U production at NLO and beyond

HAL Id: in2p3-00856690

http://hal.in2p3.fr/in2p3-00856690

Submitted on 2 Sep 2013

HAL is a multi-disciplinary open access

archive for the deposit and dissemination of

sci-entific research documents, whether they are

pub-lished or not. The documents may come from

teaching and research institutions in France or

abroad, or from public or private research centers.

L’archive ouverte pluridisciplinaire HAL, est

destinée au dépôt et à la diffusion de documents

scientifiques de niveau recherche, publiés ou non,

émanant des établissements d’enseignement et de

recherche français ou étrangers, des laboratoires

publics ou privés.

U production at NLO and beyond

J.P. Lansberg

To cite this version:

Υ

_{production at NLO and beyond}

J.P. Lansberg

IPN Orsay – Paris-Sud U. –CNRS/IN2P3

Workshop on Charmonium production and decays : new results and perspectives

LAL Orsay

Part I

Reminder: QCD corrections for Υ at the Tevatron

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 1e-04 0.001 0.01 0.1 1 10 100 0 5 10 15 20 25 30 35 40 d σ /dP T ||y|<0.4 x Br (pb/GeV)

P

_T

(GeV)

ϒ(1S) prompt data x Fdirect

LO

ψ or Υ

Reminder: QCD corrections for Υ at the Tevatron

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 0.0001 0.001 0.01 0.1 1 10 100 0 5 10 15 20 25 30 35 40 d σ /dP T ||y|<0.4 x Br (pb/GeV)

P

_T

(GeV)

ϒ(1S) prompt data x Fdirect

Reminder: QCD corrections for Υ at the Tevatron

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 0.0001 0.001 0.01 0.1 1 10 100 0 5 10 15 20 25 30 35 40 d σ /dP T ||y|<0.4 x Br (pb/GeV)

P

_T

(GeV)

ϒ(1S) prompt data x Fdirect

LO NLO NNLO★ ψ or Υ α3SPT−8 g ψ or Υ g α4 SPT−6 ψ or Υ α5_SP_T−4 g g

QCD corrections for Υ at the Tevatron & the LHC

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 (3S) (GeV/c) ϒ of T p 0 5 10 15 [nb/(GeV/c)] _T /dp 3S σ d × 3S B -4 10 -3 10 -2 10 -1 10 1 10 LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5) LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5)

QCD corrections for Υ at the Tevatron & the LHC

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 (2S) (GeV/c) ϒ of T p 0 5 10 15 [nb/(GeV/c)] _T /dp 2S σ d × 2S B -4 10 -3 10 -2 10 -1 10 1 10 LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5) LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5)

QCD corrections for Υ at the Tevatron & the LHC

J.Campbell, F. Maltoni, F. Tramontano, Phys.Rev.Lett. 98:252002,2007 P.Artoisenet, J.Campbell, JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101, 152001 (2008) CDF PRL 88 (2002) 161802; LHCb EPJC 72 (2012) 2025 (1S) (GeV/c) ϒ of T p 0 5 10 15 [nb/(GeV/c)] _T /dp 1S σ d × 1S B -4 10 -3 10 -2 10 -1 10 1 10 LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5) LHCb data (2.0<y<4.5) direct NNLO* CSM (2.0<y<4.5) direct NLO CSM (2.0<y<4.5)

Analogy with the P

T

spectrum for the Z

0

boson

0.0001 0.001 0.01 0.1 1 10 100 0 5 10 15 20 25 30 35 40 d σ /dP T ||y|<0.4 x Br (pb/GeV) P_T (GeV) ϒ(1S) prompt data x Fdirect

CSM predictions account for the P

T

-integrated yield

S. J. Brodsky and JPL, PRD 81 051502 (R), 2010; JPL, PoS(ICHEP 2010), 206 (2010); NPA (2012), 10.1016/j.nuclphysa.2012.12.051

CSM predictions account for the P

T

-integrated yield

S. J. Brodsky and JPL, PRD 81 051502 (R), 2010; JPL, PoS(ICHEP 2010), 206 (2010); NPA (2012), 10.1016/j.nuclphysa.2012.12.051

Þ The

yield vs.

