First Record of Reversed Symmetry in Etropus cyclosquamus and Second Record in Citharichthys spilopterus (Bothidae, Pisces) in the Gulf of Mexico, with a Plausible Genetic Explanation for Reversal

The discovery of the first instance of reversed eye symmetry in the shelf flounder, Etropus cyclosquamus, and the second instance in the bay whiff, Citharichthys spilopterus, are reported. Two reversed bay whiffs and three reversed shelf flounders were collected in the Gulf of Mexico. Four of these specimens were taken from the vicinity of Fort Walton Beach, Okaloosa County, in northern Florida, and one was taken from Higgs Beach in Key West, Monroe County, Fl. The collection of these fish is reported because of the infrequent occurrence of reversed eye symmetry in flatfishes in the Gulf of Mexico. The fish serve as the first record of eye symmetry reversal in E. cyclosquamus and the second record for C. spilopterus in the Gulf of Mexico. This is the second record of reversal for the genus Etropus and the third record for Citharichthys in the western Atlantic Ocean. The putative causes of symmetry reversal in pleuronectiform fish are briefly examined. A plausible genetic explanation for reversal is proposed. The explanation attempts to reconcile the environmental causality of eye symmetry with the accepted genetic model of Brown and Wolpert

The Threespine Bass, Synagrops trispinosus (Perciformes; Acropomatidae), an Addition to the Fish Fauna of the Gulf of Mexico

We present the first documented record of Synagrops trispinosus in the Gulf of Mexico. This record represents a moderate extension to the known southern Caribbean distribution; it is nevertheless a new addition to the ichthyofauna of U.S. coastal waters

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

Study of the doubly charmed tetraquark T+cc

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed

First Record of Reversed Symmetry in Etropus cyclosquamus and Second Record in Citharichthys spilopterus (Bothidae, Pisces) in the Gulf of Mexico, with a Plausible Genetic Explanation for Reversal

The discovery of the first instance of reversed eye symmetry in the shelf flounder, Etropus cyclosquamus, and the second instance in the bay whiff, Citharichthys spilopterus, are reported. Two reversed bay whiffs and three reversed shelf flounders were collected in the Gulf of Mexico. Four of these specimens were taken from the vicinity of Fort Walton Beach, Okaloosa County, in northern Florida, and one was taken from Higgs Beach in Key West, Monroe County, Fl. The collection of these fish is reported because of the infrequent occurrence of reversed eye symmetry in flatfishes in the Gulf of Mexico. The fish serve as the first record of eye symmetry reversal in E. cyclosquamus and the second record for C. spilopterus in the Gulf of Mexico. This is the second record of reversal for the genus Etropus and the third record for Citharichthys in the western Atlantic Ocean. The putative causes of symmetry reversal in pleuronectiform fish are briefly examined. A plausible genetic explanation for reversal is proposed. The explanation attempts to reconcile the environmental causality of eye symmetry with the accepted genetic model of Brown and Wolpert

