Baryogenesis and Dark Matter from B Mesons
Miguel Escudero Abenza [email protected]
arXiv:1810.00880, PRD 99, 035031 (2019) with: Gilly Elor & Ann Nelson Based on: arXiv:2006.XXXXX with: Gonzalo Alonso-Álvarez, Gilly Elor & David McKeen
FPCP 2020: 10-06-2020 The Universe Baryonic Matter
5%
26% Dark Matter
69% Dark Energy
Planck 2018 1807.06209
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 2 SM Prediction:
Neutrinos
40%
60%
Photons
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 3 The Universe Baryonic Matter
5%
26% Dark Matter
69% Dark Energy
Planck 2018 1807.06209
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 4 Baryogenesis and Dark Matter from B Mesons
arXiv:1810.00880 Elor, Escudero & Nelson
1) Baryogenesis and Dark Matter are linked
2) Baryon asymmetry directly related to B-Meson observables
3) Leads to unique collider signatures
4) Fully testable at current collider experiments
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 5 Outline
1) Baryogenesis and Dark Matter from B Mesons
2) Collider implications
3) Conclusions
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 6 Baryogenesis The three Sakharov Conditions (1967):
1) C and CP violation
2) Out of equilibrium
3) Baryon number violation
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 7 Baryogenesis from B Mesons The three Sakharov Conditions (1967):
1) C and CP violation Neutral B-Meson system
2) Out of equilibrium and B meson production
Late time (τ ~ 0.01 s, TRH ~ 20 MeV) decaying particle into b-quarks
3) Baryon number violation Baryon number is conserved! Dark Matter is antibaryonic New decay mode of B mesons into Dark Matter and a Baryon
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 8 Baryogenesis and DM from B Mesons
Visible Sector Dark Sector (Baryons) (anti-Baryons)
Baryogenesis Dark Matter and 11 2 Y =8.7 10 ⌦ h =0.12 B ⇥ DM
11 A`` BR(B + Baryon + X) With the Baryon asymmetry: YB 8.7 10 ! ' ⇥ 5 10 4 0.001 ⇥ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 9 Distinctive Collider Signatures 1) Extra CP violation in B Meson decays a) Semileptonic asymmetries
b) CP violation in b → cĉs decays
2) New B Meson decay into ME and a Baryon
B+
⇤c
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 10
Key Quantity: The Semileptonic Asymmetry
q B0 f B0 f¯ Aq =Im 12 = q ! q ! `` M q B0 f + B0 f¯ ✓ 12 ◆ q ! q ! s 5 A`` SM =(2.1 0.2) 10 Standard Model | ± ⇥ Lenz & Tetlalmatzi-Xolocotzi d 4 1912.07621 A =( 4.7 0.4) 10 ``|SM ± ⇥
s 3 A =( 0.6 2.8) 10 `` ± ⇥ World averages Measurements d 3 (HFLAV) A =( 2.1 1.7) 10 `` ± ⇥
sd 5 Baryogenesis A`` > 10
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 11
4 Measured All imply Br(B + Baryon + X) > 2 10 ! ⇥ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 12
Assuming CMS-PAS-BPH-20-001 d d A`` = A`` SM Lenz et. al. | 1912.07621
1906.08356
2001.07115
s As = | 12| sin( s + +2 ) `` M s 12 s s | 12|
3 Measured φs implies Br(B + Baryon + X) > 2 10 ! ⇥ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 13
Dark Sector Baryogenesis requires: anti-Baryon 3 Br(B + Baryon + X) > 2 10 ! ⇥ B+ Best current constraint: Br(B + Baryon + X) . 10% Baryon ! ⇤c (from inclusive B meson decay measurements)
There is no available search for this process
6 BR(B K⌫⌫¯ ) 10 ! ⇠ Ongoing searches at Babar&Belle-II should test the scenario
LHCb should be able to contribute (also ATLAS&CMS) since NB ~ 1012
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 14
Distinctive experimental signatures:
0 ds 5 • Positive semileptonic asymmetry in B meson decays A`` > 10 • Neutral and charged B mesons decay into a baryon and missing energy 3 Br(B + Baryon + X) > 2 10 ! ⇥ Ongoing search for B → Baryon + ME at BaBar&Belle-II! B-factories should test this scenario given the constraints on other missing energy channels: + + 5 Br(B K ⌫⌫¯ ) < 10 ! Sharpening experimental signatures in 2006.XXXXX with: Gonzalo Alonso-Álvarez, Gilly Elor & David McKeen
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 15 Some References for 10/06/2020 Particles for Justice:
https://www.particlesforjustice.org/
https://www.particlesforjustice.org/resources
Recommended:
Ann Nelson in Physics Today:
Diversity in Physics: Are you part of the problem?
