Recent hot results &
semileptonic b hadron decays
Jeroen van Tilburg
On behalf of the LHCb collaboration
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
1
charged tracks with kaon or proton mass hypotheses, are
n the J/ψφ
checked and no resonant-like enhancements in these disange 5.5 <
tributions are found.
are shown
0
Bs yields on
We measure the ratio ρ of the yield of the new state
fixed to the
X(5568) to the yield of the Bs0 meson in two kinematic
D0 collaboration:
nal events.
ranges, 10 < pT (Bs0 ) < 15 GeV/c and 15 < pT (Bs0 ) < 30 [arXiv:1602.07588]
1 to Introduction
l is1 due
GeV/c, by repeating the m(Bs0 π) fits with free mass and
±
—  D0
announced
new
state
on
24
Feb:
X(5568)
→
B
π
thus elimwidth
parameters
for
the
X(5568)
signal.
The
results
for
s
oration
to arXiv a preprint
[1] claiming submitted to arXiv a preprint [1] claim
2
Onsubmitted
25th February
D0 collaboration
micking
the
ρ are (9.12016,
± 2.6the
± 1.6)%
and (8.2 ± 2.7 ± 1.6)%, respeca narrow
structure,
which
they
dub
the
X(5568),
3
observation
with
5.1
significance
of
a narrow
structure,
which
they dub the X(55
tively,
with
an
average
of
(8.6
±
1.9
±
1.4)%.
The
sys—
Fraction
B
from
X(5568):
s
Significance:
5.1σ+
±
0
+
+
0. ±
+
0 , B 0 ! J/
⇡
,
!
J/
,
J/
!
µ
µ
,
!
K
K
The
4 Bin
the
decay
sequence
X(5568)
!
B
⇡
,
J/
!
µ
µ
,
!
K K .
s
tematic
uncertainties
due
to
B
reconstruction
efficiency
s
s
r the meas 2
+0.9
+0.9
orted
to
be m = cancel
5567.8±2.9
(stat)
MeV/c
5 width,
parameters
of theout
X(5568)
areThe
reported
to be factor
m = 5567.8±2.9
in
thestate
ratio.
combined
of the soft(stat) 1.9 (syst) MeV
1.9 (syst)
—
ural
2
+5.0publicity from2
MeV/c
.and
This =
was
accompanied
by
pion
kinematic
acceptance,
reconstruction
efficiency,
and
6
21.9
± 6.4 (stat)
. This was
accompanied
by publicity f
ncertainties
2.5 (syst) MeV/c
ous
outlets.
Within
a picked
few days
paper from
has
selection
is the
obtained
simulated
samples
. We
eval7news
Fermilab
which
wasefficiency
up
by various
newsa outlets.
Within
a few days the paper
with
a spinless
particle
of because,
mass equal
to 5568 the decay of su
This8 isaccrued
because,
ifevents
confirmed,
the
decay
of
such
background
aofnumber
of citations
[2–9].
Thisais
if confirmed,
00
2
N
(B
J/ a for
) =an exotic
MeV/c
decayinggun
tofour
Bss !
and
charged
pion.hadron
The pion
m
prore pair
for
an
exotic
hadron
containing
di↵erently
9
state
provides
a smoking
signature
containing four di↵ere
0
efficiency
increases
with
p
(B
)
from
(26.1
±
3.2)%
to
varying
the from quarks
T
e key
plot
the D0 (or
preprint
is reproduced
in plot from the D0 preprint
skey
5582
±
100
10
flavoured
antiquarks).
The
is reproduce
0
0 the two pT (Bs0 ) ranges. The system(42.1
±
6.5)%
for
he
B
mass
0
ata11sample
in which
5582is±obtained
100 Bs !
J/ a data
decays
s
result
from
sample
in
which
5582
±
100
B
! J/
de
s
0 ±Fig. 1. The
atic
uncertainty
due
to
a
potential
difference
of
the
soft
2
B
π
)
for
2
ofs125.303
m(J/ ) < 5.423
GeV/c window
, as shown
in
are <reconstructed
in
a
signal
of
5.303
<
m(J/
)
<
5.423
GeV/c
, as show
pion reconstruction efficiency in MC and data of ±5% is
fference deFig. 2. accounted for in systematics. Within uncertainties, the
by13 forcing
production ratio ρ does not depend on pT (Bs0 ).
anging the
120
90
120
—  Many
citations:
D0 Run II, 10.4 fb
D0
Run
II,
10.4
fb
D0 Run
A
possible
interpretation
of
the
observed
structure
is II,a10.4 fb
1σ, e) usingarXiv:1603.02915,
arXiv:1603.02708, arXiv:1603.02498, arXiv:1603.02249,
80 b) a) arXiv:1603.01131, arXiv:1603.00708, arXiv:1603.00290,
100arXiv:1603.01471,
b)
100
four-quark
state
made arXiv:1602.08806,
up of a diquark-antidiquark
pair.
the fourth-arXiv:1602.08916,
arXiv:1602.08711,
arXiv:1602.09041,
70
arXiv:1602.08642,
arXiv:1602.08421, and counting
80
With the Bs0 π + produced in an S wave,
its quantum
order poly60
80
Hot result: new tetraquark
from D0?
-1
DATA
Fit with background shape fixed
Background
-1
/ 8 MeV/c 2
Moriond EW
/ 8 MeV/c 2
ts / 8 MeV/c 2
-1
Signal
Recent hot results &
semileptonic B decays, Jeroen van Tilburg
13/03/2016
2
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
3
/ndf < 5 with Ds mass and PV constraD
1948 < m(Ds ) < 1990 MeV/c2
|m(Bs0 ) 0 5367 MeV/c2 | <+30 MeV/c2
B ! D (K⇡⇡)⇡
Ds and bachelor ⇡ + IPCHI2 > 16
Bs0 IPCHI2 < 16 and DIRA > 0.9999
kaons PIDK > 2 and[LHCb-CONF-2016-004]
pions
PIDK < 2
in preparation
bachelor pion !isMuon
D
⇤c hypo mass 2
/ [2270, 2310] MeV/c2 or kaon PIDK-PI
D hypo mass 2
/ [1848, 1890] MeV/c2 or kaon PIDK
DTF 2 /ndf < 5 with J/ mass and PV constra
|m(Bs0 ) 0 5367 MeV/c2 | < +13 MeV/c2
Bs ! Ds (KK⇡)⇡
all tracks IPCHI2
> 2 and DTF ctau> 0.3 ps
kaons ProbNNp <LHCb
0.6very
and
pT > 1 GeV
preliminary
DTF
2
Hot result: new tetraquark
from LHCb?
