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1. The BGOOD experiment at ELSA, exotic structures in the light quark sector?

   https://doi.org/10.1051/epjconf/202430301015  

   Jude, Thomas; Braghieri, Alessandro; Cole, Philip; Elsner, Daniel; Di_Salvo, Rachele; Fantini, Alessia; Figueiredo, Antonio_Joao Clara; Freyermuth, Oliver; Fromberger, Frank; Ghio, Francesco; et al (January 2024, EPJ Web of Conferences)

   Hüsken, N; Danilkin, I; Hagelstein, F (Ed.)

   The BGOOD photoproduction experiment accesses forward meson angles and low momentum exchange kinematics in theudssector, which may be sensitive to molecular-like hadron structure. Recent results are presented, including strangeness photoproduction at forward meson angles, and π⁰π⁰coherent photoproduction off the deuteron. 

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2. Strangeness Photoproduction at the BGO-OD experiment

   https://doi.org/10.1051/epjconf/202024101008  

   Jude, Thomas; Alef, Stefan; Bauer, Patrick; Beck, Reinhard; Braghieri, Alessandro; Cole, Philip; Di Salvo, Rachele; Elsner, Daniel; Fantini, Alessia; Freyermuth, Oliver; et al (January 2020, EPJ Web of Conferences)

   Beck, R.; Thiel, A.; Thoma, U.; Wunderlich, Y. (Ed.)

   The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremsstrahlung photon beam to investigate the excitation structure of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating low momentum transfer processes due to the acceptance and high momentum resolution at forward angles. In particular, this enables the investigation of strangeness photoproduction where t-channel exchange mechanisms play an important role. This also allows access to low momentum exchange kinematics where extended, molecular structure may manifest in reaction mechanisms. First key results at low t indicate a cusp-like structure in K + Σ 0 photoproduction at W = 1900 MeV, line shapes and differential cross sections for K + Λ(1405)→ K + Σ 0 π 0 , and a peak structure in K 0 S Σ 0 photoproduction. The peak in the K 0 S Σ 0 channel appears consistent with meson-baryon generated states, where equivalent models have been used to describe the P C pentaquark candidates in the heavy charmed quark sector. 

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3. The BGOOD experiment at ELSA Exotic structures in the strange quark sector?

   https://doi.org/10.1051/epjconf/202227102007  

   Jude, Thomas; Alef, Stefan; Beck, Reinhard; Braghieri, Alessandro; Cole, Philip; Di Salvo, Rachele; Elsner, Daniel; Fantini, Alessia; Freyermuth, Oliver; Fromberger, Frank; et al (January 2022, EPJ Web of Conferences)

   Bielčíková, J.; Bydžovský, P.; Gazda, D.; Křížek, F.; Mareš, J.; Óbertová, J. (Ed.)

   The BGOOD photoproduction experiment accesses forward meson angles and low momentum exchange kinematics in the uds sector, which may be sensitive to molecular-like hadronic structure. Recent highlights are summarised in these proceedings. 

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4. Measurement of ω meson production in pp collisions at $$ \sqrt{s} $$ = 13 TeV

   https://doi.org/10.1007/JHEP04(2025)067  

   Acharya, S; Adamová, D; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; et al (April 2025, Journal of High Energy Physics)

   A<sc>bstract</sc> Thep_T-differential cross section ofωmeson production in pp collisions at$$ \sqrt{s} $$ $\sqrt{s}$= 13 TeV at midrapidity (|y| <0.5) was measured with the ALICE detector at the LHC, covering an unprecedented transverse-momentum range of 1.6< p_T<50 GeV/c. The meson is reconstructed via theω→π⁺π⁻π⁰decay channel. The results are compared with various theoretical calculations: PYTHIA8.2 with the Monash 2013 tune overestimates the data by up to 50%, whereas good agreement is observed with Next-to-Leading Order (NLO) calculations incorporatingωfragmentation using a broken SU(3) model. Theω/π⁰ratio is presented and compared with theoretical calculations and the available measurements at lower collision energies. The presented data triples thep_Tranges of previously available measurements. A constant ratio ofC^ω/π0= 0.578 ± 0.006 (stat.) ± 0.013 (syst.) is found above a transverse momentum of 4 GeV/c, which is in agreement with previous findings at lower collision energies within the systematic and statistical uncertainties. 

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5. Search for charge-parity violation in semileptonically tagged D0 → K+π− decays

   https://doi.org/10.1007/JHEP03(2025)149  

   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 (March 2025, Journal of High Energy Physics)

   A<sc>bstract</sc> An analysis of the flavour oscillations of the charmed neutral meson is presented. The ratio ofD⁰→K⁺π⁻andD⁰→K⁻π⁺decay rates is measured as a function of the decay time of theD⁰meson and compared with the charge-conjugated system to search for charge-parity violation. The meson flavour at production is double-tagged by the charges of the muon and pion in the preceding$$ \overline{B}\to {D}^{\ast }{(2010)}^{+}{\mu}^{-}X $$ $\overline{B}\to D^{\ast }{\left(2010\right)}^{+}{\mu }^{-}X$andD^∗(2010)⁺ → D⁰π⁺decays, respectively. These decays are selected from proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 5.4 fb⁻¹. The flavour oscillation parameters, relating to the differences in mass and width of the mass eigenstates, are found to bey′ = (5.8 ± 1.6) × 10⁻³and (x′)²= (0.0 ± 1.2) × 10⁻⁴. No evidence for charge-parity violation is seen either in the flavour oscillations or in the decay, where the direct charge-parity asymmetry is measured to beA_D= (2.3 ± 1.7) %. 

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