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 16 Questions & Comments Thank You! ⇠
B
⇤
If you are seeing this talk offline, feel free to send comments/questions to: [email protected] Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 17 Back Up
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 18 The Mechanism in a Nutshell
Out of equilibrium B-mesons decay into CP violating oscillations late time decay Dark Matter and hadrons B+ B0 B0 ¯b d s Dark Matter (anti-Baryon) B
¯0 ¯0 Baryon b B Bd Bs ⇤
d s TRH 20 MeV A A BR(B + Baryon + X) ⇠ `` `` !
Baryogenesis Dark Matter and 11 2 Y =8.7 10 ⌦ h =0.12 B ⇥ DM
11 A`` BR(B + Baryon + X) With the Baryon asymmetry: YB 8.7 10 ! ' ⇥ 5 10 4 0.001 ⇥
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 19 CP violation in the B system 20
0 0 where Cd and Cs depend on the relative production rates of B and Bs mesons, as well as their respective probabilities to have mixed (which may depend on the selection requirements). A possible additional term in Eq. (18) is discussed below. Another approach to determine these asymmetries inclusively is to tag B particles produced in top quark decays [102]. This method, recently implemented by ATLAS [103], however results in low yields so that the measurements do not currently have competitive precision.
0 d 0 s Table 4: Summary of the latest results for the B mixing (asl) and Bs mixing (asl) CP b asymmetries, as well as the inclusive dimuon asymmetry Asl measured at D0. In all cases the statistical uncertainty is quoted first and the systematic second. All values are percentages. d s b The world averages [12] are from a fit to all asl, asl and Asl results, except for the latest LHCb s asl result [104]; an earlier result [105] is included instead. The latest SM predictions [9,101] are given for comparison.
d s b asl (%) asl (%) Asl (%) +0.38 BaBar K-tag [84,106] 0.06 0.17 0.32 –– ± BaBar `` [107] 0.39 0.35 0.19 – – ± ± Belle `` [85] 0.11 0.79 0.70 – – ± ± LHCb [83,104] 0.02 0.19 0.30 0.39 0.26 0.20 – ± ± ± ± D0 [86,108,109] 0.68 0.45 0.14 1.12 0.74 0.17 0.496 0.153 0.072 ± ± ± ± ± ± World average [12] Semileptonic0.15 0.17 Asymmetries0.75 0.41 ± ± SM 0.00047 0.00006 0.0000222 0.0000027 0.023 0.004 Contents B Meson± qDecays ± B0 f B0 f¯ ± Aq =Im 12 = q ! q ! `` M q B0 f + B0 f¯ This is a measured1 The Modelin experiments: ✓ 12 ◆ q ! q ! 1 Lenz et al 1511.09466 Baryogenesis 1 Standard Model [%]
s s, d sl 5
a A`` > 10 1 The0 Model X
ν
µ
s 0 + 0 q B¯ l X B l X Expected sensitivity: −1 D q q q 12 A = D0 ! ! =Im (1.1) SL B¯0 l+X + B0 l X MLHCbq (50 fb-1) q µ q ✓ 12 ◆ !µ ! s 4
LHCb A`` 5 10
2 X − d ⇠ ⇥ 4 ν (*) A`` 5 10 µ LHCb D µνX 12 s (*) ASL =Im ⇠ ⇥ (1.2) D D0 D µνX M12 −3 BaBar D*lν ✓ ◆ D0 BaBar ll Belle-II (50 ab-1) Belle ll nB nB¯ 10 d 4 −4 10 A 5 10 (1.3) −3 −2 −1 s0 ⇠ 1 `` ⇠ ⇥ d asl [%]
Current measurement:Miguels EscuderoA (KCL)dd =( 0.0021Baryogenesis0.0017) and ,DM fromAs B Mesons=( 0.006 FPCP20200.0028) 10-06-2020 20 (1.4) Figure 6: Measurements of asl and aslSL, with simple± one-dimensionalSL averages ± (that di↵er from the values shown inmass Table eigenstates: 4) shown⇥ B as⇤ horizontal= p B andB¯ vertical⇥ bands,⇤ respectively [104]. The | RoomL/H i for| newqi ±| physicsqi i L/H yellow ellipse representstime evolve: the D0B inclusiveL/H (t) = e dimuon H BL/H measurement(0) [86] with d set to its SM expectation value. | i | i
0 ¯ ¯ d,s ⌘B ✏d,s Br(Bd,s +...)Br( ⇠)ASL (1.5) d s b / ⌘ ! ! Measurements of asl, asl and Asl have been2 performed by the BaBar, Belle, LHCb, q 2 12 q measure of CPV: 1 p = M 2 sin 12 and D0 collaborations. The latest results are12 collected in Table 4 together with the world nB nB¯ 10 10 (1.6) s ⇠
⌦ h2 0.1 (1.7) DM ⇠ B0 = ¯bq and B¯0 = bq¯ q | i q | i
–1– New B-Meson decay
c c 1.2 GeV . m , ⇠ . 2.5 GeV y Y ⇤ ub¯ y Y ¯ s +h.c L ub s (anti Baryon)
mY > 1 TeV Dark Matter (4-jet/squark) ⇠ SM Singlets Y: Colored Triplet Scalar Y (3, 1, 1/3) Y ⇠ s
¯ u b Baryon 0 ⇤ Bd d d
4 4 3 mB m 1 TeV pyuby s Br(B ⇠ + Baryon) 10 ! ' 2 GeV m 0.53 ✓ ◆ ✓ Y ◆ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 21 New Force Carrier ¯b us u ! Y: Colored Triplet Scalar ¯b Y (3, 1, 1/3) ⇠ s Same Quantum Numbers Y as a SUSY squark!