Bs0 ! Ds (KK⇡)⇡ +
—  Very preliminary.
—  Large Bs samples:
Bs0 ! J/ (µ+ µ ) (KK)
LHCb very preliminary
3.0 fb−1
205
206
207
208
209
3.0 fb−1
⇤c hyp
Dm
o✏ine50k
selection further, since most of the background70k
will come from a real B
D
combinatorial pions from the primary interaction.
+
The main fit results, including the signal yields
Bs0 !inJ/the(µsignal
µ ) mass
(KK)window d
Tab. 3, are given in Tab. 4. Results are also given for the fits with the minimu
requirement increased to 5 or 10 GeV/c.
o✏ine selection further, since most
206
combinatorial pions from the prim
207
The main fit results, including
208 van
Tab.
3, are given
in Tab. 4. Resul
13/03/2016
Recent hot results & semileptonic B decays, Jeroen
Tilburg
4
205
Moriond EW
Hot result: new tetraquark
from LHCb?
[LHCb-CONF-2016-004]
in preparation
—  Add pion:
Cross-check with B0π spectrum
very preliminary
Known B** states
[PRL110 (2013) 151803]
[JHEP 1504 (2015) 024]
—  No peak6observed
at 5568
Cross-section
ratiosMeV. Cannot confirm D0 peak.
311
—  UL cross
section
~1%ratio
We aim
to measure ratio
the cross-section
312
⌘
⇢LHCb
X
(pp ! X(5568) + anything) ⇥ B (X(5568) ! Bs0 ⇡)
,
(pp ! Bs0 + anything)
(3)
where the in
cross-sections
are forQCD
promptly produced particles within the LHCb acceptance.
—  More details
Moriond
Recall that the corresponding quantity was determined by D0 to be ⇢ = (8.6±1.9±1.4)%,
313
314
Moriond EW
315
316
where
Recent
LHCb
D0
X
the D0 acceptance requires pT > 10 GeV/c. Since (pp ! Bs0 + anything) in the
13/03/2016
hot
results has
& semileptonic
B decays,
Jeroen
van result
Tilburg
acceptance
been previously
measured
[39], any
for ⇢LHCb
can be trivially
X
5
Physics of
semileptonic B decays
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
6
Physics of
semileptonic B decays
Vub, size of smallest
CKM element
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
7
Physics of
semileptonic B decays
B oscillations (Δmd)
and CP(T) violation in
Vub, size of smallest
CKM element
mixing
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
8
Physics of
semileptonic B decays
B oscillations (Δmd)
and CP(T) violation in
Vub, size of smallest
CKM element
mixing
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
Are all leptons
equal? τ = e, µ ?
See talks this morning by
Johannes Albrecht and
Pablo Goldenzweig
13/03/2016
9
|Vub|
the smallest CKM element
VCKM
Moriond EW
0
Vud
= @ Vcd
Vtd
Vus
Vcs
Vts
1
Vub
Vcb A
Vtb
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
10
Ultimate test of
CKM unitarity
|Vub|
sin2β
Disagreement of |Vub| methods:
|Vub |(incl.) = (4.41 ± 0.22) ⇥ 10
|Vub |(excl.) = (3.72 ± 0.16) ⇥ 10
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
3
PDG
3
FNAL/MILC
[PRD 92 (2015) 014024]
13/03/2016
11
LHCb’s |Vub| with Λb→pµν
[Nature Physics 10 (2015) 1038]
—  Large backgrounds for B → π µ ν
—  ~20% of b-hadrons are Λb baryons
—  Accurate lattice prediction on Λb→p form factors
—  Uncertainty ~5%
[PRD 92 (2015) 034503 (2015)]
—  Result:
|Vub |
= 0.083 ± 0.004 ± 0.004
|Vcb |
Signal
Λb→Λc µ ν
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
12
Vub – Vcb plane
LHCb result
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
13
Bd oscillations
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
14
New re
sult
Precision measurement of Δmd
[LHCb-PAPER-2015-031], 3 fb-1
—  Time-dependent analysis of flavour-tagged semileptonic
decays
B 0 ! D(⇤) µ+ ⌫µ X
—  Decay time reconstructed
with k-factor method
—  Background from charged B decays suppressed by MVA
exploiting kinematic and isolation criteria
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
15
New re
sult
Precision measurement of Δmd
[LHCb-PAPER-2015-031], 3 fb-1
md = (505.0 ± 2.1(stat) ± 1.0(syst)) ns
—  Most precise single
1
N unmix (t) N mix (t)
A(t) = unmix
= cos( md t)
N
(t) + N mix (t)
measurement!
—  World average (without
this measurement)
md = (510 ± 3) ns
1
—  Recent lattice
improvements [arXiv:1602.03560]
allow stronger constraints
on CKM Unitarity Triangle
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
16
CP violation in B mixing
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
17
CP violation in B mixing
—  Different mixing probability for B!B and B!B
asl =
N (B!B) N (B!B)
N (B!B) + N (B!B)
—  So far, only observed in neutral kaon system (εK ≈ 0.2%)
—  SM predictions for B systems effectively zero
adsl = ( 4.1 ± 0.6) ⇥ 10
assl = (1.9 ± 0.3) ⇥ 10
Moriond EW
4
Lenz, Nierste [arXiv:1102.4274]
5
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
18
Measurement of asl
Untagged asymmetry:
N (f, t) N (f¯, t)
asl ⇣
A(t) =
= AD +
+ AP
¯
2
N (f, t) + N (f , t)
Moriond EW
asl ⌘
cos( mt)
2
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
19
Measurement of asl
Untagged asymmetry:
N (f, t) N (f¯, t)
asl ⇣
A(t) =
= AD +
+ AP
¯
2
N (f, t) + N (f , t)
Detection asymmetry AD:
•  Muons, kaons, pions.
