002914563 001__ 2914563
002914563 005__ 20250114114954.0
002914563 0248_ $$aoai:cds.cern.ch:2914563$$pcerncds:FULLTEXT$$pcerncds:CERN:FULLTEXT$$pcerncds:CERN
002914563 0247_ $$2DOI$$9APS$$a10.1103/PhysRevD.110.115033$$qpublication
002914563 035__ $$9arXiv$$aoai:arXiv.org:2410.13936
002914563 035__ $$9Inspire$$aoai:inspirehep.net:2841217$$d2024-12-26T07:36:45Z$$h2024-12-27T03:02:39Z$$mmarcxml$$ttrue$$uhttps://inspirehep.net/api/oai2d
002914563 035__ $$9Inspire$$a2841217
002914563 037__ $$9arXiv$$aarXiv:2410.13936$$chep-ph
002914563 037__ $$9arXiv:reportnumber$$aCERN-TH-2024-172
002914563 041__ $$aeng
002914563 100__ $$aMiró, Carlos$$jORCID:[email protected]$$uValencia U.$$vDepartament de Física Teòrica and Instituto de Física Corpuscular (IFIC)https://ror.org/017xch102, Universitat de València—CSIC, E-46100 Valencia, Spain
002914563 245__ $$9arXiv$$aHow large could CP violation in neutral $B$ meson mixing be? Implications for baryogenesis and upcoming searches
002914563 269__ $$c2024-10-17
002914563 260__ $$c2024-12-01
002914563 300__ $$a29 p
002914563 520__ $$9APS$$a<math display="inline"><mi>C</mi><mi>P</mi></math> violation in neutral <math display="inline"><mi>B</mi></math> meson oscillations is an experimental observable that could be directly related to the baryon asymmetry of the Universe through the <math display="inline"><mi>B</mi></math>-mesogenesis mechanism. As this phenomenon is highly suppressed in the Standard Model, it could also be a sensitive probe for many new physics scenarios that modify neutral meson mixing. Motivated by these facts, and the timely <math display="inline"><mi>B</mi></math> physics program at the LHC and Belle II, we analyze how large <math display="inline"><mi>C</mi><mi>P</mi></math> violation in the mixing of neutral <math display="inline"><msub><mi>B</mi><mi>d</mi></msub></math> and <math display="inline"><msub><mi>B</mi><mi>s</mi></msub></math> meson systems could be. We answer this question, in light of current experimental data, within three different scenarios, namely: (i) generic heavy new physics only affecting the mass mixing <math display="inline"><msubsup><mi>M</mi><mn>12</mn><mi>q</mi></msubsup></math>, (ii) vectorlike quark extensions that introduce deviations of <math display="inline"><mn>3</mn><mo>×</mo><mn>3</mn></math> CKM unitarity, and (iii) light new physics modifying the decay mixing <math display="inline"><msubsup><mi mathvariant="normal">Γ</mi><mn>12</mn><mi>q</mi></msubsup></math>. We find that enhancements of the semileptonic asymmetries, that measure the amount of <math display="inline"><mi>C</mi><mi>P</mi></math> violation in mixing, at the level of <math display="inline"><msup><mn>10</mn><mrow><mo>-</mo><mn>3</mn></mrow></msup></math> for the <math display="inline"><msub><mi>B</mi><mi>d</mi></msub></math> system and <math display="inline"><msup><mn>10</mn><mrow><mo>-</mo><mn>4</mn></mrow></msup></math> for the <math display="inline"><msub><mi>B</mi><mi>s</mi></msub></math> system can be achieved within scenarios (i) and (ii), while they are much more suppressed in realistic UV completions triggering scenario (iii). With respect to cosmology, the difficulty of finding large <math display="inline"><mi>C</mi><mi>P</mi></math> asymmetries in our analysis puts the <math display="inline"><mi>B</mi></math>-mesogenesis mechanism in tension. Finally, we conclude that upcoming experimental searches for <math display="inline"><mi>C</mi><mi>P</mi></math> violation in <math display="inline"><mi>B</mi></math> meson mixing at LHCb and Belle II are unlikely to detect a new physics signal for the most generic models.
002914563 520__ $$9arXiv$$aCP violation in neutral $B$ meson oscillations is an experimental observable that could be directly related to the baryon asymmetry of the Universe through the $B$-Mesogenesis mechanism. As this phenomenon is highly suppressed in the Standard Model, it could also be a sensitive probe for many new physics scenarios that modify neutral meson mixing. Motivated by these facts, and the timely $B$ physics program at the LHC and Belle II, we analyze how large CP violation in the mixing of neutral $B_d$ and $B_s$ meson systems could be. We answer this question, in light of current experimental data, within three different scenarios, namely: (i) generic heavy new physics only affecting the mass mixing $M_{12}^q$, (ii) vector-like quark extensions that introduce deviations of 3$\times$3 CKM unitarity, and (iii) light new physics modifying the decay mixing $\Gamma_{12}^q$. We find that enhancements of the semileptonic asymmetries, that measure the amount of CP violation in mixing, at the level of $10^{-3}$ for the $B_d$ system and $10^{-4}$ for the $B_s$ system can be achieved within scenarios (i) and (ii), while they are much more suppressed in realistic UV completions triggering scenario (iii). With respect to cosmology, the difficulty of finding large CP asymmetries in our analysis puts the $B$-Mesogenesis mechanism in tension. Finally, we conclude that upcoming experimental searches for CP violation in $B$ meson mixing at LHCb and Belle II are unlikely to detect a new physics signal for the most generic models.