√

s

(here only LO curves1₎

Unfortunately, very large th. uncertainties: masses, scales (µ

R

,

µ

F

), gluon PDFs at low x and Q

2

, . . .

Good agreement with RHIC, Tevatron and LHC data

(multiplied by a constant Fdirect)

CSM predictions account for the P

T

-integrated yield

S. J. Brodsky and JPL, PRD 81 051502 (R), 2010; JPL, PoS(ICHEP 2010), 206 (2010); NPA (2012), 10.1016/j.nuclphysa.2012.12.051

Þ The

yield vs.

√

s

(here only LO curves1₎

Unfortunately, very large th. uncertainties: masses, scales (µ

R

,

µ

F

), gluon PDFs at low x and Q

2

, . . .

Good agreement with RHIC, Tevatron and LHC data

(multiplied by a constant Fdirect)

Cross section ratio I

Cross section ratio I

Cross section ratio I

Despite th. uncertainties, CSM predictions are

parameter free

!

At LO in v

2

, one de facto

predicts direct

cross-section

ratios

Cross section ratio I

Despite th. uncertainties, CSM predictions are

parameter free

!

At LO in v

2

, one de facto

predicts direct

cross-section

ratios

Cross section ratio I

Despite th. uncertainties, CSM predictions are

parameter free

!

At LO in v

2

, one de facto

predicts direct

cross-section

ratios

Simple ratios of

Schr ¨odinger wave function

at the origin:

σ(directΥ_(3S)) σ(directΥ₍1S))= | ψ3S(0)|2 |ψ1S(0_)|2∼0.34 σ(directΥ_(2S)) σ(directΥ₍1S))= | ψ2S(0)|2 |ψ1S(0_)|2∼0.45

σ

(

Υ

₍

_1S

_)(|

_y

_{| <}

₂

₎₎

_Br

_ℓℓ

_≃

₇

.

4 nb

50%direct

−→

σ

(

direct

Υ

₍

_1S

_{)) ∼}

_{150 nb}

CMS, PRD 83, 112004 (2011)

Cross section ratio I

Despite th. uncertainties, CSM predictions are

parameter free

!

At LO in v

2

, one de facto

predicts direct

cross-section

ratios

Simple ratios of

Schr ¨odinger wave function

at the origin:

σ(directΥ_(3S)) σ(directΥ₍1S))= | ψ3S(0)|2 |ψ1S(0_)|2∼0.34 σ(directΥ_(2S)) σ(directΥ₍1S))= | ψ2S(0)|2 |ψ1S(0_)|2∼0.45

σ

(

Υ

₍

_1S

_)(|

_y

_{| <}

₂

₎₎

_Br

_ℓℓ

_≃

₇

.

4 nb

50%direct

−→

σ

(

direct

Υ

₍

_1S

_{)) ∼}

_{150 nb}

CMS, PRD 83, 112004 (2011)

Extrapolated

3S direct yield: 0.34

_×

150 nb

_∼

50 nb

σ

(

Υ

₍

_3S

_)(|

_y

_{| <}

₂

₎₎

_Br

_ℓℓ

_≃

₁

.

0 nb

100%direct

−→

σ

(

direct

Υ

₍

_3S

_{)) ∼}

_{45 nb}

Cross section ratio I

Despite th. uncertainties, CSM predictions are

parameter free

!

At LO in v

2

, one de facto

predicts direct

cross-section

ratios

Simple ratios of

Schr ¨odinger wave function

at the origin:

σ(directΥ_(3S)) σ(directΥ₍1S))= | ψ3S(0)|2 |ψ1S(0_)|2∼0.34 σ(directΥ_(2S)) σ(directΥ₍1S))= | ψ2S(0)|2 |ψ1S(0_)|2∼0.45

σ

(

Υ

₍

_1S

_)(|

_y

_{| <}

₂

₎₎

_Br

_ℓℓ

_≃

₇

.