•  Large calibration samples.
Moriond EW
asl ⌘
cos( mt)
2
Production asymmetry AP:
•  For Bs , Δms large → time-integrated analysis.
•  For Bd , Δmd small → time-dependent analysis to
disentangle asl and AP.
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
20
determined by varying the fractions by 10% to account for possib
states. The e↵ect of a dependence of the k-factor with B 0 deca
e↵ect on the di↵erence in the B momentumsldistributions betw
evaluated using B + ! J/ K + decays, is negligible.
Systematic e↵ects due to imperfect modelling of the decay ti
Untagged asymmetry:
the acceptance function and extending the fit region down to
N
(f, t) Nm
(f¯d, t)
asl ⇣
asl ⌘is taken into account.
varying
within
its
uncertainty
[11]
A(t) =
= AD +
+ AP
cos( mt)
¯
0
2 binning are2 negligible.
N
(f, t) + Nin
(f ,Bt) decay-time
variations
The B 0 –B 0 production asymmetries for the two centre-of-mass
( 0.66±0.26±0.22)%
and APasymmetry
(8 TeV) =
Production
AP:( 0.48±0.15±0.17)%, w
Detection asymmetry
A D:
•  second
For Bs , Δm
analysis.
s large → time-integrated
is
statistical
and
the
systematic.
These
asymmetries
re
•  Muons, kaons, pions.
•  For Bd , Δmd small → time-dependent analysis to
rangessamples.
2 < pT < 30 GeV/c
and 2.0
< ⌘AP<
•  Large calibration
disentangle
asl and
. 4.8, without correcting
reconstruction efficiencies. The production asymmetry at 7 TeV is
results [23] and with the production asymmetry at 8 TeV. The
semileptonic
B0 decays
Bs0 ! Ds (! asymmetry
K + K ⇡ in
)µ+
⌫
B
! D is(! K + ⇡ ⇡ )µ+ ⌫
Measurement of a
assl = ( 0.06 ± 0.50 ± 0.36)%
[PLB 728 (2014) 607] 1.0 fb−1
adsl = ( 0.02 ± 0.19 ± 0.30)% ,
[PRL 114 (2015) 041601]
3.0 fb
which is the most precise measurement to date and compatible
→ Systematic dominated
and earlier measurements
[24]. by
−1
detection asymmetries
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
713/03/2016
21
Current asl status
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
22
Current asl status
D0 measured non-zero CPV
in di-muon analysis (3.6σ)
D0 [PRD89 (2014) 012002]
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
23
Current asl status
Expected
sensitivity
with full
data set
D0 measured non-zero CPV
in di-muon analysis (3.6σ)
D0 [PRD89 (2014) 012002]
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
24
CPT violation in B mixing
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
25
CPT violation
—  CPT symmetry implies equal mass & lifetime B0 and B0 mesons
z=
m
m
i
i
/2
/2
—  Mass eigenstates:
|BL0 i
0
|BH
i
p
0
p
= p 1 z|B i + q 1 + z|B̄ 0 i
p
p
0
= p 1 + z|B i q 1 z|B̄ 0 i
—  CP violation: |q/p|≠1
—  CPT violation: z ≠ 0
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
26
CPT and Lorentz symmetry
—  CPT violation implies Lorentz invariance breaking.
[Greenberg, PRL 89 (2002)]
—  SME: EFT framework with CPT- & Lorentz-violating terms.
[Kostelecky, PRD55 (1997) 6760]
—  Experimental opportunity: measure SME parameters.
µ
z=
m
aµ
i
/2
SME coefficient for
neutral mesons
—  z depends on four-velocity
µ
= (1, ~ )
—  i.e. on momentum and
on direction in space
Δaµ
—  Δaµ is real 4-vector vacuum
expectation value à z mostly real
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
27
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
negligible
uncertainties
and arefrom
usedthe
to define
the rotation
thestamp,
coordinate
of
The timekeeping
is obtained
LHC machine
withfrom
a time
tLHC ,system
in UTC
st reference. For mesons flying along the beam axis, Re(z)
LHCb
to the constant
frame 1of
microseconds
since January
, 1970, 00:00:00 UTC. These coordinates and angles have
can
be expressed
as,
negligible
uncertainties
and are used to define the rotation from the coordinate system of
LHCb to the constant
of reference. For mesons flying along the beam axis, Re(z)
µ
aµ frame
m
µ
zRe(z)
=
→
can be expressed
as,
=
aµ
2
m i m2/2
+
/4
h m
i
⇥
⇤
a0 +2cos(µ ) aa
aY sin(⌦t̂) + aX cos(⌦t̂) ,
(7)
Re(z) ⇡
=
µ Z + sin( )
2
m
m +
/4
h
⇥
⇤i
X,Y,Z
where a
=
aX,Y,Z
and
is the) angle
of the
beam
with
to
⇡
a0 +
cos( =) 112.4
aZ + sin(
aY sin(⌦
t̂) +
aXaxis
cos(⌦
t̂) respect
,
(7)
m
the rotational axis of the Earth. The time dependence is the result of the Earth’s rotation,
giving
sidereal
sidereal
tLHC
= 0respect
is found
where a periodicity
aX,Y,Z = with
aX,Y,Z
and frequency
= 112.4 is⌦.theThe
angle
of thephase
beamat
axis
with
to
to
t̂ = (2.8126
hours.
The
B dependence
mesons haveisan
of about
5
theberotational
axis±of0.0014)
the Earth.
The
time
theaverage
result ofdeflection
the Earth’s
rotation,
with
respect
to the beam
axis. This
means that
the sidereal
LHCb detector
mostly
giving
a periodicity
with sidereal
frequency
⌦. The
phase atistLHC
= 0 sensitive
is found
to
combination
ak ⌘ The
a0 +Bcos(
) ahave
a0average
0.38 deflection
aZ , lyingofparallel
Z = an
to the
be t̂linear
= (2.8126
± 0.0014) hours.
mesons
about 5to
the
axis,
thereaxis.
is a This
muchmeans
weaker
sensitivity
to detector
the orthogonal
parameter,
withbeam
respect
to while
the beam
that
the LHCb
is mostly
sensitive
= 0.38
aZ , coming
smaller transverse
the parallel
B velocity.