002914563 540__ $$3preprint$$aCC BY 4.0$$uhttp://creativecommons.org/licenses/by/4.0/
002914563 540__ $$3publication$$aCC BY 4.0$$fSCOAP3$$uhttps://creativecommons.org/licenses/by/4.0/
002914563 542__ $$3publication$$dauthors$$g2024
002914563 595__ $$aCERN-TH
002914563 65017 $$2arXiv$$ahep-ex
002914563 65017 $$2SzGeCERN$$aParticle Physics - Experiment
002914563 65017 $$2arXiv$$aastro-ph.CO
002914563 65017 $$2SzGeCERN$$aAstrophysics and Astronomy
002914563 65017 $$2arXiv$$ahep-ph
002914563 65017 $$2SzGeCERN$$aParticle Physics - Phenomenology
002914563 690C_ $$aCERN
002914563 690C_ $$aARTICLE
002914563 700__ $$aEscudero, Miguel$$jORCID:[email protected]$$uCERN$$vTheoretical Physics Department, CERNhttps://ror.org/01ggx4157, 1211 Geneva 23, Switzerland
002914563 700__ $$aNebot, Miguel$$jORCID:[email protected]$$uValencia U.$$vDepartament de Física Teòrica and Instituto de Física Corpuscular (IFIC)https://ror.org/017xch102, Universitat de València—CSIC, E-46100 Valencia, Spain
002914563 773__ $$c115033$$mpublication$$n11$$pPhys. Rev. D$$v110$$y2024
002914563 8564_ $$82625635$$s4083$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-tree-channel-t-crop.png$$y00004 :
002914563 8564_ $$82625636$$s25503$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-argM12-vs-argG12-normalized-Bs.png$$y00016 : Caption not extracted
002914563 8564_ $$82625637$$s4394$$uhttp://cds.cern.ch/record/2914563/files/Box1-BSM-diquark-WY-crop.png$$y00010 :
002914563 8564_ $$82625638$$s22322$$uhttp://cds.cern.ch/record/2914563/files/NP33-argM12-vs-argG12-normalized-Bs.png$$y00015 : : \justifying Allowed regions in the $\arg(M_{12}^q/M_{12}^{q,\mathrm{SM}_0})$ vs.~$\arg(\Gamma_{12}^q/\Gamma_{12}^{q,\mathrm{SM}_0})$ plane for $B_d$ (upper panels) and $B_s$ (lower panels) regarding the analyses of Sec.~\ref{SEC:NPM12q} and \ref{SEC:VLQ}, together with the gray SM region as discussed in the text. Dashed contours of the semileptonic asymmetries are included for reference: they are represented assuming $|M_{12}^q/M_{12}^{q,\mathrm{SM}_0}|=|\Gamma_{12}^q/\Gamma_{12}^{q,\mathrm{SM}_0}|=1$. Notice the change of scale in the horizontal axis from the upper panels to the lower ones.
002914563 8564_ $$82625639$$s12160$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-blob-up-crop.png$$y00006 : Caption not extracted
002914563 8564_ $$82625640$$s13960$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-blob-left-crop.png$$y00005 : : \justifying Tree-level and one-loop diagrams contributing to $B_q$--$\bar{B}_q$ mixing in DVLQ models. The red vertex corresponds to the flavor-changing coupling $Z d_i \bar{d}_j$ obtained in this type of models. The blob in grey represents all possible flavor-changing one-loop topologies arising from the exchange of one or two $W$ bosons, including those where the $Z$ couples directly to one of the external lines. In this case, the other topologies where the red vertex and the grey blob exchange positions are not shown, but appropriately included in the calculations.