4 nb

50%direct

−→

σ

(

direct

Υ

₍

_1S

_{)) ∼}

_{150 nb}

CMS, PRD 83, 112004 (2011)

Extrapolated

3S direct yield: 0.34

_×

150 nb

_∼

50 nb

σ

(

Υ

₍

_3S

_)(|

_y

_{| <}

₂

₎₎

_Br

_ℓℓ

_≃

₁

.

0 nb

100%direct

−→

σ

(

direct

Υ

₍

_3S

_{)) ∼}

_{45 nb}

CMS, PRD 83, 112004 (2011)

NEW

: the 3S yield likely not 100% direct

Cross section ratio II

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(3S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(2S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0

Cross section ratio II

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(3S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(2S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0

P

T

dependence

of cross section ratios:

Mass effects at low P_T: not incoded in the v2_{results: M}Υ_(nS)

Cross section ratio II

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(3S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(2S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0

P

T

dependence

of cross section ratios:

Mass effects at low P_T: not incoded in the v2_{results: M}Υ_(nS)

NRQCD=2mb

Cross section ratio II

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(3S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(2S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0

P

T

dependence

of cross section ratios:

Mass effects at low P_T: not incoded in the v2_{results: M}Υ_(nS)

NRQCD=2mb

Feed-down: simple kinematical effect:P_Tdaughter_∼ M_Mdaughter_motherPmother T

Harmless if _dPd σ

T

Cross section ratio II

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(3S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0 10 20 30 Ratio(2S/1S) PT (GeV) CSM extrapolation LHCb 2.0 < y < 4.5 CMS |y| < 2.0

P

T

dependence

of cross section ratios:

Mass effects at low P_T: not incoded in the v2_{results: M}Υ_(nS)

NRQCD=2mb

Feed-down: simple kinematical effect:P_Tdaughter_∼ M_Mdaughter_motherPmother T

Harmless if _dPd σ

T

∝P_T−nwithn fixed,

harmfulif n changes, esp. trueat low P_T where_dPd σ

Impact of P-waves

] c [GeV/ ψ J/ T p 2 4 6 8 10 12 14 ψ J/ σ / γ ψ J/ →c χ σ 0 0.1 0.2 0.3 0.4 0.5 0.6 ChiGen NLO NRQCD -1 LHCb 36 pb LHCb = 7 TeV s (b) ChiGen: L. A. Harland-Lang and W. J. Stirling, http:// projects.hepforge.org/ superchic/chigen.html

NLO NRQCD: Y.-Q. Ma, K. Wang, K.-T. Chao, Phys. Rev. D83 (2011) 111503 (R)

The most important and

overlooked theory paper on quarkonium physics in 2010 !

Impact of P-waves

] c [GeV/ ψ J/ T p 2 4 6 8 10 12 14 ψ J/ σ / γ ψ J/ →c χ σ 0 0.1 0.2 0.3 0.4 0.5 0.6 ChiGen NLO NRQCD -1 LHCb 36 pb LHCb = 7 TeV s (b) ChiGen: L. A. Harland-Lang and W. J. Stirling, http:// projects.hepforge.org/ superchic/chigen.html

NLO NRQCD: Y.-Q. Ma, K. Wang, K.-T. Chao, Phys. Rev. D83 (2011) 111503 (R)

The most important and

overlooked theory paper on quarkonium physics in 2010 !

LHCb, Phys.Lett. B718 (2012) 431-440

LHCb: first indication that theχc fraction increases

Note: NLO NRQCD doesnot necessarilymean “Colour Octet dominance”. At NLO, the Colour-Singlet and Colour-Octet

Impact of P-waves

] c [GeV/ ψ J/ T p 2 4 6 8 10 12 14 ψ J/ σ / γ ψ J/ →c χ σ 0 0.1 0.2 0.3 0.4 0.5 0.6 ChiGen NLO NRQCD -1 LHCb 36 pb LHCb = 7 TeV s (b) ChiGen: L. A. Harland-Lang and W. J. Stirling, http:// projects.hepforge.org/ superchic/chigen.html

NLO NRQCD: Y.-Q. Ma, K. Wang, K.-T. Chao, Phys. Rev. D83 (2011) 111503 (R)

The most important and

overlooked theory paper on quarkonium physics in 2010 !