0+
toa?the
linear acombination
ak from
⌘ athe
a0 component
0.38 aZ , of
lying
to
0 + cos( ) aZ =
The
ak isand
a? isweaker
negligible.
the correlation
beam axis, between
while there
a much
sensitivity to the orthogonal parameter,
Unbinned
fits are from
applied
the decay
time distributions
decay
a?
= 0.38 alikelihood
aZ , coming
the to
smaller
transverse
component of for
theboth
B velocity.
0+
channels.
To obtain
the SME
parameters,
the sidereal variation of Re(z) is taken into
The correlation
between
ak and
a? is negligible.
account
by including
thefits
LHC
andtothe
three-momentum
of the reconstructed
B
Unbinned
likelihood
are time
applied
the
decay
time
distributions
for
both
decay
candidate
fits. In
caseparameters,
of the Bs0 meson,
the fits variation
are performed
to theisfull
angular
channels. inTothe
obtain
thethe
SME
the sidereal
of Re(z)
taken
into
distribution.
account by including the LHC time and the three-momentum
of the reconstructed B
0
In
the
invariant
mass
distributions
of
the
B
candidates,
the
background
mostly
candidate in the fits. In the case of the Bs0 meson,(s)the fits are performed
to the fullis angular
combinatorial.
both decay channels, this background is statistically subtracted using
distribution. For Recent
13/03/2016
Moriond EW
& semileptonic B decays, Jeroen van Tilburg
28
the sPlot technique [15] hot
by results
assigning
a weight to
0 each event depending on the mass of
Sidereal dependence
~ ) of the neutral meson as [13]
=negligible
(1,timekeeping
uncertainties
and arefrom
usedthe
to define
the rotation
thestamp,
coordinate
of
The
is obtained
LHC machine
withfrom
a time
tLHC ,system
in UTC
9
Sidereal dependence
st reference. For mesons flying along the beam axis, Re(z)
LHCb
to the constant
frame 1µof
microseconds
since January
, 1970, 00:00:00 UTC. These coordinates and angles have
aµ
be expressed
as,
1 can
negligible
uncertainties
z = and are used to ,define the rotation from the coordinate
(6) system of
m +ofireference.
/2
2
LHCb to the constant
For mesons flying along the beam axis, Re(z)
µ
aµ frame
m
µ
zRe(z)
=
→
3
can be expressed
as,
=
aµ
m i m2/2
g Lorentz invariance.
The 2SME
+
/4 parameter aµ describes the di↵erence
h m
i
⇥
⇤
pling constants ⇡of the valence
quarks
in
the
neutral
meson
[13].
Therefore,
a0 +2cos(µ ) aa
aY sin(⌦t̂) + aX cos(⌦t̂) ,
(7)
Re(z) =
µ Z + sin( )
2
m
ons can have di↵erent
of aµ . Since aµ is real [14], it follows that
m values
+
/4
h
⇥ of magnitude smaller than
⇤i
Im(z)
m.
For
B
mesons,
Im(z)
is
two
orders
X,Y,Z
where
a
=
aX,Y,Z
and
=) 112.4
is the
of the
beam
with
to
⇡ small
a0 +
cos(Angle
aZB+meson
sin(
) angle
aY sin(⌦
t̂) +
aXaxis
cos(⌦
t̂) respect
,
(7)
of
with
Earth
High sensitivity from m
Sidereal
frequency
bethe
ignored
in the
measurements
of time
aaxis.
. The
average
µdependence
rotational
B mesons
mostly
rotational
axisboost.
of the Earth. The
is theboost
resultof
of B
themesons
Earth’s rotation,
Δm
and B meson
along
beam:
cos(χ)≈−0.38
e of
LHCb
is h =i ⇡with
As follows
from Eq.
6,angle
this
large
boost
results
a periodicity
sidereal
frequency
sidereal
tLHC
=in0respect
is found
4 giving
where
aX,Y,Z
a20.
= 112.4
is⌦.theThe
of thephase
beamat
axis
with
to
X,Y,Z and
y to
at̂µ=[7].
(2.8126
hours.
The
B dependence
mesons haveisan
of about
5
5 to
theberotational
axis±of0.0014)
the Earth.
The
time
theaverage
result ofdeflection
the Earth’s
rotation,
respect
to the beam
axis. This
means that
the sidereal
LHCb detector
mostly
6 with
giving
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with sidereal
frequency
⌦. The
phase atistLHC
= 0 sensitive
is found
to
combination
ak ⌘ The
a0 +Bcos(
) ahave
a0average
0.38 deflection
aZ , lyingofparallel
Z = an
7
to the
be t̂linear
= (2.8126
± 0.0014) hours.
mesons
about 5to
3
the
axis,
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is a This
muchmeans
weaker
sensitivity
to detector
the orthogonal
parameter,
8
withbeam
respect
to while
the beam
that
the LHCb
is mostly
sensitive
= 0.38
aZ , coming
smaller transverse
the parallel
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0+
9
toa?the
linear acombination
ak from
⌘ athe
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lying
to
0 + cos( ) aZ =
The
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0
the correlation
beam axis, between
while there
a much
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Unbinned
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applied
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decay
1
a?
= 0.38 alikelihood
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the to
smaller
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theboth
B velocity.
0+
channels.
To obtain
the SME
parameters,
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2
The correlation
between
ak and
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account
by including
thefits
LHC
andtothe
three-momentum
of the reconstructed
B
3
Unbinned
likelihood
are time
applied
the
decay
time
distributions
for
both
decay
candidate
fits. In
caseparameters,
of the Bs0 meson,
the fits variation
are performed
to theisfull
angular
4
channels. inTothe
obtain
thethe
SME
the sidereal
of Re(z)
taken
into
distribution.
