Gustav Kramer Fest Ahmed Ali, DESY

1 Gustav Kramer Fest Heavy Quark Physics with Gustav Kramer From Quark Models to SCET

2 Gustav Kramer Fest First Meeting with Gustav Kramer

● I first met Gustav Kramer in May 1972 at the CERN School of Physics, held in Grado, Italy.

1972 CERN School of Physics, Grado, Italy, 15­31 May 1972

3 Gustav Kramer Fest First Meeting with Gustav Kramer

● This was the first time that I attended an International School on Particle Physics. Emilio Picasso was the Director of the CERN School. Among the theorists who lectured were Murray Gell­Mann, Kurt Gottfried, Michel Gourdin, Chan Hong­Mo, Gustav Kramer and Roger Phillip.

Gustav Kramer Grado

4 Gustav Kramer Fest First Meeting with Gustav Kramer

● Gustav Kramer gave a lecture course on _ “Electron­Positron Interactions”; this was the time when e e + colliders started to make their mark on particle physics, with the A.C.O. in Orsay, VEPP II in Novosibirsk, ADONE in Frascati, SPEAR at SLAC, and the Bypass Ring at CEA, all operating, with DORIS at DESY under construction.

● In his Introduction, he stated:

“This field of high energy physics has been very interesting in the past, we can expect further interesting results in the future”.

5 Gustav Kramer Fest Page 1 of Gustav Kramer's Grado Lecture

6 Gustav Kramer Fest Figure from Gustav Kramer's Grado Lecture

Pion form factor with ρ­ ω mixing measured at Orsay

7 Gustav Kramer Fest First Meeting with Gustav Kramer

● As a fresh postdoc, looking for the next position, I thought that with the start of DORIS, DESY would be a great place to go and work. Gustav Kramer suggested me to apply for an Alexander­von­Humboldt fellowship. This worked out for me.

● I came to Hamburg in October 1975 after a two­year stunt at the Stevens Institite of Technology, Hoboken, New Jersey. However, in between the 1972 CERN School and my arrival in Hamburg in 1975, particle physics had gone through a revolution; let me recount a few milestones.

Stevens Institute, Hoboken Hamburg 8 Gustav Kramer Fest Discovery of Asymptotic Freedom

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11 N − 2 n b = C f 0 12  1  t ~ 2 2 1  b0 log Q / QCD 9 Gustav Kramer Fest Discovery of the Charmonium State J/Ψ

J.J. Aubert et al.

.

J.­E. Augustin et al.

10 Gustav Kramer Fest Discovery of the Charmonium State J/Ψ

J Ψ

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11 Gustav Kramer Fest Discovery of the charmed hadron

G. Goldhaber et al.

12 Gustav Kramer Fest Discovery of the bottom quark

 1S

13 Gustav Kramer Fest Start of b­physics at DESY

14 Gustav Kramer Fest Start of Collaboration with Gustav Kramer

Z. Physik C, Particles and Fields 1, 203­231 (1979) ►

Z. Physik C, Particles and Fields 1, 269­277 (1979) ►

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15 Gustav Kramer Fest _ Jet Physics in e e annihilation with Gustav Kramer+

► Nucl. Phys. B, 167 (1980), 454­478

► Phys. Lett. B, 93B (1980), 155­160

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16 Gustav Kramer Fest Hamburg Jet Verein

With Jürgen Willrodt

Gerrit Schierholz Jürgen Körner 17 Gustav Kramer Fest B Physics and CKM Phenomenology

18 Gustav Kramer Fest Collaboration with William Palmer

Ohio State University William Palmer

● Their first paper dates back to 1969!

● 25 papers are written together. Most of them are on B­meson physics.

● Topics studied include CP violation and strong decays, angular correlations in B → VV decays, using perturbative QCD and Heavy Quark Symmetry.

19 Gustav Kramer Fest Theoretical framework

A  B  M 1 M 2 = 〈 M 1 M 2∣ H eff ∣ B 〉

Ci are the Wilson coefficients Current­Current Operators:

QCD Penguin Operators:

Dipole Operators:

20 Gustav Kramer Fest Effective Hamiltonian for B Decays

21 Gustav Kramer Fest Wilson Coefficients

22 Gustav Kramer Fest Collaboration with IHEP Group

Cai­Dian Lu came to DESY from IHEP, Bejing, as a Humbold fellow in 1997 with Gustav Kramer as his superviser. This was the start of a very productive collaboration in b­physics, which continues up to now.

23 Gustav Kramer Fest Two­body nonleptonic B­decays

24 Gustav Kramer Fest Quark­level matrix elements

eff These perturbative corrections define effective Wilson coefficients Ci

25 Gustav Kramer Fest Factorization Ansatz in B  M 1 M 2

- - Example: Matrix element of for the processO5 B  K 

Fierz transformation for D2

Replace 1/N by , a phenomenological parameter. 26 Gustav Kramer Fest Factorized Matrix Element of B -  K - 

In addition require formfactors such as in and copling constants such as and quark masses.

This framework allowed us to calculate a very large number of partial decays as well CP­violation in the decay rates.

It was very helpful for experiments at CLEO and B­factories and they are still being used.

27 Gustav Kramer Fest Emergence of Factoriziation Theorems

M. Beneke, G. Buchalla, M. Neubert, C.T. Sachrajda

Up to corrections of order , factorization holdsQCD /mb

28 Gustav Kramer Fest pQCD Approach

Factorization formula in the pQCD approach (Keum, Li, Sanda)

29 Gustav Kramer Fest CDF Results (ArXiv:1111.0485)

0 + - First evidence of Bs   

Pure annihilation

The pQCD prediction given in 2007 (Ali, Kramer, Lu et al.)

Br B0  + - ≃ 5.7×10−7 s 30 Gustav Kramer Fest

31 Gustav Kramer Fest

32 Gustav Kramer Fest Application of SCET in Radiative and Semileptonic B­decays

33 Gustav Kramer Fest SCET Factorization Formula for B → K * γ

34 Gustav Kramer Fest Estimates of Br(B → K * γ ) in SCET at NNLO

35 Gustav Kramer Fest _ SCET Factorization Formula for B → K l l* +

AA, Kramer, Zhu; EPJ C47 (2006) 625

36 Gustav Kramer Fest Recent Measurements of B  K *  +  -

37 Gustav Kramer Fest 2 * + - Zero­Point of dAFB / dq B  K   

AA, Kramer, Zhu; EPJ C47 (2006) 625

38 Gustav Kramer Fest Publications per year of Gustav Kramer

39 Gustav Kramer Fest v! usta y G thda Bir ppy Ha