PoS(EPS-HEP2011)165 http://pos.sissa.it/ SLAC-PUB-15913 . − ) ’ ( l ∓ l ± h → + c , as well as for the SM forbidden and and ¯ ν ν γγ K → † → D ∗ are shown. We also describe recent searches for the B l experiment at the Stanford Linear Accelerator Center c) ( and Λ γγ → experiment. BABAR B → B AR B A collaboration) B AR B A Work supported in part by US Department of Energy under contract DE-AC02-76SF00515. er. ches for Rare and Forbidden B and Charm [email protected] number violating mode corresponding similar charm decays Speak Dept. d’E.C.M. and ICC, Universitat de Barcelona, Martí Franquès 1, E-08028 Barcelona (Catalonia), Spain. A review of recent results of searchesysis for of rare the decays with data new recorded physics sensitivity at from the the anal- PEP-II B-Factory, is presented.rare In B particular, meson results decays, of such as searches for the (SM) eni Graugés (B ∗ † Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. c

Universitat de Barcelona E-mail: Eug Sear Decays at the The 2011 Europhysics Conference on HighJuly Energy 21-27, Physics-HEP 2011 2011, Grenoble, Rhône-Alpes France PoS(EPS-HEP2011)165 , ]. is 2 γγ [ ± ) 8 ’ ( → − l B 10 ), + c × lepton pairs. collaboration) Λ ) 6 4 τ . . 1 6 − + , or , would, if found, l + s ) BABAR c D ( , Λ pairs. Therefore resonance (10.58 GeV), + ¯ b ) D → b S 4 B ( ϒ collider. A total of approximately Eugeni Graugés ( ] or R-parity violating supersymme- − 3 experiment at SLAC PeP-II collider, e + e AR lepton) pairs as B A ¯ ν − produces an estimate of (3.1 is a charm hadron ( B τ ν c γγ + ] . Charged particle tracks are measured with a γγ X K τ 1 2 → → → 0 ,D B B − ) ’ , where ( l − ) and ∓ ’ l ( quark (and l ± ¯ γγ ∓ c h l c , were collected during its operation. The event yield contains ± → → ) , which with the two oppositely charged of different flavor h S + c B − can be either a , a or a proton; when the oppositely charged 2 ) ( occurs through a FCNC transition involving eletroweak loop diagrams. ’ → 1 ( ϒ l, X − l ) + c h γγ c ∓ ( l X Λ and → meson factories, such as the ± 0 h ) → and B S B 3 → ( ,B detector is described in detail [ γγ detector and dataset. ¯ ν ϒ + c ν X → AR K AR B experiment at the SLAC PeP-II asymmetric D B A , → A B ¯ B ν , most of them at (and near) a centre-of-mass energy of the AR 1 ν ,B B − ]) can enhance this BF due to new contributions of non-SM heavy particles occurring in the K A γγ The SM decay The searches for the above mentioned decay modes are performed using data collected by The so-called Additionally, searching for processes that are directly forbidden by the SM, such as those The 4 B → → NP scenarios beyond the SMtry (e.g., [ extended Higgs sectors [ The leading order calculation for the BF of the five-layer silicon tracker (SVT) and ation 40-layer energy drift loss, chamber dE=dx, in (DCH). the Measurementsring tracking of imaging system the Cherenkov together ioniza- with detector the (DIRC) Cherenkov areThe angle use calorimeter obtained to system from provide (EMC) a the is identification basedelectrons of on and charged CsI(TI) photons. hadrons. crystals that All measurewhich provides the the a energy above 1.5 deposition detectors T of magnetic areallowing field. further inside This discrimination flux a of return superconducting of from solenoidal this . magnetic , field is instrumented (IFR) around 470 milion pairs, 690 milion charmed meson pairs and 5003. milion Rare B meson decays: B 1. Introduction. produce actually almost as much 530fb but also at the violating baryon (BNV) or conservation (or both) like studying very suppressed, within