LHCb, Phys.Lett. B718 (2012) 431-440

LHCb: first indication that theχc fraction increases

Note: NLO NRQCD doesnot necessarilymean “Colour Octet dominance”. At NLO, the Colour-Singlet and Colour-Octet

transition yields depend –for the P waves– on the unphysical scale Λ_NRQCDand the NRQCD subtraction scheme

Impact of P-waves

] c [GeV/ ψ J/ T p 2 4 6 8 10 12 14 ψ J/ σ / γ ψ J/ →c χ σ 0 0.1 0.2 0.3 0.4 0.5 0.6 ChiGen NLO NRQCD -1 LHCb 36 pb LHCb = 7 TeV s (b) ChiGen: L. A. Harland-Lang and W. J. Stirling, http:// projects.hepforge.org/ superchic/chigen.html

NLO NRQCD: Y.-Q. Ma, K. Wang, K.-T. Chao, Phys. Rev. D83 (2011) 111503 (R)

The most important and

overlooked theory paper on quarkonium physics in 2010 !

LHCb, Phys.Lett. B718 (2012) 431-440

LHCb: first indication that theχc fraction increases

Note: NLO NRQCD doesnot necessarilymean “Colour Octet dominance”. At NLO, the Colour-Singlet and Colour-Octet

transition yields depend –for the P waves– on the unphysical scale Λ_NRQCDand the NRQCD subtraction scheme

About 40 % of Υ(1S)are from χbat the Tevatron CDF, PRL 84, 2094 (2000).

At the LHC: ) (%) P (1b χ ) from S (1 ϒ 0 10 20 30 40 50 60 70 80 90 100 LHCb = 7 TeV s

A priori: no PTdependence. However,

the plot scales are different

QCD corrections, feed-down and polarisation

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

-1 -0.5 0 0.5 1 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) LO ϒ+ bb NLO NNLO★

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

-1 -0.5 0 0.5 1 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) LO ϒ+ bb NLO NNLO★

Þ Polarisation from χQ Feed-down at NLO ?

If χQ→3S1γ is E1: αmax_{from χQ} = +1.00 and α

min

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

-1 -0.5 0 0.5 1 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) LO ϒ+ bb NLO NNLO★

Þ Polarisation from χQ Feed-down at NLO ?

If χQ→3S1γ is E1: αmax_{from χQ} = +1.00 and α

min

from χQ= −0.45

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

-1 -0.5 0 0.5 1 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) LO ϒ+ bb NLO NNLO★

Þ Polarisation from χQ Feed-down at NLO ?

If χQ→3S1γ is E1: αmax_{from χQ} = +1.00 and α

min

from χQ= −0.45

For the J/ψ: JPL J. Phys. G 38 (2011) 124110

-1 -0.5 0 0.5 1 5 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) J.P. Lansberg, Preliminary

Prompt J/ψ CDF data at s1/2_{=1.96 TeV}

NLO direct NNLO★ direct

→

-1 -0.5 0 0.5 1 5 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) P_T (GeV)

Prompt J/ψ CDF data at s1/2_{=1.96 TeV}

NLO direct

NNLO★ _prompt

QCD corrections, feed-down and polarisation

B. Gong, J.X Wang, Phys. Rev. Lett. 100,232001,2008. P.Artoisenet, J.Campbell,JPL, F.Maltoni, F. Tramontano, Phys. Rev. Lett. 101,152001,2008 JPL, EPJC 61,693,2009. JPL, PLB 695,149,2011.

ÞComplete modificationof the CSM polarisation at NLO(also at NNLO⋆₎

-1 -0.5 0 0.5 1 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) LO ϒ+ bb NLO NNLO★

Þ Polarisation from χQ Feed-down at NLO ?

