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1. Measurement of the mass dependence of the transverse momentum of lepton pairs in Drell–Yan production in proton–proton collisions at $$\sqrt{s} = 13\,\text {Te\hspace{-.08em}V} $$

   https://doi.org/10.1140/epjc/s10052-023-11631-7  

   Tumasyan, A.; Adam, W.; Andrejkovic, J. W.; Bergauer, T.; Chatterjee, S.; Dragicevic, M.; Valle, A. Escalante; Frühwirth, R.; Jeitler, M.; Krammer, N.; et al (July 2023, The European Physical Journal C)

   Abstract The double differential cross sections of the Drell–Yan lepton pair ($$\ell ^+\ell ^-$$ ${\ell }^{+}{\ell }^{-}$ , dielectron or dimuon) production are measured as functions of the invariant mass$$m_{\ell \ell }$$ $m_{\ell \ell }$ , transverse momentum$$p_{\textrm{T}} (\ell \ell )$$ $p_{\text{T}}\left(\ell \ell \right)$ , and$$\varphi ^{*}_{\eta }$$ ${\phi }_{\eta }^{\ast }$ . The$$\varphi ^{*}_{\eta }$$ ${\phi }_{\eta }^{\ast }$ observable, derived from angular measurements of the leptons and highly correlated with$$p_{\textrm{T}} (\ell \ell )$$ $p_{\text{T}}\left(\ell \ell \right)$ , is used to probe the low-$$p_{\textrm{T}} (\ell \ell )$$ $p_{\text{T}}\left(\ell \ell \right)$ region in a complementary way. Dilepton masses up to 1$$\,\text {Te\hspace{-.08em}V}$$ $\text{Te}\text{V}$ are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various$$m_{\ell \ell }$$ $m_{\ell \ell }$ ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3$$\,\text {fb}^{-1}$$ ${\text{fb}}^{-1}$ of proton–proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13$$\,\text {Te\hspace{-.08em}V}$$ $\text{Te}\text{V}$ . Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation. 

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2. A search for decays of the Higgs boson to invisible particles in events with a top-antitop quark pair or a vector boson in proton-proton collisions at $$\sqrt{s} = 13\,\text {Te}\hspace{-.08em}\text {V} $$

   https://doi.org/10.1140/epjc/s10052-023-11952-7  

   Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Escalante Del Valle, A; Hussain, P S; Jeitler, M; et al (October 2023, The European Physical Journal C)

   Abstract A search for decays to invisible particles of Higgs bosons produced in association with a top-antitop quark pair or a vector boson, which both decay to a fully hadronic final state, has been performed using proton-proton collision data collected at$${\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V}}$$ $\sqrt{s}=13\text{Te}\text{V}$ by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138$$\,\text {fb}^{-1}$$ ${\text{fb}}^{-1}$ . The 95% confidence level upper limit set on the branching fraction of the 125$$\,\text {Ge}\hspace{-.08em}\text {V}$$ $\text{Ge}\text{V}$ Higgs boson to invisible particles,$${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$ $B(\text{H}\to \text{inv})$ , is 0.54 (0.39 expected), assuming standard model production cross sections. The results of this analysis are combined with previous$${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$ $B(\text{H}\to \text{inv})$ searches carried out at$${\sqrt{s}=7}$$ $\sqrt{s}=7$ , 8, and 13$$\,\text {Te}\hspace{-.08em}\text {V}$$ $\text{Te}\text{V}$ in complementary production modes. The combined upper limit at 95% confidence level on$${\mathcal {B}({\textrm{H}} \rightarrow \text {inv})}$$ $B(\text{H}\to \text{inv})$ is 0.15 (0.08 expected). 

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3. Measurement of isolated prompt photon production in pp and p–Pb collisions at the LHC

   https://doi.org/10.1140/epjc/s10052-025-14802-w  

   Acharya, S; Agarwal, A; Aglieri_Rinella, G; Aglietta, L; Agnello, M; Agrawal, N; Ahammed, Z; Ahmad, S; Ahn, S U; Ahuja, I; et al (December 2025, The European Physical Journal C)