002914563 8564_ $$82625641$$s4644$$uhttp://cds.cern.ch/record/2914563/files/Box1-BSM-diquark-YW-crop.png$$y00009 :
002914563 8564_ $$82625642$$s30362$$uhttp://cds.cern.ch/record/2914563/files/NP33-argM12-vs-argG12-normalized-Bd.png$$y00013 :
002914563 8564_ $$82625643$$s4786$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-tree-channel-s-crop.png$$y00003 :
002914563 8564_ $$82625644$$s27278$$uhttp://cds.cern.ch/record/2914563/files/ASL_loglog.png$$y00012 \justifying Semileptonic asymmetries of the $B_d$ and $B_s$ systems in logarithmic scale. In orange we show the experimentally allowed regions at 95\% C.L. (2D-$\Delta \chi^2 = 5.99$, Eq.~\eqref{eq:ASLq-Exp}), and in dashed orange the expected sensitivity from LHCb and Belle II assuming their measurements are centered around the SM prediction, see Eqs.~\eqref{eq:ASL_sensitivities_future}. In red we highlight the region of parameter space identified in~\cite{Alonso-Alvarez:2021qfd} in which the baryon asymmetry of the Universe can be explained via the $B$-Mesogenesis mechanism~\cite{Elor:2018twp,Nelson:2019fln,Alonso-Alvarez:2021qfd}. The dashed red lines correspond to isocontours of ${\rm Br}(B \to {\rm baryon} + \psi + {\rm mesons})$. Only the region of parameter space with ${\rm Br} < 0.01$ is shown since larger branching fractions are conservatively excluded. Depending upon other parameters, the constraints can reach up to ${\rm Br} < 10^{-4}$. The dashed grey line is one of the main results of our study and highlights the values of the semileptonic asymmetries that heavy new physics models contributing to $M_{12}^q$ can reach, see Eq.~\eqref{eq:ASL_resultspeng}. We see that the overlap between the red and the grey dashed regions is small, and this puts the $B$-Mesogenesis mechanism in tension as for it to be successful $B$ mesons should posses an inclusive $\sim \mathcal{O}(1\%)$ branching ratio into a baryon, any number of light mesons, and missing energy. We finally note that semileptonic asymmetries larger than those contained in the grey contour could be obtained in tuned scenarios where $\Gamma_{12}^q$ is modified, see Sec.~\ref{SEC:G12q} for a discussion.
002914563 8564_ $$82625645$$s4116$$uhttp://cds.cern.ch/record/2914563/files/Box1-BSM-diquark-YY-crop.png$$y00011 : \justifying Box diagrams triggering $B_q$--$\bar{B}_q$ mixing from $u_i$--$Y/W$ mediation. : Caption not extracted
002914563 8564_ $$82625646$$s22103$$uhttp://cds.cern.ch/record/2914563/files/NP33-UVLQ-DVLQ-scaled.png$$y00007 \justifying \justifying Allowed regions for $A_\mathrm{SL}^d$ and $A_\mathrm{SL}^s$ within vector-like quark singlet extensions. All contours are shown at 95\% C.L. (2D-$\Delta \chi^2 = 5.99$), together with the corresponding best fit point. The pink and green contours correspond to UVLQ and DVLQ models, respectively. In blue, we further include the result of our previous analysis with heavy NP affecting $M_{12}^q$ for comparision. All results are obtained including the penguin pollution as discussed in Sec.~\ref{SEC:NPM12q}.
002914563 8564_ $$82625647$$s4987$$uhttp://cds.cern.ch/record/2914563/files/Box1-SM-crop.png$$y00000 :
002914563 8564_ $$82625648$$s64225$$uhttp://cds.cern.ch/record/2914563/files/asymNP33-zoom-scaled.png$$y00002 \justifying Allowed regions for $A_\mathrm{SL}^d$ and $A_\mathrm{SL}^s$ with heavy new physics solely affecting $M_{12}^q$. All contours are shown at 95\% C.L. (2D-$\Delta \chi^2 = 5.99$), together with the corresponding best fit point. In the left panel, the pink ellipse represents the current experimental world averages for the semileptonic asymmetries measurements as of 2024, while the ellipses in orange project the future expected sensitivity at LHCb Run 3 (23 fb$^{-1}$) and Belle II (50 ab$^{-1}$). The blue and red contours show the results of our analysis within the scenario presented in Sec.~\ref{SEC:NPM12q}, corresponding to the case where SM penguin contributions have been included or neglected, respectively. The point in black is the SM prediction, whose uncertainties are not visible in these axes. In the right panel, we provide the detail of our results along with the projected sensitivities at LHCb Run 3 and Belle II, and, in addition, at LHCb Run 5 (300 fb$^{-1}$).
002914563 8564_ $$82625649$$s4790$$uhttp://cds.cern.ch/record/2914563/files/Box2-SM-crop.png$$y00001 : : SM box diagrams mediating $B_q$--$\bar{B}_q$ mixing.
002914563 8564_ $$82625650$$s3990$$uhttp://cds.cern.ch/record/2914563/files/Box1-BSM-psi-crop.png$$y00008 \justifying Box diagram triggering $B_q$--$\bar{B}_q$ mixing from $\psi$--$Y$ mediation. The other topology is not shown, but it is considered in the calculation.
002914563 8564_ $$82625651$$s30252$$uhttp://cds.cern.ch/record/2914563/files/DVLQ-argM12-vs-argG12-normalized-Bd.png$$y00014 :
002914563 8564_ $$82625652$$s2473267$$uhttp://cds.cern.ch/record/2914563/files/2410.13936.pdf$$yFulltext
002914563 960__ $$a13
002914563 980__ $$aARTICLE