the Standard Modelto (SM), search beauty and for charm any meson possible decay modes, an unexpected enhancement excellent of place their to respective lookextra branching for fraction contributions hints (BF), to of is the newB otherwise physics (NP) very processes, suppressed beyond decay thean amplitudes. SM, or that , Processes provide and like leptons of the same lepton flavor, are examplesare of expected flavor-changing neutral to processes be (FCNP) very , which rare because they cannot occur at tree level in the SM. be unequivocally a signaturemeson of decay physics beyond thewould SM. correspond Another to example lepton-flavor violating wouldSM (LFV) be because decays, the which they charm are can essentiallyleptons occur forbidden of only the in same through the lepton are lepton-numberSM. mixing. violating (LNV) decays The and former are also decay forbidden mode in the but with two 2. The PoS(EPS-HEP2011)165 ] c 2 of c Λ set are 15 / and 1 2 7 ∗ B reso- 1 ∗ B − − E p − ~ ) 2 S 10 c 4 ( and × − ϒ ∗ B collaboration) baryon lepton p ~ 6.2 2 l ] whose BF is ∗ beam ) ]. The latest SM c ] have reached a respectively. → < modes and of the E ( 18 7 5 c ) 13 B Λ q − BABAR ][ Λ γγ ][ 6 , and the UL for the ≡ 10 → 5 12 ][ − → × B ES 5 ][ 3 B 10 . for the 1 11 × 6 resonance with an integrated − < ][ ) ) S analysis is based on 418fb . 10 ¯ 4 ν ( ν ][ γγ ϒ Eugeni Graugés ( AR of data recorded at the ], while previous measurements [ + 9 B ], and that could be enhanced by NP 1 is the beam energy, and , where the first error is statistical and K 14 A 7 → − [ B 20 − 6 → D − ∗ ][ beam 10 , significance. The corresponding 90% CL is + is an example of FCNC [ E decay to be 1.4 − B 10 19 E (and the neural network output for the ) × σ ( [ ’ ¯ ∆ × ν γγ γγ ( ]. The B l ν 11 ]. This beyond the SM process is generally inter- 3 → 15 ∓ + − 0.2) → 0.7) l and ] has been performed over a sample of 407fb 17 K , where and ± D ,D ± ± -10 5 22 ES 8 h − → ) − − , and the lepton is a muon or electron, is performed on ’ at 90% CL. ∗ beam 1.1 ( 0 + l 6 E 10 peak [ → Λ B ∓ − ± ) l − × + c S ∗ 10 B ± 6 4 X ]. . h ( (90% CL). E or a 5 × rate is (4.5 ϒ 7 17 c 4 → ≡ − < ¯ . ν Λ 2 + analysis is based on 429 fb ) ) = (1.7 c E both at 90% CL [ ν decay arise from FCNC. NP models foresee extra contributions that 10 ¯ ν ∆ ] using a dataset recorded at the 4 K < γγ ¯ ν ν 7 l, X × − ) AR 0 ) ν c ]. The difficulty to directly reconstruct kinematically this channel, forces → signal yield is extracted by means of 2-dimensional likelihood fit to the B ( → modes [ K 10 γγ K . A Λ B 0 0 16 B × 1 γγ B → (3.2) Λ → → ( − → 0 < B D → B B ) ( ( ,B ]. A preliminary analysis [ B ¯ ν ) data [ γγ B B 21 ) ν for thr S to be 1.6 K 8 → 4 − ( ¯ ν 0 E variables. The beam energy substituted mass is defined as m → of data collected at the ϒ ν B ∆ ]. The ( 0 1 8 ,B − K B and γγ The search is performed for the decay lepton and violating The most recent Similarly the In the charm meson sector, the decay → ES → 0 mode) variables. No significantand excess the corresponding event UL above at the 90% CL background are expectations set to were be observed of the order of 10 no signal yield is found beyondhas the been expected set background to events. The corresponding UL on the BF 4. Searches for lepton and baryon number violation B decays: preted as being mediated by a bosoncharged which and carries is both a color and signature leptonproach of number in some and order SU(5) is to fractionally theories. avoid bias The inextended analysis the maximum technique results. likelihood followed The a signal