TeV}$as a function of event multiplicity provides insight into the microscopic origin of strangeness enhancement in small collision systems. The jetlike and the underlying-event-like strangeness production are investigated as a function of event multiplicity. They are also compared between a lower and higher momentum region. The evolutions of the per-trigger yields within the near-side (aligned with the trigger hadron) and away-side (in the opposite direction of the trigger hadron) jets are studied separately, allowing for the characterization of two distinct jetlike production regimes. Furthermore, the $h\text{−}\varphi$correlations within the underlying event give access to a production regime dominated by soft production processes, which can be compared directly to the in-jet production. Comparisons between $h\text{−}\varphi$and dihadron correlations show that the observed strangeness enhancement is largely driven by the underlying event, where the $\varphi /h$ratio is significantly larger than within the jet regions. As multiplicity increases, the fraction of the total $\varphi \left(1020\right)$yield coming from jets decreases compared to the underlying event production, leading to high-multiplicity events being dominated by the increased strangeness production from the underlying event. ©2024 CERN, for the ALICE Collaboration2024CERN 

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