5
account by including the LHC time and the three-momentum
of the reconstructed B
0
In
the
invariant
mass
distributions
of
the
B
candidates,
the
background
mostly
6
candidate in the fits. In the case of the Bs0 meson,(s)the fits are performed
to the fullis angular
combinatorial.
both decay channels, this background is statistically subtracted using
7
distribution. For Recent
13/03/2016
Moriond EW
& semileptonic B decays, Jeroen van Tilburg
29
the sPlot technique [15] hot
by results
assigning
a weight to
0 each event depending on the mass of
0
~ ) of the neutral meson as [13]
=negligible
(1,timekeeping
uncertainties
and arefrom
usedthe
to define
the rotation
thestamp,
coordinate
of
The
is obtained
LHC machine
withfrom
a time
tLHC ,system
in UTC
9
Sidereal dependence
st reference. For mesons flying along the beam axis, Re(z)
LHCb
to the constant
frame 1µof
microseconds
since January
, 1970, 00:00:00 UTC. These coordinates and angles have
aµ
be expressed
as,
1 can
negligible
uncertainties
z = and are used to ,define the rotation from the coordinate
(6) system of
m +ofireference.
/2
2
LHCb to the constant
For mesons flying along the beam axis, Re(z)
µ
aµ frame
m
µ
zRe(z)
=
→
3
can be expressed
as,
=
aµ
m i m2/2
g Lorentz invariance.
The 2SME
+
/4 parameter aµ describes the di↵erence
h m
i
⇥
⇤
pling constants ⇡of the valence
quarks
in
the
neutral
meson
[13].
Therefore,
a0 +2cos(µ ) aa
aY sin(⌦t̂) + aX cos(⌦t̂) ,
(7)
Re(z) =
µ Z + sin( )
2
m
ons can have di↵erent
of aµ . Since aµ is real [14], it follows that
m values
+
/4
h
⇥ of magnitude smaller than
⇤i
Im(z)
m.
For
B
mesons,
Im(z)
is
two
orders
X,Y,Z
where
a
=
aX,Y,Z
and
=) 112.4
is the
of the
beam
with
to
⇡ small
a0 +
cos(Angle
aZB+meson
sin(
) angle
aY sin(⌦
t̂) +
aXaxis
cos(⌦
t̂) respect
,
(7)
of
with
Earth
High sensitivity from m
Sidereal
frequency
bethe
ignored
in the
measurements
of time
aaxis.
. The
average
µdependence
rotational
B mesons
mostly
rotational
axisboost.
of the Earth. The
is theboost
resultof
of B
themesons
Earth’s rotation,
Δm
and B meson
along
beam:
cos(χ)≈−0.38
e of
LHCb
is h =i ⇡with
As follows
from Eq.
6,angle
this
large
boost
results
a periodicity
sidereal
frequency
sidereal
tLHC
=in0respect
is found
4 giving
where
aX,Y,Z
a20.
= 112.4
is⌦.theThe
of thephase
beamat
axis
with
to
X,Y,Z and
y to
at̂µ=[7].
(2.8126
hours.
The
B dependence
mesons haveisan
of about
5
5 to
theberotational
axis±of0.0014)
the Earth.
The
time
theaverage
result ofdeflection
the Earth’s
rotation,
Hadronic
modes
larger
respect
to decay
the beam
axis. give
This
means that
the sidereal
LHCb detector
mostly
6 with
giving
a periodicity
with sidereal
frequency
⌦. The
phase atistLHC
= 0 sensitive
is found
sensitivity
than
semileptonic
to
combination
ak ⌘ The
a0 +Bcos(
) ahave
a0average
0.38 deflection
aZ , lyingofparallel
Z = an
7
to the
be t̂linear
= (2.8126
± 0.0014) hours.
mesons
about 5to
3
the
axis,
thereaxis.
is a This
muchmeans
weaker
sensitivity
to detector
the orthogonal
parameter,
8
withbeam
respect
to while
the beam
that
the LHCb
is mostly
sensitive
0
0
= 0.38
acombination
aZJ/
, coming
from
smaller transverse
the parallel
B velocity.
0 +!
9
toa?the
linearB
ak S
⌘ athe
a0 component
0.38 aZ , of
lying
to
K
0 + cos( ) aZ =
The
ak isand
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negligible.
0
the correlation
beam axis, between
while there
a much
sensitivity to the orthogonal parameter,
0
+
Unbinned
fits are
applied
the decay
time distributions
decay
K from
K the tosmaller
1
a?
= 0.38 B
alikelihood
, coming
transverse
component of for
theboth
B velocity.
0s+!aZJ/
channels.
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the SME
parameters,
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2
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between
ak and
a? is negligible.
account
by including
thefits
LHC
andtothe
three-momentum
of the reconstructed
B
3
Unbinned
likelihood
are time
applied
the
decay
time
distributions
for
both
decay
candidate
fits. In
caseparameters,
of the Bs0 meson,
the fits variation
are performed
to theisfull
angular
4
channels. inTothe
obtain
thethe
SME
the sidereal
of Re(z)
taken
into
distribution.
5
account by including the LHC time and the three-momentum
of the reconstructed B
0
In
the
invariant
mass
distributions
of
the
B
candidates,
the
background
mostly
6
candidate in the fits. In the case of the Bs0 meson,(s)the fits are performed
to the fullis angular
combinatorial.
both decay channels, this background is statistically subtracted using
7
distribution. For Recent
13/03/2016
Moriond EW
& semileptonic B decays, Jeroen van Tilburg
30
the sPlot technique [15] hot
by results
assigning
a weight to
0 each event depending on the mass of
0
~ ) of the neutral meson as [13]
=negligible
(1,timekeeping
uncertainties
and arefrom
usedthe
to define
the rotation
thestamp,
coordinate
of
The
is obtained
LHC machine
withfrom
a time
tLHC ,system
in UTC
9
Sidereal dependence
st reference. For mesons flying along the beam axis, Re(z)
LHCb
to the constant
frame 1µof
microseconds
since January
, 1970, 00:00:00 UTC. These coordinates and angles have
aµ
be expressed
as,
1 can
negligible
uncertainties
z = and are used to ,define the rotation from the coordinate
(6) system of
[LHC
m +ofireference.
/2
b-PAPERe(z)
2
LHCb to the constant
For mesons flying along the beam
axis,
µ
R-2016
aµ frame
N
m
e
-005]
w
µ
r
e
z
=
→
s
u
3
can be expressed
l
t
Re(z)m= as,
a
(p
µ
i m2/2
g Lorentz invariance.