Elops smithi Mcbride, Rocha, Ruiz-Carus & Bowen, 2010, new species

&lt;i&gt;Elops smithi&lt;/i&gt;, new species &lt;p&gt;Figure 1; Table 1&lt;/p&gt; &lt;p&gt; &lt;i&gt;Elops saurus&lt;/i&gt; non Linnaeus 1766: Regan, 1909 (in part), Hildebrand, 1943 (in part); Bertin, 1944 (in part); Fowler, 1931; Gehringer, 1959 (in part); Whitehead, 1962 (in part); Hildebrand, 1963 (in part); Eldred and Lyons, 1966 (in part); Carles, 1967; Miller and Jorgenson, 1973 (in part), Santos-Martίnez and Arboleda (1993). These studies examined what we recognize here as &lt;i&gt;E. smithi&lt;/i&gt;, either in whole or in part, based on their reports of meristic values, sample locality, or both.&lt;/p&gt; &lt;p&gt; &lt;i&gt;Elops&lt;/i&gt; sp.: Smith, 1989; Smith-Vaniz &lt;i&gt;et al.&lt;/i&gt;, 1999; Obermiller and Pfeiler, 2003&lt;/p&gt; &lt;p&gt; &lt;b&gt;Holotype.&lt;/b&gt; UF 45683, 303 mm SL, marine waters of Guyana, by trawl, 16 July 1967.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Paratypes.&lt;/b&gt; UF 45682, marine waters of Trinidad, 13 December 1967; GCRL 11950, 4, Commewijne River, Suriname, 14 October 1973; GCRL 12733, Gatun Locks, Canal Zone, Panama, 4 March 1974; UF 11269, 2, Tortuguero Lagoon, Costa Rica, August 1963.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Other museum material examined.&lt;/b&gt; &lt;i&gt;Elops saurus&lt;/i&gt;: FSBC 0 0 258, Florida, Pinellas County, 13 December 1957; FSBC 10270, Florida, Pinellas County, 15 December 1977; FSBC 12589, 3, Florida, Hillsborough County, 3 June 1983; GCRL 0 345, Louisiana, 8 September 1959; GCRL 1938, Mississippi, 8 August 1966; UF 47036, Honduras, 26 April 1967; UF 105715, 2, Florida, Volusia County, 17 November 1972.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Diagnosis.&lt;/b&gt; &lt;i&gt;Elops smithi&lt;/i&gt; is distinguished from &lt;i&gt;E. saurus&lt;/i&gt; in the number of vertebrae (73&ndash;80, usually 75&ndash;78 versus 79&ndash;87, usually 81&ndash;85, respectively). According to McBride and Horodysky (2004), vertebrae counts in the overlap range (79&ndash;80) occurred in only 94 of 3,255 (2.9%) specimens examined from the coasts of the Americas, the Bahamas, and the Caribbean islands.&lt;/p&gt; &lt;p&gt; As reported by Whitehead (1962) counts of gill rakers and total vertebrae can be used to separate all species of &lt;i&gt;Elops&lt;/i&gt;. Western Atlantic &lt;i&gt;Elops&lt;/i&gt;, now recognized as &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;smithi&lt;/i&gt; and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt;, have lower gill raker counts (10&ndash;15 on the lower part of the first arch) than &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;affinis&lt;/i&gt; (16&ndash;20) and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;lacerta&lt;/i&gt; (17&ndash;19). &lt;i&gt;Elops smithi&lt;/i&gt; and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; have higher vertebrae counts (&gt; 72; see above for ranges) than &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;senegalensis&lt;/i&gt; (67), &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;machnata&lt;/i&gt; (63&ndash;64), and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;hawaiensis&lt;/i&gt; (68&ndash;70).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description.&lt;/b&gt; Body elongate (head length 25&ndash;29% of SL) and slender (width 7.5&ndash;9.4% of SL). Mouth large (maxilla 56&ndash;60% of head length) and nearly terminal. Caudal fin deeply forked, with lobes equal. Principal dorsal-fin rays 19&ndash;20 (24&ndash;27 total); anal rays 12&ndash;13 (16&ndash;19 total); pectoral rays 17&ndash;18; pelvic rays 13&ndash;16; branchiostegal rays 30&ndash;34; gill rakers on lower arch 13&ndash;15 (total 21&ndash;23 excluding rudiments); lateralline scales (102&ndash;118, but may be higher if specimen is found north of the Caribbean Sea [see below]); and 73&ndash; 80 vertebrae (usually 75&ndash;78). Data for above description are from Table 1, Figure 2, and McBride and Horodysky (2004).&lt;/p&gt; &lt;p&gt;Meristic characters&lt;/p&gt; &lt;p&gt;continued.&lt;/p&gt; &lt;p&gt; The larvae are of leptocephalus form, and the total myomere number of the leptocephalus equals that of total vertebrae (McBride &amp; Horodysky 2004). Predorsal (61&ndash;66) and preanal (68&ndash;72) myomeres are also reliable characters for identifying premetamorphic leptocephali (Smith 1989). Others examining &lt;i&gt;Elops&lt;/i&gt; from the Caribbean Sea have noted minor variations in these meristic characters (Carles 1967; Santos-Martίnez and Arboleda 1993), indicating differences in counting methods or geographic variation.