<?xml version="1.0" encoding="UTF-8"?><?xml-stylesheet type="text/xsl" href="static/style.xsl"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-04-17T02:41:12Z</responseDate><request verb="GetRecord" identifier="oai:www.recercat.cat:20.500.14342/3156" metadataPrefix="mets">https://recercat.cat/oai/request</request><GetRecord><record><header><identifier>oai:recercat.cat:20.500.14342/3156</identifier><datestamp>2025-03-11T04:11:59Z</datestamp><setSpec>com_2072_482405</setSpec><setSpec>com_2072_183628</setSpec><setSpec>col_2072_482415</setSpec></header><metadata><mets xmlns="http://www.loc.gov/METS/" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:doc="http://www.lyncode.com/xoai" ID="&#xa;&#x9;&#x9;&#x9;&#x9;DSpace_ITEM_20.500.14342-3156" TYPE="DSpace ITEM" PROFILE="DSpace METS SIP Profile 1.0" xsi:schemaLocation="http://www.loc.gov/METS/ http://www.loc.gov/standards/mets/mets.xsd" OBJID="&#xa;&#x9;&#x9;&#x9;&#x9;hdl:20.500.14342/3156">
   <metsHdr CREATEDATE="2026-04-17T04:41:12Z">
      <agent ROLE="CUSTODIAN" TYPE="ORGANIZATION">
         <name>RECERCAT</name>
      </agent>
   </metsHdr>
   <dmdSec ID="DMD_20.500.14342_3156">
      <mdWrap MDTYPE="MODS">
         <xmlData xmlns:mods="http://www.loc.gov/mods/v3" xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-1.xsd">
            <mods:mods xsi:schemaLocation="http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-1.xsd">
               <mods:name>
                  <mods:role>
                     <mods:roleTerm type="text">author</mods:roleTerm>
                  </mods:role>
                  <mods:namePart>Badalov, Alexey</mods:namePart>
               </mods:name>
               <mods:name>
                  <mods:role>
                     <mods:roleTerm type="text">author</mods:roleTerm>
                  </mods:role>
                  <mods:namePart>Calvo Gómez, Míriam</mods:namePart>
               </mods:name>
               <mods:name>
                  <mods:role>
                     <mods:roleTerm type="text">author</mods:roleTerm>
                  </mods:role>
                  <mods:namePart>Vilasís Cardona, Xavier</mods:namePart>
               </mods:name>
               <mods:name>
                  <mods:role>
                     <mods:roleTerm type="text">author</mods:roleTerm>
                  </mods:role>
                  <mods:namePart>LHCb Collaboration - CERN</mods:namePart>
               </mods:name>
               <mods:extension>
                  <mods:dateAccessioned encoding="iso8601">2025-03-11T04:11:59Z</mods:dateAccessioned>
               </mods:extension>
               <mods:extension>
                  <mods:dateAvailable encoding="iso8601">2025-03-11T04:11:59Z</mods:dateAvailable>
               </mods:extension>
               <mods:originInfo>
                  <mods:dateIssued encoding="iso8601">2015-04-09</mods:dateIssued>
               </mods:originInfo>
               <mods:identifier type="uri">http://hdl.handle.net/20.500.14342/3156</mods:identifier>
               <mods:identifier type="doi">https://doi.org/10.1016/j.physletb.2015.02.010</mods:identifier>
               <mods:abstract>A search for the rare decays B0s→π+π−μ+μ−and B0→π+π−μ+μ−is performed in a data set corresponding to an integrated luminosity of 3.0fb−1collected by the LHCb detector in proton–proton collisions at centre-of-mass energies of 7 and 8TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5–1.3GeV/c2and with muon pairs that do not originate from a resonance are considered. The first observation of the decay B0s→π+π−μ+μ−and the first evidence of the decay B0→π+π−μ+μ−are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(B0s→π+π−μ+μ−) =(8.6 ±1.5(stat) ±0.7(syst) ±0.7 (norm)) ×10−8and B(B0→π+π−μ+μ−) =(2.11±0.51(stat)±0.15(syst)±0.16(norm))×10−8, where the third uncertainty is due to the branching fraction of the decay B0→J/ψ(→μ+μ−)K∗(892)0(→K+π−), used as a normalisation.</mods:abstract>
               <mods:language>
                  <mods:languageTerm authority="rfc3066">eng</mods:languageTerm>
               </mods:language>
               <mods:accessCondition type="useAndReproduction">Attribution 4.0 International © CERN</mods:accessCondition>
               <mods:subject>
                  <mods:topic>Gran col·lisionador d'hadrons (França i Suïssa)</mods:topic>
               </mods:subject>
               <mods:subject>
                  <mods:topic>Partícules (Física nuclear)</mods:topic>
               </mods:subject>
               <mods:subject>
                  <mods:topic>Protons</mods:topic>
               </mods:subject>
               <mods:subject>
                  <mods:topic>Col·lisions (Física nuclear)</mods:topic>
               </mods:subject>
               <mods:titleInfo>
                  <mods:title>Study of the rare B0s and B0 decays into the π+ π− μ+ μ− final state</mods:title>
               </mods:titleInfo>
               <mods:genre>info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion</mods:genre>
            </mods:mods>
         </xmlData>
      </mdWrap>
   </dmdSec>
   <structMap LABEL="DSpace Object" TYPE="LOGICAL">
      <div TYPE="DSpace Object Contents" ADMID="DMD_20.500.14342_3156"/>
   </structMap>
</mets></metadata></record></GetRecord></OAI-PMH>