If χQ→3S1γ is E1: αmax_{from χQ} = +1.00 and α

min

from χQ= −0.45

For the J/ψ: JPL J. Phys. G 38 (2011) 124110

-1 -0.5 0 0.5 1 5 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) PT (GeV) J.P. Lansberg, Preliminary

Prompt J/ψ CDF data at s1/2_{=1.96 TeV}

NLO direct NNLO★ direct

→

-1 -0.5 0 0.5 1 5 10 15 20 25 30 35 40 45 50 α =( σT -2 σL )/( σT +2 σL ) P_T (GeV)

Prompt J/ψ CDF data at s1/2_{=1.96 TeV}

NLO direct NNLO★ _prompt NNLO★ _direct For the Υ(1S): -0.5 0 0.5 1 σT -2 σL )/( σT +2 σL ) LO ϒ+ bb NLO NNLO★

→

-0.5 0 0.5 1 =( σT -2 σL )/( σT +2 σL ) Fϒ(1S) ϒ(2S)=0.1 for all PT

Fϒ(1S)direct=0.5, Fϒ(2S)direct=0.7 for all PT

αmax from χ(nP)=+1 for all PT, any n αmin from χ(nP)=-0.45 for all PT, any n

Part II

Associated production: J/ψ vs. Υ

A number of associated-production channels proposed for J/ψ

J/ψ+J/ψ

J/ψ+γ

J/ψ+c or J/ψ+D or J/ψ+lepton

J/ψ+Z

Associated production: J/ψ vs. Υ

A number of associated-production channels proposed for J/ψ

J/ψ+J/ψ

J/ψ+γ

J/ψ+c or J/ψ+D or J/ψ+lepton

J/ψ+Z

J/ψ+W

Less studies for Υ

rates are usually lower

J/ψ+c and J/ψ+J/ψ, sometimes motivated by intrinsic charm

Υ

₊

_{prompt γ}

Υ

₊

_{prompt γ}

Υ

₊

_{prompt γ}

At high energy, 2 gluons in the initial states: no quark The photon needs to be emitted by the b-quark loop

Υ

₊

_{prompt γ}

At high energy, 2 gluons in the initial states: no quark The photon needs to be emitted by the b-quark loop

Υ

₊

_{prompt γ}

At high energy, 2 gluons in the initial states: no quark The photon needs to be emitted by the b-quark loop

Gluon fragmentation associated with C = +1 octet (1S₀[8]and3P_J[8]) CO rates may beclearly lower if1S₀[8]and3P_J[8]are indeed suppressed

Υ

₊

_{prompt γ}

At high energy, 2 gluons in the initial states: no quark The photon needs to be emitted by the b-quark loop

Gluon fragmentation associated with C = +1 octet (1S₀[8]and3P_J[8]) CO rates may beclearly lower if1S₀[8]and3P_J[8]are indeed suppressed

JPL, PLB 679,340,2009.

Υ

₊

_{prompt γ}

At high energy, 2 gluons in the initial states: no quark The photon needs to be emitted by the b-quark loop

Gluon fragmentation associated with C = +1 octet (1S₀[8]and3P_J[8]) CO rates may beclearly lower if1S₀[8]and3P_J[8]are indeed suppressed

JPL, PLB 679,340,2009.

Clearly,new info on CS vs CO w.r.t inclusive case !

Possible: see(c,b) −jet+γ studies by D0 up toP

γ

Υ

₊

_{b-tagged jet}

1e-06 1e-05 1e-04 0.001 0.01 0.1 0 4 8 12 16 20 d σ /dP T ||y|<0.6 x Br (nb/GeV) PT (GeV) ϒ+bb_ Tevatron 1e-05 1e-04 0.001 0.01 0.1 1 0 4 8 12 16 20 d σ /dP T dy| y=0 x Br (nb/GeV) PT (GeV) ϒ+bb_ LHC

Υ₊b:_∼0.1 pb/GeV at the Tevatron,_∼1 pb/GeV at the LHC (14 TeV)

Υ

₊

_{b-tagged jet}

1e-06 1e-05 1e-04 0.001 0.01 0.1 0 4 8 12 16 20 d σ /dP T ||y|<0.6 x Br (nb/GeV) PT (GeV) ϒ+bb_ Tevatron 1e-05 1e-04 0.001 0.01 0.1 1 0 4 8 12 16 20 d σ /dP T dy| y=0 x Br (nb/GeV) PT (GeV) ϒ+bb_ LHC