   Abstract This paper presents the measurement of the isolated prompt photon inclusive production cross section in pp and p–Pb collisions by the ALICE Collaboration at the LHC. The measurement is performed in p–Pb collisions at centre-of-mass energies per nucleon pair of$$\sqrt{s_{\text {NN}}}={5.02}\,\textrm{TeV}$$ $\sqrt{s_{\text{NN}}}=5.02\text{TeV}$ and 8.16 TeV, as well as in pp collisions at$$\sqrt{s}={5.02}\,\textrm{TeV}$$ $\sqrt{s}=5.02\text{TeV}$ and 8 TeV. The cross section is obtained at midrapidity$$(|y|<0.7)$$ $\left(\right|y|<0.7)$ using a charged-track based isolation momentum$$p_\textrm{T}^{\text {iso,~ch}}<{1.5}\,\textrm{GeV}/c$$ $p_{\text{T}}^{\text{iso, ch}}<1.5\text{GeV}/c$ in a cone with radius$$R=0.4$$ $R=0.4$ . The data for both collision systems are well reproduced by perturbative QCD (pQCD) calculations at next-to-leading order (NLO) using recent parton distribution functions for free (PDF) and bound (nPDF) nucleons. Furthermore, the nuclear modification factor$$R_{\text {pA}}$$ $R_{\text{pA}}$ for both collision energies is consistent with unity for$$p_{\textrm{T}}$$ $p_{\text{T}}$ $$>{20}\,\textrm{GeV}/c$$ $>20\text{GeV}/c$ . However, deviations from unity ($$R_\textrm{pA}<1$$ $R_{\text{pA}}<1$ ) of up to 20% are observed for$$p_{\textrm{T}}$$ $p_{\text{T}}$ $$<{20}\,\textrm{GeV}/c$$ $<20\text{GeV}/c$ with limited significance, indicating the possible presence of nuclear effects in the initial state of the collision. The suppression increases with decreasing$$p_{\textrm{T}}$$ $p_{\text{T}}$ with a significance of$$2.3\upsigma $$ $2.3\sigma$ for a non-zero slope and yields$$R_{\textrm{pA}}<1$$ $R_{\text{pA}}<1$ with a significance of$$1.8\upsigma $$ $1.8\sigma$ at$$\sqrt{s_{\textrm{NN}}}={8.16}\,\textrm{TeV}$$ $\sqrt{s_{\text{NN}}}=8.16\text{TeV}$ for$$p_{\textrm{T}}$$ $p_{\text{T}}$ $$<{20}\,\textrm{GeV}/c$$ $<20\text{GeV}/c$ . In addition, a significance of$$1.1\upsigma $$ $1.1\sigma$ is observed for$$R_{\textrm{pA}}<1$$ $R_{\text{pA}}<1$ at the lower collision energy$$\sqrt{s_{\textrm{NN}}}={5.02}\,\textrm{TeV}$$ $\sqrt{s_{\text{NN}}}=5.02\text{TeV}$ for$$p_{\textrm{T}} < {14}\,\textrm{GeV}/c$$ $p_{\text{T}}<14\text{GeV}/c$ . The magnitude and shape of the suppression are consistent with pQCD predictions at NLO using nPDFs that incorporate nuclear shadowing effects in the Pb nucleus. 

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4. Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the $$\upmu \upmu \text{ b } \text{ b } $$ and $$\uptau \uptau \text{ b } \text{ b } $$ final states

   https://doi.org/10.1140/epjc/s10052-024-12727-4  

   Hayrapetyan, A; Tumasyan, A; Adam, W; Andrejkovic, J W; Bergauer, T; Chatterjee, S; Damanakis, K; Dragicevic, M; Del_Valle, A Escalante; Hussain, P S; et al (May 2024, The European Physical Journal C)

   Abstract A search for exotic decays of the Higgs boson ($$\text {H}$$ $\text{H}$ ) with a mass of 125$$\,\text {Ge}\hspace{-.08em}\text {V}$$ $\text{Ge}\text{V}$ to a pair of light pseudoscalars$$\text {a}_{1} $$ ${\text{a}}_1$ is performed in final states where one pseudoscalar decays to two$${\textrm{b}}$$ $\text{b}$ quarks and the other to a pair of muons or$$\tau $$ $\tau$ leptons. A data sample of proton–proton collisions at$$\sqrt{s}=13\,\text {Te}\hspace{-.08em}\text {V} $$ $\sqrt{s}=13\text{Te}\text{V}$ corresponding to an integrated luminosity of 138$$\,\text {fb}^{-1}$$ ${\text{fb}}^{-1}$ recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level ($$\text {CL}$$ $\text{CL}$ ) on the Higgs boson branching fraction to$$\upmu \upmu \text{ b } \text{ b } $$ $\mu \mu \text{b}\text{b}$ and to$$\uptau \uptau \text{ b } \text{ b },$$ $\tau \tau \text{b}\text{b},$ via a pair of$$\text {a}_{1} $$ ${\text{a}}_1$ s. The limits depend on the pseudoscalar mass$$m_{\text {a}_{1}}$$ $m_{{\text{a}}_1}$ and are observed to be in the range (0.17–3.3) $$\times 10^{-4}$$ $\times {10}^{-4}$ and (1.7–7.7) $$\times 10^{-2}$$ $\times {10}^{-2}$ in the$$\upmu \upmu \text{ b } \text{ b } $$ $\mu \mu \text{b}\text{b}$ and$$\uptau \uptau \text{ b } \text{ b } $$ $\tau \tau \text{b}\text{b}$ final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} \rightarrow \ell \ell \text{ b } \text{ b})$$ $B(\text{H}\to {\text{a}}_1{\text{a}}_1\to \ell \ell \text{b}\text{b})$ at 95%$$\text {CL}$$ $\text{CL}$ , with$$\ell $$ $\ell$ being a muon or a$$\uptau $$ $\tau$ lepton. For different types of 2HDM+S, upper bounds on the branching fraction$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$ $B(\text{H}\to {\text{a}}_1{\text{a}}_1)$ are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space,$${\mathcal {B}}(\text {H} \rightarrow \text {a}_{1} \text {a}_{1} )$$ $B(\text{H}\to {\text{a}}_1{\text{a}}_1)$ values above 0.23 are excluded at 95%$$\text {CL}$$ $\text{CL}$ for$$m_{\text {a}_{1}}$$ $m_{{\text{a}}_1}$ values between 15 and 60$$\,\text {Ge}\hspace{-.08em}\text {V}$$ $\text{Ge}\text{V}$ . 