t-channel DM mediator
4 4 3 mB m 1.6 TeV pyuby s Br(B + Baryon + X) 10 ! ' 2 GeV m 0.6 ✓ ◆ ✓ Y ◆ Right in the LHC window
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 22 Back Up: Flavorful Variations
Operator Initial State Final state M (MeV) Bd + ⇤ (usd) 4163.95
0 Bs + ⌅ (uss) 4025.03 bus ⇠ B+ + ⌃+ (uus) 4089.95 ¯ 0 Y ⇤b + K 5121.9 s Bd + n (udd) 4340.07 ¯b u ⇤ Bs + ⇤ (uds) 4251.21 B0 bud d B+ + p (duu) 4341.05 d d 0 ⇤b ¯ + ⇡ 5484.5
0 Bd + ⌅c (csd) 2807.76
Bs + ⌦c (css) 2671.69 bcs + + u B + ⌅c (csu) 2810.36 + ¯ + K ⇤b + D + K 3256.2 s¯ Bd + ⇤c + ⇡ (cdd) 2853.60 u 0 ⇠ Bs + ⌅c (cds) 2895.02 ¯ bcd 0 ? + ⇤b b Y ? B + ⇤c (dcu) 2992.86 0 ⇤b ¯ + D 3754.7 d u¯ ⇡ Table 1: Here we itemize the lightest possible initial and final states for the d B decay process to visible and dark sector states resulting from the four pos- sible operators. The diagram in Figure ?? corresponds to the first line. The mass di↵erence between initial and final visible sector states corresponds to the kinematic upper bound on the mass of the dark sector baryon.
Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 23 Back Up: Parameters
8
Parameter Description Range Benchmark Value Constraint
m mass 11 100 GeV 25 GeV - 23 21 22 Inflaton width 3 10 < /GeV < 5 10 10 GeV Decay between 3.5MeV
m⇠ Majorana DM 0.3GeV
TABLE II. Parameters in the model, their explored range, benchmark values and a summary of constraints. Note that the q benchmark value for A`` Br(Bq ⇠ + Baryon + X), for v and v ⇠ are fixed by the requirement of obtaining the ⇥ ! 11 h i h i 2 observed Baryon asymmetry (YB =8.7 10 ) and the correct DM abundance (⌦DMh =0.12) respectively. ⇥ e↵ects are small, this is e↵ectively equivalent to the lep- by Br(B ⇠ + Baryon + X)); the greater the value tonic charge asymmetry for which one integrates over all of this branching! fraction, the more DM is generated. times. Therefore, in the present work we will use the two From Equation (16), we see that the asymmetry also de- interchangeably. pends on this parameter but weighted by a small number; 0 q 3 Maintaining the coherence of B oscillation is crucial A`` < 4 10 . Therefore, generically a region of param- for generatingMiguel Escudero the asymmetry; (KCL) additionalBaryogenesis interactions and DMeter from space B⇥ Mesons that produces the FPCP2020 observed baryon10-06-2020 asymmetry 24 with the B mesons can act to “measure” the state of the will overproduce DM, and we require additional interac- 0 ¯0 B meson and decohere the Bq Bq oscillation [32, 33], tions with the DM to deplete this symmetric component 2 thereby diminishing the CPV and so too the generated and reproduce ⌦DMh =0.120. baryon asymmetry. B mesons, despite being spin-less and charge-less particles, may have sizable interactions with electrons and positrons due to the B’s charge dis- B. Numerics and Parameters tribution. Electron/positron scattering e±Bq e±Bq,if faster than the B0 oscillation, can spoil the coherence! of q We use Mathematica [36] to numerically integrate the the system. We have explicitly found that this interaction set of Boltzmann Equations (9), (10), (11), (13), and (16) rate is two orders of magnitude lower than for a generic subject to the constraint Equation (8). To simplify the baryon [29], but for temperatures above T 20 MeV numerics it is useful to use the temperature T as the evo- the process (e B e B) occurs at a much higher' rate ± ± lution variable