Υ₊b:_∼0.1 pb/GeV at the Tevatron,_∼1 pb/GeV at the LHC (14 TeV)

hard P_T spectrum w.r.t. the inclusive LO CSM

Υ

₊

_{b-tagged jet}

1e-06 1e-05 1e-04 0.001 0.01 0.1 0 4 8 12 16 20 d σ /dP T ||y|<0.6 x Br (nb/GeV) PT (GeV) ϒ+bb_ Tevatron 1e-05 1e-04 0.001 0.01 0.1 1 0 4 8 12 16 20 d σ /dP T dy| y=0 x Br (nb/GeV) PT (GeV) ϒ+bb_ LHC

Υ₊b:_∼0.1 pb/GeV at the Tevatron,_∼1 pb/GeV at the LHC (14 TeV)

hard P_T spectrum w.r.t. the inclusive LO CSM

Υ_{+b: CSM vs. COM channels}

Different topologies:

CSM: 1 b away, 1 b near(er)

Q

+ vector boson

Q

+ vector boson

Υ₊vector boson

Q

+ vector boson

Υ₊vector boson

95% C.L. upper limits obtained with_{L =}83pb−1by CDF

σ[p ¯p_→Υ₍1S) +W±_{] ×}Br(Υ₍1S_{) →}µµ) <2.3 pb

σ[p ¯p_→Υ₍1S) +Z0_{] ×}Br(Υ₍1S_{) →}µµ) <2.5 pb

(1)

CDF Collaboration,PRL. 90 (2003) 221803

NRQCD predictions (Signal dominated by CO into χb)

σ[p ¯p→Υ_{(1S) +W}±_{] ×Br(}Υ_{(1S) →µµ) ≃0}

.025 pb

σ[p ¯p→Υ_{(1S) +Z}0_{] ×Br(}Υ_{(1S) →µµ) ≃0.0075 pb} (2)

Q

+ vector boson

Υ₊vector boson

95% C.L. upper limits obtained with_{L =}83pb−1by CDF

σ[p ¯p_→Υ₍1S) +W±_{] ×}Br(Υ₍1S_{) →}µµ) <2.3 pb

σ[p ¯p_→Υ₍1S) +Z0_{] ×}Br(Υ₍1S_{) →}µµ) <2.5 pb

(1)

CDF Collaboration,PRL. 90 (2003) 221803

NRQCD predictions (Signal dominated by CO into χb)

σ[p ¯p→Υ_{(1S) +W}±_{] ×Br(}Υ_{(1S) →µµ) ≃0}

.025 pb

σ[p ¯p→Υ_{(1S) +Z}0_{] ×Br(}Υ_{(1S) →µµ) ≃0.0075 pb} (2)

E. Braaten, J. Lee, and S. Fleming, PRD 60, 91501 (1999)

Q

+ vector boson

Υ₊vector boson

95% C.L. upper limits obtained with_{L =}83pb−1by CDF

σ[p ¯p_→Υ₍1S) +W±_{] ×}Br(Υ₍1S_{) →}µµ) <2.3 pb

σ[p ¯p_→Υ₍1S) +Z0_{] ×}Br(Υ₍1S_{) →}µµ) <2.5 pb

(1)

CDF Collaboration,PRL. 90 (2003) 221803

NRQCD predictions (Signal dominated by CO into χb)

σ[p ¯p→Υ_{(1S) +W}±_{] ×Br(}Υ_{(1S) →µµ) ≃0}

.025 pb

σ[p ¯p→Υ_{(1S) +Z}0_{] ×Br(}Υ_{(1S) →µµ) ≃0.0075 pb} (2)

E. Braaten, J. Lee, and S. Fleming, PRD 60, 91501 (1999)

Q

+ vector boson

Υ₊vector boson

95% C.L. upper limits obtained with_{L =}83pb−1by CDF

σ[p ¯p_→Υ₍1S) +W±_{] ×}Br(Υ₍1S_{) →}µµ) <2.3 pb

σ[p ¯p_→Υ₍1S) +Z0_{] ×}Br(Υ₍1S_{) →}µµ) <2.5 pb

(1)