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Coloration.&lt;/b&gt; Living adults bright silver, particularly on sides; may be bluish-gray on back with yellowish hue on fins. Not as silvery in preservative.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Comparisons.&lt;/b&gt; We found no character other than counts of vertebrae that separates adult &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;smithi&lt;/i&gt; from &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; (Table 1). Although lateral-line scale counts appeared to be a diagnostic character, the scales are formed late in larval development so this character is indicative of latitude where larval transformation occurs instead of where spawning occurred. To demonstrate this, it can be shown that lateral-line scale counts are distinct among &lt;i&gt;E. smith&lt;/i&gt; and &lt;i&gt;E. saurus&lt;/i&gt; that had not been dispersed outside their typical range (Table 1, Fig. 2 A), but the lateral-line scale counts are not distinct among a test collection from the southern Indian River Lagoon, Florida, which included &lt;i&gt;E. smithi&lt;/i&gt; that had presumably been dispersed from their spawning grounds (Fig. 2 B). This disconnect can be explained because vertebral number is set during embryogenesis but scales are not developed until about 50 mm in the late metamorphic period (Gehringer 1959). Thus, lateral-line scale counts will be a misleading diagnostic character when measured from specimens collected within areas of sympatry. The leptocephalus larva, common to this genus, is associated with long-distance dispersal (McBride &amp; Horodysky 2004), so scale counts may be problematic as a taxonomic character in other species of &lt;i&gt;Elops&lt;/i&gt; as well. In addition, the scales of these species are small and easily displaced, further confounding their use as a taxonomic character.&lt;/p&gt; &lt;p&gt; Mitochondrial DNA sequence data provide an independent character for recognizing two species of &lt;i&gt;Elops&lt;/i&gt; in the western North Atlantic. We observed 14 haplotypes in two primary lineages corresponding to &lt;i&gt;E. saurus&lt;/i&gt; and &lt;i&gt;E. smithi&lt;/i&gt; (Table 2). These sequences have been deposited in GenBank under accession numbers GQ183881 &ndash; GQ183882 (&lt;i&gt;E. saurus&lt;/i&gt;, haplotypes A, B) and GQ183883 &ndash; GQ183894 (&lt;i&gt;E. smithi&lt;/i&gt;, haplotypes C &ndash; N). The genetic difference (&lt;i&gt;d&lt;/i&gt;) between the &lt;i&gt;E. saurus&lt;/i&gt; haplotypes and the &lt;i&gt;E. smithi&lt;/i&gt; haplotypes ranged from 0.023 to 0.029 (Fig. 3). Obermiller and Pfeiler (2003) reported a similar level of divergence between what we recognized as &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;smithi&lt;/i&gt; and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; (&lt;i&gt;d&lt;/i&gt; = 0.021 with 12S and 16S rRNA mtDNA sequences). In addition, Obermiller and Pfeiler (2003) observed a similar level of divergence between &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;hawaiiensis&lt;/i&gt; (&lt;i&gt;d&lt;/i&gt; = 0.024), two recognized species that occupy different ocean basins.&lt;/p&gt; &lt;p&gt; &lt;b&gt;TABLE 2.&lt;/b&gt; Data associated with fish used in the genetic analysis. Collection date and locale are listed, along with standard length (SL), and total number of vertebrae (Vert.). Fish are sorted as vertebrae morph (high vs. low-count) and haplotype. *Mismatches between phenotype and genotype are indicated with an asterisk. Locality codes are: IR = Indian River Lagoon (northern or southern regions of the lagoon), southeast Florida, CK = Cedar Key, west coast Florida, and FW = Fort Walton, panhandle Florida.&lt;/p&gt; &lt;p&gt; continued next page Although the mtDNA data presented here and data presented previously by Obermiller and Pfeiler (2003) indicate two evolutionary lineages, the mtDNA character was not absolutely diagnostic. In seven of 56 specimens (12.5%), there was a mismatch between classification based on genetics and that on morphology (Table 2). Five of these individuals had morphology similar to &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;smithi&lt;/i&gt; but haplotypes in the &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; lineage, and two had the reverse. These mismatches may indicate ecophenotype plasticity within species, hybridization, or retention of ancestral polymorphisms. All three phenomena have been documented in fishes (see Rocha &lt;i&gt;et al.