The 2SME
+
/4 parameter aµ describes the di↵erencereliminary)
h m
i
⇥
⇤
pling constants ⇡of the valence
quarks
in
the
neutral
meson
[13].
Therefore,
a0 +2cos(µ ) aa
aY sin(⌦t̂) + aX cos(⌦t̂) ,
(7)
Re(z) =
µ Z + sin( )
2
m
ons can have di↵erent
of aµ . Since aµ is real [14], it follows that
m values
+
/4
h
⇥ of magnitude smaller than
⇤i
Im(z)
m.
For
B
mesons,
Im(z)
is
two
orders
X,Y,Z
where
a
=
aX,Y,Z
and
=) 112.4
is the
of the
beam
with
to
⇡ small
a0 +
cos(Angle
aZB+meson
sin(
) angle
aY sin(⌦
t̂) +
aXaxis
cos(⌦
t̂) respect
,
(7)
of
with
Earth
High sensitivity from m
Sidereal
frequency
bethe
ignored
in the
measurements
of time
aaxis.
. The
average
µdependence
rotational
B mesons
mostly
rotational
axisboost.
of the Earth. The
is theboost
resultof
of B
themesons
Earth’s rotation,
Δm
and B meson
along
beam:
cos(χ)≈−0.38
e of
LHCb
is h =i ⇡with
As follows
from Eq.
6,angle
this
large
boost
results
a periodicity
sidereal
frequency
sidereal
tLHC
=in0respect
is found
4 giving
where
aX,Y,Z
a20.
= 112.4
is⌦.theThe
of thephase
beamat
axis
with
to
X,Y,Z and
y to
at̂µ=[7].
(2.8126
hours.
The
B dependence
mesons have
average
of about
5
5 to
theberotational
axis±of0.0014)
the Earth.
The
time
isan
the
result
ofdeflection
theofEarth’s
rotation,
Re(z)
as
function
sidereal
phase
Hadronic
modes
larger
respect
to decay
the beam
axis. give
This
means that
the sidereal
LHCb detector
mostly
6 with
giving
a periodicity
with sidereal
frequency
⌦. The
phase atistLHC
= 0 sensitive
is found
sensitivity
than
semileptonic
to
combination
ak ⌘ The
a0 +Bcos(
) ahave
a0average
0.38 deflection
aZ , lyingofparallel
Z = an
7
to the
be t̂linear
= (2.8126
± 0.0014) hours.
mesons
about 5to
preliminary
3
the
axis,
thereaxis.
is a This
muchmeans
weaker
sensitivity
to detector
the orthogonal
parameter,
8
withbeam
respect
to while
the beam
that
the LHCb
is mostly
sensitive
0
0
= 0.38
acombination
aZJ/
, coming
from
smaller transverse
the parallel
B velocity.
0 +!
9
toa?the
linearB
ak S
⌘ athe
a0 component
0.38 aZ , of
lying
to
K
0 + cos( ) aZ =
The
ak isand
a? isweaker
negligible.
0
the correlation
beam axis, between
while there
a much
sensitivity to the orthogonal parameter,
0
+
Unbinned
fits are
applied
the decay
time distributions
decay
K from
K the tosmaller
1
a?
= 0.38 B
alikelihood
, coming
transverse
component of for
theboth
B velocity.
0s+!aZJ/
channels.
To obtain
the SME
parameters,
the sidereal variation of Re(z) is taken into
2
The correlation
between
ak and
a? is negligible.
account
by including
thefits
LHC
andtothe
three-momentum
of the reconstructed
B
3
Unbinned
likelihood
are time
applied
the
decay
time
distributions
for
both
decay
candidate
fits. In
caseparameters,
of the Bs0 meson,
the fits variation
are performed
to theisfull
angular
4
channels. inTothe
obtain
thethe
SME
the sidereal
of Re(z)
taken
into
distribution.
5
account by including the LHC time and the three-momentum
of the reconstructed B
0
In
the
invariant
mass
distributions
of
the
B
candidates,
the
background
mostly
6
candidate in the fits. In the case of the Bs0 meson,(s)the fits are performed
to the fullis angular
combinatorial.
both decay channels, this background is statistically subtracted using
7
distribution. For Recent
13/03/2016
Moriond EW
& semileptonic B decays, Jeroen van Tilburg
31
the sPlot technique [15] hot
by results
assigning
a weight to
0 each event depending on the mass of
0
10
X
Conclusion
0.4
BB0→J / ψ K 0
Re(
LHCb⇥ 10 15 GeV ,
aY = (+0.44S ± 1.26 (stat) ± 0.29 (syst))
0.2
32
The CP T -violating
and Lorentz-violating parameters aµ in the B 0 and B 0 systems in
337
which is consistent with no CP T and no Lorentz violation. In addition, the speriodogram
33
the SME have 0been measured using LHCb data corresponding to an integrated luminosity
338
method is used to generalize the search for time-dependent, Lorentz-violating signals by
34
of 3 fb 1 . A-0.2
maximum-likelihood fit is performed
on the decay rate distributions of B 0
0
[LHCb
339
scanning a broad range of frequencies. For B , the0 maximum peak is found at a frequency
-PAPER
35
!J/ KS0 and Bs0 ! J/
,
respectively.
For
the
B
system,
taking
into
account
the
boost
-2016N
1
e
005]
340
of 1.5507 solar-day
and has a false-alarm probability
of 0.57. From a total of w
about
r
e
0
-0.4
s
u
lt (preli
36 (direction ind
absolute space and size) of the B mesons results in
minary
341
5’200 sampled frequencies there are 1’559 frequencies with a larger power than the one at
0
+
−
)
0.4
0
0
0
4
8
12
16
20
24
0
B
B s →Jthe
15
/ψ
K
K0.82
342
the siderealafrequency.
data
for B(stat)
is compatible
with
no
time-dependence.