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5. Charm fragmentation fractions and $$\mathbf {c\overline{c}}$$ cross section in p–Pb collisions at $$\mathbf {\sqrt{s _{NN}}=5.02 TeV}$$

   https://doi.org/10.1140/epjc/s10052-024-13394-1  

   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, The European Physical Journal C)

   Abstract The total charm-quark production cross section per unit of rapidity$$\textrm{d}\sigma ({{\textrm{c}}\overline{\textrm{c}}})/\textrm{d}y$$ $\text{d}\sigma \left(\text{c}\overline{\text{c}}\right)/\text{d}y$ , and the fragmentation fractions of charm quarks to different charm-hadron species$$f(\textrm{c}\rightarrow {\textrm{h}}_{\textrm{c}})$$ $f(\text{c}\to {\text{h}}_{\text{c}})$ , are measured for the first time in p–Pb collisions at$$\sqrt{s_\textrm{NN}} = 5.02~\text {Te}\hspace{-1.00006pt}\textrm{V} $$ $\sqrt{s_{\text{NN}}}=5.02\text{Te}\text{V}$ at midrapidity ($$-0.96 $-0.96<y<0.04$ in the centre-of-mass frame) using data collected by ALICE at the CERN LHC. The results are obtained based on all the available measurements of prompt production of ground-state charm-hadron species:$$\textrm{D}^{0}$$ ${\text{D}}^0$ ,$$\textrm{D}^{+}$$ ${\text{D}}^{+}$ ,$$\textrm{D}_\textrm{s}^{+}$$ ${\text{D}}_{\text{s}}^{+}$ , and$$\mathrm {J/\psi }$$ $J/\psi$ mesons, and$$\Lambda _\textrm{c}^{+}$$ ${\Lambda }_{\text{c}}^{+}$ and$$\Xi _\textrm{c}^{0}$$ ${\Xi }_{\text{c}}^0$ baryons. The resulting cross section is$$ \textrm{d}\sigma ({{\textrm{c}}\overline{\textrm{c}}})/\textrm{d}y =219.6 \pm 6.3\;(\mathrm {stat.}) {\;}_{-11.8}^{+10.5}\;(\mathrm {syst.}) {\;}_{-2.9}^{+8.3}\;(\mathrm {extr.})\pm 5.4\;(\textrm{BR})\pm 4.6\;(\mathrm {lumi.}) \pm 19.5\;(\text {rapidity shape})+15.0\;(\Omega _\textrm{c}^{0})\;\textrm{mb} $$ $\text{d}\sigma \left(\text{c}\overline{\text{c}}\right)/\text{d}y=219.6\pm 6.3\left(\mathrm{stat}.\right)_{-11.8}^{+10.5}\left(\mathrm{syst}.\right)_{-2.9}^{+8.3}\left(\mathrm{extr}.\right)\pm 5.4\left(\text{BR}\right)\pm 4.6\left(\mathrm{lumi}.\right)\pm 19.5\left(\text{rapidity shape}\right)+15.0\left({\Omega }_{\text{c}}^0\right)\text{mb}$ , which is consistent with a binary scaling of pQCD calculations from pp collisions. The measured fragmentation fractions are compatible with those measured in pp collisions at$$\sqrt{s} = 5.02$$ $\sqrt{s}=5.02$ and 13 TeV, showing an increase in the relative production rates of charm baryons with respect to charm mesons in pp and p–Pb collisions compared with$$\mathrm {e^{+}e^{-}}$$ $e^{+}{e}^{-}$ and$$\mathrm {e^{-}p}$$ $e^{-}p$ collisions. The$$p_\textrm{T}$$ $p_{\text{T}}$ -integrated nuclear modification factor of charm quarks,$$R_\textrm{pPb}({\textrm{c}}\overline{\textrm{c}})= 0.91 \pm 0.04\;\mathrm{(stat.)} ^{+0.08}_{-0.09}\;\mathrm{(syst.)} ^{+0.05}_{-0.03}\;\mathrm{(extr.)} \pm 0.03\;\mathrm{(lumi.)}$$ $R_{\text{pPb}}\left(\text{c}\overline{\text{c}}\right)=0.91\pm 0.04{(\mathrm{stat}.)}_{-0.09}^{+0.08}{(\mathrm{syst}.)}_{-0.03}^{+0.05}(\mathrm{extr}.)\pm 0.03(\mathrm{lumi}.)$ , is found to be consistent with unity and with theoretical predictions including nuclear modifications of the parton distribution functions. 

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