&lt;/i&gt; 2007). The sympatric sturgeons &lt;i&gt;Scaphirhynchus albus&lt;/i&gt; and &lt;i&gt;S. platorynchus&lt;/i&gt; share mtDNA haplotypes because of their recent speciation and hybridization (Campton &lt;i&gt;et al.&lt;/i&gt; 2000). The marine angelfishes &lt;i&gt;Centropyge argi&lt;/i&gt; and &lt;i&gt;C. aurantonotus&lt;/i&gt; are sister species that share haplotypes despite diagnostic differences in coloration (Bowen &lt;i&gt;et al.&lt;/i&gt; 2006). And the Atlantic bluefin tuna (&lt;i&gt;Thunnus thynnus&lt;/i&gt;) has haplotypes derived from both Pacific bluefin (&lt;i&gt;Thunnus orientalis&lt;/i&gt;) and albacore (&lt;i&gt;Thunnus alalunga&lt;/i&gt;; Alvarado Bremer &lt;i&gt;et al.&lt;/i&gt; 2005). Surveys of multiple nuclear loci have resolved these phenomena in other species and could profitably be applied to &lt;i&gt;Elops&lt;/i&gt;. Nonetheless, given these genetic results, it is unlikely that we are observing an intraspecific, or population-level, genetic phenomenon, so we reject the hypothesis that &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;smithi&lt;/i&gt; and &lt;i&gt;E&lt;/i&gt;. &lt;i&gt;saurus&lt;/i&gt; are ecophenotypes.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution.&lt;/b&gt; &lt;i&gt;Elops smithi&lt;/i&gt; occurs along the northern coast of South America, in the Caribbean Sea, and throughout the Bahamas; it also occurs sympatrically with &lt;i&gt;E. saurus&lt;/i&gt; in the Gulf of Mexico and along the eastern seaboard of North America (Smith 1989; see McBride &amp; Horodysky [2004] for distribution maps of larvae, juveniles and adults). In addition, there are two records of &lt;i&gt;Elops&lt;/i&gt; from Bermuda (Linton 1907) although no resident population has been found there (Smith-Vaniz &lt;i&gt;et al.&lt;/i&gt; 1999). Only one specimen is available, a 181 mm SL fish (BAMZ 1990-083-037) with 73 vertebrae; this apparently represents a waif from the population inhabiting the Caribbean (Smith-Vaniz &lt;i&gt;et al.&lt;/i&gt; 1999).&lt;/p&gt; &lt;p&gt; &lt;i&gt;Elops smithi&lt;/i&gt; is found in a wide range of salinities. Mature adults and early-life-history stages are found in offshore, marine habitats, where spawning presumably occurs (Gehringer 1959; Santos-Mart&iacute;nez &amp; Arboleda 1993; McBride &amp; Horodysky 2004). Transforming larvae and subadults are found throughout estuaries, as far up as the oligohaline zone, as well as in hypersaline lagoons (Carles 1967; McBride &lt;i&gt;et al.&lt;/i&gt; 2001; McBride &amp; Horodysky 2004).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Etymology.&lt;/b&gt; The specific epithet honors David G. Smith, of the Smithsonian Institution, for his thoroughness in examining leptocephali of &lt;i&gt;Elops&lt;/i&gt; to reveal that two morphs were present. We recommend the vernacular name Malacho, which is already used for &lt;i&gt;Elops&lt;/i&gt; in several countries bordering the Caribbean basin.&lt;/p&gt;Published as part of &lt;i&gt;Mcbride, Richard S., Rocha, Claudia R., Ruiz-Carus, Ramon &amp; Bowen, Brian W., 2010, A new species of ladyfish, of the genus Elops (Elopiformes: Elopidae), from the western Atlantic Ocean, pp. 29-41 in Zootaxa 2346&lt;/i&gt; on pages 31-38, DOI: &lt;a href="http://zenodo.org/record/193392"&gt;10.5281/zenodo.193392&lt;/a&gt

Search for Bc+→π+μ+μ−B_c^+\to\pi^+\mu^+\mu^- decays and measurement of the branching fraction ratio B(Bc+→ψ(2S)π+)/B(Bc+→J/ψπ+){\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+)

International audienceThe first search for nonresonant $B_c^+\to\pi^+\mu^+\mu^-$ decays is reported. The analysis uses proton-proton collision data collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb$^{-1}$. No evidence for an excess of signal events over background is observed and an upper limit is set on the branching fraction ratio ${\cal B}(B_c^+\to\pi^+\mu^+\mu^-)/{\cal B}(B_c^+\to J/\psi \pi^+) < 2.1\times 10^{-4}$ at $90\%$ confidence level. Additionally, an updated measurement of the ratio of the $B_c^+\to\psi(2S)\pi^+$ and $B_c^+\to J/\psi \pi^+$ branching fractions is reported. The ratio ${\cal B}(B_c^+\to\psi(2S)\pi^+)/{\cal B}(B_c^+\to J/\psi \pi^+)$ is measured to be $0.254\pm 0.018 \pm 0.003 \pm 0.005$, where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the leptonic $J/\psi$ and $\psi(2S)$ decays. This measurement is the most precise to date and is consistent with previous LHCb results