0.38 Hence,
aB
(
0.10
±
±
0.54
(syst))
⇥
10
GeV
,
0
Z =
0.2 B0 of Ba0 Bµ 0 presented here is the world’s best. Under13assumption of the
343
The measurement
O(103) more precise
0.38 a0 + aZ = ( 0.20 ± 0.22 (stat)
± 0.04 (syst)) ⇥ 10 GeV ,
1
344
Standard Model
0.0027 ps [12], it is an improvement in precision of
d =
0 prediction
than BaBar result
B0
aX with
= (+1.97
± 1.30
(stat)
± 0.29best
(syst))
10 15 GeV
, using the
345
three orders of magnitude
respect
to the
previous
of ⇥
BaBar.
When
[PRL 100 (2008) 131802]
1
B0
15
346
one-sigma -0.2
experimentalauncertainty
on
of
0.007
ps
,
the
improvement
is
still
more
d
GeV ,
Y = (+0.44 ± 1.26 (stat) ± 0.29 (syst)) ⇥ 10
347
than two orders
-0.4 of magnitude.
B0
37
is consistent
with
no CP T and
andLorentz-violating
no Lorentz violation.
In addition,
thethe
periodogram
348 which
Similarly,
the CP
T -violating
parameters
aµ s for
Bs0 system
0
4
8
12
16
20
24
38
is used
to been
generalize
the search
349 method
in the SME
measured
to be for time-dependent, Lorentz-violating signals by
shave
t is[hfound
] at a frequency
0
39
scanning a broad
range
of
frequencies.
For
B
,
the
maximum
peak
sid
0
0
B
Bs
1
a0 s 0.38
aZhas
= a( false-alarm
0.89 ± 1.41 probability
(stat) ± 0.36of(syst))
10 14aGeV
40
of 1.5507 solar-day
and
0.57. ⇥From
total, of about
0
B0
Bs0 from
ure
1: Values
of Re(z)
fits
in 0.39
bins
of sidereal
for
(top)
the
41
5’200
sampled
frequencies
1’559
frequencies
a larger
one at
O(10) more precise
0.38
a0 s obtained
+ aZthere
= (are0.47
±
(stat)
±with
0.08phase
(syst))
⇥power
10 12 than
GeVB,thesample
0
0
the B
Projection
of Re(z) using the aµ results
the full fits arethan recent D0 result
42(bottom)
the sidereal
frequency.
with nofrom
time-dependence.
s sample. Hence,
Bs0 0 the data for B is compatible
14
a
=
(+1.01
±
2.08
(stat)
±
0.71
(syst))
⇥
10
GeV ,
B
erimposed,
using an average
43
The measurement
of B
aXµmomentum.
presented here is the world’s best. Under assumption
of the
[PRL 115 (2015) 161601]
0
1
Bs
14
44
Standard Model prediction
=
0.0027
ps
[12],
it
is
an
improvement
in
precision
of
aY =d( 3.83 ± 2.09 (stat) ± 0.71 (syst)) ⇥ 10 GeV ,
45
three orders of magnitude with respect to 0the previous best of BaBar. When using the
1
s
mplex
CP T -violating
parameter
z in the
found
toimprovement
be
46
experimental
uncertainty
on Bas0B
of 0.007
, the
is invariance,
still more
350 one-sigma
making
this
the first
measurement
of
to
date.isps
When
assuming
Lorentz
µ dsystem
(no assumption
on Lorentz breaking)
0
s
47
twoT orders
of magnitude.
351 than
the CP
-violating
parameter z in the Bs system is found to be Re(z) = 0.022 ±
0
Bs0
s
Re(z
) = and0.022
0.033
(stat)
0.003
(syst)
, aB
352
0.033
(stat) ±the
0.003
Im(z)
= 0.004
±±
0.011
(stat)
± 0.002
is theFirst measurement
48
Similarly,
CP (syst)
T -violating
and±Lorentz-violating
parameters
for thewhich
Bs0 system
µ (syst),
0
0
0
353 in
first
ofBthis
parameter
the Bs system. For Bs , the periodogram method
49
themeasurement
SME have
been
to ±
bein
s measured
Im(z
) = 0.004
0.011 (stat)
± 0.002 (syst) .
of z in Bs system
354
has been used
as
well.
The
maximum
peak
is
found
at a frequency of 14
1.3301 solar-day 1
0
0
Bs
Bs
a0
0.38probability
aZ = ( 0.89
± 1.41
(stat)
± 0.36
(syst))5’200
⇥ 10 sampled
GeV ,frequencies
355
and
has
a false-alarm
ofspecific
0.06.
From
a total
of about
Since
the
SME
fits consider
only
one
frequency,
i.e.
the
sidereal
frequency,
a wide
0
0
Bs
Bs with a larger power than the one at the 12
356
there are 0.38
3’386afrequencies
sidereal
frequency.
+
a
=
(
0.47
±
0.39
(stat)
±
0.08
(syst))
⇥
10
GeV
,
0
Zby means of the periodogram method. The periodogram is
ge of frequencies is scanned
357
Hence, the data for Bs0 isBcompatible
with no time-dependence.
0
14
s
ained by a discrete Fourier
transform
of
the data,
where
the time
domain
a
=
(+1.01
±
±
0.71 (syst))
⇥ 10
GeVis, given by
X
358
Already in the corresponding
sin 2 2.08
and (stat)
s analyses, the systematic uncertainties are
0
LHC
time
the Lomb-Scargle
periodogram
[19]theisTilburg
used. angles.
The 13/03/2016
Moriond
EWstamps. In this
Recent
hot results
& semileptonic B
decays, Jeroen
Banalysis,
359
small due
to the dependence
decay-time
and, ⇥
for10B0014, van
a s =on
( the
3.83charge,
± 2.09 the
(stat)
± 0.71 (syst))
GeVdecay
,
31
0
Results
—  B system (SME):
—  B system (SME):
—  B system:
Consistent with CPT and Lorentz symmetry
32
Periodogram test
[LHCb
-
PAPER
-2016New re
005]
sult (pr
elimina
ry)
Scan large frequency range (not only sidereal):
preliminary
à No significant peaks found at p-values of 0.57 and 0.06
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
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33
Conclusions
—  No confirmation of X(5568) (LHCb-CONF-2016-004 preliminary)
—  Semileptonic decays challenging, but interesting
results:
—  Bd oscillations, CP violation, |Vub/Vcb|.