CDF Collaboration,PRL. 90 (2003) 221803

NRQCD predictions (Signal dominated by CO into χb)

σ[p ¯p→Υ_{(1S) +W}±_{] ×Br(}Υ_{(1S) →µµ) ≃0}

.025 pb

σ[p ¯p→Υ_{(1S) +Z}0_{] ×Br(}Υ_{(1S) →µµ) ≃0.0075 pb} (2)

E. Braaten, J. Lee, and S. Fleming, PRD 60, 91501 (1999)

CSM yield expected to be 300 times smaller (to be re-checked ...) With 1 fb−1at√s =7 TeV and a larger_{(E × A)(}Υ₎, one should see events if CO’s are at work

J/ψ+Z andJ/ψ+W recently computed at NLO in αs

L.Gang et al. PRD83,014001,2011; JHEP02(2011)071

Υ

₊

_{Z cross sections}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

Υ

₊

_{Z cross sections}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

Rates similar for Υ+Z and J/ψ+Z !

Υ

₊

_{Z cross sections}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

Rates similar for Υ+Z and J/ψ+Z !

1e-07 1e-06 1e-05 0.0001 0.001 0.01 0.1 1 25 50 75 100 125 150 d σ /dP T x Br (fb/GeV) P_TJ/ψ (GeV) sqrt(s)=8 TeV µR=µF=mZ |yJ/ψ| < 2.4 NLO LO 1e-06 1e-05 0.0001 0.001 0.01 0.1 0 25 50 75 100 125 150 d σ /dP T x Br (fb/GeV) Pϒ_T (GeV) sqrt(s)=8 TeV µ_R=µ_F=m_Z |yϒ| < 2.4 NLO LO

Mass effects (mc↔mbless relevant because of mZ)

Υ

₊

_{Z :Υ polarisation}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

Υ

₊

_{Z :Υ polarisation}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

-1 -0.5 0 0.5 1 0 10 20 30 40 α (P ϒ )T Pϒ_T(GeV) |yϒ| < 2.4 PTϒ > 3 GeV sqrt(s)=14 TeV LO: µ_R=µ_F=m_Z NLO: µ_R=µ_F=m_Z

Υ

₊

_{Z :Υ polarisation}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

-1 -0.5 0 0.5 1 0 10 20 30 40 α (P ϒ )T Pϒ_T(GeV) |yϒ| < 2.4 PTϒ > 3 GeV sqrt(s)=14 TeV LO: µ_R=µ_F=m_Z NLO: µ_R=µ_F=m_Z

Υ_{polarisation at LO and NLO aresimilar}

unlike the inclusive case

Υ

₊

_{Z :Υ polarisation}

B. Gong, J.P. Lansberg, C. Lorc ´e, J.X. Wang, arXiv:1210.2430 [hep-ph] to appear in JHEP

-1 -0.5 0 0.5 1 0 10 20 30 40 α (P ϒ )T Pϒ_T(GeV) |yϒ| < 2.4 PTϒ > 3 GeV sqrt(s)=14 TeV LO: µ_R=µ_F=m_Z NLO: µ_R=µ_F=m_Z

Υ_{polarisation at LO and NLO aresimilar}

unlike the inclusive case

not clear why: need for further investigation

Part III

Absorption: Υ vs. J/ψ

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

σ_absΥ should be small_→nuclear PDF should play the major role

Absorption: Υ vs. J/ψ

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

σ_absΥ should be small_→nuclear PDF should play the major role

At RHIC:

at y >0, t_f =γ×0.4fm_≫rAu: pre-resonnant state exiting the nucleus

Absorption: Υ vs. J/ψ

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

σ_absΥ should be small_→nuclear PDF should play the major role

At RHIC:

at y >0, t_f =γ×0.4fm_≫rAu: pre-resonnant state exiting the nucleus

σ_absb ¯b ≃0.1σ_absc ¯c

at y <0, t_{f ≤}r_Au, fully formed in the nucleus: σ_absΥ(2S)≥4σ_absΥ(1S)

