# First measurement of $Ξ_{\rm c}^0$ production in pp collisions at $\mathbf{\sqrt{s}}$ = 7 TeV

The production of the charm-strange baryon $\Xi_{\rm c}^0$ is measured for the first time at the LHC via its semileptonic decay into e$^+\Xi^-\nu_{\rm e}$ in pp collisions at $\sqrt{s}=7$ TeV with the ALICE detector. The transverse momentum ($p_{\rm T}$) differential cross section multiplied by the branching ratio is presented in the interval 1 $<~$ $p_{\rm T}$ $<~$ 8 GeV/$c$ at mid-rapidity, $|y|$ $<~$ 0.5. The transverse momentum dependence of the $\Xi_{\rm c}^0$ baryon production relative to the D$^0$ meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.

Figures

## Figure 1

 (a) Invariant-mass distribution of $\Xi^- \rightarrow \pi^-\Lambda$ (and charge conjugate) candidates integrated over \pt. The arrow indicates the world average $\Xi^-$ mass from Ref.~ and the dashed lines indicate the selected interval. (b) Invariant-mass distributions of right-sign and wrong-sign (and charge conjugate) pairs integrated over the whole \pt\ interval. The arrow indicates the \xicz\ mass~. ## Figure 2

 Correlation between the generated \xicz-baryon \pt\ and the reconstructed \exipair\ pair \pt, obtained from the simulation based on {\sc pythia 6} described in the text. ## Figure 3

 Product of acceptance and efficiency ($A\times\varepsilon$) of \xicz\ baryons generated in $|y|< 0.8$ decaying into ${\rm e}^+\Xi^-\nu_{\rm e}$ as a function of \pt, determined from simulations {\sc pythia} 6 (see text). ## Figure 4

 Inclusive \xicz-baryon \pt-differential production cross section multiplied by the branching ratio into ${\rm e}^+\Xi^-\nu_{\rm e}$, as a function of \pt\ for $|y|< 0.5$, in \pp collisions at $\sqrt{s} =$ 7 TeV. The error bars and boxes represent the statistical and systematic uncertainties, respectively. The contribution from \xib\ decays is not subtracted. ## Figure 5

 Ratio of the \pt-differential cross sections of \xicz\ baryons (multiplied by the branching ratio into ${\rm e}^+\Xi^-\nu_{\rm e}$) and \Dzero mesons~ as a function of \pt\ for $|y|< 0.5$, in \pp collisions at $\sqrt{s} =$ 7 TeV. The error bars and boxes represent the statistical and systematic uncertainties, respectively. Predictions from theoretical models, (a) {\sc pythia 8} with different tunes (b) {\sc dipsy}~ and {\sc herwig 7}~, are shown as shaded bands representing the range of the currently available theoretical predictions for the branching ratio of the considered \xicz\ decay mode.
{"ft_lang_label":"__label__en","ft_lang_prob":0.7790423,"math_prob":0.99751633,"size":785,"snap":"2019-26-2019-30","text_gpt3_token_len":231,"char_repetition_ratio":0.1306018,"word_repetition_ratio":0.0,"special_character_ratio":0.28152865,"punctuation_ratio":0.042857144,"nsfw_num_words":0,"has_unicode_error":false,"math_prob_llama3":0.9996456,"pos_list":[0,1,2,3,4,5,6,7,8,9,10],"im_url_duplicate_count":[null,2,null,2,null,2,null,2,null,2,null],"WARC_HEADER":"{\"WARC-Type\":\"response\",\"WARC-Date\":\"2019-07-18T19:56:46Z\",\"WARC-Record-ID\":\"<urn:uuid:5a7823eb-f356-41a8-9c4c-0ce9755318c6>\",\"Content-Length\":\"30832\",\"Content-Type\":\"application/http; msgtype=response\",\"WARC-Warcinfo-ID\":\"<urn:uuid:837b0724-97cf-4ac6-8015-3079176e43c9>\",\"WARC-Concurrent-To\":\"<urn:uuid:1b599fe7-7931-4448-945d-9755e044ec06>\",\"WARC-IP-Address\":\"188.184.37.205\",\"WARC-Target-URI\":\"http://alice-publications.web.cern.ch/node/4123\",\"WARC-Payload-Digest\":\"sha1:FTTNGGUXKGK3KNBKJUQNLQETXLOZZSBU\",\"WARC-Block-Digest\":\"sha1:45JTKZ7KMAOOTYSTD53AOPDQY6EKFZGS\",\"WARC-Identified-Payload-Type\":\"text/html\",\"warc_filename\":\"/cc_download/warc_2019/CC-MAIN-2019-30/CC-MAIN-2019-30_segments_1563195525793.19_warc_CC-MAIN-20190718190635-20190718212635-00126.warc.gz\"}"}