fit yield "blind" to was ap- obtained the by m means of an unbinned order of 10 5. Rare charm meson decays: suppressed within the SM atcontributions [ levels of 10 have established the bestB UL for the to recontruct the other B meson inamong the the event remaining (though a particles semi-leptonic of decay),signal and the evidence, look event. and for the the The signal corresponding resultchannels UL of to be at this 90% search fails CL to are find set any for significant the neutral and charged decay , where the baryon is429 either fb a m B loop of the leading-order Feynmanbest diagrams. upper Previous limit measurements (UL) on [ this BF at 90 % confidence level (CL) of BF( and the energy difference is the three momentum and energysignal of yield the to B be candidate,the respectively. second The is systematic, BF which is corresponds calculated to from a 1.8 the prediction for the total on-peak ( set to by the Belle experimentluminosity of [ 104 fb nance [ allow for up to five-fold BF increase with respect to the SM [ PoS(EPS-HEP2011)165 ) of φ 1 − and ω , ρ collaboration) is a charm hadron c BABAR X , 201803 (2004). , 014009 (2002). , 115006 (2006). 93 , where 66 73 , 1 (2002). − ) ]. Although no signal evidence D D ’ ( 0904, 022 (2009). l 23 479 , 032006 (2011). , 112002 (2010). , 091101(R) (2011). ∓ vector resonances like l A Eugeni Graugés ( 83 82 83 , 035008 (2004). − ± l JHEP D h D D , 485 (1970). 70 + 2 l , 24 (2001). Phys. Rev. D840720062011 Phys. Rev. Phys. Rev. Lett. D → D 87 can be either a pion, a kaon or a proton. The + , 221802 (2007). resonance[ c ± ) X 99 h , (1995). S ]. A search has been performed on 384 fb γγ , 504 074008 (2001). 4 Phys. Rev. D , (2006). Phys. Rev. Phys. Rev. ( 19 , 4 64 . . 363 → [ 0707, 072 (2007). ϒ Phys. Rev. 73 Phys. Rev. 8 D B Phys. Rev. , 304 (2001). , 095014 (1998). D ,D − et al et al et al − 58 ) 500 ’ JHEP ( D Phys. Rev. Lett. Nucl. Instrum. Methods l B Phys. Rev. , Journal , , ∓ . l , 0208:054 (2002). ± Phys. Rev. Phys. Lett. et al h Phys. Rev. et al et al et al , , → JHEP , 114001 (2009). Phys. Rev. , 014025 (2008). + c et al Phys. Lett. et al 79 77 l, X D D ) c ( is an electron or muon, and Λ ± ) ’ → ( l ,B Phys. Rev. ), ¯ Phys. Rev. ν + c ν Λ K → , or + s ,B annihilation data collected at or close the D γγ The rare or forbidden charm decays of the form , − e + → [9] T. M. Aliev, A. S. Cornell and N. Gaur, [8] BaBar Collaboration. P. del Amo Sanchez [7] Belle Collaboration. Villa [6] BaBar Collaboration. B. Aubert [5] L3 Collaboration. Acciarri [4] A. Gemintern, S. Bar-Shalom, and G. Eilam, [2] S.W. Bosch and G. Buchalla, [3] T. M. Aliev and E. O. Iltan, [1] BaBar Collaboration. B. Aubert + D [22] BaBar collaboration. SLAC-PUB-14392, arXiv:1110.6480 [hep-ex] [23] BaBar collaboration. P. del Amo [21] S. Prelovsek and D.Wyler, [20] S. Fajfer, P. Singer, and J. Zupan, [19] G. Burdman, E. Golowich, J. L. Hewett, and S. Pakvasa, [16] BaBar Collaboration. P. del Amo Sanchez [17] BaBar Collaboration. P. del Amo Sanchez [18] S. L. Glashow, J. Iliopoulos, and L. Maiani, [13] D. McKeen, [14] W. Altmannshofer, A. J. Buras, D. M.[15] Straub and Belle M. Collaboration. Wick, K. F. Chen [12] C. Bird, P. Jackson, R. V. Kowalewski and M. Pospelov, [10] Y. Yamada, [11] P. Colangelo, F. De Fazio, R. Ferrandes and T. N. Pham, is found, the corresponding UL atexperimental 90 limits, % and CL in represent many an modes improvement by with more respect than to one the oerder previous ofReferences magnitude. B e are predicted to have a BF of the order of 10 SM rare but allowed cases (not considering the resonant (