Yet,equal suppression found by E772 in the backward region:

Absorption: Υ vs. J/ψ

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

σ_absΥ should be small_→nuclear PDF should play the major role

At RHIC:

at y >0, t_f =γ×0.4fm_≫rAu: pre-resonnant state exiting the nucleus

σ_absb ¯b ≃0.1σ_absc ¯c

at y <0, t_{f ≤}r_Au, fully formed in the nucleus: σ_absΥ(2S)≥4σ_absΥ(1S)

Yet,equal suppression found by E772 in the backward region:

σ_absΥ(2S)−σ_absΥ(1S)small_⇒ σ_absΥ(1S)small

nPDF uncertainty on Υ production in d Au collisions at RHIC

nPDF uncertainty on Υ production in d Au collisions at RHIC

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

nPDF uncertainty on Υ production in d Au collisions at RHIC

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

nPDF uncertainty on Υ production in d Au collisions at RHIC

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

Similar trend for the three nPDFs used (EKS98, EPS08, nDSg) Uncertainty from the nPDFs: larger than our conservative estimate for that from the absorption x-section (0-1 mb)

nPDF uncertainty on Υ production in d Au collisions at RHIC

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

Similar trend for the three nPDFs used (EKS98, EPS08, nDSg) Uncertainty from the nPDFs: larger than our conservative estimate for that from the absorption x-section (0-1 mb)

A priori, uncertainties smaller than for J/ψ

Idea of a measurement for LHCb

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

Cross section ratio for opposite rapidities in cms frame

Idea of a measurement for LHCb

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

Cross section ratio for opposite rapidities in cms frame

[shift y_labby -0.47] The physical interpretation (the meaning of a departure from unity)

Idea of a measurement for LHCb

E.G. Ferreiro et al. arXiv:1110.5047 v4 [hep-ph]

Cross section ratio for opposite rapidities in cms frame

[shift y_labby -0.47] The physical interpretation (the meaning of a departure from unity)

does NOT depend on the pp yield

| |y 0 1 2 3 4 5 FB pPb

R

0.4 0.6 0.8 1 pPb 5 TeV, EPS09 LO quark-like EMC (central set) min. EMC

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

LO

CSM

fails

as far as

d σ/dP

T

is concerned

Higher-QCD corrections open

leading

P

T

channel: they are

needed !

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

LO

CSM

fails

as far as

d σ/dP

T

is concerned

Higher-QCD corrections open

leading

P

T

channel: they are

needed !

2

_→

3, 2

_→

4 channels

Drawback

: large theoretical uncertainties. . .

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

LO

CSM

fails

as far as

d σ/dP

T

is concerned

Higher-QCD corrections open

leading

P

T

channel: they are

needed !

2

_→

3, 2

_→

4 channels

Drawback

: large theoretical uncertainties. . .

Dominant contributions are known only at Born order

(gg→Υ_ggg)

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

LO

CSM

fails

as far as

d σ/dP

T

is concerned

Higher-QCD corrections open

leading

P

T

channel: they are

needed !

2

_→

3, 2

_→

4 channels

Drawback

: large theoretical uncertainties. . .

Dominant contributions are known only at Born order

(gg→Υ_ggg)

In pA at RHIC, small nuclear effect on Υ

But

backward-Υ

sensitive to gluon EMC effect, which can be large

Conclusions and Outlooks

LO

pQCD (CSM)

reproduces the P

T

-integrated yield

:

relevant for heavy-ion studies: LO CSM is gg

_{→ Q}

g

LO

CSM

fails

as far as

d σ/dP

T

is concerned

Higher-QCD corrections open

leading

P

T

channel: they are

needed !

2

_→

3, 2

_→

4 channels

Drawback

: large theoretical uncertainties. . .

Dominant contributions are known only at Born order

(gg→Υ_ggg)

In pA at RHIC, small nuclear effect on Υ

But

backward-Υ

sensitive to gluon EMC effect, which can be large

[hint from the data]

Suggestion for the pPb data: forward-backward ratio