[LHCb-PAPER-2015-031]
[PLB 728 (2014) 607]
[NP 10 (2015) 1038]
[PRL 114 (2015) 041601]
—  New results on CPT & Lorentz violation
—  Improved limits SME parameters in Bd system
—  First measurements in Bs system ( aµ and z)
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
[LHCb-PAPER-2016-005]
13/03/2016
34
Backup
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Recent hot results & semileptonic B decays, Jeroen van Tilburg
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35
More Bsπ spectra
Bs signal region
Sideband region
Moriond EW
[LHCb-CONF-2016-004]
in preparation
Bs signal region
pT(Bs) >10 GeV
Sideband region
pT(Bs) >10 GeV
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
36
Systematic uncertainties
Table 3: Systematic uncertainties on aµ for
Contributions marked with – are negligble.
B0
B 0 mixing
Source
Mass correlation
Wrong PV assignment
Production asymmetry
External input Cf , Sf
Decay width di↵erence
Neutral kaon asymmetry
Quadratic sum
Bs0 mixing
Source
Mass correlation
Peaking background
Decay time acceptance
Angular acceptance
Quadratic sum
152
153
154
155
mixing and on
aµ and z for
ak
a?
aX,Y
15
[⇥10
GeV]
–
–
0.04
–
1
–
0.28
1
0.05
0.46
4
0.28
0.07
–
–
–
1
–
0.54
4
0.29
ak
a?
aX,Y
14
[⇥10
GeV]
0.10
3
0.24
0.14
3
0.15
0.30
7
0.65
–
–
–
0.36
8
0.71
[LHCb
-
PAPER
-2016Nmixing.
ew resu
005]
lt (preli
minary
)
Bs0
Largest contribution:
Fixed Cf & Sf due to
correlation with z. External
input not affected by LIV,
due to low boost. Only
works for SME approach.
Re(z)
Im(z)
0.001
0.003
–
0.002
0.003
0.002
–
0.001
0.001
0.002
Small à No systematic effects expected
from the correlation between with
the mass
and decay and
time and
from the
accuracy on the length
sidereal
boost
dependence.
scale and momentum scale of the detector.
The components of the SME parameter aµ for B 0 mixing, obtained from the fit to
the sample of selected B 0 !J/ KS0 candidates, are
Moriond EW
0
aB
= ( 0.10
0.82 (stat)
± 0.54 (syst))
⇥ 10 15Jeroen
GeV , van Tilburg
hot±results
& semileptonic
B decays,
k Recent
13/03/2016
37
LHCb’s |Vub| with Λb→pµν
[Nature Physics 10 (2015) 1038]
—  Backgrounds too large for inclusive decays and
for exclusive B→πµν
—  ~20% of b-hadrons are Λb baryons
—  Use BF(Λc→pKπ) for normalisation: 5% uncertainty
—  Belle measurement [PRL 113 (2014) 04002]
How it was done
—  Accurate lattice prediction onΛb→p form factors:
—  Uncertainty ~5%
—
[Phys. Rev. D 92, 034503 (2015)]
—  Analysis strategy:
Reduced low q2 dependence
●
The LQCD calculation is most accurate at high q2
●
A cut at 15 GeV2 (7 GeV2) is good for Λb→pµυ (Λb→Λcµυ)
arXiv:1503.01421
—  Normalization & main
background Λb→Λcµν
—  Corrected mass from flight
direction (+uncertainty)
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
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38
Are all leptons equal?
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
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39
Semitauonic branching ratio
(⇤)
B(B
!
D
⌧ ⌫)
(⇤)
R(D ) =
B(B ! D(⇤) µ⌫)
•  Branching ratio to tau leptons sensitive to charged Higgs
•  Large, anomalous BR in B → D(*) τ ν at BaBar.
•  3.2σ tension with SM
[PRL 115 (2015) 111803]
•  LHCb:
•  Start with cleaner D*
and τ→µνν mode.
•  Fit to m2miss and Eµ
in q2 bins.
Moriond EW
Recent hot results & semileptonic B decays, Jeroen van Tilburg
13/03/2016
40
ch
systematic
uncertainty
thatand
is by comparing to simulated
by introduces
binning thea control
samples
di↵erently
ples
di↵erently
by and
comparing
to simulated
entification.
Theand
signal
normalization
form factors alter the expected ratio
* respect to the world averages are
rmalization
alter the
expected
acceptances,form
and factors
1 variations
in these
withratio
a systematic
uncertainty.
Finally,
the uncertainty
in the current world
nsassign
in these
with respect
to the world
averages
are
lue
B(⌧ !
⌫ µ ⌫⌧ ) contributes
a small world
normalization uncertainty.
ty. of
Finally,
theµuncertainty
in the current
—  LHCb measurement
confirms BaBar
result.
lusion,a the
ratio
of branchinguncertainty.
fractions R(D⇤ ) = B(B 0 ! D⇤+ ⌧ ⌫ ⌧ )/B(B 0 !
butes
small
normalization
0
115 measured
(2015) 111803] value
is
measured
to⇤ )be
0.3360 !
± 0.027
± 0.030
The
fractions
R(D
= B(B
D⇤+ ⌧ (stat)
⌫ ⌧ )/B(B
! (syst). [PRL
agreement
previous
BaBar and Belle [3, 5] and is 2.1
.027
(stat) ±with
0.030
(syst). measurements
The measuredatvalue
—  Increases
with
eviations
greater
thantension
the
expectation
asurements
at BaBar
andSM
Belle
[3,SM
5] andofis0.252
2.1 ± 0.003 [8]. This is the first
ent
of any decay
of a ±
b hadron
into
a final
expectation
of 0.252
0.003 [8].
This
is thestate
firstwith tau leptons at a hadron
ndinto
the atechniques
in this
open the possibility to study a
n
final statedemonstrated
with tau leptons
at aletter
hadron
ge
b hadron
modes with
multiple
edofinsimilar
this letter
open decay
the possibility
to study
a missing particles in hadron
n the future.
modes
with multiple missing particles in hadron
ress our gratitude to our colleagues in the CERN accelerator departments for
eagues in the CERN accelerator departments for
LHCb
8
Difference with
8SM 3.9σ (HFAG)
BR of B→D τν at LHCb
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Recent hot results & semileptonic B decays, Jeroen van Tilburg
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41