instead of time. Conservation of energy than the B meson oscillation! and therefore precludes the yields the following relation [37, 38]: CP violating oscillation. We refer the reader to Ap- pendix 1 for the explicit calculation of the e±B e±B ! dT 3H(⇢SM + pSM) n m scattering process in the early Universe. = , (19) Generically, decoherence will be insignificant if oscilla- dt d⇢SM/dT tions occur at a rate similar or faster then the B0 me- which above the neutrino decoupling temperatures T & son interaction. By comparing the e±B e±B rate q ! q 3 MeV simplifies to [39]: with the oscillation length mBq , we construct a step- like function (we have explicitly checked that a Heaviside 4 2 dT 4Hg ,sT (30/⇡ ) m n function yields similar results) to model the loss of coher- = ⇤ ⇥ . (20) 4 d log g ence of the oscillation system in the thermal plasma: dt T g (1 + ⇤ ) ⇤ d log T
0 0 q (e±Bq e±Bq )/ mBq fdeco = e ! . (18) We can therefore use Equation (20) in place of Equa- tion (10). For the number of relativistic species con- 13 We take mBd =3.337 10 GeV and mBs = tributing to entropy and energy g ,s(T ) and g (T ), we use 11 ⇥ 0 0 ⇤ ⇤ 1.169 10 GeV [5], and e±B e±B = the values obtained in [40]. Finally, since the DM parti- ⇥ q ! q 10 11 GeV (T/20 MeV)5 (see Appendix 1 for details). cles generically have masses greater then a GeV we can Even without numerically solving the Boltzmann equa- safely neglect the inverse scatterings in the DM Boltz- 2 tions, we can understand the need for additional interac- mann equations i.e. the neq term. To make the inte- tions in the dark sector v ⇠, . From Equations (11) gration numerically straightforward we change variables and (13), we see that theh i DM abundance is sourced and solve the equations for log n and log T , such that An Explicit Model Minimal Particle Content B-mesons decay into DM (missing energy) and a Baryon Field Spin QEM Baryon no. Z2 Mass
0 0 0 +1 11 100 GeV ⇠ Y 0 1/3 2/3 +1 (TeV) O Y s 1/2 0 1 +1 (GeV) O ¯ u ⇠ 1/2 0 0 1 (GeV) b O 0 ⇤ Bd 0 0 1 1 (GeV) O d d Heavy Colored Triplet Scalar:
c c y Y ⇤ ub¯ y Y ¯ s +h.c mY > 1 TeV (4-jet/squark) L ub s yuby s eff = 2 usb also possible csb ,udb ,cdb H mY (CP and Baryon B =0 operator induces new b-quark decay ¯b us ! number conserving) 4 4 3 mB m 1 TeV pyuby s Br(B ⇠ + Baryon) 10 ! ' 2 GeV m 0.53 ✓ ◆ ✓ Y ◆ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 25 An Explicit Model Minimal Particle Content B-mesons decay into DM (missing energy) and a Baryon Field Spin QEM Baryon no. Z2 Mass
0 0 0 +1 11 100 GeV ⇠ Y 0 1/3 2/3 +1 (TeV) O Y s 1/2 0 1 +1 (GeV) O ¯ u ⇠ 1/2 0 0 1 (GeV) b O 0 ⇤ Bd 0 0 1 1 (GeV) O d d The Dark Sector:
ψ : Dirac Dark Baryon
For the b-quark decay to happen: m • ψ needs to have decays into other dark sector particles or will decay 4 back to visible baryons and undo the Baryogenesis ⌧( p + ⇡ ) 10 years ! ⇠ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 26 An Explicit Model Minimal Particle Content B-mesons decay into DM (missing energy) and a Baryon Field Spin QEM Baryon no. Z2 Mass 0 0 0 +1 11 100 GeV ⇠ Y 0 1/3 2/3 +1 (TeV) O Y s 1/2 0 1 +1 (GeV) O ¯ u ⇠ 1/2 0 0 1 (GeV) b O 0 ⇤ Bd 0 0 1 1 (GeV) O d d The Dark Sector: φ : Charged Stable Scalar anti-Baryon ξ : Dark Stable Majorana Fermion Minimal Dark sector interaction y ¯ ⇠ with Z2 symmetry • L d • Constraints: • ψ -> φξ Decay: m + m⇠ Miguel Escudero (KCL) Baryogenesis and DM from B Mesons FPCP2020 10-06-2020 27